Shruti Prabhu

Colon targeted drug delivery system is capable of protecting the drug in route to the colon i.e. drug gets released and absorbed once it reaches the colon. A multiparticulate system combining pH sensitive property and biodegradability has been investigated to prepare and evaluate Eudragit S-100 coated Sodium alginate microspheres for colon targeting of Tramadol Hydrochloride. Uncoated Tramadol Hydrochloride microspheres were prepared by ionotropic gelation technique using different ratios of Tramadol Hydrochloride and Sodium alginate. Coated Tramadol Hydrochloride microspheres were prepared by coacervation phase separation technique using different ratios of uncoated Tramadol Hydrochloride and Eudragit S-100/ Eudragit L-100. Uncoated and coated Tramadol Hydrochloride microspheres were evaluated for percentage yield, particle size, surface morphology, flow properties, drug content and entrapment efficiency and were found to be within the acceptable range. The uncoated microspheres sustained the release upto 8 hrs whereas coated microspheres sustained the release upto 12 hrs in a pH progression medium mimicking the condition of GIT. The drug release from MC4 formulation coated with Eudragit S-100 (1:4) showed desired rate as there was no drug release observed upto 4-5 hrs, while in colonic fluid controlled drug release was observed releasing about 69.66 % after 12 hrs. The release kinetics followed Peppas showing Super Case II transport. Stability studies suggested formulations were stable. It is concluded from the present investigation that Eudragit S-100 coated Sodium alginate microspheres are promising controlled release carriers for colon targeted delivery of Tramadol Hydrochloride.

Gastroretentive systems have the unique quality to remain in the gastric region for several hours. Due to this they prolong the gastric residence time of the drug significantly. Floating microspheres possess the advantage of better flowing properties attributed to the use of low density polymers. Clarithromycin is a broad-spectrum antibiotic and extensively absorbed orally. It is used in the eradication of H. Pylori infection combined with an acid suppressing agent. Clarithromycin floating microspheres were prepared using polymer Ethyl Cellulose in different concentrations by solvent evaporation method. The FTIR studies showed no interaction between drug and polymers. The floating microspheres were evaluated for angle of repose, percentage yield, particle size, SEM, buoyancy percentage, drug content, percentage drug entrapment, in-vitro dissolution studies, kinetics of drug release and stability studies. Formulation F3 was found to be the best formulation showing the highest degree of sustained release that is 73.86% at the end of 12 hours. Formulations were seen to follow zero order release profile and Korsemeyer-Peppas model was the best fitting model. Marginal changes were observed in the drug content, buoyancy time and In-vitro dissolution studies which are insignificant. Storage conditions were carried out at 40±20C/75±5%RH for 6 months.