U.S. patent application number 12/776909 was filed with the patent office on 2010-09-02 for implant for subcutaneous or intradermal injection.
This patent application is currently assigned to Aventis Pharmaceuticals. Invention is credited to Jerome Asius, Hatem Fessi, Franck Gouchet, Benedicte Laglenne, Elisabeth Laugier-Laglenne.
Application Number | 20100221684 12/776909 |
Document ID | / |
Family ID | 9507929 |
Filed Date | 2010-09-02 |
United States Patent
Application |
20100221684 |
Kind Code |
A1 |
Asius; Jerome ; et
al. |
September 2, 2010 |
IMPLANT FOR SUBCUTANEOUS OR INTRADERMAL INJECTION
Abstract
The invention concerns an injection implant for filling up
wrinkles, thin lines, skin cracks and scars, for reparative or
plastic surgery, aesthetic dermatology, and for filling up gums in
dental treatment. The invention concerns the use of biologically
absorbable polymer microspheres or microparticles suspended in a
gel. Said suspension is produced either ready-for-use or
freeze-dried. The biological absorbability of the microspheres is
controlled and enables the production of implants having well
defined persistence and deliberately limited to 3 years.
Inventors: |
Asius; Jerome; (Mauguio,
FR) ; Fessi; Hatem; (Lyon, FR) ; Gouchet;
Franck; (Donnery, FR) ; Laglenne; Benedicte;
(Mauguio, FR) ; Laugier-Laglenne; Elisabeth;
(Paris, FR) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ LLP
1875 EYE STREET, N.W., SUITE 1100
WASHINGTON
DC
20006
US
|
Assignee: |
Aventis Pharmaceuticals
Bridgewater
NJ
|
Family ID: |
9507929 |
Appl. No.: |
12/776909 |
Filed: |
May 10, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10809349 |
Mar 26, 2004 |
7731758 |
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12776909 |
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09242103 |
Feb 8, 1999 |
6716251 |
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PCT/FR98/01241 |
Jun 12, 1998 |
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10809349 |
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Current U.S.
Class: |
433/215 ;
604/506 |
Current CPC
Class: |
A61L 2400/06 20130101;
A61P 17/00 20180101; A61P 17/02 20180101; A61L 27/18 20130101; A61P
1/02 20180101; A61L 27/50 20130101; A61L 27/58 20130101; A61K
2800/412 20130101; A61F 2/0059 20130101; A61K 2800/91 20130101;
A61K 8/042 20130101; A61Q 19/08 20130101; A61Q 19/00 20130101; A61L
27/18 20130101; A61K 8/85 20130101; A61K 8/025 20130101; C08L 67/04
20130101 |
Class at
Publication: |
433/215 ;
604/506 |
International
Class: |
A61C 19/06 20060101
A61C019/06; A61M 31/00 20060101 A61M031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 13, 1997 |
FR |
9707334 |
Claims
1. A method of performing reparative or esthetic dermatologic
surgery which comprises subcutaneously or intradermally injecting
into a subject a bioresorbable injectable implant consisting
essentially of bioresorbable microspheres or microparticles
suspended in a gel, wherein said microspheres or microparticles
consist of at least one polymer selected from the group consisting
of lactic acid polymers, glycolic acid polymers, and lactic
acid-glycolic acid co-polymers.
2. The method according to claim 1 wherein said surgery is for
filling wrinkles, fine lines, skin cracks or scars.
3. The method according to claim 1 wherein said surgery is for
filling the gums for dentistry.
4. The method according to claim 1 wherein said implant consists
essentially of materials of non-animal origin.
5. The method according to claim 1 wherein said microspheres or
microparticles have a mean diameter greater than 5 .mu.m and less
than 150 .mu.m.
6. The method according to claim 1 wherein said microspheres or
microparticles have a mean diameter greater than 20 .mu.m and less
than 80 .mu.m.
