title: Assessing equivalence of innovator and generic formulations of betamethasone dipropionate cream and ointment.
abstract: A series of tests was used to compare two formulations of the topical steroid beta-methasone dipropionate, Diprolene (manufactured by the innovator, Schering Corp.) and Topilene (a generic formulation, manufactured by Technilab). Cream and ointment formulations produced by both manufacturers were compared with respect to physicochemical characteristics, skin sensitivity in rabbits, and a vasconstrictor assay indicative of topical availability in man. The physicochemical tests revealed no differences between innovator and generic ointment formulations, whereas excipients varied widely for the cream products. Similarly, the ointment formulations were comparable on the skin sensitivity tests in rabbits, whereas the generic cream product was much more irritating than the innovator cream in this test. On the vasoconstrictor assay in man the ointments were comparable, while the activity of the generic cream was much lower (approximately 30%) than that of the innovator cream; this difference was highly statistically significant. The difference in vasoconstrictor activity of the two cream products is discussed in relation to the differences in their physicochemical properties. It is concluded that the generic Topilene cream is not interchangeable with the innovator Diprolene cream, and that both pharmacists and physicians should be very careful when substituting one topical steroid formulation for another.
authors.affiliation: Schering-Plough Research, Pointe-Claire, Quebec, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Sequira
authors.forename: M
authors.initials: M
authors.lastname: Berardi
authors.forename: T M
authors.initials: TM
authors.lastname: Chan
authors.forename: J
authors.initials: J
authors.lastname: Letarte
authors.forename: R
authors.initials: R
authors.lastname: Malchow
authors.forename: B
authors.initials: B
authors.lastname: Pramanick
authors.forename: H N
authors.initials: HN
authors.lastname: Wolkoff
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D001623:Betamethasone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D002626:Chemistry, Pharmaceutical; D016568:Drugs, Generic / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D005260:Female; D005938:Glucocorticoids; D006801:Humans; D008297:Male; D009824:Ointments; D011817:Rabbits; D012882:Skin Tests; D013810:Therapeutic Equivalency
chemical_list: D000893:Anti-Inflammatory Agents; D016568:Drugs, Generic; D005938:Glucocorticoids; D009824:Ointments; C011175:betamethasone-17,21-dipropionate; D001623:Betamethasone