Quantification of amlodipine and atorvastatin in human plasma by UPLC-MS/MS method and its application to a bioequivalence study

Spectrophotometric platform windows' exploitation for the green determination of Alcaftadine in presence of its oxidative degradation product

This study presents the determination of Alcaftadine (ALF) in its oxidative degradation product presence by applying comprehensive study comparative of four different green stability indicating spectrophotometric approaches through successful exploitation of different spectrophotometric platform windows. Window I; based on absorption spectrum zero order data manipulation using the newly developed extended absorbance difference (EAD). Window II; based on derivative spectra by second order derivative (D²) data manipulation. Window III; based on ratio spectra applying constant multiplication (CM) and absorptivity centering via factorized ratio difference spectrum (ACT-FSR_ΔP) methods data manipulation. Finally, window IV; based on derivative of ratio spectrum by virtue of first derivative of ratio spectral (DD¹) method data manipulation. Calibration curves construction were over linearity range; 1.0-14.0 µg/mL for ALF. The proposed methods accuracy, precision, and linearity range were determined and validated as per ICH guidelines. Moreover, they were able to analyze ALF in raw form, dosage form and in existence of its oxidative degradation product. Statistical comparisons were done between the proposed methods and the reported one showing no significant difference concerning accuracy and precision. Furthermore, greenness profile assessment was accomplished by means of four metric tools; namely: analytical greenness (AGREE), green analytical procedure index (GAPI), analytical eco-scale, and national environmental method index (NEMI).

Bioanalytical LC-MS/MS method for simultaneous estimation of atorvastatin, its major active metabolites and ezetimibe

Background: Hyperlipidemia is one of the most common chronic diseases encountered globally, and atorvastatin (ATV) is mainly metabolized into two major active metabolites. Methodology: Hence, we aimed to estimate ATV and ezetimibe (EZE) simultaneously in the presence of ATV major and active metabolites using a validated LC-MS/MS method. Conclusion: The proposed method was linear (r² >0.99), accurate (92.02-109.94%) and precise (CV% ≤14) over the concentration range of 0.50-120 ng/ml, 0.20-48 ng/ml, 0.50-120 ng/ml and 0.20-48 ng/ml for ATV, EZE, 2-hydroxy ATV and 4-hydroxy ATV, respectively. The applied liquid-liquid extraction gave rise to reliable extraction recoveries of 84.91 ± 1.14%, 85.20 ± 1.62%, 85.46 ± 0.41% and 105.46 ± 2.35% for ATV, EZE, 2-hydroxy ATV and 4-hydroxy ATV, respectively.

A validated LC-MS/MS method for determination of antiviral prodrug molnupiravir in human plasma and its application for a pharmacokinetic modeling study in healthy Egyptian volunteers

A fully validated, simple, rapid and reproducible liquid chromatography-tandem mass spectrometry method was developed to determine NHC (N-hydroxycytidine), the active metabolite of Molnupiravir (MOL) in human plasma; one of the limited treatment options for SARS-CoV-2 in plasma of healthy volunteers. The internal standard (IS) used was ribavirin. The extraction of analyte and IS from plasma was performed using acetonitrile as a solvent for protein precipitation. Agilent Zorbax Eclipse plus C₁₈, 4.6 × 150 mm, (5 µm) was used for chromatographic separation using a mixture of methanol0.2 % acetic acid (5:95, v/v) as a mobile phase that was pumped at a flow rate of 0.9 mL/min. Detection was performed on a triple quadrupole mass spectrometer operating in multiple reaction monitoring (MRM) employing positive ESI interface using API4500 triple quadrupole tandem mass spectrometer system, with the transitions set at m/z 260.10 → 128.10 and 245.10 → 113.20 for NHC and IS respectively. Method validation was performed in accordance with United States FDA bioanalytical guidance. The concentration range of 20.0-10000.0 ng/mL was used to establish linearity via weighted linear regression approach (1/x²). Moreover, the analyzed pharmacokinetic data from twelve Egyptian healthy volunteers were used to develop a population pharmacokinetic model for NHC. The developed model was used to perform simulations and evaluate the current MOL dosing recommendations through calculating the maximum concentration (C_max) "the safety metric" and area under the curve (AUC_0-12 h) "the efficacy metric" for 1000 virtual subjects. Geometric mean ratios (GMR) with their associated 90% confidence intervals (CI) compared to literature values were computed. Geometric means of simulation-based Cmax and AUC0-12 were 3827 ng/mL (GMR = 1.05; 90% CI = 0.96-1.15) and 9320 ng.h/mL (GMR = 1.04; 90% CI = 0.97-1.11), respectively indicating that current MOL dosage can achieve the therapeutic targets and dose adjustment may not be required for the Egyptian population. The developed model could be used in the future to refine MOL dosage once further therapeutic targets are identified.