7. The method according to claim 1 wherein said microspheres or
microparticles have a mean diameter greater than 20 .mu.m and less
than 40 .mu.m.
8. The method according to claim 1 wherein said polylactic acid has
a molecular mass of between 70,000 and 175,000 Daltons.
9. The method according to claim 1 wherein said polylactic acid has
a molecular mass of between 120,000 and 170,000 Daltons.
10. The method according to claim 1 wherein said polylactic acid
has an intrinsic viscosity of between 3 and 4 dl/g.
11. The method according to claim 1 wherein said polylactic acid
has an intrinsic viscosity of between 3.35 and 3.65 dl/g.
12. The method according to claim 1 wherein said microspheres or
microparticles are present in said gel at a concentration of from
50-300 g/l.
13. The method according to claim 1 wherein said microspheres or
microparticles are present in said gel at a concentration of from
60-200 g/l.
14. The method according to claim 1 wherein said gel consists
essentially of water, from about 0.1 to about 7.5% (wt/wt) of an
injectable gelling agent, and a surfactant.
15. The method according to claim 1 wherein said gel consists
essentially of water and 0.1 to 7.5% by weight
carboxymethylcellulose (CMC) or hydroxypropylmethylcellulose.
16. The method according to claim 14 wherein said gelling agent is
a cellulose derivative.
17. The method according to claim 16 wherein said cellulose
derivative is selected from the group consisting of
carboxymethylcellulose and hydroxypropylmethylcellulose.
18. The method according to claim 14 wherein wherein said gelling
agent is synthetic hyaluronic acid.
19. The method according to claim 14 wherein wherein said
surfactant is selected from the group consisting of polyoxyethylene
sorbitan monooleate and pluronic acid.
20. The method according to claim 1 wherein said microparticles
consist of a polymer selected from the group consisting of
poly-L-lactic acid, poly-D-lactic acid, and mixtures thereof.
Description
[0001] This application is a continuation of co-pending application
Ser. No. 10/809,349 filed on Mar. 26, 2004, which is a divisional
of co-pending application Ser. No. 09/242,103 filed on Feb. 8, 1999
(now U.S. Pat. No. 6,716,251), which was the National Stage of
International Application No. PCT/FR98/01241 filed Jun. 12, 1008,
and claims priority of Application No. 9707334 filed in France on
Jun. 13, 1997 under 35 U.S.C. .sctn. 119. The entire contents of
each of these applications are hereby incorporated by
reference.
[0002] The present invention relates to an implant for subcutaneous
or intradermal injection, intended to be used in humans in
reparative or plastic surgery and in esthetic dermatology, for
filling wrinkles, fine lines, skin cracks, acne scars and other
scars, as well as in dentistry for filling the gums.
[0003] Up until now, a number of products have been used for this
purpose. Each product has advantages and disadvantages.
[0004] Silicone gel (or silicone oil) is easy to use. However, the
migration of droplets of silicone into the tissues situated below
the point of injection, by simple gravity, has been observed after
injection. Silicone is frequently the cause of chronic
inflammation, of formation of granulomas, and even of tardive
allergic reactions. Silicone is not biodegradable, and it is often
found in the liver.
[0005] Teflon paste is a suspension of polytetrafluoroethylene
particles (diameter 10 to 100 .mu.m) in glycerine. This product, in
numerous cases, caused severe and chronic serous infections and had
to be removed after a few months from dermal and subdermal tissues
for most patients. It has also been proved that small
polytetrafluoroethylene particles were found in the liver.
[0006] Collagen suspensions have been very widely used in the last
ten years. The results have however been quite disappointing since
collagen is resorbed within 1 to 3 months. Allergic reactions are
also noted in about 2% of patients. Finally, it should be noted
that collagen is of bovine origin.
[0007] Biological samples from the patient himself: the idea was
certainly interesting, but clinical experience has shown the
failure of the reimplantation of the fatty cells, which are
absorbed and disappear within a few weeks.
