spectrophotometric determination of tropicamide in bulk and pharmaceutical formulations

a simple and sensitive extractive spectrophotometric method is described for determination of tropicamide. the method is based on the reaction of tropicamide and bromocresol green. the ion-paired colored complex was extracted with chloroform at ph 3. the extracted complex showed maximum absorbance at 423 nm. the complex was stable up to 2 days and obeyed beer's law over the concentration ranges of 1.32-100.81 μg/ml. no significant interference was observed from the excipients, coloring and flavoring agents commonly used in the tropicamide pharmaceutical preparations. the proposed method was applied successfully for determination of tropicamide in commercial eye drop dosage forms.