Cross-linked gels of hyaluronic acid and products containing such gels
First Claim
1. A method of preparing a mixed cross-linked gel of hyaluronic acid and at least one other hydrophilic polymer having a functional group capable of reacting with divinyl sulfone, said method comprising subjecting a mixture of sodium hyaluronate and said other hydrophilic polymer in a dilute aqueous alkaline solution at a pH of not less than about 9 to a cross-linking reaction with divinyl sulfone at about 20°
- C.
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Accused Products
Abstract
Disclosed are cross-linked gels of hyaluronic acid, alone or mixed with other hydrophilic polymers and containing various substances or covalently bonded low molecular weight substances and processes for preparing them. These products are useful in numerous applications including cosmetic formulations and as drug delivery systems.
424 Citations
28 Claims
- 1. A method of preparing a mixed cross-linked gel of hyaluronic acid and at least one other hydrophilic polymer having a functional group capable of reacting with divinyl sulfone, said method comprising subjecting a mixture of sodium hyaluronate and said other hydrophilic polymer in a dilute aqueous alkaline solution at a pH of not less than about 9 to a cross-linking reaction with divinyl sulfone at about 20°
- 7. A method of preparing a cross-linked gel of hyaluronic acid or a mixed cross-linked gel of hyaluronic acid and at least one other hydrophilic polymer having a functional group capable of reacting with divinyl sulfone, either of which further includes an inert water insoluble substance, said method comprising subjecting sodium hyaluronate or a mixture of sodium hyaluronate and said other hydrophilic polymer in a dilute aqueous alkaline solution at a pH of not less than about 9, to which has been added an inert water insoluble substance to a cross-linking reaction with divinyl sulfone at about 20°
- 14. A method of preparing a cross-linked gel of hyaluronic acid or a mixed cross-linked gel of hyaluronic acid and at least one other hydrophilic polymer having a functional group capable of reacting with divinyl sulfone, either of which further includes a low molecular weight substance covalently bonded to the macromolecular network, said method comprising subjecting sodium hyaluronate or a mixture of sodium hyaluronate and said other hydrophilic polymer in a dilute aqueous alkaline solution at a pH of not less than about 9, to which has been added a low molecular weight substance having a functional group with active hydrogen atoms reactive to divinyl sulfone to a cross-linking reaction with divinyl sulfone at about 20°
- 21. A mixed cross-linked gel of hyaluronic acid and at least one other hydrophilic polymer having a functional group capable of reacting with divinyl sulfone, wherein the combined concentration of sodium hyaluronate and the other hydrophilic polymer is 1-8% by weight and the sodium hyaluronate comprises from 5-95% of the total.
- 23. A cross-linked gel of hyaluronic acid or a mixed cross-linked gel of hyaluronic acid and at least one other hydrophilic polymer having a functional group capable of reacting with divinyl sulfone and further comprising an inert water insoluble substance, wherein the concentration of sodium hyaluronate or the mixture of sodium hyaluronate and the other hydrophilic polymer is 1-8% by weight and the inert water insoluble substance is present in an amount of 1-95% by weight based on the total weight of polymers plus inert water insoluble substance.
- 26. A cross-linked gel of hyaluronic acid or a mixed cross-linked gel of hyaluronic acid and at least one other hydrophilic polymer having a functional group capable of reacting with divinyl sulfone and further comprising a low molecular weight substance covalently bonded to the macromolecular network, wherein the concentration of sodium hyaluronate or the mixture of sodium hyaluronate and the other hydrophilic polymer is 1-8% by weight and the low molecular weight substance is present in an amount of 1-95% by weight based on the total weight of the polymer.
Specification