Effect of crospovidone and hydroxypropyl cellulose on carbamazepine in high-dose tablet formulation

The aim of this study was to develop a high-dose tablet formulation of the poorly soluble carbamazepine (CBZ) with sufficient tablet hardness and immediate drug release. A further aim was to investigate the influence of various commercial CBZ raw materials on the optimized tablet formulation. Materials and methods: Hydroxypropyl cellulose (HPC-SL) was selected as a dry binder and crospovidone (CrosPVP) as a superdisintegrant. A direct compacted tablet formulation of 70% CBZ was optimized by a 3(2) full factorial design with two input variables, HPC (0-10%) and CrosPVP (0-5%). Response variables included disintegration time, amount of drug released at 15 and 60?min, and tablet hardness, all analyzed according to USP 31. Results and discussion: Increasing HPC-SL together with CrosPVP not only increased tablet hardness but also reduced disintegration time. Optimal condition was achieved in the range of 5-9% HPC and 3-5% CrosPVP, where tablet properties were at least 70 N tablet hardness, less than 1?min disintegration, and within the USP requirements for drug release. Testing the optimized formulation with four different commercial CBZ samples, their variability was still observed. Nonetheless, all formulations conformed to the USP specifications. Conclusions: With the excipients CrosPVP and HPC-SL an immediate release tablet formulation was successfully formulated for high-dose CBZ of various commercial sources.