[0008] Another system consisted in adding plasma from the patient
to a collagen gelatin of bovine and porcine origin. The results are
even more disappointing, and the product is of animal origin.
[0009] Hyaluronate gels provided a good alternative by virtue of
their biocompatibility and their lack of toxicity. They are
moreover widely used in eye surgery. However, their rapid
bioresorbability (maximum 2 months) makes them ineffective for use
in plastic surgery.
[0010] Bioplastics are polymerized silicone particles (diameter 70
to 140 .mu.m) dispersed in polyvinylpyrrolidone. The product had to
be withdrawn given the chronic inflammation and the rejection
reactions caused by it.
[0011] Polymethyl methacrylate (PMHA) microspheres having a
diameter of 20 to 40 .mu.m in suspension either in a solution of
gelatin or in a solution of collagen. PMMA is not biodegradable,
but not enough time has elapsed in order to know what this implant
gives after 5 or 6 years. Moreover, the vector remains a solution
of collagen of bovine origin, with the problems of allergy which
are known for it.
[0012] The aim of the invention is to overcome the disadvantages of
known products.
[0013] The invention uses microspheres or microparticles consisting
of a neutral polymer chosen for its innocuousness and which is
already widely used by the pharmaceutical industry either by the
oral route or by the parenteral route.
[0014] The implant according to the invention combines ease of use
without prior manipulations, syringeability of the product,
resorbability over a controlled time of the polymer as well as of
the vector gel, and absence of allergenicity of the product, which
makes any preliminary test unnecessary.
[0015] The microspheres or microparticles should have a controlled
bioresorbability offering a resorbability time of between 1 and 3
years. This means that the polymer will be degraded, after
injection in situ, into lowmolecular-weight compounds which will be
eliminated from the body by natural processes. In no case does a
nonresorbable implant appear to be desirable. It is still a foreign
body placed in a living tissue.
[0016] The microspheres or microparticles are suspended in a gel.
They should have a diameter greater than 5 .mu.m and preferably
greater than 20 .mu.m, so as not to be absorbed by the macrophages.
They should have a diameter of less than 150 .mu.m, and preferably
less than 40 .mu.m, so that, on the one hand, they can be injected
by a fine needle and, on the other hand, they do not create a
granular mass under the finger.
[0017] Two families of polymers essentially meet the preceding
definition: the polycaprolactones (and in particular the
poly-.epsilon.-caprolactones), as well as the polylactides
(polylactic acids or PLA), the polyglycolides (polyglycolic acids
or PGA) and their copolymers (polylactic-co-glycolic acids or
PLAGA).
[0018] Given the numerous studies already carried out and the good
knowledge of the products, in particular as regards the manufacture
of microspheres and resorbability, it appears advantageous to use a
mixture of polylactic acid (PLA) and polylactic-co-glycolic acid
(PLAGA). The proportions of each of these two acids make it
possible to determine the persistence of the product.
[0019] Numerous trials have also led to a preference for a polymer
consisting of a poly-L-lactic acid (crystalline), a poly-D-lactic
acid (amorphous), or a mixture of these two acids. Its molecular
mass, calculated by viscometry, is advantageously between 70,000
and 175,000 Dalton, and preferably between 120,000 and 170,000
Dalton, an intrinsic viscosity of between 3 and 4 dl/g, and
preferably between 3.35 and 3.65 dl/g, a specific rotation of
between -150 and -160.degree., a melting point of between 178.0 and
190.1.degree. C., a heat of fusion of between 85.0 J/g and 90.0
J/g, a quantity of residual solvents <0.01% and a proportion of
residual monomer (lactic acid) <0.1%. Such a product is
available from PURAC BIOCHEM in Gorinchem (The Netherlands).
