U.S. patent application number 15/214983 was filed with the patent office on 2016-11-10 for composition comprising hyaluronic acid and mepivacaine.
The applicant listed for this patent is Teoxane. Invention is credited to Francois Bourdon, Stephane Meunier.
Application Number | 20160325021 15/214983 |
Document ID | / |
Family ID | 51570796 |
Filed Date | 2016-11-10 |
United States Patent
Application |
20160325021 |
Kind Code |
A1 |
Bourdon; Francois ; et
al. |
November 10, 2016 |
COMPOSITION COMPRISING HYALURONIC ACID AND MEPIVACAINE
Abstract
Compositions and methods for the surface appearance of the skin
a subject are provided. An injectable composition comprising at
least hyaluronic acid or a salt thereof; and an effective amount of
at least mepivacaine or a salt thereof are provided. The hyaluronic
acid optionally has an average molecular weight ranging from 50,000
to 10,000,000 Daltons, and may be crosslinked hyaluronic acids,
non-crosslinked hyaluronic acids, or a combination, in some
embodiments. The compositions and methods of the present invention
are useful for treating and preventing the cutaneous signs of
chronological aging and/or induced by external factors such as
stress, air pollution, tobacco or prolonged exposure to ultraviolet
(UV) exposure, impaired surface appearance of the skin, impaired
viscoelastic or biomechanical properties of the skin, and/or the
long-lasting filling of volume defects of the skin.
Inventors: |
Bourdon; Francois;
(Gaillard, FR) ; Meunier; Stephane; (Thoiry,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Teoxane |
Geneve |
|
CH |
|
|
Family ID: |
51570796 |
Appl. No.: |
15/214983 |
Filed: |
July 20, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13954360 |
Jul 30, 2013 |
9421198 |
|
|
15214983 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61P 17/18 20180101;
A61K 2800/524 20130101; A61K 47/02 20130101; A61K 31/445 20130101;
A61P 23/00 20180101; A61K 9/0019 20130101; A61K 9/0024 20130101;
A61K 31/167 20130101; A61K 31/16 20130101; A61K 2800/91 20130101;
A61L 2300/402 20130101; A61P 1/02 20180101; A61L 27/12 20130101;
A61K 8/735 20130101; A61L 2400/06 20130101; A61P 17/02 20180101;
A61K 31/451 20130101; A61L 27/20 20130101; A61P 17/00 20180101;
A61K 31/728 20130101; A61P 19/00 20180101; A61P 17/16 20180101;
A61K 2800/75 20130101; A61Q 19/08 20130101; A61K 8/4926 20130101;
A61K 8/24 20130101; A61L 27/54 20130101; A61L 2300/204 20130101;
A61K 31/451 20130101; A61K 2300/00 20130101; A61K 31/728 20130101;
A61K 2300/00 20130101; A61K 31/167 20130101; A61K 2300/00 20130101;
A61K 31/445 20130101; A61K 2300/00 20130101 |
International
Class: |
A61L 27/54 20060101
A61L027/54; A61L 27/12 20060101 A61L027/12; A61K 9/00 20060101
A61K009/00; A61L 27/20 20060101 A61L027/20 |
Claims
1. A method comprising: treating (i) skin surface appearance, (ii)
cutaneous signs of chronological aging and/or signs induced by
external factors such as stress, air pollution, tobacco or
prolonged exposure to ultraviolet (UV) exposure, (iii) impaired
surface appearance of the skin, (iv) impaired viscoelastic or
biomechanical properties of the skin, (v) skin volume defects,
and/or (vi) deficiencies and defects in gingival architecture and
bony tissue by injecting a single sterile, injectable composition
into a patient in need thereof, wherein: the single sterile,
injectable composition comprises: (a) an effective amount of
hyaluronic acid or a salt thereof; and (b) mepivacaine or a salt
thereof as an anesthetic agent at a concentration ranging from 0.05
to 3 wt % of an overall weight of the single, sterile injectable
composition.
2. The method according to claim 1, wherein the method further
comprises administering a balanced salt solution, concurrently with
the single, sterile injectable composition.
3. The method according to claim 1, wherein the hyaluronic acid is
selected from the group consisting of crosslinked hyaluronic acids,
non-crosslinked hyaluronic acids, and a mixture thereof.
4. The method according to claim 2, wherein the salt of mepivacaine
is chlorhydrate mepivacaine.
5. The method according to claim 4, wherein the single, sterile
injectable composition further comprises an effective amount of
lidocaine or a salt thereof as a second anesthetic agent, lidocaine
or the salt thereof being present in the single, sterile injectable
composition at a ratio ranging from 0.1:1 to 1:1 of lidocaine to
mepivacaine or the salt thereof.
6. The method according to claim 2, wherein the balanced salt
solution is a phosphate saline buffer.
7. The method according to claim 1, wherein the single sterile
injectable composition further comprises a balanced salt solution
that is a phosphate saline buffer.
8. The method according to claim 7, wherein the hyaluronic acid has
an average molecular weight ranging from 50,000 to 10,000,000
Daltons.
9. The method according to claim 8, wherein the hyaluronic acid
comprises crosslinked and non-crosslinked hyaluronic acid at a
ratio of 1:1 to 1:0.02 of crosslinked to non-crosslinked hyaluronic
acid in the single, sterile injectable composition.
10. The method according to claim 9, wherein mepivacaine or salt
thereof is present at a concentration of 0.3 wt % of the overall
weight of the single, sterile injectable composition.
11. The method according to claim 10, wherein the hyaluronic acid
or the salt thereof comprises crosslinked hyaluronic acids.
Description
FIELD OF INVENTION
[0001] The present invention relates to the field of sterile and
injectable compositions comprising hyaluronic acid or a salt
thereof, and especially soft tissue filler compositions, for in
particular the augmentation and/or repair of soft tissue, including
periodontal tissue, and especially for treatment of defects and
imperfections of keratin materials, like the skin. The invention is
also directed to related methods.
BACKGROUND OF THE INVENTION
[0002] There have been efforts to develop compositions useful to
correct defects in skin such as scars and wrinkles or to augment
the tissue of a subject in order to improve the appearance of the
skin, particularly facial skin. The principal method employed to
correct such defects involves injecting a filler composition into
the dermal layer of the skin proximate to the effect or desired
tissue augmentation.
[0003] The hyaluronic acid is the major component of the
extracellular matrix (ECM). It is thus found in large quantities
mainly in the skin. It is also the major physiological component of
the articular cartilage matrix and is particularly abundant in
synovial fluid.
[0004] Accordingly, the hyaluronic acid, in its acid or salt form,
is a biomaterial largely used as injectable filler material for
tissue engineering application and especially for augmentation of
dermal tissue or other soft tissue like gingival tissue.
[0005] Hyaluronic acid is a linear non-sulfated glycosaminoglycan
composed of repeating units of D-glucuronic acid and
N-acetyl-D-glucosamine (Tammi R., Agren U M., Tuhkanen A L., Tammi
M. Hyaluronan metabolism in skin. Progress in Histochemistry &
Cytochemistry 29 (2): 1.-81, 1994).
