Analgesic compositions
AssigneeAmerican Home Products Corporation
InventorsDhiraj S. Mody, Robert G. Blank, Gary R. Agisim, Gloria Y. Chen
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Abstract
The invention provides an analgesic cream containing ibuprofen with superior skin penetration properties obtained in part by maintaining a pH of 4 to 7.2 such that the ibuprofen is suspended in substantially solid crystalline form.
Claims8
A topical anagesic composition consisting essentially of an oil-in-water emulsion containing about 5% to about 12% by weight of ibuprofen, the emulsion containing about 60% to about 90% by weight of water and having minimum ibuprofen solubility characteristics in both the water and oil phases, the composition having a pH of about 4 to about 7.2 such that at least about 70% by weight of the ibuprofen is suspended in the emulsion in substantially solid crystalline form.
A topical analgesic composition consisting essentially of an oil-in-water emulsion containing about 5% to about 12% by weight of ibuprofen, the emulsion containing about 70% to a 80% by weight of water and having minimum ibuprofen solubility characteristics in both the oil and water phases, the composition having a pH of 5 to 5.8 such that about 95% to about 100% by weight of the ibuprofen is suspended in the emulsion in solid crystalline form, the ibuprofen being added to the oil-in water emulsion in solid crystalline form at a temperature below about 35.degree. C., and the topical analgesic composition additionally containing an alkali and about 0.4 to about 0.85% by weight of the total composition of a polymer of acrylic acid cross-linked with a polyalkenyl polyether, the polymer having a molecular weight between 500,000 and 4,000,000, and the amount of alkali being not greater than 20% by weight of the polymer.
Dependencies are inferred from the claim text.