STUDY OF THE PROLONGED RELEASE OF A DRUG FROM ENCAPSULATED GRANULES PREPARED WITH BEESWAX

The in vitro dissolution studies of encapsulated sodium salicylate granules coated with beeswax is presented. The factors investigated were the effects of concentration, presence of a hydrophilic fatty material, polyethylene glycol 6000 (PEG 6000), and technique (pan-coating, fusion and granulation) on the sustained release of drug when coated with beeswax. Comparison of release rates was based on the use of a parameter, t70% (time for 70% of drug to be released). The greater the concentration of beeswax, ranging from 13.04 to 28.75%, the more prolonged the release. The presence of PEG 6000 at a concentration of 1:9 beeswax in the coating fluid significantly (p<0.05) increased the release rate, and at a concentration of 1:1 nullified the sustained release effect of beeswax. The t70% for the fusion, granulated and pan-coated batches were in the increasing order of 25min., 1hr.35min. and 2hr.45min, respectively.