New steps in acute coronary syndrome and antihyperlipidemic treatment: determination of statins and metabolites by liquid chromatography tandem mass spectrometry

Our aim in this study was to develop a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the measurement of atorvastatin, rosuvastatin and their major metabolites, furthermore to evaluate patients' adherence to statin therapy and to investigate the effect of statin therapy on various hematological and biochemical parameters. A simple protein precipitation was performed for the extraction of analytes and the extracted samples were injected directly. The levels of drugs and their metabolites were measured by the validated method in a total of 210 patients diagnosed with unstable angina pectoris, ST-elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction (NSTEMI). Various biochemical and hematological parameters were measured. Linearity range for atorvastatin and rosuvastatin were 1.22-2500 ng/mL and 0.97-2000 ng/mL, respectively. The inter-assay CV% for all analytes is ≤ 6%. In patients diagnosed with USAP, STEMI, and NSTEMI, treatment compliance rates were 22.1%, 23.5%, 41.2% for atorvastatin and 36.1%, 40.2%, 67.1% for rosuvastatin, respectively. An economical, simple and reliable measurement method has been developed. Our findings supported the poor patient compliance with statin therapy in the included population. It was observed that 6 months of statin treatment caused slight changes in biochemical and hematological parameters.

A review on liquid chromatographic methods for the bioanalysis of atorvastatin

Background

The unsatisfied clinical need has encouraged the development and validation of bioanalytical procedures for the quantification of drugs in biological samples because the monitoring of drug concentrations helps in personalizing the patient’s pharmacotherapy, assessing the adherence to therapy, and is also extensively useful for pharmacokinetics and drug-drug interactions studies.

Main Body

The present review aimed to provide insightful information about the various liquid chromatographic methods developed till 2019 for the analysis and quantification of atorvastatin, its metabolites, and co-administered drugs in the various biological matrices like the serum, plasma, and urine with special emphasis on sample preparation techniques applied before chromatographic analysis along with different chromatographic conditions and their validation data. A total of 88 published papers that have used liquid chromatography techniques to quantify atorvastatin in biological fluids are included in the study. Out of the total reported liquid chromatographic methods, 34% used UV spectrophotometer as a detector, and 55% used MS/MS as a detector. Whereas 38% of them used protein precipitation procedure, 33% applied liquid-liquid extraction approach, and 12% employed solid-phase extraction technique for sample preparation.

Conclusion

In the last decade, numerous bioanalytical procedures have been developed for the quantification of atorvastatin in different biological samples using liquid chromatographic techniques. Moreover, advancement in technology developed several new and advanced sample preparation approaches like dispersive liquid-liquid extraction, microextraction by packed sorbent, which have high recovery rates than conventional procedures. Thus, the summarized review may be consulted as an informative tool to support the optimization of new bioanalytical methods for the quantification of atorvastatin.

An LC-MS/MS Method for Determination of Triple Drugs Combination of Valsartan, Amlodipine and Hydrochlorothiazide in Human Plasma for Bioequivalence Study

Background:

Current guidelines for the treatment of hypertension recommend combination therapy, which intends to control blood pressure and enhance cardiovascular protection.

