U.S. patent application number 12/521947 was filed with the patent office on 2010-02-18 for implantation compositions for use in tissue augmentation.
This patent application is currently assigned to BIOFORM MEDICAL, INC.. Invention is credited to Dale Devore, Robert Voigts.
Application Number | 20100041788 12/521947 |
Document ID | / |
Family ID | 38802386 |
Filed Date | 2010-02-18 |
United States Patent
Application |
20100041788 |
Kind Code |
A1 |
Voigts; Robert ; et
al. |
February 18, 2010 |
Implantation Compositions for Use in Tissue Augmentation
Abstract
A composition of matter and method for preparation of a tissue
augmentation material. A polysaccharide gel composition is prepared
with rheological properties selected for a particular selected
application. The method includes preparing a polymeric
polysaccharide in a buffer to create a polymer solution or gel
suspending properties in the gel and selecting a rheology profile
for the desired tissue region.
Inventors: |
Voigts; Robert; (Wind Lake,
WI) ; Devore; Dale; (Chelmsford, MA) |
Correspondence
Address: |
SWANSON & BRATSCHUN, L.L.C.
8210 SOUTHPARK TERRACE
LITTLETON
CO
80120
US
|
Assignee: |
BIOFORM MEDICAL, INC.
San Mateo
CA
|
Family ID: |
38802386 |
Appl. No.: |
12/521947 |
Filed: |
July 31, 2007 |
PCT Filed: |
July 31, 2007 |
PCT NO: |
PCT/US2007/017131 |
371 Date: |
July 1, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11650696 |
Jan 8, 2007 |
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12521947 |
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11348028 |
Feb 6, 2006 |
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11650696 |
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Current U.S.
Class: |
523/113 |
Current CPC
Class: |
A61K 47/02 20130101;
A61L 2400/06 20130101; C08L 1/286 20130101; A61L 2/0023 20130101;
A61L 27/20 20130101; A61K 47/10 20130101; A61L 27/20 20130101; A61K
31/167 20130101; A61K 47/38 20130101; A61L 27/50 20130101; A61L
2430/34 20130101; C08L 1/26 20130101 |
Class at
Publication: |
523/113 |
International
Class: |
A61F 2/00 20060101
A61F002/00 |
Claims
1. A method of preparing an implant with a desired rheological
property selected to be compatible with at least one tissue
rheological feature and at least one acceptable tissue rheological
range at a tissue site of implantation, the method comprising:
establishing at least one of a particular rheological feature and
an acceptable rheological range characteristic of the tissue at the
tissue implantation site; identifying an implant having at least
one of the at least one particular rheological feature and the
acceptable range; and preparing the implant having the desired
rheological property.
2. The method as defined in claim 1 wherein the step of identifying
an implant with the at least one particular rheological feature and
acceptable rheological range comprises; collecting data for a
plurality of test implants, the data being characteristic of
chemical variables and rheological variables for each of the
plurality of test implants; and mapping the data to define at least
one of characteristic phase lines and characteristic closed phase
region which meet the at least one particular rheological feature
and acceptable rheological range for the rheological property
3. The method as defined in claim 1 wherein the step of mapping the
data comprises establishing the characteristic closed phase region
within which a plurality of the chemical variables provide the
implant having a plurality of associated rheological properties
compatible with the tissue at the implantation site.
4. The method as defined in claim 1 wherein the step of identifying
an implant includes establishing sensitivity of changes in the
rheological property of the implant as a function of change in
chemical variables.
5. The method as defined in claim 1 further including the step of
establishing statistical boundaries for at least one of the
characteristic phase lines and the characteristic closed phase
region.
6. The method as defined in claim 1 wherein the particular
rheological feature comprises a cross-over of functionality of G'
and G''.
7. The method as defined in claim 1 wherein the rheological
property comprises compatibility of phase angle versus frequency
for the implant and the tissue.
8. The method as defined in claim 1 wherein the implant comprises a
polysaccharide polymer.
9. The method as defined in claim 1 wherein the implant comprises a
polysaccharide polymer having an Fo value of at least about 22.
10. The method of claim 9, wherein the polysaccharide polymer is
selected from the group consisting of an alginate polysaccharide, a
cellulose polysaccharide and a hemicellulose polysaccharide.
11. The method of claim 9, wherein the cellulose based
polysaccharide polymer is selected from the group consisting of:
sodium carboxymethylcellulose, hydroxyethyl cellulose,
ethylhydroxyethyl cellulose, carboxymethyl cellulose,
carboxyethylhydroxyethyl cellulose, hydroxypropylhydroxyethyl
cellulose, methyl cellulose, methylhydroxylmethyl cellulose,
methylhydroxyethyl cellulose, carboxymethylmethyl cellulose, and
modified derivatives thereof.
12. The method as defined in claim 1 wherein the step of preparing
the implant includes addition of a buffer.
13. The method of claim 12 wherein the buffer comprises a potassium
phosphate.
14. The method as defined in claim 1 wherein the step of preparing
the implant includes adding a lubricant.
15. The method as defined in claim 14 wherein the lubricant
comprises glycerin.
16. The method as defined in claim 1 wherein the step of preparing
the implant comprises adding particles.
17. The method as defined in claim 16 wherein the particles
comprise a ceramic.
18. The method as defined in claim 17 wherein the ceramic particles
have a size range of about 20 to 200 microns and have a volume
percent of about 5 to 65 percent.
19. A tissue implant product for a tissue site comprising: a
polysaccharide polymer having an Fo value between about 22 and 34
and a buffer component, wherein rheology parameters of the implant
product include a cross-over of G' and G'' and phase frequency
functionality of the implant product exhibits a behavior in three
regions of tissue functionality of the same category as the tissue
site.
20. The tissue implant product as defined in claim 19 further
including the feature that phase frequency functionality of the
implant product exhibits a behavior in three regions of tissue
functionality of the same category as the tissue site.
21. The tissue implant product as defined in claim 19 further
including a rheological feature requirement for the implant product
of being within a phase region meeting a plurality of rheological
parameters characteristic of the tissue site.
22. An implant having a rheological properly selected to be
compatible with tissue at an implant site, prepared in accordance
with a method comprising the steps of: establishing at least one
required rheological feature for the tissue at the implant sites;
identifying an implant having the required rheological feature; and
preparing the implant having the required rheological feature so as
to be compatible with the tissue at the implant site.
23. The implant as defined in claim 22 wherein the steps of
identifying an implant includes establishing at least one chemical
variable associated with the required rheological feature.
24. The implant as defined in claim 22 wherein the step of
identifying an implant having the required rheological feature
comprises mapping the at least one required rheological feature
versus a plurality of chemical variables to identify a combination
of the chemical variables which enables meeting the at least one
required rheological feature.
25. The implant as defined in claim 24 wherein the at least one
required rheological feature comprises G' and G'' functional
behavior intersecting each other between about 0.1-10 Hz tissue
response.
26. The implant as defined in claim 25 wherein G'' is greater than
G' until intersection.
27. The implant as defined in claim 24 wherein the step of mapping
the at least one required rheological feature comprises statistical
analysis of changing the chemical variables to establish at least
one of a line and a volume of desirability associated with an
implant rheological feature which is compatible with the at least
required rheological feature.
28. A method for identifying an implant for a selected tissue
implant site of a particular type of patient, the method
comprising: a supplier providing a clinician rheological data for
tissue of a particular type of patient at a prospective tissue
implant site; and a clinician reviewing data from the supplier of a
plurality of potentially useful implant products, the data from the
supplier providing (a) information on the rheological properties of
each of the plurality of the implant products and (b) further
indicating whether the rheological properties will meet
compatibility requirements for the particular type of patient
tissue at the implant site.
29. The method as defined in claim 28 wherein the data from the
supplier includes information on change of a rheological parameters
for the implant as a function of change of chemical variables of
the implant.
30. A method of implanting a tissue augmentation product in a
patient, comprising the steps of: characterizing a tissue in a
particular type of patient; reviewing data from a supplier which
includes identifying a tissue augmentation product having
rheological properties compatible with the tissue of the particular
type of patient; and implanting the tissue augmentation product in
the patient in accordance with the data from the supplier.
31. A method of establishing a treatment protocol for implantation
of a tissue augmentation product which is compatible with a patient
tissue site, comprising the steps of: identifying particular
rheological properties associated with tissue of a particular type
of patient; providing implant rheological data for a plurality of
tissue augmentation products; and identifying selected tissue
augmentation products which have implant theological data which is
indicative of being compatible with the tissue of the particular
type of patient.
32. The method as defined in claim 31 wherein the tissue of the
particular type of patient is selected from the group consisting
of: vocal fold, nasolabial folds, marionette lines, cheek
augmentation, lips, urinary tract, and wrinkles and folds.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] The present application is a continuation-in-part of U.S.
patent application Ser. No. 11/348,028, filed Feb. 6, 2006 and U.S.
patent application Ser. No. 11/650,696 filed Jan. 8, 2007 both of
which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to tissue
augmentation, and more particularly to injection of resorbable,
biocompatible, gel and solid composites to correct and augment soft
tissue with specific application for cosmetic augmentation of
tissues.
BACKGROUND OF THE INVENTION
[0003] There are a number of non-resorbable, particle-based
compositions used for permanent correction or augmentation of soft
tissue defects or augmentation for cosmetic purposes. Each
composition is associated with certain advantages and
disadvantages. Silicone gel was frequently used to treat dermal
defects, such as wrinkles, folds, and acne scars in the 1970's and
1980's but has since been prohibited from use in these
applications. Silicone was frequently associated with chronic
inflammation, granuloma formation, and allergic reactions.
TEFLON.RTM. paste is a suspension of polytetrafluoroethylene
particles in glycerin. This composition was primarily used for
vocal fold augmentation and has been associated with granuloma
formation. Bioplastics composed of polymerized silicone particles
dispersed in polyvinylpyrrolidone. This composition has been
withdrawn from commercial application due to frequent chronic
inflammation and tissue rejection. Polymethylmethacrylate (PMMA)
microspheres having a diameter of 20-40 .mu.m and suspended in a
bovine collagen dispersion have been described by Lemperle (U.S.
Pat. No. 5,344,452). Since the composition contains collagen from a
bovine source, skin testing is required. In addition, the
composition is associated with sterilization challenges; the bovine
collagen dispersion is damaged by standard terminal sterilization
techniques, including heat and gamma irradiation. PMMA is also
labile to heat sterilization conditions.
[0004] Carboxymethylcellulose and other polysaccharides are
examples of material used in gel or solution form for a variety of
medical and non-medical applications. Sodium carboxymethylcellulose
("CMC") is cellulose reacted with alkali and chloroacetic acid. It
is water soluble and biodegradable and used in a number of medical
and food applications. It is also commonly used in textiles,
detergents, insecticides, oil well drilling, paper, leather,
paints, foundry, ceramics, pencils, explosives, cosmetics and
adhesives. It functions as a thickening agent, a bonder,
stabilizer, water retainer, absorber, and adhesive.
[0005] The prior art gel materials teachings treat the gel merely
as a carrier, incidental to the actual augmentation function of the
gel; and there has been no directed effort to understanding how
best to prepare an implant which is truly compatible rheologically
and chemically with an implant site. Further, conventional methods
and products fail to address several problems with current gels.
More specifically, the injectable materials of the prior art fail
to address the specific difficulties in applying implants across a
wide range of locations in the body and consequently fail to
provide the appropriate type of implant. For example, current
implants can experience occlusion, or irregular implantation during
the implantation procedure when a fine gauge needle is used. While
in certain applications a fine gauge needle may not be required, it
is vital to the success of several applications. In addition, a
smaller gauge needle leaves a smaller puncture point, which is
often desirable to patients. Furthermore, the propensity for
occlusions often results in uneven, erratic and discontinuous
implantation, which causes highly undesirable results.
[0006] In another aspect of conventional methods and products,
current implants have failed to address the viscoelastic properties
of the implant in the syringe, such that current implants require a
significant amount of force, and even irregular levels of force, to
extrude the implant from the needle, much more so as the needle
gauge is reduced. This presents fatigue issues for medical
professionals who may well be performing many injections in a day.
This also makes any given injection more difficult to perform, and
also perform proper injection amounts and distributions, because of
the necessity to exert a large amount, or an irregular amount of
force on the syringe, while maintaining a steady needle during
injection.
[0007] Conventional methods and current implant materials also fail
to address the wide range of distinctions in the different tissues
in which the implants are placed. Implants can undergo unwanted
agglomeration, chemical reaction, phase separation, and premature
breakdown of the implanted mass into discontinuous variable shapes,
all of which can consequently manifest different undesirable
mechanical properties and performance relative to the implant
tissue region.
[0008] Material composition and its associated mechanical,
chemical, and even electrical and other physical properties are
important relative to: compatibility and stability at the tissue
implant site; controlled and proper tissue in-growth and to
implement integration into the tissue, immuno-histo tissue
response, and mechanical and visual appearance. The augmentation
performance for the patient encompasses proper aesthetic outcome
arising from the function of the physical components and the
chemical composition of the composite of gel and particles implant.
In particular, prior art implants utilizing gels have relied on the
gel as a carrier but have failed to recognize and solve the problem
of providing an implant with a gel which is designed to cooperate
with the solid particles to mimic, both mechanically and
chemically, the tissue into which it is injected and to behave in a
symbiotic controlled manner when embedded in the tissue.
[0009] Implants using prior art gels exhibit a tendency to form
nodules, or to migrate from the desired implantation location, or
to undergo unwanted and undesired chemical and/or mechanical
breakdown, such as phase separation or formation of unwanted
geometries and cosmetic appearance in the body. None of these is an
acceptable result for a patient. Nodule formation has been
previously reported for known compositions by M. Graivier and D.
Jansen, "Evaluation of a Calcium Hydoxylapatite-Based Implant
(Radiesse) for Facial Soft-Tissue Augmentation," Plastic and
Reconstructive Surgery Journal, Vol. 118, No. 3s, pg. 22s
(2006).
SUMMARY OF THE INVENTION
[0010] The present invention is directed to systems and methods for
preparation of implant materials which enable compatible tissue
augmentation. In particular, the systems and methods relate to
augmentation implants preformed in accordance with carefully
preparing implant matrix materials using a precise protocol to
manipulate a plurality of chemical variables to achieve a designed
end product and with well define rheological characteristics. In
one embodiment, the implants comprise gels having specific
compatibility and stability at the tissue implant site; controlled
and proper tissue in-growth to implement integration into the
tissue, minimized immuno-histo tissue response, and improved
mechanical and visual appearance In one embodiment, the implant
comprises gels having particles suspended therein with specific
compatibility and stability at the tissue implant site; controlled
and proper tissue in-growth to implement integration into the
tissue, minimized immuno-histo tissue response, and improved
mechanical and visual appearance. The implants have physical and
chemical properties selected to achieve a desired rheological and
chemical behavior when implanted. For example, it is preferable to
replace or augment tissue structure with a material exhibiting
physiological properties, including rheological, chemical,
biological, and mechanical properties, which are similar to and/or
compatible with those of the treated tissue and/or designed to
accommodate tissue in growth in a controlled manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates behavior of G' and G'' for two different
body tissue fluids;
[0012] FIG. 2 illustrates G' and G'' for three different age body
tissue fluids;
[0013] FIG. 3 illustrates a schematic method of manufacture of
implant products;
[0014] FIG. 4 illustrates phase angle versus frequency behavior of
lip tissue;
[0015] FIG. 5 illustrates Fo behavior versus viscosity for
representative implant products;
[0016] FIG. 6 illustrates a flow chart of an analytical statistical
method to analyze chemical variables to map to a target tissue
rheology;
[0017] FIG. 7A shows a list of chemical variables and a tabular key
for a first range of rheological variables; FIG. 7B(i) shows Fo
versus percent CMC and viscosity; FIG. 7B(ii) shows the same
chemical variables versus G' at 0.7 Hz; FIG. 7B(iii) same but for
G' at 4 Hz; FIG. 7B(iv) same but for frequency response at 0.7 Hz;
FIG. 7B(v) same but for tan 6 at 0.7 Hz; FIG. 7B(vi) same but for
G'' at 0.7 Hz; FIG. 9B (vii) same but G'' at 4 Hz; and FIG.
7B(viii) same but for frequency response at 4 Hz; and FIG. 7C shows
the 2D plot of a region of rheological merit (white) versus a
region not meeting the parameters (dark);
[0018] FIG. 8 illustrates a flow chart of the steps in creating
prediction profiles;
[0019] FIG. 9A(i) is a 3D contour of CMC percent versus PBS(mM)
versus tan .delta.; FIG. 9A(ii) is CMC versus PBS versus viscosity
at 0.7 Hz with planar cross-sections for FIG. 9B shown; FIG.
9A(iii) is CMC versus PBS versus G' at 0.7 Hz; FIG. 9A(iv) is CMC
versus PBS versus G'' at 0.7 Hz; FIG. 9A(v) is CMC versus PBS
versus tan 6 at 4 Hz; FIG. 9A(vi) is CMC versus PBS versus G' at 4
Hz; FIG. 9A(vii) is CMC versus PBS versus G'' at 4 Hz; FIG.
