The evaluation of microwave drying on the polymorphic characteristics of carbamazepine granules prepared by the wet granulation process.

Abstract

The drying conditions of granules for tabletting prepared by the wet granulation process traditionally involve conduction, convection and radiation heat transfer. Despite various technological advances utilizing combinations of these conditions, the drying rates for pharmaceutical granules remain relatively high. Microwave drying is an alternate source of drying for pharmaceutical granules providing a faster drying rate, cost reduction benefits as well as reduced shrinkage and structural damage to granules. Polymorphic transformation of compounds in pharmaceutical products have become an important focus area since it can have disastrous economic, therapeutic and legal transform infrared (FTIR) spectral analysis to determine whether microwave drying would alter the polymorphic characteristics of carbamazepine (CBZ) contained in granules and tablets prepared by a wet granulation process, in comparison to convection tray drying. In addition, the compressed tablets from each drying method were subjected to the British Pharmacopendial [5] quality control standards to verify compliance. Preformulation studies were conducted on CBZ and selected excipients to establish compatibility and suitability in the development of a simple fast release tablet formula. The commercial CBZ powder, termed beta (B)-polymorph, was used to prepare an alpha (a)- and a dihydrate (DHD) polymorph. All three polymorphs were fully characterized by XRPD and FTIR spectral analysis and served as fingerprint markers for granule and tablet evaluation.