Captopril In Pharmaceutical Formulations Research Articles

Square-wave voltammetric (SWV) determination of Captopril in reconstituted serum and pharmaceutical formulations

A simple, fast and sensitive square-wave voltammetric (SWV) method for the determination of trace amounts of Captopril in pharmaceutical formulation and reconstituted serum is reported. A three-electrode system containing the static mercury drop electrode (SMDE) working electrode, Pt auxiliary electrode and Ag/AgCl reference electrode was used throughout. Sodium sulfite was used as both supporting electrolyte and oxygen removing agent. No nitrogen purging is needed for oxygen removal from sample solution. Calibration graph showed good linearity in the concentration range of 0.5–50.0 μg mL −1 of Captopril and regression coefficient of 0.9957 is obtained. R.S.D. for eight replicate measurements and LOD of the proposed method are 1.2% and 6.28 × 10 −3 μg mL −1, respectively. The effect of various parameters (equilibration time, scan increment, pulse height, drop size, frequency and sodium sulfite concentration) on the determination were investigated. The procedure was successfully applied to the determination of Captopril in pharmaceutical formulation and reconstituted serum.

Potentiometric determination of captopril in pharmaceutical formulations

A simple, precise, rapid and low-cost potentiometric method for captopril determination in pureform and in pharmaceutical preparations is proposed. Captopril present in tablets containing knownquantity of drug was potentiometrically titrated in aqueous solution with NaOH using a glass pH elec-trode, coupled to an autotitrator. No interferences were observed in the presence of common compo-nents of the tablets as lactose, microcrystalline cellulose, croscarmellose sodium, starch and magnesiumstearate. The analytical results obtained by applying the proposed method compared very favorably withthose obtained by the United States Pharmacopoeia Standard procedure. Recovery of captopril fromvarious tablet dosage formulations range from 98.0 to 102.0%.

Potentiometric determination of captopril in pharmaceutical formulations

A simple, precise, rapid and low-cost potentiometric method for captopril determination in pure form and in pharmaceutical preparations is proposed. Captopril present in tablets containing known quantity of drug was potentiometrically titrated in aqueous solution with NaOH using a glass pH electrode, coupled to an autotitrator. No interferences were observed in the presence of common components of the tablets as lactose, microcrystalline cellulose, croscarmellose sodium, starch and magnesium stearate. The analytical results obtained by applying the proposed method compared very favorably with those obtained by the United States Pharmacopoeia Standard procedure. Recovery of captopril from various tablet dosage formulations range from 98.0 to 102.0%.

Sequential injection analysis of captopril based on colorimetric and potentiometric detection

The development of an analytical procedure based on the sequential injection analysis (SIA) concept for the analytical control of captopril in pharmaceutical formulations is described. The robustness of the proposed system is established by accuracy assessment that consists in yielding a versatile manifold for the carryout of two quasi-independent analytical determinations. One of the captopril determination procedures is based on the colorimetric measurement of the captopril–palladium complex in acid media at the 400 nm. No interference from other compounds usually contained in the samples was found, even when its concentration was 25 times higher than that of the analyte. The other procedure involves the potentiometric titration of captopril with a 10 −3 mol/l Ag(I) solution used as titrant and the application of the Gran’s method for ascertaining the equivalence point. Accuracy of the proposed approach was attained by developing an in-line calibration procedure for the assessment of the electrode slope and performing titration in four different titrant/analyte mixtures. Precision of the developed procedures was better than 1.3%, being similar to that of the reference chromatographic method. The results attained were statistically similar to those given by the reference method and, thus, the accuracy assessment concept may be used for the determination of failures of the analytical procedure when performing large-scale analysis.