Structure determination and characterization of carbendazim hydrochloride dihydrate
- 293 Downloads
The objective of this study was to synthesize and characterize the hydrochloride salt of carbendazim with the aim of improving the intrinsic solubility of the parent compound. Carbendazim hydrochloride dihydrate was synthesized for the purpose of increasing the aqueous solubility of the parent drug, carbendazim. This was done with the commonly used saturation and cooling method. The structure was determined by single crystal radiograph crystallography, and the hydrochloride salt was found to be a dihydrate. The salt crystallized in a P 21 21 21 (#19) space group, which is typical for nonplanar, achiral, and noncentrosymmetric molecules. The asymmetric unit is comprised of 1 molecule each of carbendazim and chloride and 2 water molecules. The carbendazim molecules arrange themselves in a helical structure, with the waters and the chloride molecules in the channel linking the helix. The crystal lattice is held together by numerous hydrogen bonds, as well as van der Waals interactions. The melting point of the salt is 125.6°C. The solubility of the salt is 6.08 mg/mL, which is a thousand-fold increase from the intrinsic solubility (6.11 μg/mL) of the free base.
Keywordscarbendazim dihydrate hydrochloride radiograph crystallography helical structure enantiotropic
- 4.Serajuddin ATM, Pudipeddi M. Salt selection strategies. In: Stahl PH and Wermuth CG, eds.Handbook of Pharmaceutical Salts Properties Selection and Use. Verlag Helvetica Chemica Acta (Switzerland) and Wiley-VCH (Federal Republic of Germany), 2002;158–159.Google Scholar
- 8.Bighley LD, Berge SM, Monkhouse DC. Presevation of pharmacuetical products to salt forms of drugs and absorption. In: Swarbrick J, Boylan JC, eds.Encyclopedia of Pharmaceutical Technology 13. New York, NY: Marcel Dekker; 1996;453–499.Google Scholar
- 9.Massa W.Crystal structure determination. New York: Springer-Verlag; 2000.Google Scholar