Simultaneous determination of ivabradine and its metabolites in human plasma by liquid chromatography--tandem mass spectrometry

Label-free green estimation of atenolol and ivabradine hydrochloride in pharmaceutical and biological matrices by synchronous spectrofluorimetry

In this work, a label-free, rapid, and sensitive synchronous spectrofluorometric method was implemented to assay atenolol (ATL) and ivabradine hydrochloride (IVB) in pharmaceutical and biological matrices. Simultaneous determination of ATL and IVB by conventional spectrofluorometry cannot be implemented because of the clear overlap of the emmision spectra of ATL and IVB. To overcome this problem, synchronous fluorescence measurements at a constant wavelength difference (Δλ) combined with mathematical derivatization of the zero order spectra were perforemed. The results indicated a good resolution between emission spectra of the studied drugs when the first-order derivative of the synchronous fluorescence scans at Δλ = 40 nm was conducted using ethanol as the optimum solvent which is less hazardous than other organic solvents such as methanol and acetonitrile, keeping the method safe and green. The amplitudes of the first derivative synchronous fluorescent scans of ATL and IVB in ethanol were monitored at 286 and 270 nm to simultaneously estimate ATL and IVB, respectively. Method optimisation was conducted by assessing different solvents, buffer pHs, and surfactants. The optimum results were obtained when ethanol was utilized as a solvent without using any other additives. The developed method was linear over concentration ranges of 10.0-250.0 ng mL^-1 for IVB and 100.0-800.0 ng mL^-1 for ATL with detection limits of 3.07 and 26.49 ng mL^-1 for IVB and ATL, respectively. The method was utilized to assay the studied drugs in their dosages and in human urine samples with acceptable % recoveries and RSD values. The greenness of the method was implemented by three approaches involving the recently reported metric (AGREE) which ensured the eco-freindship and safety of the method.

Chemometrically assisted RP-HPLC method development for efficient separation of ivabradine and its eleven impurities

The aim of this study was to develop a novel reversed-phase high-performance liquid chromatography (RP-HPLC) method for efficient separation of ivabradine and its 11 impurities. Similar polarity of impurities in the sample mixture made method optimization challenging and accomplishable only when different chemometric tools, such as principal component analysis (PCA), Box–Behnken design (BBD), and desirability function as a multicriteria approach, were employed. The presence of 3 positional isomers (impurities III, V, and VI), keto–enol tautomerism of impurity VII, and diastereoisomers of impurity X made separation of this complex mixture even more challenging. Chromatographic retention parameters obtained with the mobile phase consisting of 30 mM phosphate buffer and acetonitrile (80:20, v/v) on four different RP-HPLC columns at varying pH values (3.0, 4.0, and 5.0) were subjected to the PCA analysis to select the column with the most appropriate selectivity. Then the column temperature, pH of the aqueous component of mobile phase, phosphate buffer molarity and the organic solvent content in the mobile phase were estimated employing BBD. Valid and reliable mathematical models towards resolution of twelve critical peak pairs were obtained. After determination of the desirability making criteria for all responses, desirability functions were established and used in optimization. The proposed optimal chromatographic conditions included the Zorbax Eclipse Plus C18 chromatographic column (100 × 4.6 mm, 3.5 μm), the column temperature of 34 °C, the mobile phase flow rate of 1.6 mL min−1 and the UV detection at 220 nm. The mobile phase consisted of the 28 mM phosphate buffer at pH 6.0 and acetonitrile (85:15, v/v). Separation of one pair of positional isomers was not achieved, so methanol was added to the organic part of mobile phase in small increments with the optimal ratio of methanol to acetonitrile 59:41, v/v. The overall organic component of the mobile phase also increased to 18%, accelerating the chromatographic analysis.

Is there enough evidence to classify cycloalkyl amine substituents as structural alerts?