[0006] In the skin, hyaluronic acid is primarily synthesized by
dermal fibroblasts and epidermal keratinocytes (Tammi R., cited
above). Through its residues bearing a negative charge, hyaluronic
acid acts as a water pump for maintaining the elasticity of the
skin.
[0007] In addition, the ECM is a dynamic structure with a
structural and regulatory role for the tissues. The ECM is composed
of collagen and elastin and also fundamental substance, mainly
water, minerals and proteoglycans. This matrix gives to the skin
its turgor and mechanical properties of firmness, elasticity and
tone.
[0008] Regarding the skin, it is noticed that, with age, the amount
of hyaluronic acid and its degree of polymerization decreases,
resulting in a decrease in the amount of water retained in the
connective tissue.
[0009] Meanwhile, ECM components are degraded, mainly by
endopeptidase type enzymes called matrix metalloproteinases or
MMPs.
[0010] Finally, decreases in cellular defenses increase damage and
disorders induced by external stresses such oxidative stress.
[0011] The skin is then subjected to an aging process leading to
the appearance of defects and blemishes of keratinous substances,
in particular of the skin.
[0012] In the field of wrinkle fillers, gels consisting mainly of
hyaluronic acid, the case arising chemically crosslinked, are
injected intradermally to fill the depression dug by the ride. The
crosslinking can increase the persistence of the product within the
dermis. Such gels based on hyaluronic acid, if necessary
crosslinked, allow a reduction of wrinkles by the mechanical effect
of the filler resulting from the vacuum skin wrinkle.
[0013] However, it is known that the injection of such gels often
produces a painful sensation for the patient, this sensation being
further exacerbated more the gel is highly viscous and/or
elastic.
[0014] Today, so as to overcome this technical problem, the main
fillers based on hyaluronic acid are available with a local
anesthetic agent to ensure greater patient comfort. This local
anesthetic agent is only lidocaine, with a dosage of about
0.3%.
[0015] However, it is known that lidocaine may display the
disadvantage, regarding its vasodilatory properties, to imply a too
rapid absorption by the patient's body and sometimes an exacerbated
occurrence of hematoma which are, for obvious aesthetic reasons, to
be avoided as much as possible. A solution to overcome the
above-mentioned problems may consist to implement the lidocaine in
association with a vasoconstrictor, in particular epinephrine (J.
Endod. 2013 May; 39(5):597-9). However, the presence of a
vasoconstrictor like epinephrine may require adding a preservative
which isn't always inert with respect to the patient and may
conduct to allergies.
[0016] Therefore, it remains a need to develop gels consisting
mainly of hyaluronic acid, the case arising chemically crosslinked,
which overcomes the above-mentioned technical problems of the
painful sensation for the patient during the injection and which
also do not involve any problem of allergies nor exacerbated
occurrence of hematoma.
SUMMARY OF INVENTION
[0017] According to a first aspect, the invention relates to a
method comprising at least the administering by injection to a
patient in need thereof of:
[0018] (a) at least an efficient amount of hyaluronic acid or a
salt thereof; and
[0019] (b) at least an efficient amount of mepivacaine or a salt
thereof as anesthetic agent,
[0020] said mepivacaine being administered before or concurrently
with the hyaluronic acid.
[0021] According to specific aspect, the method of the invention is
intended to soft tissue augmentation.
[0022] The target tissue may be skin but also gingival tissue.
[0023] More particularly, the present method may be efficiently
used (i) for preventing and/or treating the surface appearance of
the skin.
[0024] The present method may thus advantageously be used (ii) to
prevent and/or treat cutaneous signs of chronological aging and/or
induced by external factors such as stress, air pollution, tobacco
or prolonged exposure to ultraviolet (UV) exposure, (iii) to
prevent and/or treat impaired surface appearance of the skin, (iv)
to prevent and/or treat impaired viscoelastic or biomechanical
properties of the skin and/or (v) for the long-lasting filling of
volume defects of the skin, and in particular the filling of
wrinkles.
[0025] Furthermore, the method of the invention may be
advantageously also used for treating sites of deficiencies and
defects in gingival architecture and contour and bony tissue such
as occur with teeth loss, increase in age, periodontal disease and
disorders, periodontal trauma and after tooth implants, for the
enhancement of fit and function of dental prosthetics including but
not limited to implants, crown, bridges . . . .
[0026] According to another embodiment, the method of the invention
is also useful for cartilage regeneration.
[0027] According to another embodiment, the method of the invention
may be used as a treatment for arthritis.
[0028] At last, the hyaluronic acid is a thick transparent liquid
similar to the natural fluid located in eyes. Accordingly, it is
already proposed for maintaining eyes fluid volume during surgery.
Thus the method of the invention is also useful in most ophthalmic
intraocular surgeries, including cataract extraction, Intraocular
Lens (IOL) insertion and removal, corneal surgery, glaucoma
surgery, trauma surgery, ocular plastic surgery and muscle
surgery.
[0029] According to a second aspect, the invention relates to a
sterile and injectable composition, more particularly a soft tissue
filler composition, comprising an effective amount of at least
hyaluronic acid or a salt thereof and including an effective amount
of at least mepivacaine or a salt thereof as anesthetic agent.
[0030] Finally, according to another aspect, the invention relates
to a method of preparing a sterile and injectable composition, more
particularly a soft tissue filler composition, the method
comprising at least the steps of:
[0031] a) providing at least one gel of a hyaluronic acid or a salt
thereof, said hyaluronic acid being selected under a crosslinked
hyaluronic acid form, a non-crosslinked hyaluronic acid form or a
mixture thereof;
[0032] b) adding to said gel of hyaluronic acid at least
mepivacaine or a salt thereof as anesthetic agent; and
[0033] c) sterilizing the mixture obtained in step b).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] According to a first aspect, the invention relates to a
method comprising at least the administering by injection to a
patient in need thereof:
[0035] (a) at least an efficient amount of hyaluronic acid or a
salt thereof; and
[0036] (b) at least an efficient amount of mepivacaine or a salt
thereof as anesthetic agent,
[0037] said mepivacaine being administered before or concurrently
with the hyaluronic acid.
[0038] The inventors have indeed found that a method according to
the invention may constitute a viable alternative to current
methods for in particular preventing and/or treating the surface
appearance of the skin which consider the implementation of
hyaluronic acid with lidocaine but also (i) for treating sites of
deficiencies and defects in gingival architecture and contour and
bony tissue, (ii) for ophthalmic intraocular surgeries, (ii) for
the regeneration of the cartilage and (iv) in the treatment of
arthritis.
[0039] Firstly, in contrast to lidocaine, mepivacaine do not
displays significant vasodilatory properties than lidocaine.
