Variable-temperature X-ray powder diffraction analysis of the crystal transformation of the pharmaceutically preferred polymorph C of mebendazole.
Mebendazole is a common benzimidazole anthelmintic that is water insoluble. It is reported to exist in three different polymorphic forms in the solid state, i.e. polymorph A, B and C. Form C is the pharmaceutically preferred form because of its increased aqueous solubility. This paper deals with the use of variable-temperature X-ray powder analysis (VTXRPD) to study the transformation of Form C. Results showed that Form C was stable and transformed to the more stable polymorph A at high temperature (>180 degrees C). This transformation is a first-order process with activation energy of 238 +/- 16 kJ/mole. Further studies showed that compression did not cause any significant changes in the crystal structure of polymorph C.
de Villiers
Melgardt M
MM
School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana 71209, USA. devilliers@ulm.edu
Terblanche
Rudolf J
RJ
Liebenberg
Wilna
W
Swanepoel
Erna
E
Dekker
Theo G
TG
Song
Mingna
M
D000871:Anthelmintics / Q000032:analysis* / Q000737:chemistry; D003460:Crystallization; D007536:Isomerism; D008463:Mebendazole / Q000032:analysis* / Q000737:chemistry; D015394:Molecular Structure; D013678:Technology, Pharmaceutical / Q000379:methods; D013816:Thermodynamics; D044366:Transition Temperature; D014961:X-Ray Diffraction / Q000379:methods*
D000871:Anthelmintics; D008463:Mebendazole