A Mathematical Morel for Drug Release from 0/W Emulsions: Application to Controlled Release Morphine Emulsions

Abstract

Stable morphine submicronized emulsions were prepared under optimal experimental conditions. Mean droplet size and zeta potential of the morphine emulsions ranged from 400 to 700 nm and from -50 to -70 mv respectively. In vitro release kinetic analysis indicated that the drug transfer from the oily dispersed droplets into the external aqueous phase was the rate determining step in the overall kinetic process providing the main portion of the drug ‘twas localized in the oily phase. A kinetic equation model was proposed and found suitable for the description of morphine release from the emulsion due to conformity of the experimental data to the expected kinetic data as calculated by means of this equation.