HIGH PERFORMANCE LIQUID CHROMATOGRAPHY, TLC-DENSITOMETRY, AND FIRST-DERIVATIVE SPECTROPHOTOMETRY FOR SIMULTANEOUS DETERMINATION OF AMLODIPINE AND PERINDOPRIL IN BULK POWDER AND ITS TABLETS

Abstract

Three simple, sensitive, and specific methods were developed for simultaneous determination of amlodipine besylate (AML) and Perindopril Erbumine (PER) without previous separation. The first method was dependent on the first derivative of the ratio spectra by measuring the amplitudes at 348 nm for amlodipine using 50 µg mL⁻¹ of perindopril as a divisor and at 227 nm for perindopril using 30 µg mL⁻¹ of amlodipine as a divisor. The second method was based on ion-pair RP-HPLC. Satisfactory resolution was achieved using RP-C18 chromatographic column Zorbax Extend column and a mobile phase consists of potassium dihydrogen phosphate buffer (0.05 M, pH 3.0 ± 0.02 adjusted by orthophosphoric acid): acetonitrile 30:70 v/v at a flow rate 1 mL/min using 0.002 M sodium heptanesulfonate in the aqueous phase. UV detection was performed at 215 nm. The third method was based on TLC; the separation was carried out on Fluka TLC aluminum sheets silica gel 60 F₂₅₄, using n-butanol:water:glacial acetic acid (4:5:1, v/v/v) as the mobile phase. The validation of the proposed methods was applied according to ICH guidelines and LOD and LOQ were calculated. The suggested methods were successfully applied for the determination of the cited drugs in bulk powder and commercial tablets.

Keywords:

• amlodipine besylate
• COVERAM tablets
• derivative ratio spectrophotometry
• perindopril erbumine
• RP-HPLC
• TLS-Densitometry

ACKNOWLEDGMENT

The authors express their sincere thanks for the provision of necessary research facilities, as this work has been supported by the bioequivalence center at the October University for Modern Sciences and Arts (MSA), 6th October City, Egypt.

Notes

*The concentration in TLC method is µg spot⁻¹.

*Average of 3 determinations.

Concentration was measured in µg mL⁻¹ for the HPLC, spectrophotometric methods and in µg spot⁻¹ for the TLC method.

^a Average of 5 determinations.

^b Average of 3 determinations.

The values between parenthesis are the theoretical values of t- and F- at P = 0.05.

*Reported HPLC method^{[ 4 ]}; using C8 column, Mobile phase; Buffer: Acetonitrile (65:35) and pH adjusted to 2.6 with dilute Ortho- Phosphoric Acid was delivered at the flow rate 1.0 mL/min. Detection was performed at 210 nm.