Abstract
In this research, a study has been made with sorbitan esters
Span 20, Span 40, and Span 80, which are used in the preparation of w/o emülsion type ointment bases. The water numbers, oil numbers and melting points of different mixtures, made by incorporating these emulsifiers in white petrolatum, were determined.
The effect of the HLB numbers, viscosity and the concentration of the emulsifiers on these phenomena, together with the effect of temperature, auxilary materials and time were investigated. A new practical method was modified in oil number determinations
of white petrolatum, absorption and emulsion bases.
The water number of white petrolatum and Span (Span 20, Span 80) mixtures with different emulsifier concentrations were determined. The influence of these emulsifiers' HLB numbers on the water number of ointment bases were observed. The oil number
of Span-white petrolatum mixtures, before and after the water number determinations were determined and from these, the relations between water number and oil number were established. First, relationship between the oil numbers and melting points of the bases on the ointments made by 5 % of Span 20, 40 and 80 in
white petrolatum were determined. Later, this same relationship, by incorporating in these ointments (5, 10, 20 %) auxilary substances was again investigated. The conclusions from this research were, the effect of each auxilary substance, on the, storage of the ointment bases according to the pharmaceutical technology and ointment base's dermatologic diffusions. It was observed that HLB numbers and viscosities of this nonionic emulsifiers were effective on the oil numbers and diffusions of the emulsion bases. Also, it is proposed that, the chromatographic stability control of nemi - solid w/o emulsions made by methylene blue, could be a useful method.