Materials and Methods:

A sensitive, reliable and selective tandem mass spectrometry (LC-MS/MS) method has been developed for simultaneous quantification of amlodipine (AML), valsartan (VAL) and hydrochlorothiazide (HCTZ) in human plasma. The chromatographic system was equipped with ACE 5 C8 (50 X 2.1 mm) column and utilized a mobile phase composition of 0.5 mM Ammonium Chloride & 0.04% FA-Methanol (45:55% v/v). The method used three internal standards; AML-D4, HCTZ-D2 C13 and VAL-D3 with 10% intra- and inter-day precision, and 6% bias for all the analytes.

Results:

The assay was found to be linear with R-2 > 0.998, and the limits of quantification for AML, VAL and HCTZ were 0.2, 50.0 and 2.0 ng/mL, respectively. The analytes were found to be stable in plasma samples over short and long term storage.

:

The developed method is rapid with a run time of 3.5 min and cost-effective since the simple sample preparation method is adopted. This method was successfully applied for the bioequivalence study of AML, VAL, and HCTZ in human plasma after administration of the fixed-dose combination tablet of (10/160/25 mg). Pharmacokinetic parameters (Cmax and AUC0-72) for AML and (Cmax, AUC0-t, AUC0-∞) for VAL and HCTZ were used for bioequivalence assessment. These were determined by noncompartmental analysis of concentration data.

Conclusion:

The result showed 90% confidence intervals (obtained by ANOVA) which were within the predefined ranges. As a consequence, this method can be successfully applied for measuring and quantifying a large number of samples.

Determination of amlodipine, indapamide and perindopril in human plasma by a novel LC-MS/MS method: Application to a bioequivalence study

A robust and rapid UPLC-MS/MS method has been developed, optimized and validated for determination of amlodipine (AML), indapamide (IND) and perindopril (PRN) in human plasma. A positive electrospray ionization mode was used in a Xevo TQD LC-MS/MS instrument. A single sample preparation step using extraction technique was applied to extract the three analytes from plasma samples. There was no need to extract indapamide from blood samples in a further step. Extraction of the three drugs and internal standards was done using a solvent mixture composed of methyl tertiary butyl ether, dichloromethane and ethyl acetate. The prepared samples were analyzed using an Acquity UPLC HSS C₁₈ (100 × 2.1 mm, 1.7 μm) column. Ammonium acetate and methanol, pumped at a flow rate of 0.3 ml/min, were used as a mobile phase. Method validation was done as per the US Food and Drug Administration guidelines. Linearity was achieved in the range of 0.2-15 ng/ml for AML, 0.5-50 ng/ml for IND and 0.5-120 ng/ml for PRN. Accuracy and precision were estimated and found to be within the acceptable ranges. The rapid chromatography permits analysis of many samples per batch, making the method suitable for clinical and pharmacokinetic investigations. The developed and validated method was applied to estimate AML, IND, and PRN in a fasting bioequivalence study in healthy human volunteers.

A novel direct method to determine adherence to atorvastatin therapy in patients with coronary heart disease

AIMS

Objective methods to monitor statin adherence are needed. We have established a liquid chromatography-tandem mass spectrometry assay for quantification of atorvastatin and its metabolites in blood. This study aimed to develop an objective drug exposure variable with cut-off values to discriminate among adherence, partial adherence and nonadherence to atorvastatin therapy in patients with coronary heart disease.

METHODS

Twenty-five patients treated with atorvastatin 10 mg (n = 5), 20 mg (n = 6), 40 mg (n = 7) and 80 mg (n = 7) participated in a directly observed atorvastatin therapy study to confirm baseline adherence. After the directly observed therapy, half of the patients (test group) were instructed to stop taking atorvastatin and return for blood sample collection the subsequent 3 days. Levels of atorvastatin and metabolites were compared between the test group and the adherent control group.

