Influence of formulation parameters on properties of alginate/Eudragit beads containing a diclofenac salt

The effect of formulation variables on the preparation of diclofenac hyrdox yethylpyrrolydine alginate/Eudragit L beads was investigated Their morpholo gies il el-e evaluated bq scanning electron microscopy. Alginate bead drug entrapment was tested when the incorporation of Eudragit L was made as ail aqueous dispersion and as a partially; neutralized solution. An increase in the entrapment efficiency was achieved when the polymer was added as ail a queous dispersion. Therefore, the higher is the degree of neutralization, t he lower the percentage entrapment. Release of the drug in simulated intest inal fluid was significantly higher than in an acidic medium or in distille d water: These results can be explained in terms of drug solubility, the in ternal porous bead structure and the behaviour of both polymers (alginate a nd Eudrangit) on the,media. The release studies revealed that the presence of Eudragit L as a dispersion or as a neutralized solution determined the r elease problems.