Claims for Patent: 3,906,108

Summary for Patent: 3,906,108

Title:	Stabilized tretinoin cream emulsion
Abstract:	A stabilized cream emulsion of tretinoin, capable of being stored without refrigeration for long periods of time without losing therapeutic effectiveness and while maintaining the uniformity and stability of the cream, contains xanthan gum as the stabilizer.
Inventor(s):	Felty; Lanny G. (Jackson, NJ)
Assignee:	Johnson & Johnson (New Brunswick, NJ)
Application Number:	05/406,126
Patent Claims:	1. In a tretinoin cream emulsion for topical application comprising from about 0.005 to about 0.5% by weight of tretinoin, from about 1.0 to about 10.0% by weight of an emulsifier, from about 15.0 to about 50.0% by weight of a hydrophobic material selected from the group consisting of petrolatum, beeswax, sperm wax, lanolin, mineral oil, the liquid and solid fatty acids having from about 12 to about 20 carbon atoms, fatty alcohols having from about 12 to about 20 carbon atoms, and fatty acid esters wherein the fatty acid moiety has from about 12 to about 20 carbon atoms, from about 0.05 to about 1.0% by weight of a preservative, from about 0.01 to about 1.0% by weight of an antioxidant, and water, the improvement which comprises also having therein as a stabilizer to prevent breaking of the emulsion, from about 0.1 to about 1.0% by weight of xanthan gum. 2. The product of claim 1 wherein the emulsifier is a non-ionic emulsifier. 3. The product of claim 1 which contains from about 0.3 to about 0.5% by weight of xanthan gum. 4. The product of claim 2 wherein the emulsifier is selected from the group consisting of polyoxyethylene 25 oxypropylene stearate, polyoxyl 40 stearate, polyethylene glycol 400 monostearate, polyethylene glycol 600 monostearate, polyoxyethylene 20 stearyl ether and polyoxyethylene 2 stearyl ether. 5. The product of claim 1 wherein the preservative is sorbic acid. 6. The product of claim 1 wherein the antioxidant is a member selected from the group consisting of butylated hydroxytoluene, and dl-alpha tocopherol. 7. The product of claim 1 wherein the hydrophobic material is selected from the group consisting of a stearyl alcohol, petrolatum, stearic acid, isopropyl myristate, cetyl alcohol, beeswax, sperm wax, lanolin, mineral oil and glyceryl monostearate.