Basic amine substituents provide several pharmacokinetic benefits relative to acidic and neutral functional groups, and have been extensively utilized as substituents of choice in drug design. On occasions, basic amines have been associated with off-target pharmacology via interactions with aminergic G-protein coupled receptors, ion-channels, kinases, etc. Structural features associated with the promiscuous nature of basic amines have been well-studied, and can be mitigated in a preclinical drug discovery environment. In addition to the undesirable secondary pharmacology, α-carbon oxidation of certain secondary or tertiary cycloalkyl amines can generate electrophilic iminium and aldehyde metabolites, potentially capable of covalent adduction to proteins or DNA. Consequently, cycloalkyl amines have been viewed as structural alerts (SAs), analogous to functional groups such as anilines, furans, thiophenes, etc., which are oxidized to reactive metabolites that generate immunogenic haptens by covalently binding to host proteins. Detailed survey of the literature, however, suggests that cases where preclinical or clinical toxicity has been explicitly linked to the metabolic activation of a cycloalkyl amine group are extremely rare. Moreover, there is a distinct possibility for the formation of electrophilic iminium/amino-aldehyde metabolites with numerous cycloalkyl amine-containing marketed drugs, since stable ring cleavage products have been characterized as metabolites in human mass balance studies. In the present work, a critical analysis of the evidence for and against the role of iminium ions/aldehydes as mediators of toxicity is discussed with a special emphasis on often time overlooked detoxication pathways of these reactive species to innocuous metabolites.

The Effect of Ivabradine on the Human Atrial Myocardial Contractility in an In Vitro Study

Purpose

Ivabradine has emerged as a new antiarrhythmic agent that could compete with the traditional ones, such as beta-blockers. This experimental study aims to ascertain whether ivabradine directly interferes with the myocardial contractility in an in vitro environment.

Methods

Myocardial tissues from the right atrial appendages of patients undergoing cardiac surgery were dissected to obtain 40 specimens from 20 patients (length: 3 mm), which were exposed to electrical impulses at a frequency of 75 bpm for 30 min to reach a steady state. Specimens were then categorised into four groups (each including five patients). The first group was the control, whereas the second, third, and fourth were treated with 60 nM, 200 nM, and 2 μM ivabradine, respectively. We assessed five different contraction parameters before and after a 15 min treatment and calculated their relative changes, which were then compared to the control group.

Results

Ivabradine has affected the force of contraction significantly in vitro (p=0.009). However, force of contraction decreased in both the control group (93.5 ± 4.7%) and the second group (94.1 ± 4.5%, p=0.8) and force of contraction remained unchanged in the third group (101.0 ± 4.1%, p=0.24) and increased significantly in the fourth group (108.9 ± 11.6%, p=0.008). There was no change in other contraction parameters, such as passive tension force (97.1 ± 5.1%, p=0.368), duration of contraction (99.1 ± 4.3%, p=0.816), time to peak (96.6 ± 3.0%, p=0.536), and time to relaxation (101.2 ± 7.0%, p=0.564).

Conclusions

Ivabradine did not interfere with the contractile behaviour of human atrial tissue when it was used in therapeutic dosages in vitro. However, it increased the contractility slightly, when it was used in supratherapeutic dosage.

Pharmacology of Ivabradine and the Effect on Chronic Heart Failure

Chronic Heart Failure (CHF) is a complex clinical syndrome with a high incidence worldwide. Although various types of pharmacological and device therapies are available for CHF, the prognosis is not ideal, for which, the control of increased Heart Rate (HR) is critical. Recently, a bradycardic agent, ivabradine, is found to reduce HR by inhibiting the funny current (If). The underlying mechanism states that ivabradine can enter the Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels and bind to the intracellular side, subsequently inhibiting the If. This phenomenon can prolong the slow spontaneous phase in the diastolic depolarization, and thus, reduce HR. The clinical trials demonstrated the significant effects of the drug on reducing HR and improving the symptoms of CHF with fewer adverse effects. This review primarily introduces the chemical features and pharmacological characteristics of ivabradine and the mechanism of treating CHF. Also, some expected therapeutic effects on different diseases were also concluded. However, ivabradine, as a typical If channel inhibitor, necessitates additional research to verify its pharmacological functions.

Voltammetric Determination of Ivabradine Hydrochloride Using Multiwalled Carbon Nanotubes Modified Electrode in Presence of Sodium Dodecyl Sulfate

Purpose: A new sensitive sensor was fabricated for the determination of ivabradine hydrochloride (IH) based on modification with multiwalled carbon nanotubes using sodium dodecyl sulfate as micellar medium to increase the sensitivity.

