Eudragit L-100.

Lornoxicam is a non steroidal anti-inflammatory drug of oxicam class and it has the same side effects of this group when taken orally and has a relatively short plasma half-life (3 to 4 h) which makes it a good candidate for colon targeting. It could avoid the systemic side effects, enhance its low oral bioavailability due to hepatic first pass metabolism and delay drug release to target the colon. Eighteen tablet formulations of lornoxicam were prepared by wet granulation and coated with different polymers (pectin, chitosan, ethyl cellulose, cellulose acetate phthalate, eudragit L-100 and eudragit L-100-55), each at three concentration. The tablets were evaluated for their physical characters, in–vitro dissolution in gradient pH, as well as, mathematical modeling using DDSolver software package. The dissolution data best fitted to first order with Tlag model with Krosmyer Pepas (n) values around unity suggesting erosion mechanism for all tablets except pectin coated ones which showed Fickian diffusion mechanism. Fitting the release data to the different erosion models suggested heterogeneous erosion mechanism. Lornoxicam tablets coated with 6% Eudragit L-100 were successfully delivered to the colon with a relative bioavailability of 531.96% compared to the conventional commercial tablets in rabbits.

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.