Patent ID: 8962696
Filing Date: 2015-02-24
Classification: A61K,A61P,Y10S

Abstract:
1. A self-microemulsifiable anhydrous base composition for use in the preparation of a spontaneously formed and thermodynamically stable microemulsion that can be used as an anesthetic composition, comprising: a) liquid propofol; b) a nonionic surfactant consisting of polyoxyethylene (POE) having the structure of [POE(n)] subm-R′-R; where POE (n) is a polyoxyethylene moiety of -mer number n, and having m of these POE functional groups attached to R′; where the value of m is one to three; where R′ is a linking moiety selected from glyceryl, sorbitan, ester, amino, or ether functions; where R is a hydrophobic moiety consisting of saturated or unsaturated alkyl or alkylphenyl groups; and where the structure of the nonionic surfactant is further defined by a ratio of A, the total number of POE -mer units in the surfactant given by the product of -mer number n and total POE chain number m per molecule, to B, the number of carbons in the hydrophobic functional group R, the ratio of A/B being in the range of about 0.7 to 4, with the base composition not containing any other surfactant other than said nonionic surfactant having said structure; c) a water-immiscible solvent which is selected from the group consisting of a biocompatible monoester, diester and triester; d) ethanol; and wherein the relative concentration of the nonionic surfactant to propofol included in the base composition is not less than about three (3) parts of the nonionic surfactant to about one (1) part propofol, the relative concentration of the water-immiscible solvent to propofol is about three (3) to five (5) parts solvent to about ten (10) parts propofol, and the relative concentration of ethanol to propofol is about five (5) to six (6) parts ethanol to about ten (10) parts propofol.