Design and Development of Liquisolid Compact of Carvedilol

It is suggested here that liquisolid technique has the potential to be optimized for the reduction of drug dissolution rate and thereby production of sustained release systems is possible. In the present study, carvedilol was dispersed in polyethylene glycol 400 as the liquid vehicle. Then a binary mixture of carrier-coating materials ((Avicel PH-102) as the carrier and silica200 as the coating material) was added to the liquid medication under continuous mixing in a mortar. The final mixture was compressed using the tablet compression machine. The effect of drug concentration, loading factor, thermal treating and on release profile of carvedilol from liquisolid compacts were investigated. The release rate of carvedilol from liquisolid compacts was compared to the release of carvedilol from matrix tablets. X-ray crystallography and DSC were used to investigate the formation of any complex between drug and excipients or any crystallinity changes during the manufacturing process. carvedilol tablets prepared by liquisolid technique showed greater retardation properties in comparison with matrix tablets. This investigation provided evidence that (HPMC) hydroxypropyl methylcellulose has important role in sustaining the release of drug from liquisolid tablets. The results also showed that wet granulation had remarkable impact on release rate of carvedilol from liquisolid compacts, reducing the release rate of drug from liquisolid compacts. The results showed that aging (liquisolid tablets were kept at 400C and 75 % relative humidity for 3 months) had no effect on hardness and dissolution profile of drug. The kinetics studies revealed that most of the liquisolid formulations followed the zero-order release pattern. Infrared spectroscopy and DSC ruled out any changes in crystallinity or complex formation during the manufacturing process of liquisolid formulations.