[0020] Bioresorbable synthetic polymers have been studied for about
15 years under the direction of Michel VERT, Director of Research
at C.N.R.S. The first clinical uses of PLAs started in 1981 for
various indications in facial traumatology. The use of lactic acid
polymers has become systematic in the context of bioresorbable
surgical implants. PLAs now have diverse and wide medical
applications (bone surgery, maxillo-facial surgery,
controlled-release pharmacological formulations: implants,
microspheres, nanospheres, vaccines).
[0021] The degradation of lactic acid and/or glycolic acid polymers
in biological medium occurs exclusively by a chemical mechanism of
nonspecific hydrolysis. The products of this hydrolysis are then
metabolized and then eliminated by the human body. Chemical
hydrolysis of the polymer is complete; the more pronounced its
amorphous character and the lower its molecular mass, the more
rapidly it occurs. Thus, the resorbability time may be adjusted by
acting on the composition of the mixture and/or on the molecular
mass of the polymer(s). The biocompatibility of the PLA and PLAGA
polymers makes them excellent supports for cellular growth and
tissue regeneration.
[0022] The microspheres or microparticles are included in a gel.
This gel, which is used as vector to maintain the microspheres or
microparticles in a homogeneous suspension, is resorbable within
approximately 2 months, which corresponds to the time necessary for
the creation of fibroses around the microspheres or microparticles.
It consists mainly of water for injection and a gelling agent
authorized in injection: cellulose derivatives, and more
particularly carboxymethylcellulose (CMC) at a concentration by
mass of 0.1 to 7.5%, and preferably from 0.1 to 5.0%. It is also
possible to use hydroxypropylmethylcellulose (HPMC) which is
commonly used in intraocular injections in the context of cataract
operations. It is also possible to use a synthetic hyaluronic acid,
which is used for intraocular injections and subcutaneous
injections. It is also possible to use lactic acid esters, caproic
acid esters and the like.
[0023] The good dispersion of the microspheres or microparticles
and the homogeneity of the gel will be provided by the use of a
surfactant chosen for its innocuousness and its authorized
subcutaneous and intradermal use. Polyoxyethylene sorbitan
monooleate (marketed under the name Tween 80) or pluronic acid will
be used.
[0024] The product may be provided in ready-for-use prefilled
sterile syringes, provided with a needle, or in vials of sterile
suspension. It may also be provided in a vial containing a
freeze-dried product accompanied by an ampule of sterile water
(water for injection), or in a two-compartment prefilled syringe,
one containing the freeze-dried product of microspheres or
microparticles, the other containing water for injection.
[0025] The implant does not require a test of allergenicity. It
does not contain any product of animal origin.
[0026] The protocol for the manufacture of the implant is described
below, in the case of a ready-for-use suspension of
microspheres.
[0027] A. Preparation of microspheres of lactic acid polymer. The
conventional solvent evaporation technique, or the so-called
controlled precipitation technique or any other technique which
makes it possible to obtain microspheres of the desired size is
used.
[0028] B. Preparation of a gel of sufficient viscosity to maintain
the microspheres in suspension. This viscosity will be adjusted
depending on the size of the micro- spheres and the proportion of
microspheres dispersed in the gel. This proportion will be from 50
to 300 g/l, and preferably from 60 to 200 g/l.
[0029] C. Distribution of the gel into syringes or into vials, in a
controlled atmosphere (class 10.sup.4).
[0030] D. Sterilization of the vials or syringes, or use of a
process which makes the finished product suitable for injection by
the subcutaneous route.
[0031] The manufacturing protocol is described below in the case of
freeze-dried PLA microparticles, whether this is the L polymer, the
D polymer or a mixture thereof.
[0032] A. Cryogrinding of the PLA under gaseous nitrogen filtered
at 0.22 .mu.m, at a temperature of less than -80.degree. C., on a
100-.mu.m screening grid.
[0033] B. Sieving of the microparticles on a 100-.mu.m stainless
steel sieve.
