ABSTRACT
The release rate of indomethacin [Ind.] from suppositories formulated with sustained release [SR] granules of drug: polymer: aerosil of different ratios was studied. The release from polyethylene glycol suppositories containing different polycarbophil concentrations was also investigated. The effect of some formulation variables, e.g. aerosil content and molecular weight [MW] of polyethylene glycol, has been evaluated. The major controlling factor appeared to be the drug: polymer ratio for the release from polyvinylacetate [PVAc] and hydroxypropylmethylcellulose [HMPC] polymers. The decrease in aerosil content in SR granules resulted in a decrease in the release rate. As the MW of PEG increased, the release rate decreased. For suppositories containing 5, 10 and 20% of polycarbophil [PC], indomethacin release decreased as PC content increased. The results indicated that these suppositories had a better controlled release of indomethacin than those formulated with either PVAc or HPMC. Different scanning calorimetry [DSC] thermograms showed an interaction between PC and PEG, and also between PEG and indomethacin