On the quantification of ciprofloxacin in proprietary Ciproxin tablets and generic ciprofloxacin tablets using handheld Raman spectroscopy

Quantification of ciprofloxacin in proprietary Ciproxin tablets and generic ciprofloxacin tablets was made using handheld Raman spectroscopy. Powder dilutions of ciprofloxacin or crushed Ciproxin tablets with excipient(s) were made. The spectra were taken either from the powder dilutions or from pellets compressed from these dilutions and were stored in the instrument library. Methods were created from these powder dilutions: each representing a separate model. The spectra of the tablets were identified within each method using the inbuilt algorithm of the instrument. The results showed that only the models made with the crushed Ciproxin tablets were semi-quantitative for the analysis of Ciproxin tablets. On the other hand, none of the models could identify generic ciprofloxacin tablets. Thus, the spectra were exported to MATLAB for off-line quantification. Whereas, univariate regression models were hardly linear, partial least square regression models gave linear calibrations with correlation coefficients above 0.99 and root mean square error of calibration below 3.75% m/m. For the prediction of tablets, the models varied in their results with the one created with ciprofloxacin and lactose giving the most satisfactory results. However, in total the method did not give the pharmacopoeial accuracy of +/- 5% and stays a semi-quantitative approach although a satisfactory identity of the constituents was achieved. Copyright (c) 2011 John Wiley & Sons, Ltd.