Precision of the method was determined in terms of repeatability and intraday and interday precisions. Repeatability Repeatability of the method was determined by analyzing six samples of same concentrations of drug. Chromatographs were recorded, and the area of each chromatograph was measured. The results of this determination are reported in Table 4. Table 4 Result of repeatability, citation intraday, and interday precision studies Intraday and interday precision Intraday precision was determined by analyzing the drugs at three different concentrations and each concentration for three times, on the same day. Interday precision was determined similarly, but the analysis being carried out daily, for three consecutive days. The results are summarized in Table 4.

Robustness The robustness of a method is its capacity to remain unaffected by small changes in conditions. To determine the robustness of the method, the experimental conditions were deliberately altered and assay was evaluated. The effect of detection wavelength was studied at ��2 nm. For changes of conditions, the sample was assayed in triplicate. When the effect of altering one set of conditions was tested, the other conditions were held constant at the optimum values. Assay of ZLT for all deliberate changes of conditions was within 98.0�C102.0 %. The results are shown in Table 5. Table 5 Result of robustness studies Ruggedness To determine ruggedness, two different analyst performed assay on marketed tablets of the drug in similar operational and environmental conditions using developed method. The results are summarized in Table 6.

Table 6 Result of ruggedness studies Solution stability The stability of the standard solution was tested at intervals of 1, 4, and 8 h. The stability of solutions was determined by comparing absorbance of ZLT. The absorbance values were within 0.5% after 8 h. These results indicate the solution was stable for 8 h at ambient temperature, because there was no change in assay value. The %RSD of assay was 1.12% and 1.03% at 243.5 and 338.0 nm, respectively, after 8 h. The results are shown in Table 7. Table 7 Stability data RESULTS AND DISCUSSION The overlay UV spectra of standard and tablet solutions of ZLT in Milli-Q water were found to be same. The UV spectrum of ZLT in Milli-Q water has two maximum absorption (��max), one at 243.5 nm and another at 338.0 nm.

The absorbance of excipients Batimastat in tablet solution did not interfere with ZLT at 243.5 and 338.0 nm. As a result, both wavelengths were selected for quantitative analysis and validation. The developed method was found to be precise as the %RSD values for intraday and interday precision were found to be less than 2%. The method was also found to be accurate, indicated by % recoveries ranging from 99.20 to 100.16%.