[0040] Furthermore, mepivacaine has a pKa of 7.6 whereas lidocaine
has a pKa of 7.9. Therefore, mepivacaine having a pKa lower than
lidocaine, it displays a better lipid solubility which improves its
diffusion through lipid barriers. Therefore, due to the fact that
mepivacaine may be absorbed more rapidly than lidocaine,
mepivacaine is therefore appropriate to better prevent a painful
sensation during the injection.
[0041] But above all, the inventors have unexpectedly observed than
a filler compositions according to the invention, i.e including
mepivacaine as anesthetic agent, may be sterilized without
significantly affecting the stability of the gel of hyaluronic
acid.
[0042] It is indeed known than the gels of hyaluronic acid are
particularly sensible to the heat treatment like required for their
sterilization and that this low stability may be increased by the
presence of further materials like the anesthetic agent.
Unexpectedly, this indesirable phenomenon is significantly lowered
with mepicavaine comparatively to lidocaine, as shown in the
following examples 1 and 2. In addition, the inventors have shown
that a composition according to the invention further complies with
the requirements in terms of stability in time, as hereinafter
shown in example 3.
[0043] According to the inventors, the manifestation of these
above-mentioned advantageous effects within soft tissue filler
compositions comprising hyaluronic acid was not known.
[0044] Preferably, the hyaluronic acid or a salt thereof is
administered concurrently with the mepivacaine or a salt
thereof.
[0045] Preferably, the administering by injection is an
intraepidermal and/or intradermal and/or subcutaneous injection.
However it may be also administered by a gingival, articular and
intraocular road.
[0046] Hyaluronic Acid
##STR00001##
[0047] As above-mentioned hyaluronic acid (also called hyaluronan
or hyaluronate) is a linear non-sulfated glycosaminoglycan composed
of repeating units of D-glucuronic acid and N-acetyl-D-glucosamine
(Tammi R., Agren U M., Tuhkanen A L., Tammi M. Hyaluronan
metabolism in skin. Progress in Histochemistry & Cytochemistry
29 (2): 1.-81, 1994).
[0048] In the skin, hyaluronic acid is primarily synthesized by
dermal fibroblasts and epidermal keratinocytes (Tammi R., cited
above). Through its residues bearing a negative charge, hyaluronic
acid acts as a water pump for maintaining the elasticity of the
skin.
[0049] As above-mentioned, the present invention considers the
implementation of hyaluronic acid as such but also a salt
thereof.
[0050] Therefore, the hyaluronic acid in accordance with the
invention may be more particularly chosen from physiologically
acceptable salts such as the sodium salt, the potassium salt, the
zinc salt, the silver salt and mixtures thereof, preferably the
sodium salt.
[0051] Preferably, the hyaluronic acid according to the invention
has a high average molecular weight, preferably ranging from 50 000
to 10 000 000 Daltons, preferably from 500 000 to 4 000 000
daltons.
[0052] One particularly preferred salt of hyaluronic acid is sodium
hyaluronate (NaHA).
[0053] As above-mentioned, hyaluronic acid is administered by
injection in an effective amount.
[0054] An "effective amount" of hyaluronic acid is an appropriate
amount to obtain the desired technical effect, notably to have a
visible result on the surface appearance of the skin. In
particular, an effective amount of hyaluronic acid is an
appropriate amount of hyaluronic acid for a good filling of volume
defects of the skin, and in particular the filling of wrinkles.
[0055] Adjusting the amount of hyaluronic acid falls within the
competence of a person skilled in the art.
[0056] Advantageously, the hyaluronic acid or a salt thereof in a
method according to the invention is present in a solution.
[0057] In this regard, an effective amount of hyaluronic acid may
range from 0.1 to 5% by weight, preferably from 1 to 3% by weight,
relative to the total weight of said solution comprising the
hyaluronic acid or a salt thereof.
[0058] According to a particular embodiment, the hyaluronic acid
may be present under an uncrosslinked form.
[0059] For the purpose of the present invention, the term
"uncrosslinked" or "non-crosslinked" is understood in the context
of the present invention to mean a gel of hyaluronic acid which is
not crosslinked or slightly crosslinked, that is to say a gel
having a phase-shift angle .delta., measured under dynamic rheology
conditions at 1 Hz, that is greater than 40.degree. when subjected
to a stress above 1 Pa.
[0060] According to another particular embodiment, the hyaluronic
acid may be present under a crosslinked form.
[0061] According to another particular embodiment, the hyaluronic
acid may be present under crosslinked and non-crosslinked
forms.
[0062] In this regard, the weight ratio "crosslinked hyaluronic
acid/non-crosslinked hyaluronic acid" is preferably greater than
1.
[0063] According to a particular embodiment, the solution
comprising the hyaluronic acid and being intended to be
administered may comprise: [0064] from 50% to 99% by weight, more
preferably 70% to 95% by weight of hyaluronic acid present in the
form of a crosslinked gel, [0065] from 1% to 50% by weight,
preferably 5% to 30% by weight, of hyaluronic acid present in the
free form or a physiologically acceptable salt thereof,
[0066] the ratio between the weight of the crosslinked hyaluronic
acid gel and the weight of the free hyaluronic acid being between
1:1 and 1:0.02.
[0067] When the hyaluronic acid is crosslinked, said crosslinked
hyaluronic acid has preferably a degree of modification ranging
from 0.1 to 20%, preferably from 0.4 to 10%.
[0068] By "degree of modification" is meant, in the sense of the
present invention, the ratio between the number of moles of
crosslinking agent attached to the hyaluronic acid and the number
of moles of hyaluronic acid forming said crosslinked hyaluronic
acid gel. This value may be measured by a NMR analysis 1D 1H of the
crosslinked gel.
[0069] By "number of moles of hyaluronic acid" is meant the number
of moles of repeating disaccharide units of the hyaluronic acid, a
disaccharide unit being composed of D-glucuronic acid and
D-N-acetylglucosamine linked together by alternated beta-1,4 and
beta-1,3 glycosidic bonds.
[0070] This degree of modification may be notably appreciated as
disclosed herein after.
[0071] Thus, the characterizing of the degree of modification of
the hyaluronic acid is carried out by spectroscopy by NMR
(spectrometer Bruker Avance 1 operating at 400 MHz (.sup.1H)).
[0072] For BDDE, the degree of modification is obtained by
integrating the signal of .sup.1H NMR N-acetyl group
(.delta..apprxeq.2 ppm) present in the hyaluronic acid and a signal
present in the crosslinking agent (two --CH2- groups,
.delta..apprxeq.1.6 ppm). The ratio of integrals of these two
signals (crosslinking agent/NaHA) relates to the degree of
modification, after correcting the number of protons attached to
each signal.
Degree of modification = [ Integral .delta. H 1.6 4 ] [ Integral
.delta. H 2.0 3 ] ##EQU00001##
[0073] Crosslinking Agent
[0074] The term "crosslinking agent" is understood to mean any
compound capable of inducing a crosslinking between the various
chains of the hyaluronic acid.
[0075] The choice of this crosslinking agent clearly falls within
the competence of a person skilled in the art.
