ABSTRACT
The absorption spectra of three kinds of medicines both before and after the expiration date: Amlodin OD(®) (5 mg), Basen OD(®) (0.2 mg) and Gaster D(®) (10 mg) have been measured by terahertz time domain spectroscopy (THz-TDS). All the medicines show some differences in the THz absorption spectra between medicines before and after the expiration dates. X-Ray powder diffraction (XRD) studies of all medicines suggest that the polymorph of the main effective compound is not changed before and after the expiration date. Therefore, the differences in the THz spectra between medicines before and after the expiration dates arise from aging variation of diluting agents and/or from modifications of intermolecular interaction between the effective compounds and diluting agents.
Subject(s)
Pharmaceutical Preparations/chemistry , Terahertz Spectroscopy/methods , Absorption , Pharmaceutical Preparations/analysis , Time Factors , X-Ray DiffractionABSTRACT
The absorption spectra of ceftazidime and its generic versions (Modacin, Mosyl, and Mobenzocin) have been measured by terahertz time domain spectroscopy (THz-TDS). Differences in the THz absorption were observed between the original and generic versions. The results show small, but significant differences in the states of ceftazidime hydrate between the original and generic versions. THz-TDS can be used to evaluate the stability of medicines as well as to control their quality.