Methods: The electrochemical behavior of IH was studied in Britton-Robinson buffer (pH: 2.0-11.0) using cyclic and differential pulse voltammetry.

Results: The voltammetric response was linear over the range of 3.984 x 10^-6-3.475 x 10^-5 mol L^-1. The limits of detection and quantification were found to be 5.160 x 10^-7 and 1.720 x 10-6 mol L^-1, respectively.

Conclusion: This method is suitable for determination of IH in tablets and plasma.

Application and Validation of Simple Isocratic HPLC-UV-DAD Method with Dual Wavelength Detection for Ivabradine Determination and Its Application in the Study of Stress Degradation

Ivabradine is a modern drug that selectively lowers the heart rate, improves cardiac energy balance, and reduces heart’s demands for oxygen and energy. Due to the chemical nature of ivabradine, which absorbs light at 207 nm and 286 nm, its detection was performed at two wavelengths. A Knauer C8 column was used to develop the RP-HPLC method for determination of ivabradine. The proposed method was linear from 5 to 100 µg/ml (r>0.999) for both wavelengths and limits of detection (LOD) and limits of quantification (LOQ) were 0.33 and 1.09 µg/ml for 207 nm and 1.19 and 3.97 µg/ml for 286 nm, respectively. After validation, the investigated method was applied to a stress degradation study. Numerous degradation products were formed from ivabradine solutions through alkaline and acid hydrolysis, oxidation, and photolysis. The largest numbers of degradation products were found in the sample exposed to 24 h radiation and alkaline hydrolysis (eight and six products, resp.). Finally, the simple method using HPLC-UV-DAD was developed and validated. Its usefulness for the monitoring of possible degradation products was demonstrated.

Advances in the management of heart failure: the role of ivabradine

A high resting heart rate (≥70–75 b.p.m.) is a risk factor for patients with heart failure (HF) with reduced ejection fraction (EF), probably in the sense of accelerated atherosclerosis, with an increased morbidity and mortality. Beta-blockers not only reduce heart rate but also have negative inotropic and blood pressure-lowering effects, and therefore, in many patients, they cannot be given in the recommended dose. Ivabradine specifically inhibits the pacemaker current (funny current, I_f) of the sinoatrial node cells, resulting in therapeutic heart rate lowering without any negative inotropic and blood pressure-lowering effect. According to the European Society of Cardiology guidelines, ivabradine should be considered to reduce the risk of HF hospitalization and cardiovascular death in symptomatic patients with a reduced left ventricular EF ≤35% and sinus rhythm ≥70 b.p.m. despite treatment with an evidence-based dose of beta-blocker or a dose below the recommended dose (recommendation class “IIa” = weight of evidence/opinion is in favor of usefulness/efficacy: “should be considered”; level of evidence “B” = data derived from a single randomized clinical trial or large nonrandomized studies). Using a heart rate cutoff of ≥ 75 b.p.m., as licensed by the European Medicines Agency, treatment with ivabradine 5–7.5 mg b.i.d. reduces cardiovascular mortality by 17%, HF mortality by 39% and HF hospitalization rate by 30%. A high resting heart rate is not only a risk factor in HF with reduced EF but also at least a risk marker in HF with preserved EF, in acute HF and also in special forms of HF. In this review, we discuss the proven role of ivabradine in the validated indication “HF with reduced EF” together with interesting preliminary findings, and the potential role of ivabradine in further, specific forms of HF.

Forced Degradation Studies of Ivabradine and In Silico Toxicology Predictions for Its New Designated Impurities

All activities should aim to eliminate genotoxic impurities and/or protect the API against degradation. There is a necessity to monitor impurities from all classification groups, hence ivabradine forced degradation studies were performed. Ivabradine was proved to be quite durable active substance, but still new and with insufficient stability data. Increased temperature, acid, base, oxidation reagents and light were found to cause its degradation. Degradation products were determined with the usage of HPLC equipped with Q-TOF-MS detector. Calculations of pharmacological and toxicological properties were performed for six identified degradation products. Target prediction algorithm was applied on the basis of Hyperpolarization-activated cyclic nucleotide-gated cation channels, as well as more general parameters like logP and aqueous solubility. Ames test and five cytochromes activities were calculated for toxicity assessment for selected degradation products. Pharmacological activity of photodegradation product (UV4), which is known as active metabolite, was qualified and identified. Two other degradation compounds (Ox1 and N1), which were formed during degradation process, were found to be pharmacologically active.

