Synchronized determination of sacubitril and valsartan with some co-administered drugs in human plasma via UPLC-MS/MS method using solid-phase extraction.

An accurate and sensitive UPLC-MS/MS method was developed and validated for the simultaneous estimation of the newly developed combination of sacubitril and valsartan and the co-administered drugs nebivolol, chlorthalidone and esomeprazole in human plasma. Solid-phase extraction was conducted for the purification and extraction of the drugs from human plasma. Chromatographic separation was carried out on an Agilent SB-C18 (1.8 µm, 2.1 × 50 mm) column using losartan as internal standard. Isocratic elution was applied using acetonitrile-0.1% formic acid in water (85: 15, v/v) as mobile phase. Detection was carried out using a triple-quadrupole tandem mass spectrometer using multiple reaction monitoring, at positive mode at m/z 412.23 → 266.19 for sacubitril, m/z 436.29 → 235.19 for valsartan, m/z 405.8 → 150.98 for nebivolol, m/z 346.09 → 198 for esomeprazole and a selected combination of two fragments m/z 423.19 → 207.14 and 423.19 → 192.2 for losartan (internal standard), and in negative ionization mode at m/z 337.02 → 190.12 for chlorthalidone. The method was linear over the concentration ranges 30-2,000 ng/ml for sacubitril, 70-2,000 ng/ml for valsartan, esomeprazole and chlorthalidone and 70-5,000 pg/ml for nebivolol. The developed method is sensitive and selective and could be applied for dose adjustment, bioavailability and drug-drug interaction studies.

Novel bio analytical method development, validation and application for simultaneous determination of nebivolol and S-amlodipine in human plasma using ultra performance liquid chromatography-tandem mass spectrometry.

A sensitive and specific ultra-performance liquid chromatography tandem mass spectrometric (UPLC-MS/MS) method has been developed, validated and applied for the assay of Nebivolol and S-amlodipine in human plasma. Sample extraction was carried out through hybrid extraction method from 250 µL of human plasma sample. Linearity of the method was (r ≥ 0.9996) was found to be dynamic for both the analytes over concentration range of 25.0-4000 pg/mL. Chromatographic separation was achieved on UPLC column {Waters Acquity UPLC BEH C18 (50 mm × 2.1 mm, 1.7 micrometer)} with the mobile phase composition of 0.1% (v/v) formic acid in 5 mM Ammonium formate in water-acetonitrile (20:80, %v/v). Analytes Stability was assured under different requisite conditions in human plasma, reconstitution solution and diluents. Inter and intra-day assay precision and relative error (accuracy) were within ±5% for both analytes. The method was applied and reproduced to support a pharmacokinetic study of 5 mg Nebivolol (NEB) and 2.5 mg S-amlodipine (LAM) tablet on 9 healthy subjects.

Heart rate is a useful marker of adherence to beta-blocker treatment in hypertension.

OBJECTIVES: Suboptimal medication adherence is common among patients with hypertension. Measurements of plasma or urinary levels of antihypertensive drugs are useful, but not widely available. The aim of our study was to investigate the relation of patients' heart rates to their serum beta-blocker levels. METHODS: We correlated 220 measurements of serum beta-blocker levels in 106 patients with apparently resistant hypertension to their corresponding office heart rate. A significant proportion, 44.6% of patients, were non-adherent to beta-blocker treatment according to serum level measurement. Non-adherent patients had significantly higher heart rates (80.9 vs. 66.6 bpm, p < .001), systolic (157.4 vs. 147.0 mm Hg, p = .002) and diastolic blood pressure (91.1 vs. 87.2 mm Hg, p = .041) in comparison to adherent patients. RESULTS: Heart rate above 75.5 beats per minute predicted non-adherence to beta-blocker treatment with a sensitivity of 62.5%, specificity 86.8% and AUC ROC 0.802 (p < .001). Higher heart rate cutoff might be applicable for nebivolol but was not determined due to the low number of patients treated with nebivolol. CONCLUSIONS: We concluded that heart rate was shown to be a good predictor of non-adherence to beta-blocker treatment, and might become a quick and easy measure to determine patient adherence in hypertensive patients.

Bioequivalence study between a fixed-dose single-pill formulation of nebivolol plus hydrochlorothiazide and separate formulations in healthy subjects using high-performance liquid chromatography coupled to tandem mass spectrometry.

Systemic arterial hypertension is a major risk factor for cerebrovascular disease. Therefore, adequate control of blood pressure is of enormous importance. One of the many fixed-dose single-pill antihypertensive formulations available on the market is the combination of nebivolol and hydrochlorothiazide. The objective of this study was to develop two distinct high-performance liquid chromatography coupled to tandem mass spectrometry methods to simultaneously quantify nebivolol and hydrochlorothiazide in human plasma. The methods were employed in a bioequivalence study, the first assay involving a nebivolol fixed-dose single-pill formulation based on healthy Brazilian volunteers. Nebilet HCT™ (nebivolol 5 mg + hydrochlorothiazide 12.5 mg tablet, manufactured by Menarini) was the test formulation. The reference formulations were Nebilet™ (nebivolol 5 mg tablet, manufactured by Menarini) and Clorana™ (hydrochlorothiazide 25 mg tablet, manufactured by Sanofi). For both analytes, liquid-liquid extraction was employed for sample preparation and the chromatographic run time was 3.5 min. The limits of quantification validated were 0.02 ng/mL for nebivolol and 1 ng/mL for hydrochlorothiazide. Since the 90% CI for Cmax , AUC(0-last) and AUC(0-inf) individual test/reference ratios were within the 80-125% interval indicative of bioequivalence, it was concluded that Nebilet HCT™ is bioequivalent to Nebilet™ and Clorana™.

Assessment of a Potential Pharmacokinetic Interaction between Nebivolol and Bupropion in Healthy Volunteers.

BACKGROUND/AIMS: The study aimed at investigating the effects of multiple-dose bupropion (potent inhibitor of CYP2D6) on the pharmacokinetics (PKs) of single-dose nebivolol (CYP2D6 substrate) and to evaluate the clinical relevance of this potential drug interaction. METHODS: This open-label, nonrandomized clinical study had a 2-period design: during period 1 (reference), a single dose of 5 mg nebivolol was administered, while during period 2 (test), 5 mg nebivolol + 300 mg bupropion were ingested concomitantly, after a pretreatment regimen with bupropion (7 days). The PK parameters of nebivolol and its active metabolite were analyzed by noncompartmental modeling, while the pharmacodynamic (PD) parameters (blood pressure and heart rate) were assessed at rest. RESULTS: Bupropion plus nebivolol increased the mean peak plasma concentrations (Cmax) of nebivolol (1.67 ± 0.69 vs. 3.80 ± 1.70 ng/ml) and its active metabolite (0.68 ± 0.22 vs. 1.13 ± 0.38 ng/ml) compared to nebivolol alone. After bupropion pretreatment, the exposure to nebivolol was increased by 7.2-fold for the parent drug and 4-fold for the hydroxylated active metabolite. The difference between the PD parameters measured during the 2 periods was not significant. CONCLUSION: The study concluded that bupropion influenced the PKs of nebivolol in healthy volunteers, but a clinical relevance was not established. However, this latter aspect requires further investigation.