[0076] A crosslinking agent in accordance with the invention may be
chosen from difunctional or multifunctional epoxy crosslinking
agents but also polyamines like for example hexamethylenediamine
(HMDA) or endogeneous polyamines.
[0077] By "endogenous polyamine" within the meaning of the present
invention is meant a polyamine naturally present in living
organisms and particularly the human body. As representative of
endogenous polyamines, may be especially mentioned those cited in
eukaryotes animals, such as the putrescine (or 1,4-diaminobutane),
the spermidine (or 1,8-diamino-5-azaoctane) and the spermine
(1,12-diamino-5,9-diazadodecane), preferably the spermine.
[0078] More particularly, a crosslinking agent according to the
present invention may be preferably selected from the group
consisting of 1,4-butanediol diglycidyl ether (BDDE),
1,4-bis(2,3-epoxypropoxy)butane, 1,4-bisglycidyloxybutane,
1,2-bis(2,3-epoxypropoxy)ethylene and
1-(2,3-epoxypropyl)-2,3-epoxycyclohexane, an endogenous polyamine,
and mixtures thereof.
[0079] Preferably, a crosslinking agent according to the invention
is 1,4-butanediol diglycidyl ether (BDDE).
[0080] In the particular embodiment wherein the crosslinking agent
is a polyamine, and more particularly an endogenous polyamine, the
coupling reaction with the hyaluronic acid may be carried out in
the presence of at least one activator, and the case arising
associated with at least one auxiliary coupling.
[0081] In this regard, the activator may be selected from
water-soluble carbodiimides such as
1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC),
1-ethyl-3-(3-25 trimethylaminopropyl)carbodiimide hydrochloride
(ETC), 1-cyclohexyl-3-(2-morphilinoethyl)carbodiimide (CMC) and a
salt thereof, and mixtures thereof, preferably is represented by
the EDC.
[0082] Regarding the coupling auxiliary, when it is present, it may
be selected from N-hydroxy succinimide (NHS),
N-hydroxybenzotriazole (HOBt),
3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazole (HOOBt),
1-hydroxy-7-7azabenzotriazole (HAt) and N-hydroxysylfosuccinimide
(sulfo NHS), and mixtures thereof, preferably is represented by the
HOBt.
[0083] The crosslinking agent is implemented in an effective
amount.
[0084] An "effective amount" of crosslinking agent is an
appropriate amount to obtain an appropriate degree of crosslinking
of hyaluronic acid.
[0085] Adjusting the amount of crosslinking agent falls within the
competence of a person skilled in the art.
[0086] Advantageously, an effective amount of crosslinking agent
may range from 0.05 to 15% by weight relative to the total weight
of the hyaluronic acid or a salt thereof.
[0087] Advantageously, when the hyaluronic acid is crosslinked, and
when the crosslinking agent is BDDE, the amount in mole ratio of
nBDDE/n hyaluronic acid may range between 0.01 and 0.5, preferably
between 0.04 and 0.25.
[0088] Anesthetic Agent
[0089] An anesthetic agent according to the present invention has
the particular advantage to reduce or eliminate the pain sensation
experienced by the patient during and/or following the
injection.
[0090] Moreover, an anesthetic agent according to the present
invention is chosen among compounds which do not raise risk of
incompatibility with other compounds used in a composition
according to the invention, especially with hyaluronic acid.
[0091] As above-mentioned, an anesthetic agent according to the
present invention is mepivacaine, or a salt thereof.
[0092] The mepivacaine is a local anesthetic of the amino-amids
family of the formula (I):
##STR00002##
[0093] The mepivacaine is notably sold under the name
Carbocaine.RTM. by the company Cook-Waite.
[0094] The mepivacaine is a molecule having a good stability. Its
main degradation product is 2,6-dimethylaniline. Mepivacaine is a
molecule containing a chiral center (asymmetric carbon). Thus,
there are the R and S enantiomers. In the following examples, it is
considered the racemic mixture of the two forms of mepivacaine.
[0095] Preferably, the mepivacaine is under a salt form, and more
particularly the salt of mepivacaine is chlorhydrate
mepivacaine.
[0096] As above-mentioned, the mepivacaine or a salt thereof is
administered by injection in an effective amount.
[0097] An "effective amount" of mepivacaine or a salt thereof is an
appropriate amount to effectively reduce or eliminate the pain
sensation experienced by the patient during and/or following the
injection.
[0098] Adjusting the amount of mepivacaine or a salt thereof falls
within the competence of a person skilled in the art.
[0099] Advantageously, the mepivacaine or a salt thereof in a
method according to the invention is present in a solution.
[0100] In this regard, an effective amount of the mepivacaine or a
salt thereof may range from 0.05 to 3% by weight relative to the
weight of the solution comprising said mepivacaine or a salt
thereof.
[0101] The method may further comprises the administration, the
case arising joint to the mepivacaine, of at least one additional
anesthetic agent or a salt thereof different from the
mepivacaine.
[0102] This further anesthetic agent may be in particular selected
from ambucaine, amolanone, amylocaine, benoxinate, benzocaine,
betoxycaine, biphenamine, bupivacaine, butacaine, butamben,
butanilicaine, butethamine, butoxycaine, carticaine,
chloroprocaine, cocaethylene, cocaine, cyclomethycaine, dibucaine,
dimethysoquine, dimethocaine, diperodone, dycyclonine, ecgonidine,
ecgonine, ethyl chloride, etidocaine, beta-eucaine, euprocine
fenalcomine, formocaine, hexylcaine, hydroxytetracaine, isobutyl
p-aminobenzoate, leucinocaine mesylate, levoxadrol, lidocaine,
meprylcaine, metabutoxycaine, methyl chloride, myrtecaine,
naepaine, octacaine, orthocaine, oxethazaine, parethoxycaine,
phenacaine, phenol, piperocaine, piridocaine, polidocanol,
pramoxine, prilocaine, procaine, propanocaine, proparacaine,
propipocaine, propoxycaine, pseudococaine, pyrrocaine, ropivacaine,
salicyl alcohol, tetracaine, tolycene, trimecaine, zolamine, or a
salt thereof, and a mixture thereof.
[0103] Preferably, this additional anesthetic agent is lidocaine or
a salt thereof.
[0104] According to a first embodiment, the additional anesthetic
agent is administered alone, previous to the hyaluronic acid and
the mepivacaine or a salt thereof.
[0105] According to a second embodiment, the additional anesthetic
agent is administered together with the mepivacaine or a salt
thereof, previous to the hyaluronic acid or a salt thereof.
[0106] According to a third embodiment, the additional anesthetic
agent is administered together with the mepivacaine or a salt
thereof and the hyaluronic acid or a salt thereof.
[0107] In the specific embodiment where both anesthetic agents are
contained in a same composition, they may be present therein in a
ratio "mepivacaine/lidocaine" 1:1, preferably a ratio 1:0.1.
