A dynamic thermal ATR-FTIR/chemometric approach to the analysis of polymorphic interconversions. Cimetidine as a model drug

A PCA-based chemometrics-assisted ATR-FTIR approach for the classification of polymorphs of cimetidine: Application to physical mixtures and tablets

“…Bauer-Brandl has shown that some CIM polymorphs can undergo transformations in the dry state upon milling [38]. On the other hand, we have recently reported a study on the dehydration of form M1 to polymorph B [39].…”

“…The polymorphs employed in this work were prepared according to recently reported procedures [39], using distilled water and analytical grade reagents. The phase purity and identity of the forms were confirmed by optical, thermal and spectroscopic means.…”

“…Polymorphic forms A, B, D and monohydrate M1 (the designation of the polymorphs is according to Hegedüs and Görög [23]) were obtained as previously reported [39] and unequivocally characterized by digital microscopy, ATR-FTIR spectroscopy, differential scanning calorimetry and solid state CP-MAS 13 C NMR spectrometry. The results were in agreement with the literature [23,24,26,38].…”

Vibrational spectroscopy used in polymorphic analysis

“…Cimetidine has several relevant solid-state forms, including four polymorphs (A, B, C and D), an amorphous form (AM) and a monohydrate (M1). Dehydration of M1 has been reported to yield mixtures of polymorphs A, B and C or just a single form [33]. It was demonstrated that, under the experimental conditions, dehydration of M1 initially resulted in the formation of polymorph B; after melting and upon cooling, polymorph B yielded an AM.…”

Formulation and Evaluation of Floating Tablets of Cimetidine

“…It is a specific competitive antagonist of histamine H 2 receptor at the parietel cell 10 . It is widely used in condition where inhibition of gastric acid secretion may be beneficial such as heart burn associated with acid reflux , duodenal and gastric ulcer , gastroesophagal reflux diseases and hyper-secretory syndrome such as Zollinger -Ellision's 11 . Literature show that cimetidine is poorly absorbed from the lower gastrointestinal tract and has a short elimination half-life.…”