title: Improvement of physicomechanical properties of carbamazepine by recrystallization at different pH values.
abstract: The morphology of crystals has an appreciable impact role on the physicochemical properties of drugs. Drug properties such as flowability, dissolution, hardness and bioavailability may be affected by crystallinity behaviours of drugs. The objective of this study was to achieve an improved physicomechanical property of carbamazepine powder through recrystallization from aqueous solutions at different pH values. For this purpose, carbamazapine was recrystallized from aqueous solutions at different pH values (1, 7, 11). The morphology of crystals was investigated using scanning electron microscopy; X-ray powder diffraction (XRPD) was used to identify polymorphism; thermodynamic properties were analyzed using differential scanning calorimetery (DSC). Dissolution rate was determined using USP dissolution apparatus. Mechanical behavior of recrystallized carbamazepine powders was investigated by making tablets under different compaction pressure and measuring their hardness. SEM studies showed that the carbamazepine crystallization in different media affected the morphology and size of carbamazepine crystals. The shape of carbamazepine crystals changed from flaky or thin plate-like to needle shape. XRPD and DSC results ruled out any crystallinity changes occurring due to the temperature during recrystallization procedure or pH of crystallization media. The crushing strength of tablets indicated that all of the recrystallized carbamazepine samples had better compactiblity than the original carbamazepine powder. In vitro dissolution studies of carbamazepine samples showed a higher dissolution rate for carbamazepine crystals obtained from media with pH 11 and 1. Carbamazepine particles recrystallized from aqueous solutions of different pH values (all media) appeared to have superior mechanical properties to those of the original carbamazepine sample.
authors: Faculty of Pharmacy and Drug, Applied Research Centre, Tabriz University of Medical Sciences, Tabriz 51664, Iran. javadzadehy@yahoo.com
authors: Yousef
authors: Y
authors: Javadzadeh
authors: Ameneh
authors: A
authors: Mohammadi
authors: Nazaninossadat Seyed
authors: NS
authors: Khoei
authors: Ali
authors: A
authors: Nokhodchi
mesh_terms: D000927:Anticonvulsants / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002220:Carbamazepine / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D019245:Compressive Strength; D003460:Crystallization; D018360:Crystallography, X-Ray; D006244:Hardness; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D033362:Powder Diffraction; D012995:Solubility; D013607:Tablets; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000927:Anticonvulsants; D013607:Tablets; D002220:Carbamazepine