A novel validated stability indicating high performance liquid chromatographic method for estimation of degradation behavior of ciprofloxacin and tinidazole in solid oral dosage

Abstract

Objective: The objective of current investigation was to study the degradation behavior of Ciprofloxacin and Tinidazole. The study was performed as per International Conference on Harmonization recommended stress condition. A novel stability-indicating reverse phase HPLC method was developed for the determination of Ciprofloxacin and Tinidazole purity in the presence of its impurities and forced degradation products. This method is also capable to separate placebo peaks as well in pharmaceutical dosage forms. The solid oral dosage form was subjected to the stress conditions such as oxidative, acid, base hydrolysis, heat and photolytic degradation.

Materials and methods: The method was developed using Waters symmetry shield, Reverse Phase (RP) C18, 250mm x 4.6mm, 5μ as a stationary phase. The mobile phase containing a gradient mixture of solvent A and B. 10mM phosphate buffer, adjusted pH 3.0 with phosphoric acid was used as a buffer. Buffer pH 3.0 was used as solvent A and buffer pH 3.0: Acetonitrile in the ratio of 20: 80 v/v were used as solvent B. The eluted compounds were monitored 278 nm (Ciprofloxacin), 317 nm (Tinidazole). The run time was 50 minute.

Results: In the precision study the % RSD for the result of Ciprofloxacin, Tinidazole and its impurities was below 10%. The method was linear with the correlation coefficient greater than 0.997. The percentage recoveries were calculated and observed from 93.0% to 106.7%. The peak purity of Ciprofloxacin, Tinidazole peak had not shown any flag, thus proved the stability-indicating power of the method.

Conclusion: The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness.

Keywords: Ciprofloxacin; degradation; related substances; tinidazole; validated.

Figure 1

Structure of ciprofloxacin and its related compound (I-II). Structure of tinidazole and its related compound (III-V)

Figure 2

Typical chromatograms ciprofloxacin at 278 nm (placebo, resolution solution, standard solution, test spiked with impurities and degradation test) at optimized chromatographic conditions (a-h) typical chromatograms tinidazole at 317 nm (placebo, standard solution, test spiked with impurities and degradation test) at optimized chromatographic conditions (i-o)