Method For Determination Of Captopril Research Articles

GREEN PROCEDURE INDEX ASSESSMENT OF THE NOVEL STABILITY-INDICATING RP-HPLC METHOD FOR THE DETERMINATION OF CAPTOPRIL FROM PHARMACEUTICAL DOSAGE FORM

Objective: In this study, it was aimed to develop a novel reverse-phase liquid chromatography method for the ultra-sensitive determination of the antihypertensive drug captopril, using paracetamol, which is the common pain killer, as the internal standard. Optimization of all experimental conditions including composition of mobile phase, flow rate, and column temperature was carried out step by step, and the method validity of the developed method was examined according to international validation guidelines. Calibration range, linearity, the limit of determination, the limit of quantification, robustness, accuracy from commercial tablet samples, and method stability were examined in detail. In addition, the greenness profile for the developed method was assessed with the Green Analytical Procedure Index and Analytical Greenness Calculator techniques, which are frequently used in the literature. Material and Method: The chromatographic method was conducted with an XBridge C18 column (25 cm x 4.6 mm ID; 5 µm) packed with fully porous silica materials. All analyses were performed isocratically with a mobile phase containing acetonitrile:5 mM, pH 7.0 ammonium acetate solution (50:50, v/v) at a flow rate of 1.5 ml min-1. The injection volume was 5 μl, and the column was kept at 25°C in a column oven. The column eluate was monitored at 220 nm. Under optimized conditions, retention times of captopril, and paracetamol were approximately 1.59, and 2.0 min, respectively. Result and Discussion: This study described a fully validated, simple, sensitive, accurate, linear, precise, and reproducible reversed-phase liquid chromatography method for the determination of captopril in tablet samples. Under optimal experimental conditions, the linear range was found in the range of 0.5-200 µg ml-1 and the correlation coefficient was greater than 0.99. Method precision was acceptable, with coefficients of variation between 0.05% and 0.61%. In addition, as a result of the recovery studies carried out on the tablet samples, the accuracy was found to be within satisfactory limits between 99.45% and 102.55%. Moreover, the greenness profile of the developed method also showed that the method is environmentally friendly.

Area under curve UV spectrophotometric method for determination of captopril in bulk and chromatographic method development for the identification of captopril by TLC.

Area under curve UV spectrophotometric method for determination of captopril in bulk and chromatographic method development for the identification of captopril by TLC.

New Batch and Flow Injection Spectrophotometric Method for Determination of Captopril in Some Pharmaceutical Products

New Batch and Flow Injection Spectrophotometric Method for Determination of Captopril in Some Pharmaceutical Products

Molecular Counting of Captopril by a Microfluidic Chip-Thermal Lens Microscopy System

Background: The photo thermal lens microscopy is a technique based on measurement of the temperature rise which is generated in an illuminated matrix because of non-radiative relaxation of absorbed energy from a laser. It is an ideal system for low detection volume measurements in a micro channel. Hence, in this study, a combined microfluidic chip-photo thermal lens microscopy (MFCPTLM) system was assembled for highly sensitive determination of captopril. Captopril is an angiotensin-converting enzyme (ACE) inhibitor used to treat hypertension, congestive heart failure and kidney problem caused by diabetes. Captopril had no absorption in visible range but due to its thiol group, it could interact with Gold nanoparticles (GNPs). So, GNPs act as its labeling agent and the semi-selective measurement of captopril was achieved. Methods: A 3.35 nM GNPs and captopril solution by the same flow rate were introduced to the microchannels by microsyringe pumps. The mixture was detected with an assembled PTLM system. The applicability of optimized method for determination of captopril in human Serum and pharmaceutical sample was investigated as well. Results: The thiol group of captopril bonded to the surface of GNPs, created the core-shell form and reduced the surface plasmon resonance of GNPs; as a consequence, the PTLM signal of GNPs decreased following the increase in captopril concentration. The difference between the PTLM signals of sample and blank was calculated as a ΔPTLM signal. The detection volume of the PTLM was calculated to be 2.68 fL. At the optimum condition this optical view comprised of 5.4 GNPs, surrounded by 65-1049 captopril molecules. Conclusion: In this study, we proposed a sensitive method for the determination of captopril, based on photo thermal lensing of GNPs in a glass microfluidic chip. The S-type form of microchannel and the micro space scale of that enhanced the surface interaction of captopril molecules and GNPs and resulted in more effective reaction. In addition to the fast interaction time and low detection volume, the main features of this method are simplicity, good analytical performance, and low reagent consumption in comparison with batch procedures. The combination of this system with a highly sensitive method such as PTLM reduced the difficulty of sampling which makes it more attractive. The results show the capability of the method for sensitive measurement of captopril in human serum sample and pharmaceutical tablets. Keywords: Microfluidic chip (MFC), photo thermal lens microscopy (PTLM), captopril, gold nanoparticles (GNPs), surface plasmon resonance (SPR), and molecular scale measurement.

Liquid chromatographic method for the simultaneous determination of captopril, piroxicam, and amlodipine in bulk drug, pharmaceutical formulation, and human serum by programming the detector

A highly sensitive LC method with UV detection has been developed for the simultaneous determination of coadministered drugs captopril, piroxicam, and amlodipine in bulk drug, pharmaceutical formulations, and human serum at the isosbestic point (235 nm) and at individual λmax (220, 255, and 238 nm, respectively) by programming the detector with time to match the individual analyte's chromophore, which enhanced the sensitivity with linear range. The assay involved an isocratic elution of analytes on a Bondapak C18 (10 μm, 25 × 0.46 cm) column at ambient temperature using a mobile phase of methanol/water 80:20 at pH 2.9 and a flow rate of 1.0 mL/min. Linearity was found to be 0.25-25, 0.10-6.0, and 0.20-13.0 μg/mL with correlation coefficient >0.998 and detection limits of 7.39, 3.90, and 9.38 ng/mL, respectively, whereas calibration curves for wavelength-programmed analysis were 0.10-6.0, 0.04-2.56, and 0.10-10.0 μg/mL with correlation coefficient >0.998 and detection limits of 5.79, 2.68, and 3.87 ng/mL, respectively. All the validated parameters were in the acceptable range. The recovery of drugs was 99.32-100.39 and 98.65-101.96% in pharmaceutical formulation and human serum, respectively, at the isosbestic point and at individual λmax . This method is applicable for the analysis of drugs in bulk drug, tablets, serum, and in clinical samples without interference of excipients or endogenous serum components.

