Two masterful alternative spectrophotometric methods for the determination of ramipril in tablets

Abstract

The aim of the work was to develop two simple, rapid, economic, alternative spectrophotometric methods for the determination of ramipril in tablets based on the reaction with sulfonephthalein dyes (bromphenol blue (BPB) and cresol red (CR)). Materials and methods. Analytical instrumentation: Shimadzu UV-1800 double beam UV-VIS spectrophotometer (Japan) with attached UV-Probe ver. 2.62 software, RAD WAG AS 200/C precise analytical balance (Poland). Ramipril (purity ≥98 % (HPLC)) was purchased from AARTI Industries Limited (India). Ramipril tablets 5 mg and 10 mg were purchased from a local pharmacy. Results and discussion. Two spectrophotometric methods for the determination of ramipril in tablets have been developed. We have tested various sulfophthalein dyes (BPB, bromocresol green, bromthymol blue, thymol blue, CR) in order to choose the optimal for the method development. According to the results of the experimental studies, we chose BPB and CR as reagents, and the solvent was acetonitrile for both methods. The optimal conditions for the quantitative determination of ramipril in tabletsy using BPB were established: dye concentration - 2.35×10-4 mol/L, volume of BPB solution – 1.0 ml, without heating, wavelength – 598 nm, reaction time – 5 min, temperature of the solution – 25 °C. The optimal conditions for the quantitative determination of ramipril in tabletsusing CR were established: dye 1.33×10-4 mol/L, volume of CR solution – 1.0 ml, without heating, wavelength – 395 nm, reaction time – 5 min, temperature of the solution – 25 °C. The spectrophotometric method by using BPB was linear in the concentration range of 1.99-5.96 µg/mL, LOD – 0.20 µg/mL, LOQ – 0.60 µg/mL. The spectrophotometric method using CR was linear in the concentration range of 0.42-5.44 µg/mL, LOD – 0.10 µg/mL, and LOQ – 0.36 µg/mL. The results of the study on robustness, accuracy, and precision were within the acceptance criteria. The results of studying the «greenness» of both methods indicate an excellent «green» analysis.Conclusions. Developed methods can be used as an alternative method for the routine analysis of ramipril tablets