[0108] Balanced Salt Solution
[0109] According to a particular embodiment, the method according
to the invention may further comprise at least a step of
administering by injection to said patient of (c) at least a
balanced salt solution, concurrently with said hyaluronic acid
and/or mepivacaine, preferably with mepivacaine.
[0110] The implementation of this balanced salt solution is
particularly interesting in that it allows still reducing the
injection pain (see Farley J. S. et al., Regional Anesthesia A.,
1994, Vol. 19: 48).
[0111] Preferably, said balanced salt solution is a phosphate
buffered saline, and more particularly is a phosphate buffered
saline and particularly a KH.sub.2PO.sub.4/K.sub.2HPO.sub.4 saline
buffer.
[0112] According to a particular embodiment, said balanced salt
solution may further comprise at least one compound selected from
the group consisting of an alpha-lipoic acid; N-Acetyl-L-cysteine;
reduced glutathion; amino acid such as L-Arginine, L-Isoleucine,
L-Leucine, monohydrated L-Lysine, Glycine, L-Valine, L-Threonine,
L-Proline; pyridoxine Hydrochloride; dehydrated zinc acetate;
pentahydrates copper sulphate, and mixture thereof.
Composition According to the Invention
[0113] As above-mentioned, the present invention also relates to a
sterile and injectable composition, in particular a soft filler
composition, comprising an effective amount of at least hyaluronic
acid or a salt thereof and including an effective amount of at
least mepivacaine or a salt thereof as anesthetic agent.
[0114] By "sterile", in the sense of the present invention, is
meant an environment capable of guaranteeing to the considered
compounds in a composition according to the invention safety
requirements for the administration routes such as above-mentioned,
notably into or through the skin. Indeed, for obvious reasons, it
is essential that a composition according to the invention be
devoid of any contaminant body capable of initiating an undesirable
side reaction at the host organism.
[0115] The hyaluronic acid, the crosslinking agent, and the
anesthetic agent(s) are such as above-mentioned.
[0116] Regarding the hyaluronic acid, a composition according to
the invention may comprise from 0.1 to 5% by weight, preferably
from 1 to 3% by weight of hyaluronic acid, relative to the total
weight of said composition.
[0117] According to a particular embodiment, as above-mentioned,
the hyaluronic acid may be present in crosslinked and
non-crosslinked forms.
[0118] In this regard, the ratio "crosslinked hyaluronic
acid/non-crosslinked hyaluronic acid" is preferably greater than
1.
[0119] More particularly, a composition according to the invention
may comprise: [0120] from 50% to 99% by weight, more preferably 70%
to 95% by weight of hyaluronic acid present in the form of a
crosslinked gel, [0121] from 1% to 50% by weight, preferably 5% to
30% by weight of hyaluronic acid present in a non-crosslinked
form,
[0122] the ratio between the weight of the crosslinked hyaluronic
acid gel and the weight of the non-crosslinked hyaluronic acid
being between 1:1 and 1:0.02.
[0123] Regarding the anesthetic agent(s), a composition according
to the invention may comprise from 0.01% to 5% by weight,
preferably from 0.05% to 3% by weight of anesthetic agent(s), based
on the total weight of said composition.
[0124] By its injectable character, a composition according to the
invention necessarily comprises a physiologically acceptable
medium.
[0125] A "physiologically acceptable medium" means a medium devoid
of toxicity and compatible with the injection and/or the
application of the composition such as considered in the present
invention.
[0126] The composition may comprise a solvent or a mixture of
physiologically acceptable solvents.
[0127] The composition may comprise a physiologically acceptable
aqueous medium.
[0128] As an aqueous medium suitable for the invention, may be for
example mentioned water.
[0129] As isotonic agents suitable for the preparation of a
composition according to the invention, it may be mentioned sugars
and sodium chloride.
[0130] According to a particular embodiment, a composition
according to the invention may further comprise at least a balanced
salt solution such as above-mentioned.
[0131] According to a particular embodiment, a composition
according to the invention may further comprise at least one
compound selected from the group consisting of an alpha-lipoic
acid; N-Acetyl-L-cysteine; reduced glutathion; amino acid such as
L-Arginine, L-Isoleucine, L-Leucine, monohydrated L-Lysine,
Glycine, L-Valine, L-Threonine, L-Proline; pyridoxine
Hydrochloride; dehydrated zinc acetate; pentahydrates copper
sulphate, and mixture thereof.
[0132] A composition according to the invention may comprise, in
addition to the above-mentioned compounds, at least one additional
compound compatible with use in the field of soft tissue filler
composition compositions.
[0133] In this regard, additional compounds which may be
implemented in a composition according to the invention may be
chosen from copper salt, alpha-lipoic acid, acetylated derivative
of cysteine or mixture thereof.
[0134] The amounts of these additional compounds depend on the
nature of the compound in question, the desired effect, and the
destination of the composition according to the invention.
[0135] These parameters belong to the general skill of the art.
[0136] A composition further comprising at least one copper salt
may preferably comprises said copper salt in an amount ranging from
0.1 to 50 ppm based on the total weight of said composition.
[0137] A composition further comprising at least one alpha-lipoic
acid preferably comprises said alpha-lipoic acid in an amount
ranging from 0.5 to 10,000 ppm, preferably from 5 to 100 ppm of
alpha-lipoic acid, based on the total weight of said
composition.
[0138] A composition further comprising at least one acetylated
derivative of cysteine preferably comprises said acetylated
derivative of cysteine in an amount ranging from 0.5 to 10,000 ppm
based on the total weight of said composition.
[0139] Among the other additional compounds which may be used in
the present invention, may be mentioned antioxidants, amino acids,
vitamins, minerals, nucleic acids, co-enzymes, adrenal derivatives,
and mixtures thereof, said additional compounds being distinct from
those indicated above.
[0140] As an antioxidant, it may be mentioned glutathione, ellagic
acid, spermine, resveratrol, retinol, L-carnitine, polyols,
polyphenols, flavonols, theaflavins, catechins, caffeine,
ubiquinol, ubiquinone, and mixture thereof.
[0141] As amino acid, there may be mentioned arginine, isoleucine,
leucine, lysine, glycine, valine, threonine, proline, methionine,
histidine, phenylalanine, tryptophan, and mixture thereof.
[0142] As vitamins and their derivatives, may be mentioned vitamins
E, A, C, B, especially vitamins B6, B8, B4, B5, B9, B7, B12, and
pyridoxine better.
[0143] As minerals, mention may in particular be made of zinc
salts, magnesium salts, calcium salts, potassium salts, manganese
salts, sodium salts, and mixtures thereof.
[0144] As nucleic acids, may be mentioned in particular the
derivatives of adenosine, cytidine, guanosine, thymidine, the
cytodine and mixture thereof.
[0145] As co-enzymes, may be cited coenzyme Q10, CoA, NAD, NADP,
and mixtures thereof.
[0146] As an adrenaline derivatives, may be mentioned adrenaline,
noradrenaline.
