Release of betamethasone 17-valerate from extemporaneous dilutions of a proprietary topical cream.

Six different vehicles for topical use were used to prepare 50% dilutions of Betnovate (betamethasone 17-valerate, 0.1%) cream. Blanching assessment as undertaken immediately after preparing the various dilutions and at 1 and 3 months thereafter. Few statistically significant differences were noted between any of the preparations tested indicating hat the rate of release of betamethasone 17-valerate is relatively unaffected by dilution. All preparations were assayed by a stability indicating high pressure liquid chromatographic technique for corticosteroid content. A diminution in the content of betamethasone 17-valerate in the E45 dilution was found 14 months after preparation. All other formulations tested were found to comply with label claim specifications.