Hydroxypropylcellulose (HPC)

The objective of the study was preparation of sustained release matrix tablets by hot melt extrusion (HME) and process optimization for continuous manufacturing. Furthermore, HME tablets were evaluated with respect to in vitro release rate, erosion behavior and water uptake study. Hydroxypropylcellulose (HPC) was used as release retarding polymer. The drug chosen for study was first line anti tuberculosis drug rifampicin. 50 % drug loaded HME tablets were prepared. The HME tablets were characterized by DSC, FTIR and SEM. No chemical interaction was found between drug and polymer as per DSC and FTIR. Dispersion of drug particles and internal micro pores was observed by SEM. In vitro release study revealed 50% drug loaded HPC matrix tablets gave sustained release of 101.41±1.02% at the end of 24 h. Release rate of rifampicin from HME tablets was found to be dependent on the concentration of polymers and plasticizer. The release rate from the edges and circumference of tablets suggested the hydration of the tablets from the circumference was more significant than at edges of the tablets. Drug release from HME matrix tablets was found to follow Super case-II transport mechanism. HME tablets were stable for six months as per ICH guideline.