[0147] In addition, a composition according to the invention may
further comprise any excipient commonly used in the technical
field, such as for example mono- and/or di-hydrated
dihydrogenophosphate sodium and sodium chloride, in physiological
concentrations.
[0148] The amounts of additional active agents and/or excipients of
course depend on the nature of the compound in question, the
desired effect, and the destination of the composition according to
the invention.
[0149] According to a particular embodiment, a composition
according to the invention may have a complex viscosity .eta.* of
between about 5 Pa*s and about 450 Pa*s when measured at about 1
Hz.
[0150] According to a particular embodiment, a composition
according to the invention made up of crosslinked hyaluronic acid
may have a viscosity between 200 and 2000 Pas, preferably between
1000 and 1800 Pas.
[0151] The viscoelastic properties of a composition according to
the invention may be measured using a rheometer (notably Haake
RS6000) with a cone/plate geometry (1.degree. cone angle/35 mm
diameter plate). A strain scan is carried out and the elastic
modulus G' (in Pa) and the phase-shift angle .delta. (in .degree.)
are measured for a stress of 5 Pa.
[0152] Method for Preparing a Sterile and Injectable Composition
According to the Invention
[0153] As above-mentioned, the present invention also relates to a
method of preparing a sterile and injectable composition, more
particularly a soft tissue filler composition, the method
comprising at least the steps of:
[0154] a) providing at least one gel of a hyaluronic acid or a salt
thereof, said hyaluronic acid being selected under a crosslinked
hyaluronic acid form, a non-crosslinked hyaluronic acid form or a
mixture thereof;
[0155] b) adding to said gel of hyaluronic acid at least
mepivacaine or a salt thereof as anesthetic agent; and
[0156] c) sterilizing the mixture obtained in step b).
[0157] According to a preferred embodiment, the mepivacaine or a
salt thereof is added to an injectable form of hyaluronic acid.
[0158] In other words, the gel of hyaluronic acid considered in
step a) already exhibits a concentration in hyaluronic acid, in
crosslinking agent residues if presents, and physiological and/or
pH conditions which are compatible with an injectable use, in
particular in the fields of the applications considered above.
[0159] By this way, the risks affecting the stability of the
hyaluronic acid in the mixture hyaluronic acid and mepivacaine by
imposing additional purification steps, such as above-defined, are
significantly reduced.
[0160] The mixture advantageously undergoes only one sterilization
step. This step is preferably carried out on the mixture already
packaged in its delivery device, usually a syringe, as herein after
defined.
[0161] Advantageously, the sterilization step can be performed by
thermal means.
[0162] Advantageously, the sterilization is carried out at a
temperature ranging from 120 to 140.degree. C.
[0163] In particular, the sterilization step can be performed in an
autoclave (moist heat) T.degree. C..gtoreq.121.degree. C., to
obtain a F0>15 (sterilizing value).
[0164] In this regard, and as above-mentioned, a composition
according to the invention is particularly advantageous in that it
displays a very interesting high resistance to this sterilization
step.
[0165] Indeed, as shown in the examples 1 and 2, the loss of G'
generated by sterilization for a composition according to the
invention is less than for a composition comprising lidocaine
instead of mepivacaine.
[0166] According to a particular embodiment, the method for
preparing a gel of hyaluronic acid according to the invention may
further comprise a step d) consisting of adding an additional
anesthetic agent or a salt thereof, different from the mepivacaine
or a salt thereof, such as above-mentioned, preferably lidocaine or
a salt thereof, said step d) being carried out before,
simultaneously and/or after the step b).
[0167] When the gel considered in step a) comprises a crosslinked
hyaluronic acid form, this last may be obtained beforehand from an
uncrosslinked form of hyaluronic acid.
[0168] The reticulation may be performed by a conventional way with
at least one crosslinking agent, such above-mentioned.
[0169] The aqueous mixture comprising the crosslinking agent and
the hyaluronic acid to crosslink is advantageously homogenized
before performing the crosslinking.
[0170] The purpose of this operation is more particularly for the
hyaluronic acid or a salt thereof in the aqueous medium to be
hydrated and homogenized perfectly and thus to help to optimize the
properties of the gel of hyaluronic acid expected. This step of
homogenization is more important when the hyaluronic acid has a
high molecular weight, because the hydration of such a compound
tends to result in the formation of a high-viscosity solution
within which the appearance of agglomerates is commonly
observed.
[0171] The purpose of this operation is also intended to homogenize
perfectly the crosslinking agent within the mixture so as to
subsequently assure a homogeneous crosslinking reaction.
[0172] The homogenization is considered to be satisfactory when the
solution obtained is uniformly coloured, with no agglomerates, and
has a uniform viscosity. The homogenization may advantageously be
carried out under mild operating conditions so as to prevent
degradation of the hyaluronic acid chains.
[0173] The duration of this homogenization step depends on the
nature of the hyaluronic acid or a salt thereof, and more
particularly the molecular weight and the concentration thereof, on
the operation conditions within the aqueous medium and on the
homogenizing device used, generally a device which allows a soft
mechanical agitation.
[0174] Preferably, a homogenization step may take place over a time
of less than 200 minutes, preferably less than 150 minutes, or even
between 15 and 100 minutes.
[0175] The purpose of the crosslinking reaction is to create
bridges between the hyaluronic acid chains making it possible to
obtain a dense solid three-dimensional network from a viscous
solution.
[0176] The particular conditions to be adopted in order to
stimulate the crosslinking reaction may depend on the molecular
weight of the hyaluronic acid, on the aqueous medium and on the
nature of the crosslinking agent. In general, this reticulation may
be achieved by bringing the mixture comprising the non crosslinked
hyaluronic acid and at least one crosslinking agent as
above-mentioned, into contact with a triggering element, or
stimulant, such as, for example by heating or exposure to UV, or
even by bringing said mixture into contact with a material of the
catalyst type.
[0177] The choice of such a triggering element falls within the
general knowledge of a person skilled in the art.
[0178] In the context of the present invention, this triggering
element is advantageously represented by an increase in temperature
imposed on the mixture "non-crosslinked hyaluronic acid/aqueous
medium/crosslinking agent".
[0179] A particularly suitable temperature for the crosslinking
reaction is between 35.degree. C. and 60.degree. C., preferably
between 45 and 55.degree. C., and better still between 48 and
52.degree. C.
[0180] The degree of crosslinking also depends on the crosslinking
time and of the temperature imposed on the mixture "non-crosslinked
hyaluronic acid/aqueous medium/crosslinking agent". The longer the
time is, the higher the degree of crosslinking will be, with
however an optimum not to be exceeded without running the risk of
degrading the hyaluronic acid.
[0181] Thus, at a temperature ranging from 35.degree. C. and
60.degree. C., the crosslinking reaction may be carried out over a
time ranging from 30 to 300 minutes, preferably 100 to 200 minutes,
and better still 150 to 190 minutes.
