Effects of sphere size, polymer to drug ratio and plasticizer concentration on the release of theophylline from ethylcellulose microspheres

Theophylline sustained release microspheres were prepared by applying the non-solvent addition method. The in-vitro release of the drug from the prepared microspheres of different size ranges [

In-vitro and in-vivo evaluation of commercial and microencapsulated sustained release tablets containing diclofenac sodium

Diclofenac sodium microcapsules were prepared using the phase separation technique induced by non-solvent addition. Ethl1cellulose and Eudragit RS100 were used as well forming materials in two core: wall ratios [1: 1 and 1: 2]. The prepared microcapsules were compressed into tablets without excipients. The influence of tableting type of wall forming material and the core: wall ratio on the release pattern of the drug from microcapsules were determined in Ph 1.2 and pH 6.8. compression of the microcapsules significantly [p < 0.05] decreased the rate of drug release due to the reduction of the surface area. Less than 2.0% of the drug was released in 0.1N HC1 during the first two hours of dissolution from microcapsules before and after tableting. On the other hand, the dissolution results of the tableted ethy1cellulose microcapsules with 1:1 and 1:2 core: wall ratios showed that 88.6 and 70.6% of the drug were released to the phosphate buffer solution, while only 45.0 and 24.4% of the drug in the tableted eudragit microcapsules was released within 8 h of dissolution. The tableted ethy1cellulose microcapsules with 1:2 core: wall ratio showed almost identical release of the drug as that from commercial tablets therefore, it was chosen for bioavailability study in six beagle dogs. The in-vivo data showed that the tableted microcapsules gave bioavailability of 87.5% relative to that of the commercial voltaren retard tablets. The prepared tablets show that it is possible to use ethy1cellulose microcapsules to prepare tablets that are pharmaceutically and biologically equivalent to those of the commercially available voltaren retard tablets

Effect of deoxycholic acid, polycarbophil or both on the relative hyperglycemia of rectal insulin suppositories containing sodium salicylate in diabetic rabbits

The effect of insulin [50 u] suppositories containing sodium salicylate [50 mg] without and with 50 mg of either polycarbophil, deoxycholic acid or 50 mg of each on plasma glucose levels of hyperglycemic rabbits was studied. The hypoglycemia of these formulations was determined relative to that produced after s.c. injection of insulin suspension and were 45.6%, 46.7%, 48.2% and 39.5% respectively. Insulin suppositories containing sodium salicylate were effective in reducing plasma glucose levels which steadily decreased and reached 66% of the initial values by the 3rd h.the addition of polycarbophil to insulin suppositories containing sodium salicylate induced faster and higher rate of insulin absorption as indicated by the shorter Tmax and higher Cmax. addition of deoxycholic acid increased non significantly the Tmax MRT, AUC0-7 h of that of insulin suppositories containing sodium salicylate. The incorporation of both polycarbophil and deoxycholic acid in insulin suppositories containing sodium salicylate is not recommended as these additives reduced the Cmax and AUC0-7 h. accordingly, insulin suppositories containing sodium salicylate with and without the addition of polycarbophil or deoxycholic acid may be considered as a good alternative to insulin injection