RESULTS

The sum of parent drug and all measured primary metabolites correlated well with the atorvastatin dose administered (Spearman's rho = 0.71, 95% CI 0.44-0.87). The dose-normalized atorvastatin plus metabolites concentrations completely separated the partially adherent test group from the controls at 0.18 nM/mg after 3 days without atorvastatin. To reduce the risk of misinterpreting adherent patients as partially adherent, a corresponding cut-off at 0.10 nM/mg is proposed. A metabolite level of 2-OH atorvastatin acid <0.014 nmol/L provided the optimal cut-off for nonadherence.

CONCLUSION

A direct method to discriminate among adherence, partial adherence and nonadherence to atorvastatin therapy in patients with coronary heart disease has been developed. This tool may be important for novel studies on adherence and potentially useful in clinical practice.

UHPLC-MS/MS assay for simultaneous determination of amlodipine, metoprolol, pravastatin, rosuvastatin, atorvastatin with its active metabolites in human plasma, for population-scale drug-drug interactions studies in people living with HIV

Thanks to highly active antiretroviral treatments, HIV infection is now considered as a chronic condition. Consequently, people living with HIV (PLWH) live longer and encounter more age-related chronic co-morbidities, notably cardiovascular diseases, leading to polypharmacy. As the management of drug-drug interactions (DDIs) constitutes a key aspect of the care of PLWH, the magnitude of pharmacokinetic DDIs between cardiovascular and anti-HIV drugs needs to be more thoroughly characterized. To that endeavour, an UHPLC-MS/MS bioanalytical method has been developed for the simultaneous determination in human plasma of amlodipine, metoprolol, pravastatin, rosuvastatin, atorvastatin and its active metabolites. Plasma samples were subjected to protein precipitation with methanol, followed by evaporation at room temperature under nitrogen of the supernatant, allowing to attain measurable plasma concentrations down to sub-nanogram per milliliter levels. Stable isotope-labelled analytes were used as internal standards. The five drugs and two metabolites were analyzed using a 6-min liquid chromatographic run coupled to electrospray triple quadrupole mass spectrometry detection. The method was validated over the clinically relevant concentrations ranging from 0.3 to 480 ng/mL for amlodipine, atorvastatin and p-OH-atorvastatin, and 0.4 to 480 ng/mL for pravastatin, 0.5 to 480 ng/mL for rosuvastatin and o-OH-atorvastatin, and 3 to 4800 ng/mL for metoprolol. Validation performances such as trueness (95.4-110.8%), repeatability (1.5-13.4%) and intermediate precision (3.6-14.5%) were in agreement with current international recommendations. Accuracy profiles (total error approach) were lying within the limits of ±30% accepted in bioanalysis. This rapid and robust UHPLC-MS/MS assay allows the simultaneous quantification in plasma of the major currently used cardiovascular drugs and offers an efficient analytical tool for clinical pharmacokinetics as well as DDIs studies.

Developing spectral numerical factor technique for the determination of amlodipine besylate and the latest generation of statins in their new pharmaceutical combination

Spectral numerical factor techniques have been developed for quantification of a new pharmaceutical combination. Five simple, fast and accurate spectrophotometric methods using spectral factor manipulation have been tested and validated so as to determine quantitatively a new fixed-dose combination tablet containing both amlodipine besylate (ADB) and rosuvastatin calcium (ROS). Namely, these methods are induced dual wavelength, absorbance correction, absorbance subtraction, amplitude correction and advanced amplitude subtraction. Their corresponding spectral factors are equality, absorption, absorbance, amplitude and unity factor, respectively. Calibration curves of ADB and ROS were set up for all the previously mentioned methods under the optimum conditions in a concentration range of 3.0-21.0 μg/mL with correlation coefficients ≥0.9990. Selectivity was calculated by analyzing laboratory-prepared synthetic blends of the cited drugs. A comparative study between these methods and the reported ones has been carried out statistically forming a judgment that the difference between both results is totally insignificant. Actually, the suggested spectral factor technique is so effective for use in routine laboratory essay owing to its simplicity, rapidity and precision. Generally, the proposed factor procedures have the ability to run smoothly without any interference from additives that may deteriorate analysis efficiency of a pharmaceutical combination.