5, 25, and 37.5 ��g/ml) to a preanalyzed formulation sample and the total concentration was determined using the proposed method (n = 5). The accuracy was calculated as percentage recovery = [Ct/ (Ca+Cs)] �� 100, where Ct is the total drug concentration measured after standard addition; Cs is drug concentration in the Tenatoprazole? formulation sample; Ca is drug concentration added to formulation [Table 3]. Table 2 Accuracy data for the developed method (n = 5) Table 3 Standard addition of disodium edetate in formulation for accuracy (n = 5) Repeatability was determined by using different levels of drug concentrations from independent stock solutions and analyzed in triplicates, three different times in a day and studied for intraday variation. The intermediate precision was determined by interday variation.

The estimation was followed for three different days to study interday variation. One set of different levels of the concentrations was reanalyzed using the UV-VIS spectrophotometer. The percent relative standard deviation (%RSD) of the predicted concentrations from the regression equation was taken as precision [Table 3]. Limit of detection and limit of quantitation The limit of detection (LOD) and limit of quantitation (LOQ) for disodium edetate by the proposed method were determined using calibration standards. LOD and LOQ were calculated by using the formula as 3.3 ��/S and 10 ��/S, respectively, where S is the slope of the calibration curve and �� is the standard deviation of y-intercept of regression equation (n = 5) [Table 1].

RESULTS AND DISCUSSION The ��max of disodium edetate in solution was found to be 270 nm by scanning the sample solutions in entire UV region. The developed method was found to be linear in the range of 5�C50 ��g/mL, where Beer’s law was well obeyed. Calibration curve was constructed by using linear regression equation. The regression equation was originate y = 0.0191x – 0.0013. The correlation coefficient (r2) of the regression curve was found to be 0.9997 [Figure 2]. All the validation parameters for disodium edetate are listed in Table 1. Figure 2 Calibration curve of disodium edetate Specificity and selectivity The UV spectras of disodium edetate alone and with excipients were found to be similar, indicated no effect of excipients on the absorption of disodium edetate.

Hence, it can be said that the proposed analytical method is specific and selective for the estimation of disodium edetate in topical gel formulations. Linearity, accuracy, and precision The linearity range for disodium edetate was found to be 5�C50 ��g/mL with r2 value Carfilzomib of 0.9997 [Table 1]. The quality of fit of the regression equations was supported by the high-regression coefficient values [Table 1]. For accuracy, recovery studies were carried out and the percentage recovery was found in the range of 98.48�C100.16.