Determination of lisinopril using anion exchange chromatography with integrated pulsed amperometric detection

DEVELOPMENT OF SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF LISINOPRIL IN TABLET DOSAGE FORM

Aim. The research aims at developing a fast, simple, reliable spectrophotometric method according to "green" chemistry principles for the determination of lisinopril in pure substance and in drugs presented on the Ukrainian market. Materials and Methods. Chemical reference standard of lisinopril dihydrate (Sigma-Aldrich, ³98%, HPLC), methanol R (Honeywell Riedel-de Haen™, 99.9%), tablets of Lisinopril-Astrapharm 10 mg), Lisinopril-KRKA 10 mg (Slovenia) and Lisinopril-Teva 10 mg (Germany) were used in this study. Double-beam scanning spectrophotometer "Shimadzu UV-1800" (Japan) connected with software package UV-Probe 2.62 were used for measurements. Absorbance of the solutions in the UV region were recorded in 1 cm quartz cells vs. methanol R. Laboratory electronic balance RAD WAG AS 200 / C, ultrasonic bath Sonorex Digitec DT100H and measuring glassware of grade A were used. Statistical processing and determination of validation parameters were performed in accordance with the requirements of State Pharmacopoeia of Ukraine 2.0 and ICH Q2. Results and Discussions. The spectrophotometric method for the determination of lisinopril by direct measurement of the absorbance of the tested solutions in the ultraviolet region of the spectrum has been developed (lmax=212 nm). Validation parameters including linearity, range of application, specificity, accuracy, precision, limit of detection and limit of quantification, robustness were calculated for the proposed analytical procedure. The correctness of the analytical method was proved by calculating the complete uncertainty of the latter. The calculated uncertainty of sample preparation (DSP) for the determination of lisinopril in tablets was 2.46%. It was established that the maximum contribution to the uncertainty of sample preparation for operations of the quantification of lisinopril in tablets, make the operations of lisinopril CRS sampling and aliquots pipetting. The total uncertainty of the analytical procedure (DAs) in the analysis of the drug was 2.56%. The predicted complete uncertainty of the analysis results did not exceed critical values (DAs=2.56 % £ maxDAs=3.2 %), the method is correct. The specificity is proved by the absence of interfering influence of excipients due to nonoccurence of absorption at the analytical wavelength in the analysis of methanolic extract of placebo-tested tablets, Beers law was obeyed in the ranges of 20-100 mg / ml. The least squares method was used for statistical processing of the results. Regression analysis yielded the following calibration equation: y=26,791x-0,4398. The limit of detection and the limit of quantification were 2,3 і 6,9 mg/ml. Robustness of the method was estimated by studying of absorbance stability changes of tested solutions over time. Robustness was assessed by studying the absorbance stability of the tested solutions over time. It was found that freshly prepared solutions should be used within 100 min. Developed procedure for lisinopril determination in pure substance and tablet dosage form proved to be an excellent green analysis according to analytical eco-scale. Conclusions. Fast, simple, reliable, cost-effective, in accordance with the principles of "green" chemistry spectrophotometric method for determination of lisinopril in pure substance and tablets has been proposed. Validation of the analytical procedure on the parameters of linearity, application range, specificity, accuracy, precision, robustness, limit of detection and limit of quantification was carried out. The complete uncertainty of the analytical procedure at the level of 2.56% was obtained, which proves the possibility of obtaining correct analysis results in other laboratories.

An innovative validated spectrofluorimetric method for determination of Lisinopril in presence of hydrochlorothiazide; application to content uniformity testing

A new sensitive and discriminating spectrofluorimetric method has been developed and validated for determination of Lisinopril, one of the angiotensin converting enzyme inhibitors, in its pure bulk form and pharmaceutical tablets. The reaction of Lisinopril with ethylacetoacetate and formaldehyde in acidic buffered medium (pH3.8) has yielded a pale yellow product that exhibited a high fluorescence measured at 438nm after excitation at 350nm. All the experimental parameters affecting the formation and stability of the produced fluorophore were carefully investigated and optimized to give the maximum sensitivity. The fluorescence intensity was directly proportional to the drug concentration in the range of 0.5-4.5μg/mL with a limit of detection equal to 0.16μg/mL. The method was successfully applied in the analysis of the commercially available pharmaceutical tablets containing the single drug or its binary mixtures with Hydrochlorothiazide. Furthermore, the developed procedure was adapted for studying the content uniformity test of some dosage forms containing the cited drug.

Switch on fluorescence probe for the selective determination of lisinopril in pharmaceutical formulations: application to content uniformity testing

Lisinopril, an ACE inhibitor, was selectively determined in pharmaceutical products through switch on the fluorescence of fluorescamine.