Validated Spectrophotometric Methods for Determination of Weakly UV absorbed Perindopril Arginine in Bulk and Combined Dosage Form

Abstract

Five simple, specific, accurate and precise spectrophotometric methods were developed and validated for the simultaneous determination of the oral antihypertensive drugs; perindopril arginine (PER) and amlodipine besylate (AML) in their combined dosage form. AML can be determined directly by measuring its absorbance at λ_max357 nm. On the other hand PER was determined by five different methods. The first two methods, ratio derivative (RD) and Derivative subtraction coupled with the constant multiplication method (DS-CM), were performed using the ratio spectra. While the other three methods, amplitude factor (P-Factor), amplitude subtraction (AS) and modified amplitude subtraction (MAS), were developed based on derivative spectroscopy followed by mathematical manipulation. No preliminary separation steps were required for the proposed spectrophotometric methods. Linearity, accuracy and precision of the method was found to be acceptable over the concentration ranges of 20-80 μg/mL for PER and 5-40 μg/mL for AML. The proposed spectrophotometric methods were statistically compared to that of reference methods using one-way analysis of variance (ANOVA). The results showed that there was no significant difference between them.

Key words:

• Derivative subtraction coupled with constant multiplication method
• Amplitude subtraction
• Modified amplitude subtraction method
• Perindopril arginine
• Amlodipinebesylate