9A(viii) is CMC versus PBS versus frequency response at 0.7 Hz; and
FIG. 9(ix) is CMC versus PBS versus frequency response at 4 Hz; and
FIG. 9B is a prediction profile set and shows columns of
rheological behavior for various chemical variables, each taken
from a cross-section from the contours of FIGS. 9A(i)-9A(ix);
[0020] FIG. 10 illustrates a plot of elastic viscous modulus and
complex viscosity as a function of frequency for the composition of
Example 1;
[0021] FIG. 11 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 2;
[0022] FIG. 12 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 3;
[0023] FIG. 13 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 4;
[0024] FIG. 14 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 5;
[0025] FIG. 15 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 6;
[0026] FIG. 16 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 7;
[0027] FIG. 17 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 8;
[0028] FIG. 18 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 9;
[0029] FIG. 19 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 10;
[0030] FIG. 20 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 11;
[0031] FIG. 21 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 12;
[0032] FIG. 22 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 13;
[0033] FIG. 23 illustrates a plot of elastic and viscous modulus
and complex viscosity as a function of frequency for the
composition of Example 14;
[0034] FIG. 24 illustrates the viscosities for each of the
materials as sheer rate varies;
[0035] FIG. 25 illustrates the loss modulus for each of the
materials as sheer rate varies;
[0036] FIG. 26 illustrates the viscosity modulus for each of the
materials as sheer rate varies;
[0037] FIG. 27 illustrates the tan .delta. for each of the
materials as sheer rate varies;
[0038] FIG. 28 demonstrates time dependency of the elasticity for
varying gel compositions with varying concentrations of particles
(30% & 40% solids in 2.6 CMC: 1.5% glycerin carrier vs. 30%
solids in a 3.25% CMC: 15% glycerin carrier);
[0039] FIG. 29 illustrates the loss modulus G', the elastic modulus
G'' and tan .delta. (G'/G'') for compositions of Example 16;
[0040] FIG. 30 illustrates viscosity and tan 5 properties for
compositions of Example 16; and
[0041] FIG. 31A shows a 3D desirability plot of glycerin versus Fo
holding CMC and PBS constant; FIG. 31B shows Fo versus PBS holding
CMC and glycerin constant; FIG. 31C shows PBS versus CMC holding
glycerin and Fo constant; FIG. 31D shows glycerin versus CMC
holding PBS and Fo constant; FIG. 31E shows Fo versus CMC holding
PBS and glycerin constant; and FIG. 31F shows glycerin versus PBS
holding CMC and Fo constant.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] The present invention is directed to tissue augmentation
implants and generally to programmable rheology polysaccharide
gels. More particularly, the invention relates to polysaccharide
compositions containing carboxymethylcellulose or other
polysaccharide polymers formulated to exhibit rheological
characteristics which are designed particularly to match the
characteristics of the body tissue implant region of interest. For
example, the invention can be applied to provide tissue implant
product throughout the body, such as, for example, urinary tract,
vocal fold, lip tissue, cheek, other dermal tissue for various uses
including clinical and restorative applications and cosmetic
applications like nasolabial folds, marionette lines, lip
augmentation and wrinkles and folds. In considering tissue
augmentation implants, it is important to understand that physical
properties of body tissue are closely related to tissue function;
and in one aspect tissue cell response to the rheological
characteristics (e.g., elasticity) of their microenvironment must
be properly accounted for. Understanding the physical structure and
function of tissues is of fundamental and therapeutic interest. It
is therefore most preferable to replace or augment tissue structure
with a material exhibiting physical properties, including
rheological, and also chemical and biological properties similar to
those of the treated tissue. This provides improved tissue
compatibility of the implant material and encourages normal cell
responsiveness. In addition, the similar behavior of the implant
and the surrounding tissue provides for a more natural appearance
to the augmented area and also can more readily accommodate
controlled tissue in-growth. The particular way in which the
"similarity" of the implant rheology is determined and control of
the product manufacture are important aspects of the invention. The
details of the selection of the chemical and thermal treatment
variables for the implant product and their mapping to appropriate
rheological values will be described in detail hereinafter.
Different tissues exhibit unique biomechanical and chemical
characteristics associated with tissue functions; and the effects
of tissue properties should be considered when augmenting or
replacing these tissues. Consequently, the implant products are
formulated to achieve the desired rheological properties to achieve
tissue compatibility, as well as avoid unwanted chemical reactions
and phase separation.
[0043] Carboxymethylcellulose ("CMC") and other polysaccharides are
examples of material used in gel or solution which are used for a
variety of medical and non-medical applications. Sodium
carboxymethylcellulose ("NaCMC") is cellulose reacted with alkali
and chloroacetic acid. It is one of the most abundant cellulose
polymers available. It is water soluble and biodegradable and used
in a number of medical and food applications. It is also commonly
used in textiles, detergents, insecticides, oil well drilling,
paper, leather, paints, foundry, ceramics, pencils, explosives,
cosmetics and adhesives. It functions as a thickening agent, a
bonder, stabilizer, water retainer, absorber, and adhesive.
[0044] A number of literature references describe
carboxymethylcellulose and other ionic polysaccharides as being
viscoelastic and pseudoplastic. See, for example: (Andrews G P,
Gorman S P, Jones D S., Rheological Characterization of Primary and
Binary Interactive Bioadhesive Gels Composed of Cellulose
Derivatives Designed as Ophthalmic Viscosurgical Devices,
Biomaterials. 2005 February; 26 (5): 571-80; Adeyeye M C, Jain A C,
Ghorab M K, Reilly W J Jr., Viscoelastic Evaluation of Topical
Creams Containing Microcrystalline Cellulose/sodium Carboxymethyl
Cellulose as Stabilizer, AAPS PharmSciTech. 2002; 3 (2): E8; Lin S
Y, Amidon G L, Weiner N D, Goldberg A H., Viscoelasticity of
Anionic Polymers and Their Mucociliary Transport on the Frog
Palate, Pharm. Res. 1993, March: 10 (3): 411-417; Vais, A E, Koray,
T P, Sandeep, K P, Daubert, C R. Rheological Characterization of
Carboxymethylcellulose Solution Under Aseptic Processing
Conditions, J. Food Science, 2002. Process Engineering 25:
41-62).
[0045] The Aqualon Product Information publication from Hercules,
Inc. describes the effects of various parameters on rheology of
sodium CMC. Viscosity increases with increasing concentration, and
CMC solutions are pseudoplastic and viscoelastic. Exposure to heat
results in a reduction in viscosity and effects are reversible
under normal conditions. After long periods of time, CMC will
degrade at elevated temperatures with permanently reduced
viscosity. For example, moderate MW (Aqualon 7L) CMC heated for 48
hours at 180.degree. F. will lose 64% of viscosity. CMC is
relatively stable to changes in pH and effects of pH on viscosity
are minimal in the physiologically relevant range of pH 6-9. There
is some loss of viscosity above 10 and some increase below 4. Salts
may also affect rheology of CMC; and monovalent cations interact to
form soluble salts. If CMC is dissolved in water and then salts are
added, there is little effect on viscosity. If CMC is added dry to
salt solution, the viscosity can be depressed through ionic
repulsion. Polyvalent cations will not generally form crosslinked
gels. Viscosity is reduced when divalent salts are added to CMC
solution and trivalent salts precipitate CMC.
[0046] As can be concluded from consideration of the prior art,
rheological and chemical properties of the implant involve many
complex factors. As such, one can vary each of those components of
the implant in order to design an implant with specific controlled
in vivo properties. Such degrees of freedom are in fact so large
and complex that designing the proper implant is a formidable
task.
[0047] In order to resolve these complex tasks, it is instructive
to consider the rheology of selected body tissue components. Shown
in FIG. 1 are two different body tissue fluids composed of the same
basic hyaluronic acid (sometimes referred to as hyluronic acid)
component but that show significantly different storage and loss
modulus under the same physiological strain conditions. Both
solutions demonstrate shear thinning and the material conversion
from a viscous material (G'' predominant or Tan .delta.>1) to an
elastic material (G' dominant) over a relatively small
physiological shear stress of 0.1 to 180 radians/sec ( 0.159 Hz to
28.6 Hz).
[0048] For example, it has been demonstrated that physiological
fluids conform to the stress imposed on them in varying ways.
Dominant characteristics of a material can change from a viscous
lubrication material to elastic anchoring character as outside
forces are imposed. Shown in FIG. 2 are three of the same body
tissue fluids composed of the same basic hyaluronic acid component
but that show significantly different storage and loss modulus
under the same physiological strain conditions based on the age of
an individual. The materials labeled "young" and "old" demonstrate
shear thinning and the material conversion from a viscous material
(G'' predominant or tan .delta.>1) to an elastic material (G'
dominant) over a relatively small physiological shear stress of 0.1
to 180 radians/sec. Material cross-over (G''=G') and relative
amplitude is dependent on age. The material labeled
"osteoarthritis" did not cross-over under the same shear conditions
and the storage G' and loss modulus G'' amplitudes were
significantly less than the other two materials. Therefore, it is
demonstrated herein through formulation and physical manipulation
of the cellulose based implant that biologically relevant
biomechanical gel properties can be manufactured that can be
tailored for the specific application required. It is thus
important to recognize this type of transition point for biological
acceptance of materials. Various controlling parameters, such as
implant product parameters can be manipulated, including buffer
strength (such as PBS), polysaccharide choice and concentration
(such as NaCMC), lubricant content (such as glycerin); and
autoclave time can also be manipulated so that mechanical outputs
of viscosity and elasticity may be adapted to the desired outcome
without creating all of the problems apparent in the prior art.
[0049] For example, in one preferred embodiment of the present
invention the method of manufacture and product are directed to
implants for tissue augmentation of the lips. As stated earlier,
physical properties of body tissue are closely related. Cellular
propagation, cellular infiltration and cellular function during
tissue repair has been shown across several cellular models to be
dependent on the rheological characteristics (e.g., elasticity) of
their microenvironment. As described hereinbefore, understanding
the physical structure and function of tissues is of fundamental
therapeutic interest during tissue augmentation and repair. It is
therefore preferable to replace or augment tissue structure with a
material exhibiting physical properties, including theological, as
well as chemical, biological, and mechanical properties, similar to
those of the treated tissue. The implants therefore provide an
opportunity to match the properties of the implant with that of the
tissue in which the implant is to be placed. This provides improved
tissue compatibility of the implant material and encourages normal
cell responsiveness designed to provide controlled tissue in
growth. In addition, the similar behavior of the implant and the
surrounding tissue provides for a more natural appearance to the
augmented area.
[0050] In one most preferred embodiment, the implant comprises gels
of 2.6% CMC with 1.5% glycerin in a 25mM phosphate buffer (PBS) at
7.4 pH. The phase angle ranged from 48 degrees to 140 degrees over
the frequency range of 0.1 Hz to 10 Hz. This is consistent with
published measurements for experimentally measured phase angle for
the oblicularis oris superior and inferior under voluntary
stimulation where the phase angle ranged from near 0 degrees to 150
degrees over the frequency range of 0.1 Hz to 10 Hz.
[0051] The magnitude of the initial phase angle is larger for the
implant as the material demonstrates more viscous character at
f<0.05. However, the material G'=G'' cross-over is 0.2; and the
elastic character starts to dominate so as to simulate the elastic
behavior which has been experimentally measured in the art. For
both the experimentally measured and the proposed implant the phase
angle demonstrates little change over the frequency range of 0.1 Hz
to 1 Hz with similar phase shifts noted over the same biologically
relevant ranges.
[0052] In one embodiment, the implant comprises gels of 2.6% CMC
with 1.5% glycerin in a 25 mM phosphate buffer at 7.4 pH with 30%
v/v 25 um to 45 um calcium hydroxylapatite particles. The material
rheology is similar to the tissue site, especially at low
frequencies where the phase angle is linear. The material tests as
an elastic material over the frequency range. However, the tan
.delta. starts at 0.9 (approximately G'=G") and decreases as the
material shear thins over the physiologically relevant range of 0.1
Hz to 10 Hz.
[0053] It is also useful to understand certain terminologies used
herein; including "rheology", which is the study of the deformation
and flow of matter. "Newtonian fluids" (typically water and
solutions containing only low molecular weight material), the
viscosity of which is independent of shear strain rate and a plot
of shear strain rate. Non-Newtonian fluid is a fluid in which the
viscosity changes with the applied shear force. The rheological
outputs that describe a material are typically .eta., G', G'', tan
.delta., deflection angle relative to a linear force (shear) or
oscillating force (Hz) of activity on the tissue at an implant
site. The parameter .eta. is the viscosity, which is an indication
of the materials measure of the internal resistance of a material
to deform under shear stress. For liquids, it is commonly perceived
as "thickness", or resistance to pouring. G' is the storage
modulus, which is an indicator of elastic behavior and reveals the
ability of the polymer system to store elastic energy associated
with recoverable elastic deformation. G'' is the loss modulus,
which is a measure of the dynamic viscous behavior that relates to
the dissipation of energy associated with unrecoverable viscous
loss. The loss tangent (tan .delta.) is defined as the ratio of the
loss modulus to the storage modulus (G''/G') and is dimensionless.
It is a measure of the ratio of energy lost to energy stored in a
cycle of deformation and provides a comparative parameter that
combines both the elastic and the viscous contribution to the
system. A tan .delta. greater than 1 means the fluid is more
liquid. A tan .delta. less than 1 means the fluid is more solid.
Deflection angle is defined as the angle from a steady state after
a force is applied to a material. The physiologically relevant
range of shear force and oscillation force is the body tissue
activity range for typical human function for that tissue. These
ranges will be particularly evident, if a target implant is
directed to soft dermal tissue, dense collagenous tissue, muscle or
bone.
[0054] The biomechanical behavior of biomaterials can therefore be
characterized by measuring their rheological properties. Rheology
is related to viscoelasticity and viscoelastic shear properties.
Viscoelastic shear properties are quantified by complex shear
modulus which includes elastic shear modulus and viscous shear
modulus. The magnitude of the complex shear modulus has been used
to indicate overall shear elasticity, stiffness, and rigidity. If a
material is purely elastic, then tan .delta.=0. If the material is
purely viscous, the tan .delta.=infinity. All tissues exhibit a tan
.delta. between these two extremes.
[0055] Different tissues exhibit unique biomechanical
characteristics associated with tissue functions and the effects of
tissue properties should be considered when augmenting or replacing
these tissues. This invention describes compositions that are
formulated to simulate the biomechanical properties of the tissues
in which the compositions are injected or implanted and avoid
unwanted chemical reactions and phase separation. Many different
variables together provide the overall mechanical, chemical and
biologic properties of the implant. As such, one may vary each of
those components of the implant in order to design an implant with
specific controlled in vivo properties. Sterility is a necessary
design requirement. Therefore, the sterilization mode and
parameters associated with the sterilization process are vital to
the material design because the intended use of the material is for
tissue augmentation or replacement.
[0056] The implant is a composite injectable into soft tissue. The
composite material comprises a biocompatible gel with or without
particles. Prior to and during injection, the gel functions, in
part, as a carrier for particles which might be present. In vivo,
the gel forms an integral part of the implant, providing the
necessary pre-selected mechanical and chemical microenvironment
previously described for the implant to achieve the desired article
of manufacture.
[0057] As stated hereinbefore, the carrier preferably includes a
polysaccharide gel wherein the polysaccharides that may be utilized
in the present invention include, for example, any suitable
polysaccharide and combinations thereof, within the following
classes of polysaccharides: celluloses/starch, chitin and chitosan,
hyaluronic acid, hydrophobe modified systems, alginates,
carrageenans, agar, agarose, intramolecular complexes,
oligosaccharide and macrocyclic systems. Examples of
polysaccharides grouped into four basic categories include: 1.
nonionic polysaccharides, including cellulose derivatives, starch,
guar, chitin, agarose and. dextron; 2. anionic polysaccharides
including cellulose derivatives starch derivatives, carrageenan,
alginic acid, carboxymethyl chitin/chitosan, hyaluronic acid and
xanthan; 3. cationic polysaccharides, including cellulose
derivatives, starch derivatives guar derivatives, chitosan and
chitosan derivatives (including chitosan lactate); and 4.
hydrophobe modified polysaccharides including cellulose derivatives
and alpha-emulsan. In one embodiment, the polysaccharide polymer is
selected from the group of sodium carboxymethylcellulose,
hydroxyethyl cellulose, ethylhydroxyethyl cellulose, carboxymethyl
cellulose, carboxyethylhydroxyethyl cellulose,
hydroxypropylhydroxyethyl cellulose, methyl cellulose,
methylhydroxylmethyl cellulose, methylhydroxyethyl cellulose,
carboxymethylmethyl cellulose, and modified derivatives thereof.
Preferred polysaccharides for use in the present invention include,
for example, agar methylcellulose, hydroxypropyl methylcellulose,
ethylcellulose, microcrystalline cellulose, oxidized cellulose,
chitin, chitosan, alginic acid, sodium alginate, and xanthan gum.
In certain embodiments, more than one material may be utilized to
form the gel, for example two or more of the above listed
polysaccharides may be combined to form the gel. In certain
embodiments, more than one material may be utilized to form the
crosslinked gel, for example two or more of the above listed
polysaccharides may be combined to form the gel.
