The kinetic study of dexamethasone release from multiple emulsions

Four oil-in-water (O/W), 8 water-in-oil (W/O) and 5 oil-in-water-in-oil (O/W/O) emulsions were prepd. by a conventional 2-stage method. Olive squalane was used as the oil of the emulsions. The Phytocream 2000 played the role in a hydrophilic emulsifier, while the Cithrol PG3PR was the lipophilic emulsifier. The multiple emulsions were composed of 80% primary emulsion, 5% W/O emulsifier and 15% squalene. They were used as an active substance carrier. The drug release test was used for evaluation of the formulations. The released amt. of dexamethasone through dialysis membranes from O/W/O emulsion was 15%. This value was lower than that obtained in a ref. tests (O/W and W/O simple emulsions). The release profile of dexamethasone from O/W/O emulsion confirmed that this system can play a role as a carrier with delayed release of the active substance.