US EPA

8162190 

Journal Article 

Optimized and validated spectrophotometric methods for the determination of gatifloxacin in pharmaceuticals using N-bromosuccinimide and three dyes 

Basavaiah, K; Anil Kumar, UR 

2006 

72 

4 

225-229 

English 

Three new visible spectrophotometric methods which are simple, sensitive and cost-effective are proposed for the determination of gatifloxacin (GTF) using N-bromosuccinimide (NBS), and three dyes, thymol blue, indigo carmine and methyl orange as reagents. The methods engross the addition of a known excess of NBS to GTF in hydrochloric acid medium followed by determination of unreacted oxidant after a preset time by reacting with a fixed amount of either thymol blue and measuring the absorbance at 550 nm (Method A) or indigo carmine and measuring the absorbance at 610 nm (Method B) or methyl orange and measuring the absorbance at 520 mn (Method C). In all the methods, the amount of NBS reacted corresponds to the amount of GTF and the absorbance is found to increase linearly with concentration of GTF. Under the optimum conditions, GTF could be assayed in the concentration range 0.5-10, 0.5-7.5 and 0.5-1.5 μg mL-1 by method A, method B and method C, respectively. The apparent molar absorptivities are calculated to be 3.4×,104. 2.9×104 and 1.8×105 L mol-1 cm-1 for method A, method B, and method C, respectively, and the corresponding Sandell sensitivity values are 0.012, 0.014 and 0.002,μg cm-2. The limits of detection and quantification are also reported. The intra-day and inter-day precision and accuracy of the methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the determination of GTF in pharmaceutical preparations without interference from any of the pharmaceutical adjuvants. The results are in agreement with the reference method. The reliability of the methods was further checked by recovery experiments. 

Assay; Formulations; Gatifloxacin; N-bromosuccinimide; Spectrophotometry