Preparation and evaluation of tolmetin sodium conventional and sustained-release suppositories

Conventional suppositories of tolmetin sodium were prepared by using two different types of Witepsol as an oily base and two different ratios of polyethylene glycol 400: polyethylene glycol 4000 as an water-soluble base. In addition, sustained- release suppositories were prepared by adding Eudragit L-100 ta the suppositories. The effects of the suppository base and the ratios of the polyethylene glycol 400: polyethylene glycols 4000 on the in vitro release characteristics were investigated. The release rate of tolmetin sodium from the conventional suppositories prepared with polyethylene glycol was slower than the other suppositories prepared with Witepsol. All of the suppositories with Eudragit L-100 showed slow-release profiles and the drug release rates clearly depended on the Eudragit L-100 content. When dissolution results were evaluated kinetically, zero order kinetic was observed with the sustained- release suppositories of tolmetin sodium prepared with polyethyleneglycol 400: polyethyleneglycol 4000 by adding Eudragit L-100.