ABSTRACT
Different polymorphs of drugs have different molecular arrangements or molecular forces. Raman spectroscopy can reflect the change of molecular polarizability and can be used for the detection of drug polymorphs. The technology has been recorded for the analysis of polymorphism in European Pharmacacopoeia, British Pharamacopoeia and Chinese pharmacopoeia. This review focuses on the application of Raman spectroscopy in the study of pharmaceutical polymorphism. The advances in Raman spectroscopy in the qualitative, quantitative and dynamic processes of drug polymorphism are summarized and analyzed systematically, aiming to provide reference for researchers in related fields.
ABSTRACT
Objective To study the pharmacokinetics difference of levofloxacin polymorphs in rats, evaluate the advantageous medical polymorph,and explore the effects of different polymorphs on clinical medicine. Methods Four crystal forms of levofloxacin were administered intragastrically to rats,and high performance liquid chromatography( HPLC)was used to measure the contents of levofloxacin in rat plasma. The pharmacokinetic parameters were calculated and compared Results After a single oral dose,the peak plasma concentration(Cmax)of crystal forms ofⅠ,Ⅱ,ⅢandⅣof levofloxacin was 6. 984,9. 692,9. 405,6.424 mg·L-1;the time to peak(tmax)was 0.6,0.9,1.0,1.0 h;the half-life(t1/2)was 4.207,2.97,4.857,1.695 h;theareaunderthecurve(AUC0→12h)was31.478,42.385,32.406,31.636mg·h·L-1. Conclusion Thereisnostatistically significant difference in pharmacokinetic parameters. However,compared with other crystal forms,plasma concentration of crystal form II is higher and maintained longer. Therefore,crystal form II of levofloxacin is an advantageous polymorph for medicine.