Indirect spectrophotometric method for determination of captopril using Cr(VI) and diphenylcarbazide

A spectrophotometric method for the indirect determination of captopril (CP) in pharmaceutical formulations is proposed. The proposed procedure is based on the oxidation of captopril by potassium dichromate and the determination excess oxidant on the basis of its reaction with diphenylcarbazide (DPC). Under the optimum conditions, a good linear relationship (r = 0.9997) was obtained in the range of 0.08-3.5 µg mL-1. The assay limits of detection and quantitation were 0.024 and 0.08 µg mL-1, respectively. The results obtained for captopril determination in pharmaceuticals using the proposed method and those obtained with the US Pharmacopoeia method were in good agreement at the 95% confidence level.

Development and Application of a Highly Selective Biomimetic Sensor for Detection of Captopril, an Important Ally in Hypertension Control

A biomimetic sensor is proposed as a promising new analytical method for determination of captopril in different classes of samples. The sensor was prepared by modifying a carbon paste electrode with iron (II) phthalocyanine bis(pyridine) [FePc(dipy)] complex. Amperometric measurements in a batch analytical mode were first carried out in order to optimize the sensor response. An applied potential lower than 0.2 V vs Ag|AgCl in 0.1 mol L-1 of TRIS buffer at pH 8.0 provided the best response, with a linear range of 2.5 x 10-5 to 1.7 x 10-4 mol L-1. A detailed investigation of the selectivity of the sensor, employing seventeen other drugs, was also performed. Recovery studies were carried out using biological and environment samples in order to evaluate the sensor's potential for use with these sample classes. Finally, the performance of the biomimetic sensor was optimized in a flow injection (FIA) system using a wall jet electrochemical cell. Under optimized flow conditions, a broad linear response range, from 5.0 x 10-4 to 2.5 x 10-2 mol L-1, was obtained for captopril, with a sensitivity of 210 ± 1 μA L mol-1.

Flow-Injection Spectrophotometric Determination of Captopril Exploiting Silver Chloranilate Solid-Phase Reactor

A novel, simple, and rapid flow-injection method for the spectrophotometric determination of captopril in pharmaceutical products, using a solid-phase reactor with silver chloranilate (Ag2C6Cl2O4) immobilized in a polyester resin, is presented. This method explored the formation of an insoluble salt between Ag(I) and captopril in the solid-phase reactor, releasing chloranilate anion (). Then, this anion reacted with ferric ions to produce a complex, , which was monitored spectrophotometrically at 528 nm. The analytical curve was linear in the captopril concentration range from 1.0 × 10−5 to 5.0 × 10−4 mol l−1 with a detection limit of 8.0 × 10−6 mol l−1. The relative standard deviation (RSD) was 0.35% (n = 10) for a solution of 3.0 × 10−4 mol l−1 captopril solution, and an analytical frequency of 70 h−1 was obtained. The effects of excipients frequently found with captopril in pharmaceutical formulations, such as lactose, microcrystalline cellulose, starch, and magnesium stearate, were evaluated using the proposed flow-injection method. None of these substances caused significative interference in the proposed method. The method was successfully applied to the determination of captopril in pharmaceutical products, and the results were compared with results obtained using a potentiometric method.

Sensitive high-performance liquid chromatographic method for determination of captopril in plasma.

A rapid, simple and sensitive high-performance liquid chromatographic method for the determination of captopril in plasma has been developed. Captopril is derivatized with a new reagent, 2-bromo-2'-acetonaphthone to form a product that showed ultraviolet-absorbing properties. For plasma samples, the protein was removed with 6% perchloric acid and the derivatized captopril was extracted with diethyl ether. The chromatographic separation was performed on an analytical mu bondapak NH2 column (300 x 3.9 mm, i.d.) with an isocratic mobile phase consisting of n-hexane-2-propanol-methanol-acetic acid (68:15:15:2). Using ultraviolet detection at 246 nm, the quantification limit for captopril in plasma was 10 ng/ml. The calibration curve was linear over the concentration range 12.5-500 ng/ml. The average recovery was 95% for plasma. The inter-day and intra-day assay coefficients of variation were found to be less than 12%.

Sensitive method for determination of captopril in biological fluids by gas chromatography—mass spectrometry

A sensitive method for the determination of captopril in blood and urine by gas chromatography—mass spectrometry is described. In order to prevent oxidative degradation of captopril, its sulph-hydryl group was immediately protected by treatment with N-ethylmaleimide (NEM), and the resulting NEM adduct was then converted into the bis(pentafluorobenzyl) derivative. Derivatized captopril was separated on a 2% OV-1 column, exhibiting a single peak of the correct theoretical shape. The detection limit was estimated to be 100 pg by using S-benzylcaptopril as an internal standard. The blood level and urinary excretion of unchanged captopril orally administered to dogs were determined by the proposed method. In addition, epimerization of the proline moiety and formation of the sulphoxide or sulphone through the esterification step are also described.