IN-VITRO RELEASE CHARACTERISTICS OF PAPAVERINE HYDROCHLORIDE FROM MULTIPLE EMULSION SYSTEMS

Document Type : Original Article

Authors

Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt

Abstract

A two-step emulsification procedure was adopted to prepare stable multiple emulsion of the W/O/W type. An aqueous solution of the drug and paraffin oil at ratio of 1:2 were used to prepare a W/O type primary emulsion (1st step) using blend of surfactants (HLB 3.8) at 10% concentration. While a blend of surfactants (HLB 12.3) was used as the second emulsifying agent for incorporating the prepared primary emulsion into the outer aqueous phase (1:2) to produce the final emulsion. Drug release from the prepared system was evaluated 24 hours after preparation and periodically at weekly intervals thereafter for four weeks. Multiple emulsion system, each containing either sodium chloride, sorbitol or methylcellulose were similarly prepared and evaluated for drug release thereof. Drug release from the prepared system was found to be greatly retarded in comparison with that from the corresponding aqueous solutions. The drug release rate from the prepared system, with the exception of those containing methylcellulose was slightly changed to lower values. The effect was greater at the second week testing while, a constant release pattern was found thereafter. The presence of methyl cellulose lead to a greater lowering in the release rate.