Sustained-release pharmaceutical-cosmetic compsns - with carrier having narrow -necked pores

摘要

Compsn. comprises a high porosity powdered carrier of particle size 10 mu m which is virtualy insol. in skin secretion, the surface being loaded with an active ingredient (I) which is also contained within the internal pores ((I) is soluble in skin secretion) and the carrier contains internal cavities connected to the outer surface by narrow necks and the mean sectional dia. of the cavity is > twice the mean internal width (w) of the neck; w is predominantly 0.1 mu m. Carriers are esp. Al, Si or Zr oxides, produced e.g., by dehydrating and drying a hydroxide or hydrated oxide gel, hydrolysing an alcoholate dissolved in org. solvent etc., or a polymer. Formulation is suitably as a cream or liq. suspension (e.g., for spray application).