Study On Hydroxypropyl Methylcellulose And Konjac Glucomannan As Excipients Of Metronidazole Extended Release Tablet

In this work, we prepared Metronidazole (MNZ) extended release tablets with HPMC and KGM by wet granulation method. The influence of the content of excipients, the viscosity of excipients and particle size of MNZ et al were examined. Using differential scanning calorimetry (DSC) and infrared (IR), the interaction between excipients was studied. Results as follows:In the HPMC matrix tablets, we studied the effect of the content and the viscosity of HPMC, particle size of MNZ, shape and weight of tablets and release medium on drug release. The experimental result indicated that the drug release decrease with the enhance of HPMC content and viscosity. However, it is no obvious differences among the release rate for systems containing HPMC above 4000mPa.s. The drug release increase with larger particle size of MNZ. It was found that the drug release from oval tablets is faster than that from round tablets and the drug release in 0.1M HCl solution is much faster than in pH=6.8 phosphate buffer.In the KGM matrix tablets, we checked the effect of the content and the viscosity of KGM, particle size of MNZ, tablets figure, release medium and adhesives on drug release. The experimental result indicated that the drug release decrease with the raise of KGM concentration. However, the drug release has little change with KGM of different viscosity and MNZ of different particle size. As the same as HPMC matrix tablets, the drug release from oval tablets is faster than that from round tablets and the drug release in 0.1M HCl solution is much faster than in pH=6.8 phosphate buffer. It was indicated that the drug release from matrix tablets using water as adhesive is faster than from matrix tablets using 2% HPMC solution or starch paste as adhesives. However, there is little difference in drug release among starch paste of different concentration.Through the assay of DSC and IR, it was demonstrated that the excipients have no interaction in HPMC matrix tablets and interaction in KGM matrix tablets. Compared the release character of HPMC and KGM as excipients and the influence of factors on drug release, the results showed that the matrix tablets using KGM as excipient have better sustained release property at the beginning of drug release. Following the increase of excipients content, the rate of drug release is reduced, but the difference of the influence of excipients content on drug release is not distinguished. If the excipients have high viscosity, the viscosity has little effect on the...