Method development and validation for simultaneous estimation of amlodipine besylate and enalapril maleate in solid dosage form

A rapid, sensitive, specific, accurate and precise high pressure liquid chromatographic method (HPLC) method involving UV detection has been developed for the determination and quantification of Amlodipine Besylate and Enalapril maleate in bulk and combined dosage form. The determination was carried out on a Phenomenex C18 column (Dimention : 250 x 4.6 mm, 5 μm). The sample was analysed using filtered and degassed mixture of methanol : 0.1N HCl (1:1) as mobile phase at a flow rate of 1ml/min and effluent was monitored at 218nm. The retention time for Amlodipine besylate was 7.6 min and for Enalapril maleate 3.2 min. Amlodipine besylate and Enalapril maleate showed a linear response in the concentration range of 10-50μg/ml. The correlation co-efficient ('r' value) for Amlodipine besylate and Enalapril maleate was 0.9992 and 0.9994, respectively. The method was validated in terms of linearity, precision, accuracy, specificity, robustness and solution stability. The proposed method can be used for routine analysis of Amlodipine Besylate and Enalapril maleate in bulk and combined dosage form

Development and Validation of a Method for the Semi-Quantitative Determination of N-Nitrosamines in Active Pharmaceutical Ingredient Enalapril Maleate by Means of Derivatisation and Detection by HPLC with Fluorimetric Detector

A novel HPLC method with fluorimetric detection was developed for the determination of potentially carcinogenic N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) in active pharmaceutical ingredient enalapril maleate. N-nitrosamines were subject to denitrosation followed by derivatisation with dansyl chloride or fluorenylmethoxycarbonyl chloride (Fmoc-Cl). Fmoc-Cl offers much better sensitivity and repeatability than dansyl chloride derivatisation. A satisfactory linearity was obtained for the method, with R2 = 0.9994 for NDMA and 0.9990 for NDEA, and a limit of quantification level of 0.038 μg/g for NDMA and 0.050 μg/g for NDEA. The precision decreased with the concentration to a maximum level of about 10%. The recoveries were in the range of 74.2 ± 4.2% to 101.6 ± 16.1% for NDMA and 90.6 ± 2.9% to 125.4 ± 7.4% for NDEA. Dansyl chloride was found to be an inappropriate derivatisation agent, mainly due to potential contamination with dimethylamine, leading to unrepeatable peaks in the blank solution. Since the method involves the derivatisation of amines liberated from the N-nitrosamines, it was necessary to remove the amines from the test sample. Several critical points in the standard/sample preparation have been mentioned, which affect the reproducibility of the method and are not covered in similar articles.

Direct Spectrophotometric Determination of Perindopril Erbumine and Enalapril Maleate in Pure and Pharmaceutical Dosage Forms using Bromocresol Green

In this article, it has been reported new, simple, sensitive and direct spectrophotometric methods for the determination of Perindopril Erbumine (PPE) and Enalapril Maleate (ENL) in pure and in pharmaceutical forms. Spectrophotometric methods are based on the formation of yellow colored ion-pair complexes between PPE, ENL and sulphonphthalein acid dye, Bromocresol green (BCG) into chloroform were measured at the wavelength of 414 and 415nm for PPE and ENL, respectively. The optimal analytical conditions were determined. The obtained complexes (BCG: PPE) and (BCG: ENL) reached maximum absorbance directly after formation at room temperature for a stability period of 24 h. Beer’s law were obeyed in the concentration ranges of (2-20)µg/mL for PPE and (8- 44)µg/mL for ENL, the limit of detection of 0.125μg/mL and 0.230μg/mL were found for PPE and ENL, respectively. The molar absorptivity coefficients were 4.4045*104 L.moL-1.cm-1 for PPE and 1,9330*104 L.moL-1.cm-1 for ENL. The stoichiometry of the complexes formed between PPE, ENL and BCG were 1:1. No interference was observed from common excipients occurred in pharmaceutical formulations and the proposed methods have been successfully applied to determine the PPE and ENL in some pharmaceutical products and in ENL combination dosage forms with hydrochlorothiazide (HCTZ). The proposed methods were successfully validated to be utilized in the quantitative analysis of PPE and ENL in their pure and pharmaceutical products. A good agreement between the developed spectrophotometric methods with the results obtained from official reference methods for the determination of the two drugs in some real samples demonstrate that the proposed methods were suitable to quantify PPE and ENL in pharmaceutical formulations.

The use of liquid chromatography method for quantitative determination of active substances in Enalapril-H tablets

The aim. Combination therapy is used to treat hypertension. Strengthening the action of the ACE inhibitor enalapril is carried out in combination with the thiazide diuretic hydrochlorothiazide. On the pharmaceutical market, such combined preparations are presented by different manufacturers in various concentrations of the active ingredients of enalapril maleate and hydrochlorothiazide. Development of methods for the quantitative determination of active substances in combined drugs by liquid chromatography is topical. Materials and methods. Shimadzu Nexera X2 LC-30AD liquid chromatograph equipped with DAD SPD-M20A diode array detector, SIL-30AC autosampler and CTO-20AC column thermostat; analytical balance - UniBloc AUW120D; pH meter - Knick type 911pH; chromatographic column ACE C18, size 250 mm × 4.6 mm, packed with octadecylsilyl silica gel for chromatography with a particle size of 5 μm. Results. Based on the results of the work, a method for the quantitative determination of enalapril and hydrochlorothiazide in the presence of HPLC was proposed. The obtained validation characteristics indicate that the method for the quantitative determination of hydrochlorothiazide in Enalapril-H tablets corresponds to the following parameters: correctness, precision, linearity ( =0.70 ≤ max =1.60, d=0.22 ≤ maxd = 0.51, a=0.71 max a=2.60, r = 0.9997 min r=0.9981). In the quantitative determination of enalapril maleate in combined tablets, it was found that correctness, precision, linearity are performed ( =1.21 ≤ max =1.60, d=0.24 ≤ max d=0.51, a=1.35 max a=2.60, r = 0.9991 min r= 0.9981). Conclusions. The method of quantitative chromatographic determination of enalapril maleate and hydrochlorothiazide in an antihypertensive combination drug has been improved. The proposed parameters of the chromatographic separation of the mixture in comparison with the initial ones contribute to a decrease in the costs of monitoring, a decrease in the volume of harmful emissions and cause an extension of the life of the chromatographic column