Faculty of Pharmacy, Rhodes University, P.O. Box 94, Grahamstown, South Africa
Fauzee, A.F.B., Faculty of Pharmacy, Rhodes University, P.O. Box 94, Grahamstown, South Africa; Khamanga, S.M., Faculty of Pharmacy, Rhodes University, P.O. Box 94, Grahamstown, South Africa; Walker, R.B., Faculty of Pharmacy, Rhodes University, P.O. Box 94, Grahamstown, South Africa
Objectives: The purpose of the study was to evaluate the effect of different homogenization speeds and times, anchor speeds and cooling times on the viscosity and cumulative % clobetasol 17-propionate released per unit area at 72h from pilot scale cream formulations. A 24 full factorial central composite design for four independent variables were investigated. Materials and methods: Thirty pilot scale batches of cream formulations were manufactured using a Wintech® cream/ointment plant. The viscosity and in vitro release of CP were monitored and compared to an innovator product that is commercially available on the South African market, namely, Dermovate® cream. Results and discussion: Contour and three-dimensional response surface plots were produced and the viscosity and cumulative % CP released per unit area at 72h were found to be primarily dependent on the homogenization and anchor speeds. An increase in the homogenization and anchor speeds appeared to exhibit a synergistic effect on the resultant viscosity of the cream whereas an antagonistic effect was observed for the in vitro release of CP from the experimental cream formulations. The in vitro release profiles were best fitted to a Higuchi model and diffusion proved to be the dominant mechanism of drug release that was confirmed by use of the Korsmeyer-Peppas model. Conclusion: The research was further validated and confirmed by the high prognostic ability of response surface methodology (RSM) with a resultant mean percentage error of (±SD) 0.17±0.093 suggesting that RSM may be an efficient tool for the development and optimization of topical formulations. © 2014 Informa Healthcare USA, Inc.
clobetasol propionate; clobetasol; skin cream; Article; cooling; cream; drug diffusion; drug formulation; drug manufacture; drug release; in vitro study; viscosity; medicinal chemistry; pilot study; procedures; synthesis; topical drug administration; Administration, Topical; Chemistry, Pharmaceutical; Clobetasol; Pilot Projects; Skin Cream
