Reversible gelation compositions and methods of use
First Claim
1. An aqueous pharmaceutical composition of matter exhibiting the property of reversible gelation in response to substantially simultaneous variations in both temperature and pH over predetermined ranges, said composition comprising:
- an aqueous solution including approximately 0.1% to 30% by weight thermally-sensitive gelling polymer and approximately 0.01% to 10% by weight pH sensitive gelling polymer whereby said aqueous composition exhibits a reversible viscosity change ranging between approximately 200 to 1,000,000 cP in response to substantially simultaneous variations in both temperature and pH over respective ranges between approximately 0°
C. to 60°
C. and pH 2.5 to pH 7.5.
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0 Petitions
Accused Products
Abstract
Reversibly gelling aqueous compositions are disclosed which undergo significant changes in viscosity in response to substantially simultaneous changes in both temperature and pH. The compositions are formed of relatively low concentrations of a stable combination of at least one pH-sensitive reversibly gelling polymer and at least one temperature-sensitive reversibly gelling polymer. The compositions can be formulated to exhibit a sol-gel transition over a wide range of conditions and viscosities and may be modified to incorporate a pharmaceutical compound for utilization as droppable or injectable drug delivery systems which will gel following administration to a physiological system for the sustained delivery of such pharmaceutical compounds.
146 Citations
39 Claims
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1. An aqueous pharmaceutical composition of matter exhibiting the property of reversible gelation in response to substantially simultaneous variations in both temperature and pH over predetermined ranges, said composition comprising:
an aqueous solution including approximately 0.1% to 30% by weight thermally-sensitive gelling polymer and approximately 0.01% to 10% by weight pH sensitive gelling polymer whereby said aqueous composition exhibits a reversible viscosity change ranging between approximately 200 to 1,000,000 cP in response to substantially simultaneous variations in both temperature and pH over respective ranges between approximately 0°
C. to 60°
C. and pH 2.5 to pH 7.5.- View Dependent Claims (21, 22, 23, 24, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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2. An aqueous pharmaceutical composition of matter exhibiting the property of reversible gelation in response to substantially simultaneous variations in both temperature and pH over predetermined ranges, said composition comprising:
an aqueous solution including approximately 0.1% to 30% by weight thermally-sensitive gelling polymer and approximately 0.01% to 10% by weight pH sensitive gelling polymer whereby said aqueous composition exhibits a reversible viscosity change ranging between approximately 200 to 1,000,000 cP in response to substantially simultaneous variations in both temperature and pH over respective ranges between approximately 25°
C. to 37°
C. and pH 4.5 to pH 7.4.- View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25)
Specification