development and validation of a rapid derivative spectrophotometric method for determination of tropicamide in eye drops

tropicamide is an antimuscarinic agent used as eye drops for refractive examinations. the aim of this study was to develop a simple and suitable analytical method for determination of tropicamide in eye drops in the presence of excipients. a zero-crossing third and fourth derivative spectrophotometric method was described for determination of tropicamide in eye drops. the measurements were carried out at wavelengths of 263.8 and 255.4 nm for third- and fourth-derivative, respectively. the method was found to be linear (r2> 0.999) in the range of 10-100 mg/ml for tropicamide in the presence of excipients. the limit of determination was 10 mg/ml for tropicamide. the method was successfully applied for determination of tropicamide in eye drops without any interference from excipients or need to prior separation before analysis.