title: Famotidine polymorphic transformation in the grinding process significantly depends on environmental humidity or water content.
abstract: The effect of environmental humidity and additional water added on the polymorphic change of famotidine in the process of grinding was investigated. The famotidine form B powder with or without additional amount of water added was respectively ground for 30 min in an oscillatory ball mill under 25+/-2 degrees C and three relative humidities (RH) (50+/-5%, 75+/-5% or 95+/-5% RH). Each ground sample was periodically isolated for analytical determinations by using differential scanning calorimetry (DSC), thermogravimetric (TG) analysis and Fourier transform infrared (FT-IR) microspectroscopy. The results indicate that the higher environmental humidity might induce and promote the polymorphic transformation of famotidine from form B to form A in the process of grinding. Moreover, the more the amount of water externally added the easier the polymorphic transformation of famotidine from form B to form A obtained. In addition, the more grinding time spent the more formation of form A obtained. This study disavowed the results of other studies in which no polymorphic change of famotidine even by grinding. The apparent evidence shows that the solid-state polymorphic transformation of famotidine from form B to form A in the grinding process significantly depended on the relative humidity of atmosphere and the additional amount of water added.
authors.affiliation: Department of Medical Research & Education, Taipei Veterans General Hospital, Shih-Pai, Taipei, Taiwan, ROC.
authors.forename: Wen-Ting
authors.initials: WT
authors.lastname: Cheng
authors.forename: Shan-Yang
authors.initials: SY
authors.lastname: Lin
mesh_terms: D002152:Calorimetry, Differential Scanning; D004339:Drug Compounding; D004777:Environment; D015738:Famotidine / Q000008:administration & dosage / Q000737:chemistry*; D006634:Histamine H1 Antagonists / Q000008:administration & dosage / Q000737:chemistry*; D006813:Humidity; D011108:Polymers; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000032:analysis / Q000737:chemistry*
chemical_list: D006634:Histamine H1 Antagonists; D011108:Polymers; D014867:Water; D015738:Famotidine