[0182] Preferably, the crosslinking conditions are adjusted to
obtain a degree of crosslinking such that the gel of crosslinked
hyaluronic acid formed is a viscous, viscoelastic gel, or even a
solid gel.
[0183] Stopping the crosslinking reaction requires exposing the
crosslinked gel or, during crosslinking, even the receptacle
containing it, to conditions propitious for stopping the
crosslinking or else to conditions capable of stopping the
formation of bonds between the various hyaluronic acid chains.
[0184] For example, with regard to the thermal conditions that will
be applied to stimulate the crosslinking process, the crosslinking
may be stopped: [0185] by simply removing the receptacle from the
thermostatted bath and cooling it until it returns to room
temperature; [0186] by placing the receptacle in a bath of cold
water, preferably at a temperature below room temperature, until
the temperature within said receptacle is close to room
temperature; or even [0187] by extracting the gel from said
receptacle.
[0188] According to a particular embodiment, the homogenization and
crosslinking may be carried out within a hermetic cavity delimited
at least partially by a deformable wall, preferably made within a
deformable pouch, which may be deformed at least manually by
palpation, such as described notably in WO 2010/131175.
[0189] The gel obtained at the end of the crosslinking step cannot
in general be injected directly, in particular because of its high
hyaluronic acid concentration and/or of the possible presence of
crosslinking agent residues or else because of its physiological
and/or pH conditions incompatible with use in the fields of
applications considered above.
[0190] Furthermore, some gels may especially have too high a
stiffness to be injected as such into a patient. Therefore, several
additional steps, known to those skilled in the art, can be carried
out to obtain an injectable hydrogel. More particularly, a step of
neutralizing and expanding this gel is required in order to give it
its implant qualities. The chains of the hyaluronic acid network
are then stretched and hydrated, while the pH is brought to that of
the dermis.
[0191] A step of protecting and redensifying the gel can also be
carried out for further improving the qualities of the implant,
according to the know-how of a person skilled in the art. The gel
must be physiologically formulated by virtue of the presence of
salts in equivalent amounts to those of the medium injected.
[0192] For even higher purity, an additional purification step may
also be carried out.
[0193] Advantageously, the mepivacaine or salt thereof and, the
case arising, additional anesthetic agent(s), is/are added at the
end of this protocol of preparation of an injectable form of
hyaluronic acid, just before the step of sterilization, such as
above-defined.
[0194] According to a particular embodiment, the hydrogel added of
mepicacaine and optionally of additional anesthetic agent(s), may
be used to fill syringes under controlled atmosphere conditions,
said syringes then possibly undergoing a sterilization step,
preferably a thermal sterilization step such as above-defined.
[0195] Administration of the Composition
[0196] A composition according to the invention can be injected
using any of the known methods in the art.
[0197] Particularly, a composition of the invention may be
administered by means of an injection device suitable for
intraepidermal and/or intradermally and/or subcutaneously.
[0198] A composition of the invention may also be administered by
means of an injection device suitable for gingival, articular
and/or intraocular regions.
[0199] The injection device, notably when a composition of the
invention is administered by means of an injection device suitable
for intraepidermal and/or intradermally and/or subcutaneously, may
be selected from a syringe, a set of microsyringes, a laser device,
a hydraulic device, an injection gun, a needleless injection
device, a rolling with microneedles.
[0200] Preferably, the injection device may be selected from a
syringe or a set of microsyringe.
[0201] In an alternative embodiment, the injection device can be
adapted to the technique of mesotherapy.
[0202] Mesotherapy is a treatment technique by intraepidermal
and/or intradermally and/or subcutaneously active(s)
product(s).
[0203] The administration intraepidermal and/or intradermally
and/or subcutaneously according to the invention is to inject a
composition of the invention in an epidermal region,
dermo-epidermal and/or dermal.
[0204] The injection device may comprise any conventionally used
injection such as hypodermic needle or cannula.
[0205] A needle or a cannula according to the invention can have a
diameter ranging between 18 and 34 G, preferably 25 to 32 G, and a
length varying from 4 to 70 mm, preferably 4 to 25 mm.
[0206] The needle or cannula is preferably disposable.
[0207] Advantageously, the needle or cannula is associated with a
syringe or other device capable of delivering through the needle or
cannula said injectable composition. According to one embodiment, a
catheter may be inserted between the needle/cannula and
syringe.
[0208] In known manner, the syringe can be operated manually by the
practitioner or by a syringe holder as guns.
[0209] Throughout the description, including the claims, the
expression "comprising a" should be understood as being synonymous
with "comprising at least one" unless specifically stated
otherwise.
[0210] The expressions "between . . . and . . . " and "ranging from
. . . to . . . " should be understood to mean that the limits are
inclusive, unless specified otherwise.
[0211] The following examples and figures are presented by way of
non-limiting illustration of the invention.
EXAMPLES
Material and Method
[0212] The protocol herein after defined regarding the measure of
the viscoelastic properties of a composition apply for the
following examples.
[0213] The viscoelastic properties of a composition are measured
using a rheometer (Haake RS6000) with a cone/plate geometry
(1.degree. cone angle/35 mm diameter plate). A strain scan is
carried out and the elastic modulus G' (in Pa) and the phase-shift
angle .delta. (in .degree.) are measured for a stress of 5 Pa.
Example 1
Protocol of Preparing a Composition According to the Invention
Implementing a Non Crosslinked Hyaluronic Acid and Analysis
Regarding its Stability to the Sterilization
[0214] 3 g of hyaluronic acid (1.5 MDa,) and 197 g of a phosphate
buffer (as defined in FR 2 979 539) are mixed.
[0215] The protocol of preparing is as follows:
1. tridimensional homogenization of the mixture "hyaluronic
acid+phosphate buffer" at room temperature in an airtight container
(Nalgene jar) for a minimum of 20 hours; 2. separating the obtained
non-crosslinked gel into 2 equivalent fractions (called hereinafter
fractions A1 and A2); 3. regarding fraction A1, adding to gel 1% by
weight of a solution of mepivacaine (30% by weight in phosphate
buffer medium) and 0.4% by weight of a solution of NaOH 1%; or 4.
regarding fraction A2, adding to gel 1% by weight of a solution of
lidocaine (30% by weight in phosphate buffer medium) and 0.4% by
weight of a solution of NaOH 1%; and 5. homogenization, packaging
in syringes 1 mL for injection, and autoclaving (F0>15).
[0216] Results:
[0217] Tables below gives the values of the elastic moduli G' (in
Pa) of the hydrogels obtained and of the extrusion force F(N).