[0034] C. Preparation of the freeze-drying medium including the
dissolution, with stirring, of CMC (gelling agent), of apyrogenic
mannitol (cryoprotecting agent), and of polysorbate (surfactant) in
water for injection, filtration at 0.22 .mu.m of the solution
obtained under gaseous nitrogen filtered at 0.22 .mu.m, and
sterilization in an autoclave for 20 minutes at 121.5.degree.
C.
[0035] D. Distribution of the microparticles at a rate of 100 mg
per vial of 4 ml nominal capacity.
[0036] E. Distribution of the freeze-drying medium at a rate of
1.05.+-.0.05 g into the vials already containing the polylactic
acid microparticles.
[0037] F. Dispersion of the microparticles in the freeze-drying
medium by an ultrasound dispersion system in order to obtain a
homogeneous suspension.
[0038] G. Prestoppering of the bottles using pillar stoppers
(specific for freeze-drying), rapid freezing below -70.degree. C.,
storage of the frozen vials below -40.degree. C., and finally
freeze-drying and automatic stoppering of the vials.
[0039] H. Fitting of capsules and examination of the vials, before
sterilization by y irradiation.
[0040] Of course, it is possible to combine the procedures
described above, for example in order to obtain a suspension of
microparticles ready for use, or a freeze-dried product of
microspheres, the microparticles or the microspheres consisting of
any of the above-mentioned polymers and mixtures thereof.
EXAMPLE 1
[0041] 2 g of PLA are dissolved in 20 ml of an organic solvent
(ethyl acetate). This solution is dispersed in 100 ml of water
containing 5 g of polyoxyethylene sorbitan monooleate. Moderate
vortex stirring is maintained until evaporation of the solvent and
formation of microspheres having a mean diameter of 40 .mu.m. The
microspheres formed are recovered by sedimentation, filtration and
drying. They are then included in a gel consisting of water and CMC
(0.5% by mass). After moderate stirring, the distribution is
carried out.
EXAMPLE 2
[0042] 2 g of PLA are dissolved in 20 ml of an organic solvent
(methylene chloride). This solution is dispersed in 100 ml of water
containing 5 g of polyoxyethylene sorbitan monooleate. Moderate
vortex stirring is maintained until evaporation of the solvent and
formation of microspheres having a mean diameter of 80 .mu.m. The
micro-spheres formed are recovered by sedimentation, filtration and
drying. They are then included in a gel consisting of water and CMC
(0.5% by mass). After moderate stirring, the distribution is
carried out.
EXAMPLE 3
[0043] 2 g of PLA are dissolved in 20 ml of an organic solvent
(chloroform). This solution is dispersed in 100 ml of water
containing 5 g of polyoxyethylene sorbitan monooleate. Moderate
vortex stirring is maintained until evaporation of the solvent and
formation of microspheres having a mean diameter of 50 .mu.m. The
micro-spheres formed are recovered by sedimentation, filtration and
drying. They are then included in a gel consisting of water and
HPMC (1% by mass). After moderate stirring, the distribution is
carried out.
EXAMPLE 4
[0044] 600 g of polylactic acid are cryoground to a final particle
size of between 20 and 100 .mu.m, with a median at 40 .mu.m. These
microparticles are distributed at a rate of 100 mg per vial.
[0045] 6.5 kg of freeze-drying medium are manufactured by
dissolving 97.5 g of sodium CMC, 276.25 g of apyrogenic mannitol,
and 6.5 g of polysorbate 80 in qs 6.5 liters of water for
injection. This medium is distributed at a rate of 1 g per
vial.
[0046] Trials were carried out on animals (hairless mice and New
Zealand rabbits) with the products of Examples 1 to 4. The results
are identical, and during the first two months, and from the eighth
day after the injection, the appearance of giant cells surrounding
in a network the crystals of polylactic acid is observed followed
by their transformation by creation of a fibrosis which
reconstitutes the subcutaneous tissue.
* * * * *