Role of Ivabradine in the Treatment of Patients With Cardiovascular Disease

OBJECTIVE

To review the role of heart rate in myocardial ischemia and heart failure with reduced ejection fraction (HFrEF) as well as ivabradine's pharmacology and pharmacokinetics, clinical trials, and place in therapy.

DATA SOURCES

We conducted MEDLINE searches from 1980 to October 2015 using the terms heart failure, HFrEF, angina, f-channel inhibitor, and ivabradine, with forward and backward citation tracking.

STUDY SELECTION AND DATA EXTRACTION

English-language trials assessing ivabradine were obtained. Studies and narrative reviews of the topic areas were incorporated if they provided relevant data to inform the practicing clinician.

DATA SYNTHESIS

In the SIGNIFY (Study Assessing the Morbidity-Mortality Benefits of the If Inhibitor Ivabradine in Patients with Coronary Artery Disease) trial, there was no difference in the primary composite end point of cardiovascular (CV) mortality or nonfatal myocardial infarction with ivabradine use in patients with stable coronary artery disease (CAD) versus placebo (P = 0.20). In the subgroup with Canadian Cardiovascular Society angina class ≥II, there was an 18% increase in the primary end point with ivabradine versus placebo (P = 0.02). In HFrEF patients, ivabradine reduced CV mortality or heart failure hospitalizations versus placebo, as seen in the SHIFT (Systolic Heart failure treatment with the If inhibitor ivabradine Trial; P < 0.05).

CONCLUSIONS

The SIGNIFY trial negated much of the enthusiasm for using ivabradine in CAD. Ivabradine is a promising therapy in HFrEF based on the results of the SHIFT, but it is an adjunctive therapy, not a substitute for drugs with proven mortality benefits.

A Review of New Pharmacologic Treatments for Patients With Chronic Heart Failure With Reduced Ejection Fraction

Heart failure (HF) impacts an estimated 5.7 million Americans, and its prevalence is projected to increase to more than 8 million Americans in the next 15 years. Key clinical trials have established an evidence-based foundation for treatment of heart failure with reduced ejection fraction (HFrEF). Ivabradine and sacubitril/valsartan, which inhibit the f-channel and the angiotensin receptor and neprilysin, respectively, were recently approved by the Food and Drug Administration for HFrEF. In systolic heart failure, treatment with the If inhibitor ivabradine significantly reduced the combined endpoint of cardiovascular mortality or heart failure hospital admission vs placebo (P < .05). In the Prospective Comparison of angiotensin receptor-neprilysin inhibitor (ARNI) with angiotensin-converting enzyme inhibitor (ACEI) to Determine Impact on Global Mortality and Morbidity in Heart Failure trial, sacubitril/valsartan significantly reduced the combined endpoint of cardiovascular death or heart failure hospitalization vs enalapril (P < .001). The place of therapy with ivabradine and sacubitril/valsartan is defined by these trials and their interplay with guideline-directed medical therapy. Ivabradine and sacubitril/valsartan increase pharmacotherapy options for the treatment of HFrEF but are not yet first-line agents. Clinical application will be better defined in the coming years as practitioners increase their familiarity with ivabradine and sacubitril/valsartan.

Electrochemical study of ivabradine hydrochloride ion selective electrodes using different ionophores

Development of novel sensors for the determination of ivabradine hydrochloride using sulphonated calix-8-arene and cyclodextrin derivatives as neutral ionophores.

Ivabradine: a new rate-limiting therapy for coronary artery disease and heart failure

Ivabradine is a new bradycardic agent acting on the I f channels of sinoatrial nodal cells to decrease the rate of diastolic depolarization and thus heart rate. The benefit of ivabradine over other negatively chronotropic agents is its absence of negative inotropy. Effective management of coronary artery disease, in terms of reducing morbidity and mortality, is reliant on controlling heart rate. Ivabradine has been shown to safely and effectively reduce heart rate without compromising cardiac function in patients with coronary artery disease and more recently in patients with heart failure and raised heart rate. Furthermore, ivabradine has been shown to have a favourable side-effect profile compared with alternative bradycardic agents. This article reviews the evidence for ivabradine in coronary artery disease and heart failure and compares its safety with alternative bradycardic agents for these conditions.

