Drug content in cocrystals was determined by taking equivalent amount of the powder containing 10mg of levofloxacin, dissolved in 10mL of ethanol, shaken for 10-15 minutes and the volume was made up to 100mL using simulated gastric fluid (enzyme free) of pH 1.2. The samples were centrifuged and filtered through 0.45 µm filter, diluted suitably and analysed using UV-Visible spectrophotometer (Systronics, India) at λmax of 227nm. All observations were done in triplicate.
Fourier Transform Infrared Spectroscopy (FTIR)
Fourier Transform Infrared Spectroscopy was performed to characterize and investigate the interaction between levofloxacin and coformers stearic acid and saccharin sodium used. The FTIR spectra for pure levofloxacin, stearic acid, sodium saccharin, L-ST1 and L-SA2 cocrystals were recorded in the range of 4000-500 cm-1 by FTIR Spectrophotometer (Spectrum GX-FT-IR, Perkin Elmer, USA). The samples were prepared by using KBr disk method. Samples of about 2 mg were lightly ground and mixed with 200 mg IR grade dry potassium bromide and then compressed at 10 tonnes in a hydraulic press to form discs. The Spectroscopy was done at a speed of 20scans/s at room temperature …show more content…
The diffraction pattern was scanned over 2 range of 3 to 50o at a scanning rate of 1o/min. The relative degree of crystallinity (RDC) was calculated to determine the degree of drug crystallinity in formulation compared to pure drug, by using the following equation18. (Maulvi et al., 2011) EXM