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.