Evaluation of pharmacokinetic and pharmacodynamic profiles and tolerability after single (2.5, 5, or 10 mg) and repeated (2.5, 5, or 10 mg bid for 4.5 days) oral administration of ivabradine in healthy male Korean volunteers

BACKGROUND

Ivabradine, a selective inhibitor of the pacemaker current in the sinoatrial node, has shown pure heart rate (HR)-reducing effects with anti-ischemic efficacy as well as improvement in heart failure outcomes.

OBJECTIVE

The purpose of this study was to explore pharmacokinetic (PK) and pharmacodynamic (PD) characteristics and tolerability in healthy male Korean volunteers, as well as to compare them with PK/PD profiles of white subjects.

METHODS

This was a randomized, double-blind, placebo-controlled Phase I study conducted in healthy male subjects. For each of the 3 dosing groups, 9 subjects were randomized to receive ivabradine and 3 to receive placebo. Subjects received a single oral dose of ivabradine 2.5, 5, or 10 mg and after a 3-day washout period, repeat doses of 2.5, 5, or 10 mg BID for 4.5 days. Blood and urine samples were collected over 72 hours during each period, and levels of ivabradine and its metabolite S18982 were determined by using validated LC-MS/MS, followed by noncompartmental PK analysis. For PD properties and tolerability, 24-hour Holter recordings were obtained: at baseline, after a single dose, after repeated doses, and after the last dose. Serial resting 12-lead ECG assessments were also performed throughout the study.

RESULTS

Forty-eight subjects were enrolled, and 45 completed the study. After single doses of 2.5, 5, and 10 mg, respective mean Cmax levels of ivabradine were 9, 15, and 39 ng/mL, and mean AUC0-last values were 30, 52, and 121 ng h/mL. At steady state, mean Cmax,ss levels were 11, 19, and 42 ng/mL, reached at a median Tmax of 0.67 hour for all 3 doses. The mean AUC0-τ levels were 43, 58, and 139 ng h/mL, respectively. The PK findings were linear with dose and time. Decreases in mean HR on both the Holter recordings and ECGs were observed in all of the ivabradine groups compared with placebo. After the repeated doses, mean decreases in HR were greater than those for the single doses for the same period. Statistically significant differences were observed between the 5- and 10-mg ivabradine groups and placebo. A total of 3 adverse events were reported in 2 subjects receiving ivabradine; both fully recovered without sequelae.

CONCLUSIONS

Single and repeated administration of ivabradine were generally well tolerated in these healthy male Korean volunteers. Ivabradine induced significant reductions in HR, especially at doses of 5 and 10 mg. PK/PD characteristics were similar to those found in white subjects, suggesting that the dose concentration-response relationship of ivabradine is similar between Korean and white subjects.

A validated, rapid UPLC-MS/MS method for simultaneous ivabradine, reboxetine, and metoprolol analysis in human plasma and its application to clinical trial samples

A recent clinical trial assessing human autonomic cardiovascular regulation applied pacemaker channel inhibition with ivabradine, norepinephrine transporter blockade with reboxetine, and beta-adrenoreceptor blockade with metoprolol. To verify patient adherence, we developed and validated a fast UPLC-MS/MS assay measuring all three compounds simultaneously. Deuterium-labeled drugs, d3-ivabradine, d5-reboxetine and d7-metoprolol, served as internal standards. Sample preparation of 200μL human plasma consisted of a single liquid-liquid extraction step by means of ethyl acetate. Chromatographic separation was performed on a 50-mm long BEH C18 column with gradient elution using a mixture of water and methanol each containing 2mM ammonium acetate over 4.5min. The mass spectrometer was operated in the positive electrospray ionization (ESI+) mode. Characteristic product ions resulting from collision-induced dissociation of unlabeled and deuterium-labeled drugs with argon were used for quantification in the selected-reaction monitoring mode. We validated the method according to the European Medicines Agency (EMA) guideline on bioanalytical method validation over the range from 1ng/mL to 500ng/mL for all three analytes. Linear responses with correlation coefficients>0.99 over that range were acquired. The LOQ value was 1ng/mL for each drug. Regulatory criteria for accuracy (80-120%) and precision (RSD<15%) were met for all drugs. The internal standard-normalized matrix factor was close to 1 for low and high analyte concentrations. We successfully measured ivabradine, reboxetine, and metoprolol concentrations in 107 human plasma samples from a clinical trial. Quality control samples processed in parallel confirmed the method's reliability in a clinical setting.

