Processability of Extended-release Tablets Containing Carbopol® 971P NY Polymer by Roller-compaction

Purpose To determine the processability of formulations containing Carbopol® 971P NF polymer via roller compaction and study the influence of formulation and process variables on the properties of granules and tablets. Methods Two theophylline (50% w/w) formulations containing Carbopol® 971P NF polymer (10 or 20% w/w) and one guaifenesin (25% w/w) formulation containing Carbopol® 971P NF polymer (10% w/w) were dry-granulated at varying process parameters i.e. roll speed (6-12 rpm) and roll pressure (80-100 bars). The granules were blended with lubricant and compressed into tablets (800 mg) on a rotary tablet press. The granules were evaluated for density, particle size and flow characteristics. The tablets were evaluated for weight variation, breaking force, friability and dissolution properties. Reproducibility studies were carried out to ascertain the robustness of the formulations. Results Successful tablet formulations were prepared using theophylline as a model drug, Carbopol® 971P NF polymer (10% and 20% w/w) as a release rate-controlling matrix former via roller compaction. At both polymer levels, the tablets showed acceptable weight, thickness, breaking force and friability values across the process variables tested. The release of theophylline was inversely proportional to the incorporated polymer level i.e. for formulations containing 10% w/w Carbopol® 971P NF polymer complete dissolution was observed after 16 hours while for formulations containing 20% w/w Carbopol® 971P NF polymer complete dissolution was observed after 24 hours. The roller-compaction parameters studied did not appear to have a significant influence on the dissolution performance of the tablets. Guaifenesin tablets containing 10% w/w Carbopol® 971P NF polymer showed consistent and acceptable weight, thickness, breaking force and friability across the process parameters evaluated. The drug release showed low intra-batch variability and complete dissolution was observed after 16 hours. The overall performance of the tablets was found to be reproducible at all the roller compaction process parameters evaluated. Conclusion Theophylline formulations containing Carbopol® 971P NF polymer (10 or 20% w/w) and guaifenesin formulation containing Carbopol® 971P NF polymer (10% w/w) could be successfully processed by roller-compaction for preparing extended-release matrix tablets