[0058] In addition, the gel may be crosslinked. Appropriate gel
crosslinkers include for example: heat, pH, and crosslinking
through mono valent, di-valent, and tri-valent cationic
interactions. The crosslinking ions used to crosslink the polymers
may be anions or cations depending on whether the polymer is
anionically or cationically crosslinkable. Appropriate crosslinking
ions include, but are not limited to cations selected from the
group consisting of calcium, magnesium, barium, strontium, boron,
beryllium, aluminum, iron, copper, cobalt, and silver ions. Anions
may be selected from but are not limited to the group consisting of
phosphate, citrate, borate, carbonate, maleate, adipate and oxalate
ions. More broadly, the anions are derived from polybasic organic
or inorganic acids. Preferred crosslinking cations are calcium iron
and barium ions. The most preferred crosslinking cations are
calcium and iron. The preferred crosslinking anions are phosphate,
citrate and carbonate. Crosslinking may be carried out by
contacting the polymers with an aqueous solution containing
dissolved ions. Additionally, crosslinking could be accomplished
through organic chemical modification including: poly-functional
epoxy compound is selected from the group consisting of
1,4-butanediol diglycidyl ether (BDDE), ethylene glycol diglycidyl
ether (EGDGE), 1,6-hexanediol diglycigyl ether, polyethylene glycol
diglycidyl ether, polypropylene glycol diglycidyl ether,
polytetramethylene glycol digylcidyl ether, neopentyl glycol
digylcidyl ether, polyglycerol polyglycidyl ether, diglycerol
polyglycidyl ether, glycerol polyglycidyl ether,
tri-methylolpropane polyglycidyl ether, pentaerythritol
polyglycidyl ether, and sorbitol polyglycidyl ether. Additionally,
crosslinking could be accomplished through organic chemical
modification through the carbonyl or hydroxide functionality of the
polysaccharide backbone reaction. In embodiments utilizing more
than one type of polymer, the different polymers may crosslink with
each other to form further crosslinking.
[0059] As shown by the Example 19, the discussion regarding FIG.
9B, and data provided hereinafter, in one embodiment the implant
comprises a gel, the tan .delta. (ratio of the viscosity modulus
G'' to the loss modulus G') of which can be manipulated by
adjusting the concentration of salt (in this case potassium
phosphate or PBS) in NaCMC formulations that are subsequently heat
sterilized. In compositions prepared in water, the tan .delta. is
<1 before and after heat treatment, indicative of a elastic
fluid. If the compositions are prepared in dilute salt solutions,
the tan .delta. is <1 before heat treatment and >1 after heat
treatment. A tan .delta.>1 generally indicates a viscous fluid.
Both dilute salt (in this case monovalent) and heat treatment are
needed to convert the composition from a tan .delta.<1 to a tan
.delta.>1. As the salt concentration increases, the viscosity of
the composition is reduced by reducing the ability of the
polysaccharide to internally crosslink.
[0060] In selected compositions for tissue augmentation a viscosity
is preferred that will provide some bulking capability in addition
to satisfying tissue rheological behavior. Therefore, the salt
concentration is preferably carefully controlled at relatively low
levels, usually less than 100 mM.
[0061] The addition of glycerin to salt solution reduces the tan
.delta., i.e., the composition, even after heat treatment, remains
elastic, because the rheological properties of the glycerin provide
bulking rheological interaction with the polysaccharide gel. The
tan .delta. is preferably and usually <1. However, the tan
.delta. of this composition is different from the tan .delta. of
compositions prepared in water without salt. The rheological
characteristics of NaCMC can be manipulated by salt, glycerin, and
heat treatment.
[0062] In addition to the desire to accommodate the rheological
character of the implant tissue site, the gel of the present
invention can be adjusted to control extrusion, decomposition rate
(chemical and physical), moldability and porosity to modulate
tissue response. Gel characteristics also control varying rates of
resorption, as host tissue forms around the slower resorbing
ceramic particles.
[0063] In one embodiment, the present invention provides a gel
capable of supporting solid particles for injection through fine
gauge needles and forming an integral and compatible part of the
implant (and surrounding bio-environment) once injected. The
implant includes particles suspended in the gel. In certain
embodiments, the particles are ceramic based composites.
Particulate ceramic materials include, but are not limited to,
calcium hydroxyapatite, and other suitable materials including, but
are not limited to, calcium phosphate-based materials, and the
like. Examples include, but are not limited to, tetracalcium
phosphate, calcium pyrophosphate, tricalcium phosphate, octacalcium
phosphate, calcium fluorapatite, calcium carbonate apatite,
alumina-based materials, and combinations thereof. The ceramic
particles may be smooth rounded, substantially spherical, particles
of a ceramic material embedded in a biocompatible gel material that
is continuous, crosslinked or in a dehydrated configuration as
discussed below. In this embodiment, particles may range in size 20
microns to 200 microns and preferably from about 20 microns to 120
microns and most preferably from 20 microns to 45 microns.
Concentration of ceramic particles ranges from 5% to 65%, by
volume, preferably from 10% to 50% by volume and most preferably
from 30% to 45% by volume.
[0064] Particles which can be added to the gel can be made of a
biocompatible but non-biodegradable material. Suitable materials
include glass, e-PTFE, PTFE, polypropylene, polyacrylamide,
polyurethane, silicone, polymethylmethacrolate, Dacron, carbon
particles, TEFLON.RTM., metals of iron, copper nickel titanium
alloys thereof including Nitinol, silver, gold, platinum, or
stainless steel. The particles can be comprised of a plurality of
layers of materials including organic polymers and proteins.
Additionally, one can select particles from organic biopolymers of
elastomers such as, for example, acrylic polymers, vinyl alcohol
polymers, acrylate polymers, polysaccharides, the acrylic family
such as polyacrylamides and their derivatives, polyacrylates and
their derivatives as well as polyallyl and polyvinyl compounds. All
of these polymers are crosslinked so as to be stable and
non-resorbable, and can contain within their structure other
chemicals displaying particular properties or mixtures thereof. The
particles may preferably include a polysaccharide particle, for
example, any suitable polysaccharide and combinations thereof,
within the following classes of polysaccharides: celluloses/starch,
chitin and chitosan, hyaluronic acid, hydrophobe modified systems,
alginates, carrageenans, agar, agarose, intramolecular complexes,
oligosaccharide and macrocyclic systems. Examples of
polysaccharides can be grouped into four basic categories and
include: 1. nonionic polysaccharides, including cellulose
derivatives, starch, guar, chitin, agarose and dextron; 2. anionic
polysaccharides including cellulose derivatives starch derivatives,
carrageenan, alginic acid, carboxymethyl chitin/chitosan,
hyaluronic acid and xanthan; 3. cationic polysaccharides, including
cellulose derivatives, starch derivatives guar derivatives,
chitosan and chitosan derivatives (including chitosan lactate); and
4. hydrophobe modified polysaccharides including cellulose
derivatives and alpha-emulsan. In one preferred embodiment, the
polysaccharide polymer is selected from the group of sodium
carboxymethylcellulose, hydroxyethyl cellulose, ethylhydroxyethyl
cellulose, carboxymethyl cellulose, carboxyethylhydroxyethyl
cellulose, hydroxypropylhydroxyethyl cellulose, methyl cellulose,
methylhydroxylmethyl cellulose, methylhydroxyethyl cellulose,
carboxymethylmethyl cellulose, and modified derivatives thereof.
Preferred polysaccharides for use in the present invention include,
for example, agar methylcellulose, hydroxypropyl methylcellulose,
ethylcellulose, microcrystalline cellulose, oxidized cellulose,
chitin, chitosan, alginic acid, sodium alginate, and xanthan gum.
In certain embodiments, more than one material may be utilized to
form the particle, for example two or more of the above listed
polysaccharides may be combined to form the particle. In certain
embodiments, more than one, such as two or more polysaccharide
materials can be utilized in conjunction with those crosslinking
agents previously listed herein, to form the crosslinked particle.
Further, particles, beads, microbeads, nanoparticles and liposomes
that may be suspended in gels may be porous, textured, coated, and
solid surfaces and can be round or other configurations.
[0065] These material compositions of the gel allow for better
extrusion characteristics through needle gauges as small as 27 to
30 gauge without the use of mechanical assistance devices, and with
less frequency of jamming or occlusion not previously accomplished
in prior art. While gels having particles suspended therein will
clearly have different extrusion characteristics than if there were
no particles, the implants of the present invention having
particles suspended in gel exhibit improved extrusion over those of
the prior art. As particle size approaches that of the needle,
extrusion becomes increasing difficult. However, particle sizes
below 75 microns allow for implants of the present invention to be
injected through fine gauge needs (such as 27 to 30 gauge). The gel
is able to suspend the particles as a carrier and allow for less
force to extrude the implant with a lower likelihood of occlusion.
Material compositions with a higher tan .delta. in the range of 0.5
to 3.5 and most preferably between 0.5 and 2.0 demonstrate the best
performance characteristic for extrusion through needle gauges as
small as 27 to 30 gauge. Material with higher tan .delta. are more
preferable for instances where mobility is the key parameter.
Decreasing tan .delta. creates more stout, moldable implant
materials. Some examples of extrusion forces for CaHA loaded gel
are in Table 1 below.
TABLE-US-00001 TABLE 1 Material composition 30% CaHA- 30% CaHA- 40%
CaHA- Physical 3.25 CMC; 15% 2.6% CMC; 1.5% 2.6% CMC; 1.5%
parameters glycerin glycerin glycerin Extrusion 6.1 5.4 4.8 Force
(lbf, 0.5'' 27 Ga.) Extrusion 11.5 9.8 7.6 Force (lbf, 1.25'' 27
Ga.)
[0066] The preferred embodiment demonstrates substantially less
required force than conventional systems.
[0067] In one embodiment, the present invention provides a gel
capable of supporting semi solid particles for injection through
fine gauge needles and forming an integral and compatible part of
the implant (and surrounding bio-environment) once injected. The
implant includes particles suspended in the gel. In certain
embodiments, the particles are excessively crosslinked
polysaccharide based composites. Particulate materials include, but
are not limited to, CMC, agar and other suitable materials
including, but are not limited to, alginate, hyaluronic acid,
chitosan and compositional combinations of the like. Examples
include, but are not limited to, hyaluronic acid/CMC, alginate/CMC
and chitosan/CMC ionically and chemically crosslinked combinations
thereof The particles may be smooth rounded, substantially
spherical, particles embedded in a biocompatible gel material that
is continuous, crosslinked or in a dehydrated configuration as
discussed below. In this embodiment, particles may range in size
from about 20 microns to 200 microns, and preferably from 20
microns to 120 microns and most preferably from 20 microns to 45
microns. Concentration of particles ranges from 5% to 90%, by
volume, preferably from 10% to 80% by volume and most preferably
from 60% to 70% by volume.
[0068] Furthermore, slight compositional changes in the gel carrier
allows selection of the biocompatibility parameters previously
described, while still allowing for homogenous particle suspension.
Tissue specific proteins may be added to facilitate tissue response
either by acceleration (infiltration of extra cellular matrix or
collagen) or decreasing the immuno histological response. Such
careful selection of these biocompatibility characteristics enable
achieving a preselected shape, cosmetic appearance, chemical
stability and bioenvironment to achieve stability of the implant or
tissue in-growth depending on the application. Increased
biocompatibility and biomechanical capability allows for the
implant to degrade into compounds native to the body according to a
specific degradation profile.
[0069] In one embodiment, a decrease in glycerin content has
provided for an improved osmolarity range that is physiologically
more similar to normal tissue physiological conditions with
improved biocompatibility not previously reported in the prior art.
The preferred form of the implant of the present invention does not
rely on high amounts of glycerin to suspend the particles, as prior
art gels have done. Despite this, the gels of the present invention
are able to suspend a higher concentration of particles than
previously taught even in prior art gels which relied heavily on
glycerin content. The decrease in glycerin content enables the
preferred embodiments to have a osmolarity range of 255 mOs to 600
mOs, preferable 255 mOs to 327 mOs, which is closer to the
physiological osmolarity of blood of 280 to 303 mOs and is
generally accepted as the range for cellular compatibility. Control
of the parameter is one degree of freedom in achieving the above
recited selection of a biocompatible implant. This preferred
embodiment is described in tabular form in Table 2.
TABLE-US-00002 TABLE 2 Material composition 30% CaHA- 30% CaHA- 40%
CaHA- Physical 3.25 CMC; 15% 2.6% CMC; 1.5% 2.6% CMC; 1.5%
parameters glycerin glycerin glycerin Osmolality 1768 to 2300 291
289 (mmol/kg)
[0070] This preferred embodiment is substantially more similar to
normal physiological conditions than any conventional product.
[0071] In addition, the decrease in glycerin and CMC allows for
material rheologies of preferred implant products that approach
these physiological conditions or physiological conditions of other
extra cellular matrixes and bodily fluids. The lower viscosity
modulus G'' and loss modulus G' allow for better tissue simulation
at stress/strain amplitudes typical to target tissue in the human
body.
[0072] The decrease in glycerin content also enables the preferred
embodiments to have a water content range of 57.9% to 70.3%, which
is closer to the physiological dermal water content of 70% in
embryonic skin to 60% in more mature skin. Materials that are
intended for tissue implantation that are closer to the
physiological water content of the target tissue create less
osmotic stress to the tissues and cells immediate to the
implant.
[0073] Another controllable degree of freedom in constructing an
implant to be biocompatible, as explained in detail herein before,
is control of CMC concentration. The decrease in CMC concentration
enables the preferred embodiments to have a thinner supporting gel
matrix which allows for more particle movement during the injection
and post injection which more closely mimics certain native tissue.
It has been demonstrated that formulation adjustment within the gel
allows for increasing the bulking material composition while still
maintaining biologically relevant rheological characteristics. This
facilitates improved baseline correction and improved durability in
the soft tissue corrections while maintaining application standards
consistent with the intended application. This creates less
regional tissue stress and strain which, in turn, limits the immuno
histological response in the form of erythema and edema thereby
reducing recovery time.
[0074] As stated hereinbefore, implants described herein may be
used in many parts of the body for tissue augmentation. For
example, soft tissue that can be augmented by the implant includes
but is not limited to dermal tissue (folds and wrinkles), lips,
vocal folds, mucosal tissues, nasal furrows, frown lines, midfacial
tissue, jaw-line, chin, cheeks, and breast tissue. It will be
appreciated that each of these areas exhibit unique mechanical and
biological properties. For example, the upper and lower lip exhibit
continuous mobility and require an implant that provides similar
mobility because of the muscle interaction and the decreased need
for elasticity. Thus implants exhibiting such characteristics
provide for both a higher degree of biocompatibility, mechanical
compatibility, and a superior visual effect. As such, the implant
may be formulated so as to be specifically designed for
implantation within a particular portion of the body for addressing
a particular indication. Table 3 illustrates the tan .delta. for
vocal folds and skin in the young and the elderly.
[0075] For typical dermis applications outside the face, the
rheological response for characterization may be better defined by
G', G'' or tan .delta.. This is summarized in Table 3 below, and
these particular rheological parameters are preferably used to
define regions of merit or volumes in desirability plots described
hereinafter.
TABLE-US-00003 TABLE 3 Tan .delta. for Intact Tissues Tissue Tan
.delta. Reference Vocal fold (human) 0.1-0.5 Chan, RW and Titze,
IR. 1999. J. (0.2-0.5 at low frequency) Acoust. Soc. Am., 106:
2008-2021 (0.1-0.3 at high frequency) Human Dermis-23 year old 0.61
Estimated as ratio of slopes of (strain rate 10% per minute)
viscous modulus to elastic modulus 1.02 from incremental
stress-strain curves (strain rate 1000% per (Silver, FH, Seehra,
GP, Freeman, minute) JW, and DeVore, DP. 2002. J. Applied Polymer
Science, 86: 1978-1985) Human Dermis-87 year old 0.36 See above
(strain rate 10% per minute) 1.16 (strain rate 1009% per
minute)
[0076] Examples of preferred parameters for selected material
compositions are set forth below in Table 4.
TABLE-US-00004 TABLE 4 Material composition 30% CaHA- 30% CaHA- 40%
CaHA- Physical 3.25 CMC; 15% 2.6% CMC; 1.5% 2.6% CMC; 1.5%
parameters glycerin glycerin glycerin Tan .delta. @ 0.5 0.453 0.595
0.581 Hz, 2.tau. 30 degree C.
[0077] Materials with higher tan .delta. are more preferable for
instances where mobility is the key parameter. Decreasing tan
.delta. creates more stout, moldable implant materials. The
preferred embodiment demonstrates closer physiological response
than conventional product materials.
[0078] For example, for addressing indications where the tissue
exhibits lower viscosity, such as the lips, an implant having a
viscosity of between 100,000 centipoise and 300,000 centipoise at
0.5 Hz with a tan 6 between 0.5 and 1 may be used. Likewise, for
addressing indications where a higher viscosity implant is desired
such as facial contouring in the midfacial area or other areas
where the implant preferably provides structural support, an
implant having a viscosity of between 300,000 centipoise and
600,000 centipoise with a tan .delta. between 0.5 and 1 may be
used. This is summarized in Table 5 below.
