Rosin, A Polymer For Microencapsulation Of Diltiazem Hydrochloride For Sustained Release By Emulsion - Solvent Evaporation Technique
Microcapsules of diltiazem hydrochloride with rosin were prepared by an emulsion-solvent-evaporation technique. Different amounts of drugs were added in order to obtain various drug to polymer ratios. The physical properties, loading efficiency and release rate depended on the drug to polymer ratio. The low drug content of microcapsules may be due to the interaction between the hydrochloride form of diltiazem and rosin in acetone, where as non-hydrochloride drug like sulphamethoxpyridazine showed complete loading efficiency. Span 80 was used to prevent aggregation. The mean size of the microcapsules decreased as the drug/polymer ratio increased. Since microcapsules were very small they were embedded into a tablet. The microcapsules produced a typical 24 h sustained release pattern. In vitro dissolution studies showed that first-order release characteristics were exhibited.