Complementary mechanisms of action and rationale for the fixed combination of perindopril and indapamide in treating hypertension - update on clinical utility

Development of new stability indicating UPLC-UV method for the extraction and quantification of perindopril and indapamide from human plasma

Background

The hypertension and cardiovascular ailments are the leading cause of deaths worldwide. The combination therapy was found to be effective on the cardiovascular illness by reducing the blood pressure. The indapamide and perindopril combination therapy showed excellent results on reducing high blood pressure. With this in mind, the stability indicating reverse phase UPLC method was developed for the simultaneous identification and quantification of indapamide and perindopril from human plasma. In this work, we developed a new solid phase extraction method for the extraction of indapamide and perindopril in human plasma. It is a simple, accurate, and selective method for the extraction of these two drugs from human plasma with elution time of 2 min. The extracted drugs were identified and quantified by using stability indicating UPLC method. The method showed high recovery rate as well as low detection and quantification limits of two drugs.

Results

A novel, simple, highly accurate, and precise stability indicating ultra-performance liquid chromatography (UPLC) method was developed for the identification and quantification of perindopril (PP) (brand name Coversyl) and indapamide (IP) (brand name Lorvas) from human plasma. In this UPLC method, HSS C18 column (100 × 2.1 mm, 1.8 μm) and mobile phase acetonitrile (ACN), 10 mM KH2PO4 buffer solution (pH 3.0) mixture was used in the ratio of 65:35. Colum temperature of 30 °C, flow rate of 1.0 mL per minute and UV wave length of 254 nm were used. PP and IP were eluted below 2 min runtime with high resolution. Solid phase extraction (SPE) method was used for the extraction of PP and IP from human plasma. Different solvents were used to extract the analyte from SPE such as ACN, methanol, acetone, tertiary butyl diethyl ether (TBDE), chloroform (CHCl3), and ethanol (EtOH). Among these, ACN gave good recovery percentages (94.56 to 101.58%). From the linearity graph, good correlation coefficient values of 0.9996 for PP and 0.9997 for IP were achieved. The coefficient variance values for intra and inter day precision is in between 1.08 and 12.5%. The LOD and LOQ values were determined by the signal to noise ratio method. LOD and LOQ values for IP and PP were found to be 8.6 and 33.5 ng/mL and 28.33 and 110.5 ng/mL respectively. The developed method was statistically validated as per ICH guidelines.

Conclusion

In summary, a novel stability indicating UPLC-UV method was developed and validated for the simultaneous identification and quantification of perindopril and indapamide drugs in human plasma and tested the stability as per ICH guidelines. It is a simple, accurate, and specific method for the extraction of these two drugs from human plasma and eluted within 2 min runtime. The method showed high recovery rate as well as low detection and quantification limits of two drugs. The developed method is suitable for routine analysis as well as in bioanalytical and clinical studies.

Graphical abstract

Simultaneous determination of indapamide, perindopril and perindoprilat in human plasma or whole blood by UPLC-MS/MS and its pharmacokinetic application

Simple and sensitive methods were developed for the determination of indapamide, perindopril and its active metabolite perindoprilat in human plasma or whole blood by hyphenated ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Indapamide-d3, perindopril-d4 and perindoprilat-d4 were used as the internal standards. The separation was performed on a Thermo BDS Hypersil C₁₈ column (4.6 mm × 100 mm, 2.4 µm) for indapamide and perindopril simultaneously following a protein precipitation pretreatment of the biosamples. The separation of perindoprilat was achieved independently on a phenomenex PFP column (4.6 mm × 150 mm, 5 µm). All the analytes were quantitated with positive electrospray ionization and multiple reactions monitoring mode. The assay exhibited a linear range of 1–250 ng/mL for indapamide, 0.4–100 ng/mL for perindopril and 0.2–20 ng/mL for perindoprilat. The methods were fully validated to meet the requirements for bioassay in accuracy, precision, recovery, reproducibility, stabilities and matrix effects, and successfully applied to the pharmacokinetic study of perindopril tert-butylamine/indapamide compound tablets in Chinese healthy volunteers and the comparative pharmacokinetic study between plasma and whole blood.

Which thiazide to choose as add-on therapy for hypertension?

Combined therapy is required in the majority of patients with hypertension to achieve blood pressure (BP) targets. Although different antihypertensive drugs can be combined, not all combinations are equally effective and safe. In this context, the combination of a renin angiotensin system inhibitor with a diuretic, usually a thiazide, particularly hydrochlorothiazide (HCTZ) or thiazide-like diuretics, such as chlorthalidone or indapamide, is recommended. However, not all diuretics are equal. Although HCTZ, chlorthalidone, and indapamide as add-on therapy effectively reduce BP levels, the majority of studies have obtained greater BP reductions with chlorthalidone or indapamide than with HCTZ. Moreover, there are data showing benefits with chlorthalidone or indapamide beyond BP. Thus, chlorthalidone seems to have pleiotropic effects beyond BP reduction. Moreover, compared with placebo, chlorthalidone has small effects on fasting glucose and total cholesterol, and compared with HCTZ, chlorthalidone achieves significantly lower total cholesterol and low-density lipoprotein cholesterol levels. Similarly, indapamide has demonstrated no negative impact on glucose or lipid metabolism. More importantly, although head-to-head clinical trials comparing the effects of indapamide or chlorthalidone with HCTZ are not available, indirect comparisons and post hoc analyses suggest that the use of chlorthalidone or indapamide is associated with a reduction in cardiovascular events. Despite this, the most frequent diuretic used in clinical practice as add-on therapy for hypertension is HCTZ. The purpose of this review is to update the published data on the efficacy and safety of HCTZ, chlorthalidone, and indapamide as add-on therapy in patients with hypertension.

An evaluation of the latest evidence relating to renin-angiotensin system inhibitors

INTRODUCTION

In the last few years, a number of important clinical trials have been completed that have investigated the inhibition of the renin-angiotensin system. New drugs, focusing on this system, have now emerged as a result.

AREAS COVERED

The authors review the most relevant information available, reported from the last 5 years, pertaining to the most important clinical trials on renin-angiotensin system blockers (ARBs). The authors' data review includes the trials of aliskiren, telmisartan, olmesartan and azilsartan. The authors also review the possible risk of cancer with ARBs.

EXPERT OPINION

The results of ASPIRE and ALTITUDE trials strongly suggested that dual inhibition of aliskiren with either ARBS or angiotensin converting enzyme inhibitors (ACEi) should be avoided. Olmesartan is an effective and safe antihypertensive agent, but special attention should be paid to high-risk patients, such as those with coronary disease, to avoid an excessive reduction in blood pressure. The authors also note that while azilsartan is probably the most potent ARB, there is still a lack of data regarding potential organ damage and the incidence of cardiovascular events. Lastly, recent evidence has shown a lack of a relationship between ARB therapy and the occurrence of cancer.