TABLE-US-00001 F(N) at Dynamic 12.5 mm/min oscillatory Ser Schott 1
mL rheology Needle F = 5 Hz F = 1 Hz TSK HPC 30 Fraction A1 G' (Pa)
G' (Pa) G: 120347 Mepivacaine Non-sterilized 103.3 36.3 9 0.3%
Sterilized 45.0 9.6 9 Loss on 56.4 73.5 sterilization (in %)
[0218] The loss in sterilization for G' at F=5 Hz is calculated as
follows:
(103.3-45.0)/103.3=56.4 (en %)
TABLE-US-00002 F(N) at 12.5 mm/min Dynamic Ser Schott oscillatory 1
mL rheology Needle F = 5 Hz F = 1 Hz TSK HPC 30 Fraction A2 G' (Pa)
G' (Pa) G: 120347 Lidocaine 0.3% Non-sterilized 105.9 37.4 9
Sterilized 36.7 7.0 9 Loss on 65.4 81.2 sterilization (in %)
[0219] In view of the above, it therefore appears that the
stability to the sterilization step of a composition comprising
uncrosslinked hyaluronic acid is at least equivalent with
mepivacaine than with lidocaine.
[0220] The results are even significantly better with
mepivacaine.
Example 2
Protocol of Preparing a Composition According to the Invention
Implementing Crosslinked and Non Crosslinked Hyaluronic Acid and
Analysis Regarding its Stability to the Sterilization
[0221] 8 g of hyaluronic acid (4 MDa), 58.7 g of sodium hydroxide
(NaOH) 1% and 0.6 g of butanediol diglycidyl ether (BDDE) are
implemented. The crosslinking reaction is induced by an incubation
for 3 hours at 52.degree. C.
[0222] The protocol of preparing is as follows:
1. Homogenization of the mixture "hyaluronic acid+NaOH 1%" at room
temperature in an airtight and deformable container (pouch such as
considered in the patent application WO 2010/131175) during about
1H30 so as to obtain a perfectly homogeneous viscous solution; 2.
Adding the crosslinking agent (BDDE) into the receptacle and new
homogenization at room temperature for about 20 min; 3. Incubation
for 3 hours at 52.degree. C. of the receptacle containing the
viscous solution of "hyaluronic acid/sodium hydroxide 1%/BDDE" so
as to initiate the crosslinking step; 4. Neutralization, swelling
and homogenizing the obtained solid (solution of crosslinked
hyaluronic acid) in a phosphate buffer (as defined in FR 2 979
539), and adding a non-crosslinked gel containing 4 g of HA 4 MDa
and 668 g of supplemented phosphate buffer, so as to obtain a
hydrogel having 11 mg/g in hyaluronic acid, at pH around
neutrality; 5. Purification by dialysis during 48 hours, and then
collecting the purified gel in a tank homogenization; 6. Sieving of
the whole gel (230 .mu.m); 7. Separation of the collected gel into
two fractions (Fraction B1 and B2); 8. Incorporation to the gel of
1% by weight of a solution of mepivacaine (30% by weight in medium
phosphate buffer) and of 0.4% by weight of a solution of NaOH 1%
(=Fraction B1); 9. Incorporation to the gel of 1% by weight of a
solution of lidocaine (30% by weight in medium phosphate buffer)
and of 0.4% by weight of a solution of NaOH 1% (=Fraction B2); 10.
Homogenization, packaging in syringes lmL for injection and
sterilization.
[0223] Results:
[0224] Tables below gives the values of the elastic modulus G' (in
Pa) of the hydrogels obtained and of the extrusion force F(N).
TABLE-US-00003 F(N) at Dynamic 12.5 mm/min oscillatory Ser Schott 1
ml, rheology Needle TSK F = 1 Hz HPC 30 G: Fraction B1 G' (Pa)
120347 Mepivacaine Non-sterilized 20.4 10 0.3% Sterilized 8.1 10
Loss on 60.3 sterilization (in %)
TABLE-US-00004 F(N) at Dynamic 12.5 mm/min oscillatory Ser Schott 1
mL rheology Needle TSK F = 1 Hz HPC 30 G: Fraction B2 G' (Pa)
120347 Lidocaine 0.3% Non-sterilized 19.2 10 Sterilized 6.2 10 Loss
on sterilization 67.6 (in %)
[0225] The loss in sterilization is calculated as displayed in
example 1.
[0226] In view of the above, it therefore appears that the
stability to the sterilization step of a composition comprising
crosslinked and uncrosslinked hyaluronic acid is at least
equivalent with mepivacaine than with lidocaine.
[0227] The results are even better with mepivacaine.
Example 3
Protocol of Preparing a Composition According to the Invention
Implementing Crosslinked and Non Crosslinked Hyaluronic Acid and
Analysis Regarding its Stability in Time
[0228] 10 g of hyaluronic acid (1.5 MDa,) 73 g of sodium hydroxide
1% and 0.9 g of butanediol diglycidyl ether (BDDE) are mixed. Then,
the crosslinking reaction is induced by incubation for 3 hours at
52.degree. C.
[0229] The preparation procedure is as follows:
1. homogenizing the mixture at room temperature "hyaluronic
acid+sodium hydroxide 1%, in an airtight and deformable container
(pocket) for about 1H30 to obtain a perfectly homogeneous viscous
solution; 2. adding the crosslinking agent (BDDE) into the
container and further homogenization at room temperature for about
20 min; 3. incubation for 3 hours at 52.degree. C. of the
receptacle containing the viscous solution of hyaluronic
acid/sodium hydroxide 1%/BDDE so as to initiate the crosslinking
step; 4. neutralization, swelling and homogenizing the obtained
solid (solution of crosslinked hyaluronic acid) in a phosphate
buffer containing 2 g of non-crosslinked hyaluronic acid (1.5 MDa),
so as to obtain a hydrogel at 25 mg/g of hyaluronic acid at pH
close to neutrality; 5. purification by dialysis (during 48 hours),
and then collecting the purified gel in a degassing
vessel/homogenization; 6. incorporation in the gel of 1% by weight
of a solution of mepivacaine (30% by weight in a phosphate buffer
medium) and of 0.4% by weight of a NaOH solution 1%; 7.
homogenization, degassing, packaging in syringes lmL for injection
and sterilization (F0>15).
[0230] Results:
[0231] Table below gives the values of the phase-shift angle
.delta.(.degree.) and the extrusion force.
TABLE-US-00005 Rheology amplitude scan Extrusion Force,
(Cone/plate) measured with .delta. (.degree.) measures at needle
TSK 30G1/2 Analysis 5 Pa and 1 Hz F (N), at 12.5 min/min pH T0 17.8
.+-. 2.0 24.2 .+-. 2.5 7.1 T0 + 19 months 19.1 .+-. 2.0 23.1 .+-.
2.5 7.1
[0232] The results obtained 19 months after the date of manufacture
of the gel are equivalent to those obtained initially, and thus
demonstrate the stability of the gel.
[0233] The disclosure of all publications cited above are expressly
incorporated herein by reference, each in its entirety, to the same
extent as if each were incorporated by reference individually.
[0234] The disclosure of all publications cited above are expressly
incorporated herein by reference, each in its entirety, to the same
extent as if each were incorporated by reference individually.
[0235] It is also to be understood that the following claims are
intended to cover all of the generic and specific features of the
invention herein described, and all statements of the scope of the
invention which, as a matter of language, might be said to fall
therebetween.
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