TABLE-US-00005 TABLE 5 Material composition 30% CaHA- 30% CaHA-
3.25 CMC; 2.6% CMC; 40% CaHA- 15% 1.5% 2.6% CMC; 1.5% Physical
parameters glycerin glycerin glycerin Viscosity (.eta. @ 0.5 Hz)
413750 202865 396585 Tan .delta. @ 0.5 Hz 0.453 0.595 0.581
Viscosity modulus 1478.60 678.32 1331.8 (G' @ 0.5 Hz) Loss Modulus
671.69 404.30 773.23 (G'' @ 0.5 Hz)
[0079] The tan .delta. of human vocal fold tissue ranges from
0.1-0.5 indicative of an elastic material (Chan, R W and Titze, I
R, Viscoelastic shear properties of human vocal fold mucosa:
Measurement methodology and empirical results". 1999, J. Acoust.
Soc. Am. 106:2008-2021). The tan .delta. of human skin ranges from
0.36 (older skin) to 0.61 (younger skin) (Calculated from
stress-strain data--Silver, F H, Seehra, G P, Freeman, J W, and
DeVore, D P. 2002. J. Applied Polymer Science, 86:1978-1985). The
tan .delta. for skeletal muscles exceeds 1.0 indicative of a
viscous material. The tan .delta. for hyaluronic acid ranges from
1.3 to 0.3 as the material demonstrates shear thickening and
transitions through tan .delta. equal to 1 between 1 and 8 rad/s
(0.17 to 1.3 Hz) (Fung Y C, 1993 "Biomechanics: Mechanical
properties of living tissue", Second edition, Springer-Verlag, New
York, N.Y.). This is important when designing a composition to
augment human lips (muscle). There is even a difference in
stiffness (more elastic according to Chan and Titze, et. al)
between the upper and lower lips and between males and females. The
lower lip is stiffer than the upper lip and male lips are stiffer
than female lips (Ho, T P, Azar, K, Weinstein, and Wallace, W B.
"Physical Properties of Human Lips: Experimental Theoretical
Analysis", 1982. J. Biomechanics. 15:859-866). The present
invention describes compositions that can be formulated to a
rheology (including tan .delta.) that more closely simulates the
tissue into which the biomaterial is placed.
[0080] Human lips are primarily composed of skeletal muscle
surrounded by loose connective tissue covered by stratified
keratinized squamous (similar to the stratum corneum of skin).
There is a difference in the stiffness of the lower and upper lip.
Many references equate stiffness to elasticity. If lip tissue is
similar to skeletal muscle, lip tissue exhibits significant
elasticity. However, a composition with a higher tan .delta. may
result in fewer lip nodules, a common problem with prior art
implants. Tissue responses to any implant depend on several factors
including the chemical composition, physical configuration and
biomechanical characteristics of the implant material and on the
biomechanical forces of the micro environment of the host tissue.
Prior art CaHA/CMC compositions injected into tissues under
increased mechanical stress produce more collagenous tissue (which
may lead to undesired tissue in-growth in certain applications)
than when implanted in tissues under less mechanical stress. Part
of this response is related to the viscoelasticity of the implant.
An implant under continuous mechanical stress will react
differently depending on the viscoelastic properties of the
implant. A highly viscoelastic implant (low tan .delta.) will
continuously undergo shear thinning to a lower viscosity and
"recoil" to the initial higher viscosity. This continuous change in
implant mechanics may "turn on" or signal host cells to become more
active and to produce more collagen than an implant exhibiting more
viscous rheology (higher tan .delta.). More viscous implants will
not undergo the same level of mechanical flux compared to more
viscoelastic implants.
[0081] For prior art compositions, thick collagenous material has
been observed to encapsulate individual particles. The implant does
form a continuous mass between muscle bundles (looks like muscle
bundles were pushed apart) and particles are surrounded by a thick
fibrous ring with thinner collagen units integrating between
particles. In contrast, it has been observed in dermis and mucosal
areas that collagen integration appears as a continuous weave
between particles and not as a thick capsule around individual
particles. This thick collagenous material around individual
particles is similar to that observed in a lip nodule biopsy. This
encapsulation is likely related to the continuous biomechanical
forces in lip muscle, the elasticity and cohesiveness of the
material, and accumulation between muscle bundles.
[0082] Thus, while not limiting the scope of the invention a
composition with a higher tan .delta. may reduce the incidence of
early nodules (those apparently associated with initial
inflammatory response and foreign body response to engulf and
remove CMC) and of later nodules resulting from excess fibrous
tissue surrounding CaHA particles. A less elastic and lower
viscosity composition can provide a smoother flowing and more
intrudable implant with reduced biomechanical motion to signal host
cells, thereby resulting in fewer nodules.
[0083] In addition to a base implant product and also selectively
the use of filler materials, such as ceramics like CaHA, any number
of medically useful substances for treatment of a disease condition
of a patient can be added to the implant composition at any steps
in the mixing process. Such substances include amino acids,
peptides, vitamins, co-factors for protein synthesis; hormones;
endocrine tissue or tissue fragments; synthesizers; angiogenic
drugs and polymeric carriers containing such drugs; collagen
lattices; biocompatible surface active agents, antigenic agents;
cytoskeletal agents; cartilage fragments, living cells such as
chondrocytes, bone marrow cells, mesenchymal stem cells, natural
extracts, transforming growth factor (TGF-beta), insulin-like
growth factor (IGF-1); growth hormones such as somatotropin;
fibronectin; cellular attractants and attachment agents. In
addition, lidocaine and other anesthetic additions to the gel are
in the range of 0.1% to 5% by weight, more preferably 0.3%-2.0% and
most preferably 0.2%-0.5%.
Manufacture of a Preferred Embodiment
[0084] In order to carry out a proper design and manufacture of the
implant material, rheological parameters are selectively
established to achieve an implant product targeted for a particular
tissue site. In order to describe this process in detail, reference
will be made to FIG. 3 which sets forth the method in a stepwise
manner. In a first step 100, one selects a particular tissue site
for the implantation. For example, tissue sites can include lip
tissue, dermis and harder tissue, such as muscle tissue. The tissue
sites can be characterized by their rheological response to stress
over a range. For lip tissue as shown in FIG. 4, there are three
regions of activity. In Region 1 for an initial small stress (0.1
Hz,), the phase angle, demonstrates the material to be elastic or
muscle-like (range 0 to 5) and is linear in character. The larger
the initial phase angle, the less dominate the character of the
muscle/tissue interaction or the softer the tissue (such as
dermis). In Region 2, the general increase in stress results in
limited phase angle change. Muscle contraction does not dominate
the elastic character of muscle and has not exceeded the muscle
tissue elastic limit. In Region 3, the general increase in stress
results in phase angle change. Stress starts to dominate the
elastic character of the muscle tissue limit. The physiologically
relevant range for stress is 0.1 Hz to 10 Hz. Optimization for
dermal filler applications in the lip require consideration of the
movement of muscles and soft bulbous tissue. Lip morphology is
primarily directed by muscle interaction with soft tissue. Lip
contractions are controlled by small sets of muscle: tissue nodes
in multiple planes and dimensions. A dermal filler for the lip
should then be most preferably viscoelastic. The material should be
viscous under smalls stresses and gradually become elastic. The
elastic character is essential so that the material stays where
implanted. Amplitudes for G' & G'' should be within the
physiological range of similar ECM polysacchrides (See Fung Y C,
1993 "Biomechanics: Mechanical Properties of Living Tissue", Second
Edition, Springer-Verlog, New York, N.Y.) and may range from 10 cps
to 300 cps. This is summarized in Table 6 below.
TABLE-US-00006 TABLE 6 Material composition 3.25 CMC; 2.6% CMC;
Physical parameters 15% glycerin 1.5% glycerin G' Range 0.1 Hz to
10 Hz 86 cps to 530 cps 21 cps to 238 cps G'' Range 0.1 Hz to 10 Hz
66 cps to 262 cps 26 cps to 154 cps Tan .delta. Range 0.1 Hz to 10
Hz 0.77 to 0.49 1.19 to 0.647
[0085] A material that maintains or more closely approximates the
range of G' and G'' values would be preferred. The preferred
embodiment demonstrates a response that is substantially more
similar to a normal physiological response than any conventional
product.
[0086] In a second step 110, rheological properties of the selected
tissue site are determined and proper limits of these rheological
properties should be established. Consequently, data must be
accumulated (either by direct experimental tests or by reference to
published data) to define the range of tissue rheology and behavior
during its use.
[0087] In a next step 120, the implant material system is
identified, and in general, it is important to satisfy several
requirements in order to achieve a desirable rheology and avoid
chemical breakdown or phase separation. Initially, it is desirable
to select a polysaccharide based gel that can establish good
chemical stability in the body. In addition, the gel can be
combined with buffer and lubricants and properly sterilized to
enable creating an implant with acceptable rheological behavior
over the parameters of body tissue use. An example of one such
preferred system includes a NaCMC polysaccharide gel, a buffer such
as PBS, and a lubricant, such as glycerin. The composite material
when sterilized achieves Fo values from about 22 and above and most
preferably from about 24-33 which provides a value of about
10.sup.-6 sterility. The implant viscosity versus Fo is shown in
FIG. 5.
[0088] Other implant components are also useful and would most
preferably include other polysaccharides which have been described
before, such as, celluloses/starch, chitin and chitosan, hyaluronic
acid, hydrophobe modified systems, alginates, carrageenans, agar,
agarose, intramolecular complexes, oligosaccharide and macrocyclic
systems. In addition, any physiologically acceptable buffer can be
employed, such as and not limited to glycine, citrate, and
carbonate. A lubricant can also be employed, such as for example
and not limited to, mineral oils and complex fatty acids. All these
components must be adjusted by applying rigorous manufacturing
standards described hereinafter which enable achieving the
prescribed rheological parameter over the range of use of the
particular tissue site.
[0089] In a next step 130, the chemical parameters of the selected
implant material are varied to achieve a relatively broad range of
rheological behavior. These chemical parameters are selected to
cover such a reasonably broad range to insure the downstream
analyzation process is able to identify the full range of useful
chemical compositions from among the universe of possibilities. As
will be described and illustrated graphically hereinafter, this
broad set of chemical values enables analytical isolation of phase
zones or regions of merit where the chemical characteristics map to
an implant material having rheological behavior fitted to the
selected recipient tissue site.
[0090] As noted hereinbefore, prior art implant products have
serious deficiencies. For example, in one type of polysaccharide
gel based implant for lip tissue, the implant tends to undergo
chemical reaction or phase separation occurs, causing accumulation
in nodules causing an irregular bumpy appearance in the lip tissue.
These and other known products, as shown hereinafter, are outside
the proper rheological phase zone or region of merit. The known
implants do not demonstrate viscous behavior over the
physiologically relevant ranges (about 0.1-10 Hz for stress) and
therefore do not crossover G'' =G' or tan .delta.>1. The prior
art implants are thicker (i.e., more viscous) and cause an
increased inflammatory response as the body increasingly recognizes
the material as foreign hyaluronic acid. In yet another example of
a prior art product, the material is based on highly crosslinked
hyaluronic acid or hyaluronic acid particles which have G' and G''
plots that do not cross-over resulting in a deficient implant.
[0091] After step 130, which includes identification of the
chemical parameters and selecting a broad range of chemical implant
values, in step 140 test product specimens are prepared over a
broad range and their rheological character is determined. The
matrix of rheological values includes frequency responses as a
function of frequency (registered as phase angles), elastic modulus
G'; viscosity modulus G''; tan .delta. (G'/G'') and viscosity over
the body tissue variable range of interest. A comparative analysis
between material compositions can then be performed to isolate the
phase region of merit by methods described hereinafter.
[0092] As noted above, experimental data have been taken for a
substantial matrix of chemical variables and the end rheological
parameters determined. Various experimental data and the rheology
contours and mathematical descriptons of boundary lines for meeting
the desired rheology are set forth in Example 19 hereinafter. The
data were processed using four basic inputs: CMC concentration,
glycerin concentration, phosphate buffer concentration and Fo
values. The variation of Fo for several representative implant
products is shown in FIG. 5. In performing these complex
calculations described below and illustrated in several figures,
the Fo has been set at the end points of about 22 and 33 using a
121.degree. C. sterilization cycle; but other temperatures and
times can be used to achieve the same Fo values; and the effect of
all other chemical variables can be determined to map the chemical
variables to the targeted proper rheological property or properties
for a given tissue implant site. It is generally understood that
sterilizing material requires that a specific Fo be reached to
ensure 10.sup.-6 sterility claims for a product. The use of
different combinations of sterilization time and temperature were
studied in a Getinge Ab, Sweden autoclave to optimizing the
sterilization process. Materials were autoclaved at 121.degree. C.
for run cycles of 3 mins., 6 mins., 12 mins., and 30 mins.
Sterilization programs had sterilization efficacy (Fo) equal to 22,
25, 28 and 33 respectively and the 10.sup.-6 sterility was
achieved. Materials were autoclaved at 124.degree. C. for run
cycles of 4 mins., 7.5 mins., and 11 mins. Sterilization programs
had sterilization efficacy (Fo) equal to 26, 36, 46 respectively.
Materials were autoclaved at 127.degree. C. for run cycles of 0.5
min., 1.5 mins., and 3 mins. Sterilization programs had
sterilization efficacy (Fo) equal to 42, 49, 57 respectively.
[0093] Variations on rheological parameters used in the method of
manufacture can also be incorporated into the analytical methods
used to achieve the desired implant rheology. For example, tan
.delta.=G''/G' and such interrelationships can permit
simplification of the analysis, such as for example, given
knowledge of two of the three parameters to determine the impact of
the third variable on rheological parameters. As mentioned
hereinbefore, these may be a subset of rheological parameters of
particular interest to the selected tissue implant site which thus
may not require achieving all the above-mentioned rheological
parameter values. In addition, one or more of the rheological
parameters may be substantially insensitive to variations in one or
more of the manufacturing variables (such as, for example, content
of polysaccharide gel, buffer concentration, autoclave Fo value and
lubricant content). This would then allow preparing a product
mapping to the particular one or more rheological properties for
the tissue.
[0094] In a next step 150 in FIG. 6, an analytical method is used
to identify the precise chemical variables needed to map to the
desired rheological phase zone to achieve the rheologically matched
implant product for the particular tissue site. As stated
hereinbefore, in a preferred embodiment the sterilization was
carried to a particular range of Fo to achieve a commercially
acceptable 10.sup.-6 sterility state. Further, the Fo value
increased linearly with all treatments until the beginning of the
cooling phase. The main effect of different sterilization
temperatures on the cumulative Fo curves was an increase in the
slope of the curves with increasing sterilization temperature (see
FIG. 5). It also is possible to use higher sterilization
temperatures than usually suggested in pharmacopeias and thus
shorten the process time. This sterilization process preferably
corresponds to a Fo value range of about 22 to at least about 33,
and these values are also associated with a change in the degree of
polymeric chain breakdown, as well as achieving the desired
sterility. However, this breakdown of polymeric chain leads to an
effect on the rheological parameters; and in the most preferred
embodiment the range of 24-33 has been characterized in terms of
all the remaining preparation variables to establish proper
rheological phase zones or regions of merit within which the
implant product has the required rheological values to perform well
at the tissue implant site. The methodology can also readily be
extended to determine the effect of higher Fo values.
[0095] In this step 150, one preferred methodology for data
analysis to identify the proper implant chemistry is performed
using the set of chemical values associated with each data point to
carry out a rigorous modeling procedure. Further details are set
forth in Example 20. This embodiment can also be described as a
screening model by using four inputs: CMC concentration, glycerin
concentration, phosphate buffer concentration and Fo values. For
example, CMC was varied between 2.3 wt. % and 2.9 wt. % in 0.1%
increments, the glycerin content was set to 1.5 wt. %, the buffer
was set to 0.M, 25 mM and 100 mM concentration. The model was then
executed using two separate Taguchi array screening models as
described in Example 19.
[0096] Using JMP7.0 pull down menus, the following path was used in
the SAS JMP ver. 2.0 software:
TABLE-US-00007 Open Data set\Analyze\fit model\ Select model inputs
by highlighting: Fo, CMC concentration (% CMC), Glycerin
concentration (% Gly), PBS concentration (XmM). Use macros and
choose and/or effect screening to capture all interactions for
inputs Use linear least squares fitting for model regression Use
effect screening for report format Run Model Under linear least
squares: (graphing options of outputs) Highlight prediction
profiler to graphically represent input interactions. Use pull down
menus for setting specification limits-optional Optimization is
based on specification limits used. Desirability is a unit-less
parameter based on desirability of how well a condition meets the
specification for the input condition. Desirability may be
calculated for each condition of the data set. A graphing of
desirability allows for graphical display of all conditions which
meet specifications. Highlight Contour profiler to graphically
represent 2D input/response interactions. Highlight Surface
profiler to graphically represent 3D input/response
interactions.
[0097] Successive iteration of 2-D graphing base on two variables
allows for iterative examination of the self limiting output
function. This is an exhaustive excersize and only the limiting
condition plot is presented. Under this evaluation the
sterilization time was found to be limiting from 12 to 25 min (Fo
22 to 33).
