O/W EMULSIONS AS VEHICLES FOR MICRONIZED DRUG PARTICLES .1. DEVELOPMENT OF MICRONIZED DRUG DISPERSIONS IN OILY MEDIA

The preparation of emulsions loaded with drug particles, so-called suspension-emulsion systems, requires the provision of extremely fine-grained drug dispersions in oil. An agitated ball mill for grinding very small volumes of drugs has been developed and grinding parameters optimized. Compared to results on a conventional ball mill with agitator, the particles sizes obtained with the pilot scale mill from two model drugs (spironolactone und 1,4-dihydroxyanthraquinone) were of an equal or even finer range. Recrystallization phenomena were dependent on the solubility properties and viscosity of the oils used as grinding media. Ostwald ripening could best be avoided when cottonseed oil was used as the grinding medium. In the case of spironolactone, crystallization processes could be suppressed for several months.