Transition moment directions and selected spectroscopic properties of Ivabradine

Based on the Kawski-Gryczynski method the value of angle β=38° between absorption and fluorescence transition moments of Ivabradine was determined. Such a high value of β is responsible for low emission anisotropy of Ivabradine in a rigid polyvinyl alcohol matrix and in anhydrous glycerol despite the elongated shape of the fluorophore. Selected steady-state and time-resolved spectroscopic results support the analysis.

Development and Validation of RP-HPLC Method for the Estimation of Ivabradine Hydrochloride in Tablets

A simple, sensitive, precise and robust reverse–phase high-performance liquid chromatographic method for analysis of ivabradine hydrochloride in pharmaceutical formulations was developed and validated as per ICH guidelines. The separation was performed on SS Wakosil C18AR, 250×4.6 mm, 5 μm column with methanol:25 mM phosphate buffer (60:40 v/v), adjusted to pH 6.5 with orthophosphoric acid, added drop wise, as mobile phase. A well defined chromatographic peak of Ivabradine hydrochloride was exhibited with a retention time of 6.55±0.05 min and tailing factor of 1.14 at the flow rate of 0.8 ml/min and at ambient temperature, when monitored at 285 nm. The linear regression analysis data for calibration plots showed good linear relationship with R=0.9998 in the concentration range of 30-210 μg/ml. The method was validated for precision, recovery and robustness. Intra and Inter-day precision (% relative standard deviation) were always less than 2%. The method showed the mean % recovery of 99.00 and 98.55 % for Ivabrad and Inapure tablets, respectively. The proposed method has been successfully applied to the commercial tablets without any interference of excipients.

Applicability of bioanalysis of multiple analytes in drug discovery and development: review of select case studies including assay development considerations

The development of sound bioanalytical method(s) is of paramount importance during the process of drug discovery and development culminating in a marketing approval. Although the bioanalytical procedure(s) originally developed during the discovery stage may not necessarily be fit to support the drug development scenario, they may be suitably modified and validated, as deemed necessary. Several reviews have appeared over the years describing analytical approaches including various techniques, detection systems, automation tools that are available for an effective separation, enhanced selectivity and sensitivity for quantitation of many analytes. The intention of this review is to cover various key areas where analytical method development becomes necessary during different stages of drug discovery research and development process. The key areas covered in this article with relevant case studies include: (a) simultaneous assay for parent compound and metabolites that are purported to display pharmacological activity; (b) bioanalytical procedures for determination of multiple drugs in combating a disease; (c) analytical measurement of chirality aspects in the pharmacokinetics, metabolism and biotransformation investigations; (d) drug monitoring for therapeutic benefits and/or occupational hazard; (e) analysis of drugs from complex and/or less frequently used matrices; (f) analytical determination during in vitro experiments (metabolism and permeability related) and in situ intestinal perfusion experiments; (g) determination of a major metabolite as a surrogate for the parent molecule; (h) analytical approaches for universal determination of CYP450 probe substrates and metabolites; (i) analytical applicability to prodrug evaluations-simultaneous determination of prodrug, parent and metabolites; (j) quantitative determination of parent compound and/or phase II metabolite(s) via direct or indirect approaches; (k) applicability in analysis of multiple compounds in select disease areas and/or in clinically important drug-drug interaction studies. A tabular representation of select examples of analysis is provided covering areas of separation conditions, validation aspects and applicable conclusion. A limited discussion is provided on relevant aspects of the need for developing bioanalytical procedures for speedy drug discovery and development. Additionally, some key elements such as internal standard selection, likely issues of mass detection, matrix effect, chiral aspects etc. are provided for consideration during method development.