ASSESSMENT OF THE SPREADABILITY OF OFFICIAL PHARMACEUTICAL CREAMS AND OINTMENTS USING THE MASTER CURVE CONCEPT

Abstract. Spreadability characteristics of official creams and ointments of the British Pharmacopoeia and the British Pharmaceutical Codex were determined using the Master Curve concept and continuous shear data. Experimental results were obtained using a Ferranti-Shirley cone and plate viscometer at 25 dC and 34 dC, representing an approximate temperature range encountered during spreading of topical preparations. Data derived for creams intersected the Master Curve in the preferred region, although not at the optimum value. Ointments demonstrated large variations in spreading properties. The variation and lack of optimum spreadability characteristics were explained by considering the medicinal criteria required of topical pharmaceutical products as distinct from cosmetics.