[0098] The limiting value of Fo was then incorporated into the
development of the prediction model using the prediction formulas
from the screening model contours for each output. The screening
model was developed based on the following four inputs: CMC
concentration (% CMC), glycerin concentration (% gly), phosphate
buffer concentration (mM) and autoclave time. The CMC concentration
(% CMC) was varied between 2.3% w/v and 2.9% w/v in 0.1% w/v
increments . The glycerin concentration (%gly) was held to 0% w/v,
1.0% w/v and 1.5% w/v. The buffer concentration (mM) was varied
from 0, 25 mM, 50 mM and 100 mM concentration. This creates a full
factorial design of with 420 interative conditions. The prediction
formulas were input into a full factorial design. The rheological
outputs were calculated based on screening model prediction
formulas. See attachment II. Again, the data were analyzed by use
of SAS JMP ver. 7.0 statistical software following the steps of
FIG. 6 to generate prediction profiles, three dimension ("3D")
surface contour plots (see, for example, FIG. 7B(i)-7B(viii). The
prediction model provides statistical strength to the model
incorporating more data points into the model description. Further
details are set forth in Example 19.
[0099] Again noted hereinbefore, the analysis by use of SAS JMP
ver. 7.0 statistical software provides useful three dimensional
("3D") contour plots (see, for example, FIGS. 7B(i)-7B(viii)) FIG.
7C and also FIGS. 9A(i)-9A(ix). Other suitable conventional
statistical analysis software can also be used in this one type of
methodology to analyze the base chemical parameter data from the
test product samples. This approach can generate data fits allowing
formation of 3D surfaces and line fits to identify phase regions of
merit based on the implant/tissue constraints to determine the
three dimension plot of rheological behavior and selection of a
minimum and maximum range of those rheological parameters to meet
the preset desired rheological conditions and properties. Example
19 hereinafter also provides details of equations defining the
boundary lines and contours.
[0100] Regarding criteria for rheological variables for the implant
product, Example 19 is for an implant application in lip tissue,
wherein (1) the G' and G'' behavior should preferably be within a
range of about 0 to 300 pas to map to the desired property since
the interstitial extracellular matrix of the lip tissue comprises a
hyaluronic acid polysaccharide for which the rheology range can be
identified; and their plots should crossover at a physiologically
relevant frequency of about 0.5 to 4 Hz which is consistent with
the lip tissue functionality, and (2) the viscosity should be about
0 to 300,000 cps for the same physiologically relevant stress
ranges. The tan .delta. should be greater than 1 for low stress
conditions indicating an inherent viscous nature to the material
with decreasing tan .delta. as the stress increases demonstrating
elastic behavior of lip:tissue nodal properties. Phase or
deflection angle should be about 5 to 10 over the stress range of
0.1 Hz to 4 Hz. The SAS analytical method produced families of
rheological variable plots that met the following rheological
evaluation parameters and can be summarized in Table 7.
TABLE-US-00008 TABLE 7 Rheological parameter Viscosity (5.tau., 30
7200 cps Data based on the specification limits of a present
conventional implant degree C. parallel to 53000 cps product. This
is supported in the published references for several plate) 0.7 Hz
hyaluronic acid compositions. Tan .delta. 0.7 Hz >1 Data based
on the specification limits of the conventional product and the
desired rheology at low stresses. Material for dermal application
should show minimal elastic behavior at low stress to act more like
the surrounding tissue and the Newtonian fluid (water)
microenvironment. This is supported in the published references for
several hyluronic acid compositions as they demonstrate viscous to
elastic behavior under increasing stress and cross-over at some
stress point. G'' and G'' 0.7 Hz <300 cps Data from Fung
reference with various hyaluronic acid compositions. Hyaluronic
acid is a primary constituent of dermal extra cellular matrix. G'
and G'' 4.0 Hz <100 cps Data from Fung reference with various
hyaluronic acid compositions. Hyaluronic acid is a primary
constituent of dermal extra cellular matrix and this seems to be
applicable. Tan .delta. 11.7 Hz <1 Data set based on the
specification limits of the conventional product and the desired
rheology at higher stresses. It would be best if material
demonstrated some elastic character when subjected to higher stress
to limit movement or deformation of form. .delta.-R 0.7 Hz & 4
Hz <60 and Data supported in published references for phase
angle evaluation of <110 lips. The limits were subjective and
taken from the graphs as presented in the literature. Evaluation at
two points 0.7 Hz & 4 Hz covers the physiologically relevant
range of stresses.
[0101] In a next step 160, lines having a mathematical behavior are
part of a series of identified loci for each single one of the
rheological variables for which the conditions have been met. These
are shown in FIG. 7C as the line separating the acceptable white
zone from the adjacent dark zone. As stated hereinbefore Example 19
provides further details of the analysis and the mathematical
descriptions. Also in a step 170, a phase zone of merit can be
identified which is the white zone in FIG. 7C where the universe of
rheological parameters limits were all met. This establishes the
target implant product phase zone of merit. In some cases, as noted
hereinbefore, it is necessary to use only one of the rheological
parameters to define a "region of merit" in order to identify the
chemical characteristics which meet the implant tissue
requirements. Numerous examples are set forth hereinafter
delineating these rheological loci of proper performance or merit
and also target rheological phase zones of merit. The examples are
in particular directed to lip tissue implantation; but in view of
knowledge of other tissue rheology, the methodology described
herein can be used for any tissue site with known rheological
parameters. The statistical method is executed by the
above-referenced SAS off the shelf software formalisms, including
for example Monte Carlo calculations and which are part of the
analysis show in the statistical analysis flow chart of FIG. 3.
[0102] In another embodiment, an enhancement based on the steps 160
and 170 can be implemented to establish the applicability and
functionality of the rheological variables relative to the chemical
variables. This can be accomplished by a step 180 of generating a
predictive profiler mathematical model using the one or more inputs
of the rheological parameters in a screening model least squares
regression to form plots of chemical variables versus rheological
outputs of choice. FIG. 8 shows the steps of the predictive
profiler in step 181 of implementing the screening model of step
150 to select one of the rheological parameters as a function of
two chemical variables. From this analysis the SAS software can
generate in step 182 the 3D contours of the rheological parameters
versus the two chemical variables (see for example, FIGS.
9A(i))-9A(ix)). In a next step 183 a planar cross-section is taken
at a set value of one of the chemical variables (ee FIG. 9A(ii)).
In a next step 184, the planar intersection with the contour of the
rheological function establishes a line for the selected variables
(see FIG. 9B for a matrix of these various lines in the rheology
contours for the given parameters). In a step 185 knowledge of the
sensitivity of the rheology parameters to the chemical variables
allows control of the chemistry. (See the various plots in FIG.
9B). These prediction profiles then demonstrate how the change in
one chemical variable input has a fairly modest impact on certain
rheological variables as the other variables are held constant,
while other chemical variables have very dramatic impact on
rheological response as the other variables are held constant. For
example, as shown in FIG. 9B, the PBS chemical variable causes
quite dramatic changes in selected rheological outputs. Their
variability (or lack thereof) can be used to either simplify
manufacture of a desired end product or further effect the ultimate
value of a given rheological variable in combination with knowledge
of the location within a rheological phase zone or region suitable
for a selected tissue implant site. As described hereinbefore,
further details of the mathematical equations which are created by
the SAS software to describe contours and lines are characterized
in Example 19 and are executed by graphing scripts of the
software.
[0103] In another procedure in step 190, a "desirability" measure
or region can be determined by analyzing the input data and
rheological parameters by limiting the model to only those
conditions which meet the required output ranges. Desirability is
an index to evaluate if the testing condition meets the
specifications and to what degree. Those values that are less than
0 fail to meet one or all of the criteria for acceptable material.
Thus they are not included in the 3D plots. All other combinations
of variables that have positive desirability meet the specification
goals to some relative degree. The threshold condition of
desirability was limited to 0.5 as the predictive optimal
obtainable in this case (as no one condition optimizes all
outputs). Model strength can be further enhanced by increasing the
amount of experimental data. This can be done through the brute
force method of more iterative runs of all possible conditions or
in this case the statistical SAS JMP ver. 7.0 included a Monte
Carlo simulation to infinitely limit the degree of acceptable
material, therefore defining the surface of the acceptable region.
A threshold limit for desirability was established at 0.15 to allow
a degree of confidence in the model simulation because normal
variance was included in the Monte Carlo simulation.
[0104] The methods and products described hereinbefore can be
implemented by a supplier establishing a database of rheological
data for tissue of any one of a plurality of particular types of
patients; and understanding how to execute the methods described
herein, the supplier can then map out implant products and their
associated rheological properties to determine which products meet
the compatibility requirements for the particular tissue. Thus, the
above-described regions of merit and also desirability plots can
help define the proper product.
[0105] Examples of such a "desirability " analysis are provided
hereinafter in FIGS. 31A-31F.
[0106] The following non-limiting examples illustrate various
aspects of the invention.
Example 1
Preparation of 2.3% Sodium CMC Gel in Sterile Water.
[0107] Sodium carboxymethylcellulose was prepared in sterile water
for injection and adjusted to a pH of from about 7.1 to about 8.0
using potassium hydroxide. The dispersion was mixed in an orbital
Ross mixer@1725 RPM for 5 minutes followed by mixing in an orbital
Ross mixer@1725 RPM for 40 minutes. while holding a vacuum@26 mm Hg
or more. The composition was then steam sterilization at
121.degree. C. for times ranging from 3 minutes to 30 minutes. In
addition, one sample was sterilized for time intervals between 3
minutes and 30 minutes@121.degree. C. Results are shown in FIG. 10
where G' represents the elastic modulus, G'' represents the viscous
modulus and .eta. the complex viscosity. The profile shows that G'
and G'' intersect at 0.495 Hz (3.2 Rad/sec). Above this frequency,
the composition exhibits non-Newtonian solution characteristics
(tan .delta.<1.0).
Example 2
Preparation of 2.4% Sodium CMC Gel in Sterile Water.
[0108] Sodium carboxymethylcellulose was prepared in sterile water
for injection and adjusted to a pH of from about 7.1 to about 8.0
using potassium hydroxide. The dispersion was mixed in an orbital
Ross mixer@1725 RPM for 5 minutes followed by mixing in an orbital
Ross mixer@1725 RPM for 40 minutes while holding a vacuum@26 mm Hg
or more. The composition was then steam sterilization at
121.degree. C. for times ranging from 3 minutes to 30 minutes. In
addition, one sample was sterilized for time intervals between 3
minutes and 30 minutes@121.degree. C. Results are shown in FIG. 11
where G' represents the elastic modulus, G'' represents the viscous
modulus and .mu. the complex viscosity. The profile shows that G'
and G'' intersect at 0.0299 Hz (1.8 Rad/sec) (lower frequency than
that shown in FIG. 1). Above this frequency, the composition
exhibits non-Newtonian solution characteristics (tan
.delta.<1.0).
Example 3
Preparation of 2.5% Sodium CMC Gel in Sterile Water.
[0109] Sodium carboxymethylcellulose was prepared in sterile water
for injection and adjusted to a pH of from about 7.1 to about 8.0
using potassium hydroxide. The dispersion was mixed in an orbital
Ross mixer@1725 RPM for 5 minutes followed by mixing in an orbital
Ross mixer@1725 RPM for 40 minutes. while holding a vacuum@26 mm Hg
or more. The composition was then steam sterilization at
121.degree. C. for times ranging from 12 minutes to 30 minutes. In
addition, one sample was sterilized for time intervals between 3
minutes and 12 minutes@121.degree. C. Results are shown in FIG. 12
where G' represents the elastic modulus, G'' represents the viscous
modulus and .eta. the complex viscosity. The profile shows that G'
and G'' intersect at 0.157 Hz (1 rad/sec) frequency than shown in
FIGS. 10 and 11. Above this frequency, the composition exhibits
non-Newtonian solution characteristics (tan .delta.<1.0).
Example 4
Preparation of 2.6% Sodium CMC Gel in Sterile Water.
[0110] Sodium carboxymethylcellulose was prepared in sterile water
for injection and adjusted to a pH of from about 7.1 to about 8.0
using potassium hydroxide. The dispersion was mixed in an orbital
Ross mixer@1725 RPM for 5 minutes followed by mixing in an orbital
Ross mixer@1725 RPM for 40 minutes while holding a vacuum@26 mm Hg
or more. The composition was then steam sterilization at
121.degree. C. for times ranging from 12 minutes to 30 minutes. In
addition, one sample was sterilized for time intervals between 12
minutes and 30 minutes@121.degree. C. Results are shown in FIG. 13
where G' represents the elastic modulus, G'' represents the viscous
modulus and .eta. the complex viscosity. The profile shows the G'
and G'' intersect at 0.164 Hz (1.03 rad/sec). Above this frequency,
the composition exhibits non-Newtonian solution characteristics
(tan .delta.<1.0).
Example 5
Preparation of 2.3% Sodium CMC Gel in Potassium Phosphate
Buffer.
[0111] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer pH and adjusted to a pH of
from about 7.2 to about 8.0 using potassium hydroxide. The
dispersion was mixed in an orbital Ross mixer@1725 RPM for 5
minutes followed by mixing in an orbital Ross mixer@1725 RPM for 40
minutes while holding a vacuum@26 mm Hg or more. The composition
was then steam sterilization at 121.degree. C. for times ranging
from 3 minutes to 12 minutes. In addition, one sample was
sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 14 where G'
represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 2.401 Hz (15 rad/sec) (similar to that shown in FIG.
13). Above this frequency, the composition exhibits non-Newtonian
solution characteristics (tan .delta.<1.0).
Example 6
Preparation of 2.4% Sodium CMC Gel in Potassium Phosphate
Buffer.
[0112] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer pH and adjusted to a pH of
from about 7.2 to about 8.0 using potassium hydroxide. The
dispersion was mixed in an orbital Ross mixer@1725 RPM for 5
minutes followed by mixing in an orbital Ross mixer@1725 RPM for 40
minutes while holding a vacuum@26 mm Hg or more. The composition
was then steam sterilization at 121.degree. C. for times ranging
from 3 minutes to 12 minutes. In addition, one sample was
sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 15 where G'
represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 1.56 Hz. (9.8 rad/sec). Above this frequency, the
composition exhibits non-Newtonian solution characteristics (tan
.delta.<1.0).
Example 7
Preparation of 2.5% Sodium CMC Gel in Potassium Phosphate
Buffer.
[0113] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer pH and adjusted to a pH of
from about 7.2 to about 8.0 using potassium hydroxide. The
dispersion was mixed in an orbital Ross mixer@1725 RPM for 5
minutes followed by mixing in an orbital Ross mixer@1725 RPM for 40
minutes while holding a vacuum@26 mm Hg or more. The composition
was then steam sterilization at 121.degree. C. for times ranging
from 3 minutes to 12 minutes. In addition, one sample was
sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 16 where G'
represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 4.54 Hz (28.5 rad/sec). Above this frequency, the
composition exhibits non-Newtonian solution characteristics (tan
.delta.<1.0).
Example 8
Preparation of 2.6% Sodium CMC Gel in Potassium Phosphate
Buffer.
[0114] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer pH and adjusted to a pH of
from about 7.2 to about 8.0 using potassium hydroxide. The
dispersion was mixed in an orbital Ross mixer@1725 RPM for 5
minutes followed by mixing in an orbital Ross mixer@1725 RPM for 40
minutes while holding a vacuum@26 mm Hg or more. The composition
was then steam sterilization at 121.degree. C. for times ranging
from 3 minutes to 12 minutes. In addition, one sample was
sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 17 where G'
represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 3.61 (22.7 rad/sec) Hz. Above this frequency, the
composition exhibits non-Newtonian solution characteristics (tan
.delta.<1.0).
Example 9
Preparation of 2.7% Sodium CMC Gel in Potassium Phosphate
Buffer.
[0115] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer pH and adjusted to a pH of
from about 7.2 to about 8.0 using potassium hydroxide. The
dispersion was mixed in an orbital Ross mixer@1725 RPM for 5
minutes followed by mixing in an orbital Ross mixer@1725 RPM for 40
minutes while holding a vacuum@26 mm Hg or more. The composition
was then steam sterilization at 121.degree. C. for times ranging
from 3 to 12 minutes. In addition, one sample was sterilized for
time intervals between 3 minutes and 12 minutes@121.degree. C.
Results are shown in FIG. 18 where G' represents the elastic
modulus, G'' represents the viscous modulus and .eta. the complex
viscosity. The profile shows that G' and G'' intersect at 3.49 Hz
(21.9 rad/sec). Above this frequency, the composition exhibits
non-Newtonian solution characteristics (tan .delta.<1.0). At
this sodium CMC concentration (2.7%) the intersect shifts to a
lower frequency than that shown in FIG. 16 (2.5% CMC). The
composition still exhibits Newtonian fluid characteristics.
Example 10
Preparation of 2.8% Sodium CMC Gel in Potassium Phosphate
Buffer.
[0116] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer pH and adjusted to a pH of
from about 7.2 to about 8.0 using potassium hydroxide. The
dispersion was mixed in an orbital Ross mixer@1725 RPM for 5
minutes followed by mixing in an orbital Ross mixer@1725 RPM for 40
minutes while holding a vacuum@26 mm Hg or more. The composition
was then steam sterilization at 121.degree. C. for times ranging
from 3 minutes to 12 minutes. In addition, one sample was
sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 19 where G'
represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 4.88 Hz (30.7 rad/sec). Above this frequency, the
composition exhibits non-Newtonian solution characteristics (tan
.delta.<1.0). Since the intersect occurs at the top end
frequency, this composition exhibits Newtonian characteristics at
nearly all frequencies.
Example 11
Preparation of 2.6% Sodium CMC Gel in Potassium Phosphate Buffer
and Glycerin.
[0117] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer adjusted to a pH of from about
7.2 to about 8.0 using potassium hydroxide and containing up to 1%
glycerin. The dispersion was mixed in an orbital Ross mixer@1725
RPM for 5 minutes followed by mixing in an orbital Ross mixer@1725
RPM for 40 minutes while holding a vacuum@26 mm Hg or more. The
composition was then steam sterilization at 121.degree. C. for
times ranging from 3 minutes to 12 minutes. In addition, one sample
was sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 20 where G'
0represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 1.254 Hz (7.8 rad/sec). Above this frequency, the
composition exhibits non-Newtonian solution characteristics (tan
.delta.<1.0). The addition of glycerin to sodium CMC gel in
potassium phosphate significantly affects the rheology of the
composition, changing it from a fundamentally Newtonian fluid to a
non-newtonian fluid above a frequency of about 1.0.
Example 12
Preparation of 2.7% Sodium CMC Gel in Potassium Phosphate Buffer
and Glycerin.
[0118] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer adjusted to a pH of from about
7.2 to about 8.0 using potassium hydroxide and containing up to 1%
glycerin. The dispersion was mixed in an orbital Ross mixer@1725
RPM for 5 minutes followed by mixing in an orbital Ross mixer@1725
RPM for 40 minutes while holding a vacuum@26 mm Hg or more. The
composition was then steam sterilization at 121.degree. C. for
times ranging from 3 minutes to 12 minutes. In addition, one sample
was sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 21 where G'
represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 1.158 Hz (7.2 rad/sec). Above this frequency, the
composition exhibits non-Newtonian solution characteristics (tan
.delta.<1.0). The addition of glycerin to sodium CMC gel in
potassium phosphate significantly affects the rheology of the
composition, changing it from a fundamentally Newtonian fluid to a
non-Newtonian fluid above a frequency of about 1.0.
Example 13
Preparation of 2.8% Sodium CMC Gel in Potassium Phosphate Buffer
and Glycerin.
[0119] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer adjusted to a pH of from about
7.2 to about 8.0 using potassium hydroxide and containing up to 1%
glycerin. The dispersion was mixed in an orbital Ross mixer@1725
RPM for 5 minutes followed by mixing in an orbital Ross mixer@1725
RPM for 40 minutes while holding a vacuum@26 mm Hg or more. The
composition was then steam sterilization at 121.degree. C. for
times ranging from 3 minutes to 12 minutes. In addition, one sample
was sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 22 where G'
represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 0.914 Hz (5.7 rad/sec). Above this frequency, the
composition exhibits non-Newtonian solution characteristics (tan
.delta.<1.0). The addition of glycerin to sodium CMC gel in
potassium phosphate significantly affects the rheology of the
composition, changing it from a fundamentally Newtonian fluid to a
non-Newtonian fluid above a frequency of about 1.0.
Example 14
Preparation of 2.9% Sodium CMC Gel in Potassium Phosphate Buffer
and Glycerin.
[0120] Sodium carboxymethylcellulose was prepared in sterile 25 mM
to 100 mM potassium phosphate buffer adjusted to a pH of from about
7.2 to about 8.0 using potassium hydroxide and containing up to 1%
glycerin. The dispersion was mixed in an orbital Ross mixer@1725
RPM for 5 minutes followed by mixing in an orbital Ross mixer@1725
RPM for 40 minutes while holding a vacuum@26 mm Hg or more. The
composition was then steam sterilization at 121.degree. C. for
times ranging from 3 minutes to 12 minutes. In addition, one sample
was sterilized for time intervals between 3 minutes and 12
minutes@121.degree. C. Results are shown in FIG. 23 where G'
represents the elastic modulus, G'' represents the viscous modulus
and .eta. the complex viscosity. The profile shows that G' and G''
intersect at 1.065 Hz (6.7 rad/sec). Above this frequency, the
composition exhibits non-Newtonian solution characteristics (tan
.delta.<1.0). The addition of glycerin to sodium CMC gel in
potassium phosphate significantly affects the rheology of the
composition, changing it from a fundamentally Newtonian fluid to a
non-Newtonian fluid above a frequency of about 1.0.
Example 15
[0121] 1150 C Sintered Materials include the following Materials
and Process Conditions:
[0122] Materials of this exampled included implants having: 30% to
45% Media; 2.6% to 3.25% CMC; 0 to 15% glycerin; 0 mM to 100 mM
PBS.
[0123] The CMC, buffer, glycerin and media were added together and
mixed with a planetary mixer for 20 minutes to 3 hours under
continuous and sustained vacuum. Materials were filled into 1 cc
syringes, pouched in aluminum foil and terminally steam
sterilized@121.degree. C. for 15 min to 30 minutes.
[0124] The rheology evaluation was carried out on 30% and 40%
media, 2.6% CMC to 3.25% CMC, 1.5% to 15% glycerin, 0 to 25 mM. The
results of which are shown in FIGS. 24-28. The materials tested and
some of their properties are listed in Table A below. The first
column implant is that as taught in prior art. The second column
implant is in accordance with the principles of the present
invention for use in high mobility tissues. The third column
implant is also in accordance with the principles of the present
invention, but for usage in higher bulking required tissues
situations where contour shaping and the filling is of principle
concern.
TABLE-US-00009 TABLE A Material composition 30% CaHA- 30% CaHA-
3.25 CMC; 2.6% CMC; 40% CaHA- 15% 1.5% 2.6% CMC; 1.5% Physical
parameters glycerin glycerin glycerin Osmolality (mmol/kg) 1768 to
2300 291 289 Extrusion Force 6.1 5.4 4.8 (lbf, 0.5'' 27 Ga.)
Extrusion Force 11.5 9.8 7.6 (lbf, 1.25'' 27 Ga.) Viscosity (.eta.
@0.5 Hz) 413750 202865 396585 Tan .delta. @0.5 Hz 0.453 0.595 0.581
Viscosity modulus 1478.60 678.32 1331.8 (G'' @0.5 Hz) Loss Modulus
671.69 404.30 773.23 (G' @0.5 Hz)
[0125] FIG. 24 illustrates the viscosities for each of the
materials as shear rate varies. FIG. 25 illustrates the loss
modulus for each of the materials as sheer rate varies. FIG. 26
illustrates the viscosity modulus for each of the materials as
sheer rate varies. FIG. 27 illustrates the .delta. for each of the
materials as sheer rate varies.
[0126] Material is shear thinning. Varying the gel composition
concentrations within the gel carrier, offers the potential to
mimic other rheological variables at higher % particle medias.
Degradation rates of the particles can be manipulated through
formulation in gel rheology. The descriptive characteristics of
viscosity and elasticity can be varied or maintained through gel
composition concentrations. The lower viscosity modulus G'' and
loss modulus G' the more similar in magnitude to physiological
tissues studies and further asserts the improved biocompatibility
not previously reported in prior art.
[0127] The time dependency of the elasticity is demonstrated in
FIG. 28 for varying gel compositions with varying concentrations of
particles. 30% & 40% solids in 2.6 CMC: 1.5% glycerin carrier
vs. 30% solids in a 3.25% CMC: 15% glycerin carrier. The material
demonstrates a time dependency to material break down due to
composition. The material with less particles and lower viscosity
gels have less tendency to withstand material stresses.
Example 16
[0128] Alginate/CMC carrier with glycerin was combined with CaHa
particles which were sintered at 1150.degree. C. and include the
following constitutents (Table B). Various alginate types have been
tested and a summary of the alginates is set forth below in Table
B.
TABLE-US-00010 TABLE B Alginate (LVM, MVM, M = G, MVG and LVG)
Guluronic Acid Alginate %/Mannuronic Type acid (%) Defintion LVM
30-35/65-70 Low visocosity alginate gel with high mannuronic acid
content. MVM 35-45/55-65 Medium viscosity alginate gel with high
mannuronic acid content. M = G 45-55/45-55 High viscosity alginate
gel similar in mannuronic and guluronic acid contents. MVG
65-75/25-35 Low viscosity alginate gel that is cold soluble and has
a high guluronic acid content. LVG 65-75/25-35 Very low viscosity
alginate gel with high guluronic acid content.
[0129] M087052: was composed of 30% Media, 40 mg/ml to 100 mg/ml
alginate: 7.5 mg/ml to 12.5 mg/ml, 25 mM PBS, and 1.5%
glycerin.
[0130] The following Alginate/CMC gel formulations (mg/mL) were
prepared using the process detailed below:
[0131] The Alginate/CMC, buffer, glycerin were added together and
mixed for 20 min to 3 hours. Particles were then added in 30% by
volume and mixed for 20 min to 3 hours. Materials were filled into
1 cc syringes, pouched in aluminum foil and terminally steam
sterilized@121.degree. C. for 15 min to 30 mins.
[0132] Rheological evaluation for these materials are illustrated
in the FIGS. 29 and 30. FIG. 29 illustrates the loss modulus G',
the elastic modulus G'' and tan .delta. (G'/G''). FIG. 30
illustrates viscosity and tan .delta. properties.
Example 17
[0133] Alginate (MVM, M=G or LVM--Various alginates/CMC gels were
prepared and include the following constituents and processes:
[0134] G094035: 5 mg/ml to 100 mg/ml alginate (MVM, M=G or LVM (see
Table B)): 2.5 mg/ml to 50 mg/ml CMC, 25 mM PBS, 1.5% glycerin. The
following Alginate/CMC gel formulations (mg/mL) were prepared using
the process detailed below:
[0135] The Alginate/CMC, buffer, glycerin were added together and
mixed for 20 min to 3 hours with either an orbital rotatary mixer
or direct propeller mixer. Materials were filled into 1 cc
syringes, pouched in aluminum foil and terminally steam
sterilized@121.degree. C. for 15 min to 30 mins.
Example 18
[0136] In one embodiment, the implant may be designed for
application in the laryngeal tissue. Table C lists the parameters
for such an implant.
TABLE-US-00011 TABLE C Specification Laryngeal Implant Viscosity
107,620-517,590 cps. Osmolarity 255 mOs to 327 mOs pH 7.0 .+-. 1.0
Loss on Drying -29.7% to -43.1%. Percent Solids 54.3 to 70.5%
Extrusion Force 3.60-7.20 lbsf
Example 19
[0137] The prediction model was developed using the SAS JMP ver 7.0
statistical software. The prediction model data used the screening
model's graphing scripts, which are mathematical equations of the
surface contours of the models. These can be obtained by
highlighting the model output and saving the response prediction
formula to a data spreadsheet. Values populated the screening model
with model outputs for the screening model inputs tested. The
prediction model formulae were then exported to a separate
spreadsheet, where a full factorial model design was developed. In
one case, for example, the following optimized parameters based on
the screening model were used: Sterilization (121.degree. C.) F0
22, 25, 28, and 33 respectively. The CMC concentration (% CMC) was
varied between 2.3% w/v and 2.9% w/v in 0.1% w/v increments. The
glycerin concentration (% gly) was held to 0% w/v, 1.0% w/v and
1.5% w/v. The buffer concentration (mM) was varied from 0.25 mM, 50
mM and 100 mM concentration. The model was populated with the
screening model prediction formula outputs representing 625
individual runs. This then represents the whole prediction model
using optimized sterilization inputs based on the same inputs for
the screening model previously conducted. The model was then
re-evaluated over the same output parameters using the Simulator
function with 10000 runs.
[0138] Simulation allows the determination of the distribution of
model outputs as a function of the random variation in the factors
and model noise. The simulation facility in the profilers provides
a way to set up the random inputs and run the simulations,
producing an output table of simulated values. In this application
the boundary conditions are estimated by the defect rate of a
process that has been fit to specific rheological parameters to
determine if it is robust with respect to variation in the factors.
If specifications have been set in the response, they are carried
over into the simulation output, allowing a prospective boundary
analysis of the simulated model variable using new factors
settings. In the Profiler function, the Simulator function is
integrated into the graphical layout. Factor specifications are
aligned below each factor's profile. A simulation histogram is
shown in FIG. 9B on the right for each response.
[0139] Factors (inputs) and response (outputs) are already given
roles by being in the Profiler. Additional specifications for the
simulator are including assigning random values to the factors and
adding random noise to the responses.
[0140] For each factor, the assignment of values is important. The
Random program assigns the factor a random value with the specified
distributon and distributional parameters.
[0141] Normal truncated is a normal distribution limited by lower
and upper limits. Any random realization that exceeds these limits
is discarded and the next variate within the limits is chosen. This
is used to simulate an inspection system where inputs that do not
satisfy specification limits are discarded or sent back.
[0142] The Add Random Noise function obtains the response by adding
a normal random number with the specified standard to the evaluated
model.
[0143] The Defect Profiler function shows the defect rate as an
isolated function of each factor. This command is enabled when
specification limits are available, as described below.
[0144] The Profiler function displays profile traces. A profile
trace is the predicted response as one variable is changed while
the others are held constant at the current values. The Profiler
re-computes the profiles and provides predicted responses (in real
time) as the value of an X variable is varied. The vertical dotted
line for each X variable shows its current value or current
setting.
[0145] For each X variable, the value above the factor name is its
current value.
[0146] The horizontal dotted line shows the current predicted value
of each Y variable for the current values of the X variables.
[0147] The black lines within the plots of FIG. 9B show how the
predicted value changes when the current value of an individual X
variable is changed. In fitting platforms, the 95% confidence
interval for the predicted values is shown by a dotted blue curve
surrounding the prediction trace (for continuous variables) or the
context of an error bar (for categorical variables).
[0148] The Profiler is then a way of changing one variable at a
time and looking at the effect on the predicted response.
[0149] There are several important points to note when interpreting
a prediction profile:
[0150] 1. The importance of a factor can be assessed to some extent
by the steepness of the prediction trace. If the model has
curvature terms (such as squared terms), then the traces may be
curved.
[0151] 2. If you change a factor's value, then its prediction trace
is not affected, but the prediction traces of all the other factors
can change. The Y response line must cross the intersection points
of the prediction traces with their current value lines.
[0152] 3. Note: If there are interaction effects or cross-product
effects in the model, the prediction traces can shift their slope
and curvature as you change current values of other terms. That is
what interaction is all about. If there are no interaction effects,
the traces only change in height, not slope or shape.
[0153] Prediction profiles are especially useful in
multiple-response models to help judge which factor values can
optimize a complex set of criteria.
[0154] The Profiler shows the confidence bars on the prediction
traces of continuous factors, along with the sensitivity Indicator
displayed in triangles, whose height and direction correspond to
the value of the derivative of the profile function at its current
value. This is useful in large profiles to be able to quickly spot
the sensitive cells.
[0155] The prime reason to make random factor tables is to explore
the factor space in a multivariate way using graphical queries.
This technique is called Filtered Monte Carlo. This allows
visualization of the locus of all factor settings that produce a
given range to desirable response settings. By selecting and hiding
the points that do not qualify (using graphical brushing or the
Data Filter), the remaining opportunity space yields the result
desired.
[0156] The Simulator enables the creation of Monte Carlo
simulations using random noise added to factors and predictions for
the model. Fixed factors were set over a range of settings and
allowed for 1 s.d of model noise to random values to determine the
rate that the responses are outside the specification limits.
[0157] Often there are multiple responses measured for each set of
experimental conditions, and the desirability of the outcome
involves several or all of these responses. For example, one
response can be maximized while another is minimized, and a third
response kept close to some target value. In desirability
profiling, a desirability function is specified for each response.
The overall desirability can be defined as the geometric mean of
the desirability for each response.
[0158] The Desirabiltiy Profiler function components and examples
of desirability functions settings are discussed next. The
desirability functions are smooth piecewise functions that are
crafted to fit the control points.
[0159] The minimize and maximize functions are three-part piecewise
smooth functions that have exponential tails and a cubic
middle.
[0160] The target function is a piecewise function that is a scale
multiple of a normal density on either side of the target (with
different curves on each side), which is also piecewise smooth and
fit to the control points.
[0161] These choices give the functions good behavior as the
desirability values switch between the maximize, target, and
minimize values.
[0162] The control points are not allowed to reach all the way to
zero or one at the tail control points.
[0163] Maximize Function
[0164] The default desirability function setting is maximize
("higher is better"). The top function handle is positioned at the
maximum Y value and aligned at the high desirability, close to 1.
The bottom function handle is positioned at the minimum Y value and
aligned at a low desirability, close to 0.
[0165] Target Function
[0166] A target value can be designated as "best." In this example,
the middle function handle is positioned at Y =55 and aligned with
the maximum desirability of 1. Y becomes less desirable as its
value approaches either 70 or 42. The top and bottom function
handles at Y=70 and Y=42 are positioned at the minimum desirability
close to 0.
[0167] Minimize Function
[0168] The minimize ("smaller is better") desirability function
associates high response values with low desirability and low
response values with high desirability. The curve is the
maximization curve flipped around a horizontal line at the center
of plot.
[0169] The Desirability Profile
[0170] The last row of plots in FIG. 9B shows the desirability
trace for each response. The numerical value beside the word
Desirability on the vertical axis is the geometric mean of the
desirability measures. This row of plots shows both the current
desirability and the trace of desirabilities that result from
changing one factor at a time.
[0171] Desirability Profiling for Multiple Responses
[0172] A desirability index becomes especially useful when there
are multiple responses.
[0173] Defect Rate Function
[0174] The defect rate shows the probability of an
out-of-specification output defect as a function of each factor,
while the other factors vary randomly. This is used to help
visualize which factor's distributional changes the process is most
sensitive to, in the quest to improve the description of the
boundary functions.
[0175] Specification limits define what is a defect, and random
factors provide the variation to produce defects in the simulation.
Both need to be present for a Defect Profile to be meaningful.
[0176] The institution of a lower limit acceptable desirability is
appropriate since analysis is based on finite data sampling and the
lower limit was instituted to be values greater than 0.15. Based on
those limitations, the whole simulation model has the following
limiting parameters as follows. [0177] FO=24 to 35 [0178] PBS=22 mM
to 140 mM [0179] % CMC=2.3% w/v to 3.3% w/v [0180] % Glycerin=0.3%
w/v to 2.5 w/v
[0181] However, individual experimentation has identified limiting
parameters that are most favorable for producing the outputs within
the specification range, while maintaining a sterile product. Their
conditions are as follows: [0182] FO=22 to 30 [0183] PBS=25 mM to
100 mM [0184] % CMC=2.3% w/v to 2.9% w/v [0185] % Glycerin=0% w/v
to 1.5% w/v
[0186] An example of the 2D and 3D plots which result are shown in
FIGS. 31A-31F. These figures show the evaluation of the
desirability fimction expressed as a function two of the following
design inputs: % CMC, Fo; % glycerin and PBS. The boundary limiting
condition for the percent CMC vs. Fo is defined by the 0.7 Hz tan 6
contour trace from 2.3 to 2.7. The 2D plot shows a white region
within which the rheological parameter is met and is consistent
with the desirability function shown in FIG. 9B.
[0187] The model trace formulae for the whole model are as follows
for the following outputs.
[0188] Prediction Formula Viscosity 0.7 Hz:
TABLE-US-00012 (-0.0662001910451557) + 0.051920253378124 * :Fo +
0.0146791342721163 * :Name("PBS (mM)") + -0.218700904653452 *
:Name("% NaCMC") + -0.0202956176083598 * :Name(% Glycerin") + (:Fo
- 22.0003631356491) * ((:Fo - 22.0003631356491) *
-0.00371533851417633) + (:Fo - 22.0003631356491) * ((:Name("PBS
(mM)") - 63.5057099845838) * 0.000185185074554069) + (:Name("PBS
(mM)") - 63.5057099845838) * ((:Name("PBS (mM)") -
63.5057099845838) * -0.0000863865657255508) + (:Fo -
22.0003631356491) * ((:Name("% NaCMC") - 2.85245995014651) *
-0.0322726861725922) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% NaCMC") - 2.85245995014651) * -0.0152609626718641) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% NaCMC") -
2.85245995014651) * 0.942295293128045) + (:Fo - 22.0003631356491) *
((:Name("% Glycerin") - 1.49703269551474) * 0.0048399350260245) +
(:Name("PBS (mM)") - 63.5057099845838) * ((:Name("% Glycerin") -
1.49703269551474) * 0.00387275533427914) + (:Name("% NaCMC") -
2.85245995014651) * ((:Name("% Glycerin") - 1.49703269551474) *
-0.213067717437202) + (:Name("% Glycerin") - 1.49703269551474) *
((:Name("% Glycerin") - 1.49703269551474) * 0.052309021299775)
[0189] Prediction Formula Tan .delta. 0.7 Hz:
TABLE-US-00013 (-0.0662001910451557) + 0.051920253378124 * :Fo +
0.0146791342721163) * :Name("PBS (mM)") + -0.218700904653452 *
:Name("% NaCMC") + -0.0202956176083598 * :Name("% Glycerin") + (:Fo
- 22.0003631356491) * ((:Fo - 22.0003631356491) *
-0.00371533851417633) + (:Fo - 22.0003631356491) * ((:Name("PBS
(mM)") - 63.5057099845838) * 0.000185185074554069) + (:Name("PBS
(mM)") - 63.5057099845838) * ((:Name("PBS (mM)") -
63.5057099845838) * -0.0000863865657255508) + (:Fo -
22.0003631356491) * ((:Name("% NaCMC") - 2.85245995014651) *
-0.0322726861725922) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% NaCMC") - 2.85245995014651) * -0.0152609626718641) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% NaCMC") -
2.85245995014651) * 0.942295293128045) + (:Fo - 22.0003631356491) *
((:Name("% Glycerin") - 1.49703269551474) * 0.0048399350260245) +
(:Name("PBS (mM)") - 63.5057099845838) * ((:Name("% Glycerin") -
1.49703269551474) * 0.00387275533427914) + (:Name("% NaCMC") -
2.85245995014651) * ((:Name("% Glycerin") - 1.49703269551474) *
-0.213067717437202) + (:Name("% Glycerin") - 1.49703269551474) *
((:Name("% Glycerin") - 1.49703269551474) * 0.052309021299775)
[0190] Prediction Formula G' 0.7 Hz:
TABLE-US-00014 65.1530428282072 + -4.56421653385048 * :Fo +
-1.24220316891102 * :Name("PBS (mM)") + 53.0767618580076 * :Name("%
NaCMC") + 9.296089270897 * :Name("% Glycerin") + (:Fo -
22.0003631356491) * ((:Fo - 22.0003631356491) * 0.185460632264244)
+ (:Fo - 22.0003631356491) * ((:Name("PBS (mM)") -
63.5057099845838) * 0.0152064998484757) + (:Name("PBS (mM)") -
63.5057099845838) * ((:Name("PBS (mM)") - 63.5057099845838) *
0.0121675367725622) + (:Fo - 22.0003631356491) * ((:Name("% NaCMC")
- 2.85245995014651) * -1.59402906490529) + (:Name("PBS (mM)") -
63.5057099845838) * ((:Name("% NaCMC") - 2.85245995014651) *
-0.82120066059178) + (:Name("% NaCMC") - 2.85245995014651) *
((:Name("% NaCMC") - 2.85245995014651) * -3.41806241403989) + (:Fo
- 22.0003631356491) * ((:Name("% Glycerin") - 1.49703269551474) *
-0.194222622094197) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% Glycerin") - 1.49703269551474) * -0.237225958870055) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% Glycerin") -
1.49703269551474) * -0.363919647719381) + (:Name("% Glycerin") -
1.49703269551474) * ((:Name("% Glycerin") - 1.49703269551474) *
-0.960279042125364)
[0191] Prediction Formula G'' 0.7 Hz:
TABLE-US-00015 42.340284211014 + -4.44571705075887 * :Fo +
-0.951595662768327 * :Name("PBS (mM)") + 57.6631139101727 *
:Name("% NaCMC") + 4.93958206506618 * :Name("% Glycerin") + (:Fo -
22.0003631356491) * ((:Fo - 22.0003631356491) * 0.1897777224472) +
(:Fo - 22.0003631356491) * ((:Name("PBS (mM)") - 63.5057099845838)
* 0.00526490794925264) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("PBS (mM)") - 63.5057099845838) * 0.00750944190873103) +
(:Fo - 22.0003631356491) * ((:Name("% NaCMC") - 2.85245995014651) *
-1.59674778661272) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% NaCMC") - 2.85245995014651) * -0.55449874562251) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% NaCMC") -
2.85245995014651) * 17.0085346258082) + (:Fo - 22.0003631356491) *
((:Name("% Glycerin") - 1.49703269551474) * -0.0425836269658459) +
(:Name("PBS (mM)") - 63.5057099845838) * ((:Name("% Glycerin") -
1.49703269551474) * -0.187414471985777) + (:Name("% NaCMC") -
2.85245995014651) * ((:Name("% Glycerin") - 1.49703269551474) *
-2.3241038908658) + (:Name("% Glycerin") - 1.49703269551474) *
((:Name("% Glycerin") - 1.49703269551474) * -0.73370622281908)
[0192] Prediction Formula Tan .delta. 4 Hz
TABLE-US-00016 9.45512533634532 + -0.126696086121843 * :Fo +
-0.00117658850182967 * :Name("PBS (mM)") + -2.00308587650446 *
:Name("% NaCMC") + 0.165674034118311 * :Name("% Glycerin") + (:Fo -
22.0003631356491) * ((:Fo - 22.0003631356491) *
0.00365527346963407) + (:Fo - 22.0003631356491) * ((:Name("PBS
(mM)") - 63.5057099845838) * 0.000511204818741645) + (:Name("PBS
(mM)") - 63.5057099845838) * ((:Name("PBS (mM)") -
63.5057099845838) * 0.0000499689391927876) + (:Fo -
22.0003631356491) * ((:Name("% NaCMC") - 2.85245995014651) *
-0.0624166549775326) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% NaCMC") - 2.85245995014651) * 0.0199800709717944) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% NaCMC") -
2.85245995014651) * -8.94890476212236) + (:Fo - 22.0003631356491) *
((:Name("% Glycerin") - 1.49703269551474) * -0.0266258304941918) +
(:Name("PBS (mM)") - 63.5057099845838) * ((:Name("% Glycerin") -
1.49703269551474) * -0.0159932411399036) + (:Name("% NaCMC") -
2.85245995014651) * ((:Name("% Glycerin") - 1.49703269551474) *
1.21969695165947) + (:Name("% Glycerin") - 1.49703269551474) *
((:Name("% Glycerin") - 1.49703269551474) *
0.00451334325524632)
[0193] Prediction Formula G' 4.0 Hz
TABLE-US-00017 119.421921614245 + -12.2323465265668 * :Fo +
-2.68101314812006 * :Name("PBS (mM)") + 146.999647742916 * :Name("%
NaCMC") + 27.8854022682617 * :Name("% Glycerin") + (:Fo -
22.0003631356491) * ((:Fo - 22.0003631356491) * 0.519903664055683)
+ (:Fo - 22.0003631356491) * ((:Name("PBS (mM)") -
63.5057099845838) * 0.0209551675180216) + (:Name("PBS (mM)") -
63.5057099845838) * ((:Name("PBS (mM)") - 63.5057099845838) *
0.0232180450227683) + (:Fo - 22.0003631356491) * ((:Name("% NaCMC")
- 2.85245995014651) * -3.12498688301935) + (:Name("PBS (mM)") -
63.5057099845838) * ((:Name("% NaCMC") - 2.85245995014651) *
-1.68010649138557) + (:Name("% NaCMC") - 2.85245995014651) *
((:Name("% NaCMC") - 2.85245995014651) * 47.7871554829216) + (:Fo -
22.0003631356491) * ((:Name("% Glycerin") - 1.49703269551474) *
-0.520125030291254) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% Glycerin") - 1.49703269551474) * -0.516575698317358) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% Glycerin") -
1.49703269551474) * 7.81902442047261) + (:Name("% Glycerin") -
1.49703269551474) * ((:Name("% Glycerin") - 1.49703269551474) *
-2.08529318048302)
[0194] Prediction Formula G'' 4.0 Hz
TABLE-US-00018 9.16270416349258 + -6.65052721006341 * :Fo +
-1.30157689213324 * :Name("PBS (mM)") + 113.264274857613 * :Name("%
NaCMC") + 12.6630272567578 * :Name("% Glycerin") + (:Fo -
22.0003631356491) * ((:Fo - 22.0003631356491) * 0.278888472140156)
+ (:Fo - 22.0003631356491) * ((:Name("PBS (mM)") -
63.5057099845838) * -0.00310223504985895) + (:Name("PBS (mM)") -
63.5057099845838) * ((:Name("PBS (mM)") - 63.5057099845838) *
0.00757715798304363) + (:Fo - 22.0003631356491) * ((:Name("%
NaCMC") - 2.85245995014651) * -1.30849884761416) + (:Name("PBS
(mM)") - 63.5057099845838) * ((:Name("% NaCMC") - 2.85245995014651)
* -0.702979541219968) + (:Name("% NaCMC") - 2.85245995014651) *
((:Name("% NaCMC") - 2.85245995014651) * 57.4260758452326) + (:Fo -
22.0003631356491) * ((:Name("% Glycerin") - 1.49703269551474) *
-0.140690664543388) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% Glycerin") - 1.49703269551474) * -0.221880322555676) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% Glycerin") -
1.49703269551474) * 3.07273854570663) + (:Name("% Glycerin") -
1.49703269551474) * ((:Name("% Glycerin") - 1.49703269551474) *
-1.0565937205507)
[0195] Prediction Formula PF d-R 0.7 Hz
TABLE-US-00019 78.8594056631251 + -0.391595419225251 * :Fo +
0.194490163649969 * :Name("PBS (mM)") + -9.00551677919371 *
:Name("% NaCMC") + -1.31216569248401 * :Name("% Glycerin") + (:Fo -
22.0003631356491) * ((:Fo - 22.0003631356491) * 0.0397402622686809)
+ (:Fo - 22.0003631356491) * ((:Name("PBS (mM)") -
63.5057099845838) * 0.00616186280104159) + (:Name("PBS (mM)") -
63.5057099845838) * ((:Name("PBS (mM)") - 63.5057099845838) *
-0.00101989657856309) + (:Fo -22.0003631356491) * ((:Name("%
NaCMC") - 2.85245995014651) * -0.843405024379471) + (:Name("PBS
(mM)") - 63.5057099845838) * ((:Name("% NaCMC") - 2.85245995014651)
* -0.103279939139173) + (:Name("% NaCMC") - 2.85245995014651) *
((:Name("% NaCMC") - 2.85245995014651) * -22.9264118725924) + (:Fo
- 22.0003631356491) * ((:Name("% Glycerin") - 1.49703269551474) *
-0.0439660358574415) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% Glycerin") - 1.49703269551474) * -0.0619122070598477) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% Glycerin") -
1.49703269551474) * 10.1261963249863) + (:Name("% Glycerin") -
1.49703269551474) * ((:Name("% Glycerin") - 1.49703269551474) *
0.34697984176467)
[0196] Prediction Formula PF d-R 0.7 Hz
TABLE-US-00020 78.8594056631251 + -0.391595419225251 * :Fo +
0.194490163649969 * :Name("PBS (mM)") + -9.00551677919371 *
:Name("% NaCMC") + -1.31216569248401 * :Name("% Glycerin") + (:Fo -
22.0003631356491) * ((:Fo - 22.0003631356491) * 0.0397402622686809)
+ (:Fo - 22.0003631356491) * ((:Name("PBS (mM)") -
63.5057099845838) * 0.00616186280104159) + (:Name("PBS (mM)") -
63.5057099845838) * ((:Name("PBS (mM)") - 63.5057099845838) *
-0.00101989657856309) + (:Fo - 22.0003631356491) * ((:Name("%
NaCMC") - 2.85245995014651) * -0.843405024379471) + (:Name("PBS
(mM)") - 63.5057099845838) * ((:Name("% NaCMC") - 2.85245995014651)
* -0.103279939139173) + (:Name("% NaCMC") - 2.85245995014651) *
((:Name("% NaCMC") - 2.85245995014651) * -22.9264118725924) + (:Fo
- 22.0003631356491) * ((:Name("% Glycerin") - 1.49703269551474) *
-0.0439660358574415) + (:Name("PBS (mM)") - 63.5057099845838) *
((:Name("% Glycerin") - 1.49703269551474) * -0.0619122070598477) +
(:Name("% NaCMC") - 2.85245995014651) * ((:Name("% Glycerin") -
1.49703269551474) * 10.1261963249863) + (:Name("% Glycerin") -
1.49703269551474) * ((:Name("% Glycerin") - 1.49703269551474) *
0.34697984176467)
Example 20
[0197] This example consists of the screening model's 59
independent runs of conditions with rheological outputs registered
and see following data Tables D and E:
TABLE-US-00021 TABLE D Output Min Max Viscosity .eta.* (0.7 Hz,
30.tau., 30.degree. C.) 7200 53000 Tan .delta. (0.7 Hz, 30.tau.,
30.degree. C.) .6 1.5 G' elastic modulus, G'' viscosity Modulus
(0.7 Hz, 100 30.tau., 30.degree. C.) Tan .delta. (4 Hz, 30.tau.,
30.degree. C.) 0.3 2 G' elastic modulus, G'' viscosity Modulus (4
Hz, 30.tau., 300 30.degree. C.) Phase Angle .delta.-R (0.7 Hz,
30.tau., 30.degree. C.) 60 Phase Angle .delta.-R (0.7 Hz, 30.tau.,
30.degree. C.) 110
Example 20
TABLE-US-00022 [0198] TABLE E Screening Data PGS Conc. % Control
Extra- Lot # & Exposure Time Autoclave time (mM) MinCMC
Glycerin contant pH % LOD 1 G066 -12 min 12 0 2.3 0 7.211 43 97.85
3.6333 2 G066 -12 min 12 0 2.4 0 7.183 50 87.75 3.4001 3 G066 -12
min 12 0 2.5 0 7.132 29 97.55 5.8121 4 G066 -12 min 12 0 2.5 0
7.158 39 97.54 4.4384 5 G066 -30 min 30 0 2.3 0 7.154 30 97.54
4.0541 6 G066 -30 min 30 0 2.4 0 7.255 83 97.75 4.2755 7 G066 -30
min 30 0 2.5 0 7.151 41 97.55 3.7258 8 G066 -30 min 30 0 2.5 0
7.151 42 97.57 4.3382 9 G066 -12 min 12 50 2.3 0 7.308 150 80.81
3.9737 10 G066 -12 min 12 50 2.4 0 7.3 151 96.9 4.0315 11 G066 -12
min 12 50 2.5 0 7.295 151 96.54 4.1824 12 G066 -12 min 12 50 2.5 0
7.266 101 96.53 4.4951 13 G066 -30 min 30 50 2.3 0 7.326 155 96.9
3.5138 14 G066 -30 min 30 50 2.4 0 7.315 160 96.79 3.8584 15 G066
-30 min 30 50 2.5 0 7.312 155 96.65 3.7105 16 G066 -30 min 30 50
2.6 0 7.305 155 96.50 4.0817 17 G066 -12 min 12 100 2.3 0 7.286 277
95.89 3.0581 18 G066 -12 min 12 100 2.4 0 7.206 274 95.74 3.6172 19
G066 -12 min 12 100 2.5 0 7.286 281 96.79 2.7862 20 G066 -12 min 12
100 2.6 0 7.289 250 95.45 3.6764 21 G066 -30 min 30 100 2.3 0 7.3
270 95.5 3.967 22 G066 -30 min 30 100 2.4 0 7.306 271 95.52 3.5559
23 G066 -30 min 30 100 2.5 0 7.306 277 95.68 3.2685 24 G066 -30 min
30 100 2.6 0 7.302 277 95.53 3.2065 25 G066 -12 min 12 50 2.6 0
7.29 157 95.53 4.5655 26 G066 -30 min 30 50 2.6 0 7.274 155 96.53
3.6078 27 G066 -12 min 12 50 2.7 0 7.309 172 96.41 4.3474 28 G066
-30 min 30 50 2.7 0 7.298 171 96.83 3.8035 29 G066 -12 min 12 50
2.8 0 7.3 174 96.88 4.5474 30 G066 -30 min 30 50 2.8 0 7.255 173
96.39 3.4174 31 G066 -12 min 12 50 2.9 0 7.204 177 95.2 4.2343 32
G066 -30 min 30 50 2.9 0 7.289 177 96.14 4.4937 33 G066 -12 min 12
100 2.6 0 7.292 255 95.4 3.856 34 G066 -30 min 30 100 2.8 0 7.25
254 5.38 3.5765 35 G066 -12 min 12 100 2.7 0 7.33 252 85.49 4.1547
36 G066 -30 min 30 100 2.7 0 7.316 253 96.43 3.5843 37 G066 -12 min
12 100 2.8 0 7.325 254 95.47 3.9806 38 G066 -30 min 30 100 2.8 0
7.31 283 95.44 4.051 39 G066 -12 min 12 100 2.9 0 7.32 281 95.44
4.2354 40 G066 -30 min 30 100 2.9 0 7.314 281 95.32 3.6419 41 G066
-12 min 12 50 2.6 1 7.288 255 65.53 4.1198 42 G066 -30 min 30 50
2.6 1 7.258 288 95.45 2.7719 43 G066 -12 min 12 50 2.7 1 7.385 274
95.49 4.2726 44 G066 -30 min 30 50 2.7 1 7.25 295 94.34 4.4181 45
G066 -12 min 12 50 2.8 1 7.209 200 95.42 2.8336 46 G066 -30 min 30
50 2.8 1 7.251 285 95.32 2.9406 47 G066 -12 min 12 50 2.9 1 7.289
293 96.25 4.4409 48 G066 -30 min 30 50 2.9 1 7.263 290 94.06 3.0904
49 G066 -12 min 12 100 2.6 1 7.204 299 94.56 3.0525 50 G066 -30 min
30 100 2.6 1 7.20 397 94.5 3.942 51 G066 -12 min 12 100 2.7 1 7.302
418 94.4 3.9555 52 G066 -30 min 30 100 2.7 1 7.277 404 94.53 4.0582
53 G066 -12 min 12 100 2.8 1 7.311 400 94.46 4.062 54 G066 -30 min
30 100 2.8 1 7.296 411 94.21 3.861 55 G066 -12 min 12 100 2.9 1
7.306 407 94.27 4.3059 56 G066 -30 min 30 100 2.9 1 7.27 413 94.22
4.0409 57 G065074-Fo26 15 25 2.6 1.5 7.299 208 96.5 -- 58
G065023-Fo26 15 25 2.6 1.5 -- -- -- -- 59 G065063-Fo26 15 25 2.6
1.5 7.345 95.54 95.54 -- 0.7 Hz 0.7 Hz 4 Hz | | Crossover (%)
Crossover ( ) Crea (Hz) | ||cP| T ) 0.7 Hz 0.7 Hz |cP| 1 3.11 83.6
0.4951 2069.6 0.92814 68.588 61.969 7576.3 2 1.654 50.96 0.2990
2454.9 0.84694 51.89 71.127 5887.3 3 0.9877 46.58 0.1572 2111.6
0.77476 106.73 84.395 10879 4 1.029 48.38 0.1837 2173.6 0.78432
110.20 86.713 10 31 5 9.789 73.04 1.299 1815.8 1.1365 47.189 63.639
6610.5 6 7.808 80.22 1.21 1928.3 1.0800 57.743 62.624 7787.3 7
3.806 68.82 0.5737 2447.1 0.26272 77.801 75.00 9280.8 8 4.383 78.51
0.5003 2585.3 0.99582 80.11 80.045 10020 9 does not cross over G''
dominant -- -- 799 .4 1.5883 15.92 29.725 3005.3 10 does not cross
over G'' dominant 99.22 -- 94.8 1.5741 20.408 31.415 4235.9 11
28.52 94.19 4.54 112 . 1.3912 25.576 40.483 5266.1 12 22.7 -- 3.512
1236.6 1. 227 32.967 43.583 6641 13 does not cross over G''
dominant -- -- 2063. 2.7728 3.0743 5.5321 1364.6 14 does not cross
over G'' dominant -- -- 3406. 2.485 5.5054 13.945 2201.5 15 does
not cross over G'' dominant -- -- 3806.7 2.4264 5.8735 14.299
2228.5 16 does not cross over G'' dominant -- -- 4732.1 2.2014
7.4149 17.099 2597.4 17 does not cross over G'' dominant -- --
4324.5 1.9384 6.7202 15.947 2439.4 18 does not cross over G''
dominant -- -- 4579.5 1.9802 9.1819 19.012 2578.2 19 does not cross
over G'' dominant -- -- 5236.2 1.9248 10.628 20.502 3040.2 20 does
not cross over G'' dominant -- -- 5 .1 1.839 11.67 22.101 3151 21
does not cross over G'' dominant -- -- 918.05 3.0607 0.09062 3.9142
506.21 22 does not cross over G'' dominant -- -- 1124.1 3.1350 1.3
3 4.7414 591.51 23 does not cross over G'' dominant -- -- 1185.8
3.2698 1.4992 4. 63 794.52 24 does not cross over G'' dominant --
-- 1140.7 3.4559 1.3602 4.9175 786.79 25 does not cross over G''
dominant -- -- 100 .7 1.4728 24.9 36.777 4839.9 26 does not cross
over G'' dominant -- -- 4196.9 2.7246 7.6681 10.87 2622 27 21.95
103.3 3.494 1378.3 1.22 6 36.636 48.543 5381.2 28 does not cross
over G'' dominant -- -- 4550 2.2379 9.1896 18.325 2818.5 29 174.5
295.4 27.77 1310.0 1. 63 34.041 46.895 3981.5 30 274.5 9805 42.71
4250.7 2.1765 7.891 17.446 2844.3 31 10.63 100.5 1. 1 2057.3 1.114
50.587 67. 6222.8 32 does not cross over G'' dominant -- -- 79.4
1.9623 13.582 20.701 3 .0 33 does not cross over G'' dominant -- --
4721.6 2.012 9.2994 16.666 272 .3 34 does not cross over G''
dominant -- -- .37 1.1276 4.2449 8. 658.72 35 276.5 1153 44.03
6176.4 1.8206 13.081 23.866 923.67 36 247.5 1580 39.4 1416.2 1.9800
6.9109 2.9582 1009.3 37 250.9 1911 41.62 5012.3 1. 17.989 30.375
4131.6 38 does not cross over G'' dominant -- -- 1776.7 2.7815
2.8484 7.3742 1067.6 39 264.7 1273 45.32 6159.7 1.5952 22.105
35.409 4824.1 40 does not cross over G'' dominant -- -- 2492.2 2.
775 4.2501 10.122 1647.3 41 7.979 75.7 1.254 1365.7 1.0799 55. 71
60.485 7485.5 42 372.5 1927 43.27 4149.7 2.2834 7.3195 18.747
2558.4 43 7.274 92.75 1.158 2038.0 1.086 81.455 68.69 8204.7 44
does not cross over G'' dominant -- -- 4002.8 2.2291 7.2621 16.215
2498.7 45 5.744 65.58 0.9142 2288.3 1.0282 73.298 76.608 9836 46
285 8992 42.17 4481.4 2.3141 7.7804 18.042 2842.2 47 6.489 82.51
1.085 2308.0 1.0488 70.303 72.7 9276.2 48 273 2540 42.44 5027.2
2.1083 9.4209 20.009 3037.4 49 does not cross over G'' dominant --
-- 2 1.8 2.187 5.4521 11. 1093.5 50 does not cross over G''
dominant -- -- 1802.1 2.0471 2.6 7.40 1192.3 51 does not cross over
G'' dominant -- -- 4370.3 2.0083 9.1217 18.438 2841.3 52 172.5
331.9 27.51 2332.9 2.702 3.5 .5543 1525.3 53 does not cross over
G'' dominant -- -- 4485.5 2. 47 9.5108 17.599 2095.7 54 does not
cross over G'' dominant -- -- 3019.2 2.4278 5.0433 12.318 1966.8 55
does not cross over G'' dominant -- -- 7279.3 1.5548 18.584 27.515
3848.7 56 does not cross over G'' dominant -- -- 3273.6 2.4413
5.4400 12.365 2119.5 57 2.831 50.82 0.4505 2082.3 0.03274 66.666
62.187 7920.5 58 10.37 73.41 1.65 1477.8 1.1257 43.291 49.652
6200.3 59 0.9147 43.56 0.1458 3070.3 0.79724 106.26 64.507 10625 11
Hz 11 Hz defraction defraction 4 Hz Tan( ) 4 Hz 4 | ||cP| ta ( ) 11
Hz 11 Hz angle 0.7 Hz angle Hz 1 0.59279 159.29 110.52 2648.3
0.58949 225.99 144.01 44.853 52.382 2 0.64379 168.34 121.4 4347.9
0.549 256.37 156.48 41.53 47.023 3 0.49886 231.52 130.75 5128.2
0.54529 312.49 171.31 35.871 42 4 0.70576 237.26 148.92 5313.1
0.54453 324.49 177.25 39.212 42.029 5 0.80646 129.87 105.01 849 .9
0.74706 194.44 146.53 50.385 61.49 6 0.775 154.00 120.5 4036.2
0.70196 229.57 194.66 48.946 56.221 7 0.71134 190.89 136 4779
0.94427 276.59 178.33 45.254 40.643 8 0.73299 204.15 149.88 6807.3
0.55411 302.51 197.97 48.229 49.469 9 1.1303 55.20 73.83 2289.2
1.152 108.7 120.26 50.183 94.174 10 1.1200 71.02 79.77 2500.5
0.57000 115.85 129.51 60.258 59.874 11 10.181 93.045 94.709 2991.1
0.8 26 149.3 145.28 56.599 77.325 12 0.9 75 89.937 98.141 3104.5
0.93515 157.3 146.59 55.292 74.277 13 2.2124 14.262 31.883 1057
7.2509 13.945 72.084 83.997 151.26 14 1.7583 27.274 48.06 1516.5
2.6019 407.68 94.947 76.434 131. 15 1.7882 27.262 48.865 1551.9
2.8942 41.983 97.573 75.59 131.29 16 1.7028 33.06 58.261 1811.3
1.9732 57.343 110.15 73.241 123.27 17 1.613 23.925 51.205 1514.2
1.7832 51.717 98.99 69.152 126.13 18 1.5083 33.919 54.040 1588.7
1.9208 54.509 102.23 68.074 122.09 19 1.4878 43.06 63.25 2002.3
1.622 72.889 117.75 67.91 112.15 20 1.4554 44.996 65.453 2047.5
1.5283 76.814 118.97 57.087 111.15 21 1.2519 15.276 16.658 711.95
7.3529 10.726 45.645 108.17 189.5 22 3.5541 5. 28 15.966 772.54
29.067 5.55 62.929 98.708 157.1 23 3.668 5.7229 19.685 521.27
137.65 4.9109 58.799 97.23 163.12 24 5. 7 3.3481 19.595 237.43
659.34 5.3149 52.335 97.299 16 .27 25 1.0043 82.151 90.20 2822
1.0800 132.91 142.57 58.7 83.164 26 1.04 33.014 54.161 1704.1
2.0719 52.101 104.51 72.537 124.34 27 0.97838 111.34 109.13 3477.3
0.90647 178.52 162.07 55.128 70.395 28 1.8851 36.642 69.707 1942.7
1.5432 84.312 117.68 55.128 70.395 29 1.4050 49.038 69.045 3435.5
0.96974 171.03 155.53 05.795 107. 30 1.6791 23.074 57.153 1792.5
2.0595 55.79 109.45 71.519 122.26 31 0.86491 154.51 128.63 4458.1
0.78015 245.34 192.40 49.682 57.966 32 1.4757 56.29 53.27 2655.8
1.4154 105.82 151.06 67.269 89.878 33 1.5747 367.12 57.825 1824.5
1.8612 58.164 110.53 68.516 11 .63 34 4.6975 4.6073 21.041 842.87
6.5767 17.24 58.188 118.4 1 38 35 3.740 0.0033 22.352 2136.9 1.5265
80.833 123.73 91.583 162.12 36 2.9981 7. 991 23.947 936.42 3.9211
19.876 64.732 63.706 180 37 1.3079 53.207 82.752 2379.7 1.2644
109.88 141.25 62.577 96.24 38 2. 57 8.2391 25.901 1074.9 6.1524
13.657 73.718 83.932 168.34 39 1.7282 78.773 94.609 2970.2 1.1824
132.91 157.01 61.042 86.956 40 2.4694 15.590 78.317 1350.7 1.108
20.709 90.83 78.48 145.54 41 0.81893 145.09 119.83 3996 0.7472
220.71 187.51 48.889 58.727 42 1.7181 32.518 58.846 1776.1 2.0964
53.497 110.42 73.19 123.99 43 0.80481 161.32 130.04 4338.8 0.74847
240.77 159.27 48.403 56.189 44 1.7172 315.512 54.219 1750.1 2.0839
52.744 108.12 72.838 125.4 45 0.78768 191 150.04 5100.3 0.70813
288.89 204.86 47.189 52.516 46 1.76 4 36.554 51.906 1978.4 1.7582
62.164 121.02 13.026 118.24 47 0.79754 182.97 148.1 4991.2 0.72917
274.72 200.34 17.741 53548 48 1.873 39.146 61.626 2029.5 1.8494
58.932 126.72 70.242 113.34 49 1. 22.277 42.012 1.382 1.5247 28.571
88.975 74.034 138.09 50 2.519 11.002 27.814 1006.7 9. 194 6.3877
66.969 86.518 158.78 51 1.66 36.579 51.236 7968 1.9395 81.942
120.25 89.535 118.53 52 2.0229 17.053 34.53 1274.8 4.9474 10.88
55.270 77.327 147.4 53 1.0875 34.555 64.354 1884.3 1.8902 57.773
114.78 89.731 121.57 54 1.9714 22.134 43.504 1495.5 3.0783 33.231
97.613 76.999 137.75 55 1.3370 57.994 77.732 2437.6 1.1554 99.422
134.94 82.781 99.174 56 1. 05 24.678 47.110 1846 2.7108 38.805
96.799 76.426 134.19 57 0.7477 151.44 120.58 1123.7 0.71373 232.69
164.28 44.491 54.127 58 0.87145 117.29 102.9 2339.5 0.8340 177.54
148.83 50.589 55.228 59 0.83141 231.23 148.22 5.303 0.50547 317.72
108.12 38.685 43.642 indicates data missing or illegible when
filed
[0199] Although the present invention has been described with
reference to preferred embodiments, one skilled in the art can
easily ascertain its essential characteristics and without
departing from the spirit and scope thereof, can make various
changes and modifications of the invention to adapt it to various
usages and conditions. Those skilled in the art will recognize or
be able to ascertain using no more than routine experimentation,
various reasonable equivalents to the specific embodiments of the
invention herein. Such equivalents are to be encompassed in the
scope of the present invention. For example, the plasticizer
utilized in the examples of the present invention is primarily
glycerin. However, one of ordinary skill in the art would
appreciate that other plasticizers may be used without departing
from the spirit and scope of the invention.
* * * * *