Simultaneous determination of azilsartan and chlorthalidone in rat and human plasma by liquid chromatography-electrospray tandem mass spectrometry

Chemometry and Green Chemistry-Based Chromatographic Analysis of Azilsartan Medoxomil, Cilnidipine and Chlorthalidone in Human Plasma Using Analytical Quality by Design Approach

According to the green chemistry approach, the usage of carcinogenic and teratogenic organic solvents should be minimized in the development of the analytical method for the safety of the environment and analysts. According to the literature review, no high-performance thin-layer chromatographic (HPTLC) method has been reported yet for concomitant analysis of azilsartan medoxomil (AZM), chlorthalidone (CTD) and cilnidipine (CDP) in human plasma. Hence, a robust and accurate HPTLC method has been developed using safe and non-toxic organic solvents for the concomitant analysis of AZM, CTD and CDP in human plasma, fixed-dose combinations (FDCs) and laboratory mixtures. The HPTLC method was developed by the implementation of the analytical quality by design approach using principles of quality risk management and design of experiments (DoE) for regulatory compliance. The principal component analysis was applied for the risk assessment and analysis of potential method variables in the method development. The principle of DoE was used for the response surface modeling to link identified critical method risk parameters with critical method performance attributes using full factorial design (FFD). The method operable design region and analytical control space were navigated for the optimization of the method as per quality target analytical profile. The developed method was also applied for concomitant analysis of AZM, CTD and CDP in their FDCs and laboratory mixture and results were found in good agreement with the labeled amount of the respective drug.

Application of Taguchi OA and Box-Behnken Design for the Implementation of DoE-based AQbD Approach to HPTLC Method for Simultaneous Estimation of Azilsartan and Cilnidipine

Hypertension is the most prominent disease found in people due to stressful routines and the working environment. The fixed-dose combination (FDC) of azilsartan medoxomil (AZL) and cilnidipine (CLN) is used for the treatment of hypertension. According to the green chemistry approach, organic solvents should be minimized in the development of the analytical method for the safety of the environment. The high-performance thin-layer chromatographic (HPTLC) method required less amount of organic solvent for the analysis of the drug. Hence, it was thought of interest to develop an accurate and robust HPTLC method for the estimation of AZL and CLN in their FDC. The development of the method was carried out by the implementation of the analytical quality by design approach using the Taguchi orthogonal array and BBD for regulatory compliance as per the upcoming ICH Q14 guideline. The analytical design space and control strategy was framed for the lifecycle management of the method. The chromatographic separation was performed using silica gel GF254 and toluene ethylacetate-methanol (6.5 + 1.5 + 2.0, v/v). The method was applied for the assay of FDC and results were found in compliance with the labeled claim. The developed method was also applied for the estimation of spiked human plasma and the recovered amount of drugs was found in the range of 80-85%.

Implementation of White Analytical Chemistry-Assisted Analytical Quality by Design Approach to Green Liquid Chromatographic Method for Concomitant Analysis of Anti-Hypertensive Drugs in Human Plasma

According to current concepts of white analytical chemistry (WAC), the use of organic solvents those are teratogenic and carcinogenic must be avoided for the protection of the environment and of the analysts. This led to the development and validation of the WAC-assisted green liquid chromatographic technique (reverse-phase high-pressure liquid chromatography (RP-HPLC)) for the simultaneous analysis of anti-hypertensive drugs (azilsartan medoxomil, chlorthalidone and cilnidipine) in human plasma and their fixed-dose combinations. The analytical quality by design approach was used in conjunction with the design of experiments and chemometrics concepts to develop the method. To develop the green RP-HPLC method, critical method variables (CMVs) and critical analytical attributes were identified using the multivariate analytical tools principal component analysis and partial least square regression. Using the Box-Behnken design, the design of experiments was used for CMV optimization and response surface analysis. It was possible to explore the analytical design space for the life cycle management of the RP-HPLC method. The developed method was found to be validated following International Council for Harmonization Q2 (R1) and M10 requirements. Using the red, green and blue paradigm, the existing and proposed chromatographic methods were evaluated for their validation efficacy, greenness profile and cost-effectiveness.

Diuretics in Different Samples: Update on the Pretreatment and Analysis Techniques

Diuretics are drugs that promote the excretion of water and electrolytes in the body and produce diuretic effects. Clinically, they are often used in the treatment of edema caused by various reasons and hypertension. In sports, diuretics are banned by the World Anti-Doping Agency (WADA). Therefore, in order to monitor blood drug concentration, identify drug quality and maintain the fairness of sports competition, accurate, rapid, highly selective and sensitive detection methods are essential. This review provides a comprehensive summary of the pretreatment and detection of diuretics in various samples since 2015. Commonly used techniques to extract diuretics include liquid-liquid extraction, liquid-phase microextraction, solid-phase extraction, solid-phase microextraction, among others. Determination methods include methods based on liquid chromatography, fluorescent spectroscopy, electrochemical sensor method, capillary electrophoresis and so on. The advantages and disadvantages of various pretreatment and analytical techniques are elaborated. In addition, future development prospects of these techniques are discussed.

Chemometric and Design of Experiments-Based Analytical Quality by Design and Green Chemistry Approaches to Multipurpose High-Pressure Liquid Chromatographic Method for Synchronous Estimation of Multiple Fixed-Dose Combinations of Azilsartan Medoxomil

BACKGROUND

Azilsartan medoxomil (AZL) is an anti-hypertensive drug, and its numerous FDCs are used for the treatment of hypertension. Numerous chromatographic methods have been reported for the estimation of FDCs of AZL, but analysts have to establish a separate chromatographic condition for the analysis of each FDC of AZL. No reverse-phase high-pressure liquid chromatography (RP-HPLC) method has been reported yet that can be used for synchronous estimation of multiple FDCs of AZL.

OBJECTIVE

Hence, the RP-HPLC-PDA method has been developed for synchronous estimation of multiple FDCs of AZL to save time, cost, and solvent for the analysis.

METHOD

The RP-HPLC-PDA method has been developed by the implementation of the analytical quality by design (AQbD) approach based on chemometric and DoE as per the upcoming International Council for Harmonization (ICH) Q14 guideline.

RESULTS

The method was applied for synchronous estimation of multiple FDCs of AZL, and the assay results were found in compliance with the labeled claim of the FDCs.

CONCLUSIONS

The developed method requires less time, cost, and organic solvent for analysis of the said pharmaceutical dosage forms compared to published chromatographic methods. Hence, the developed method is green and multipurpose for the estimation of multiple FDCs of AZL.

HIGHLIGHTS

Development and validation of RP-HPLC method for synchronous estimation of multiple FDCs of AZL using chemometric (principal component analysis and PLS) and design of experiments (DoE). Applications of the method for synchronous estimation of multiple FDCs of AZL.

Application of Chemometry and Design of Experiments to Green HPTLC Method for Synchronous Estimation of Multiple FDCs of Cilnidipine

BACKGROUND

Numerous fixed-dose combinations (FDCs) of cilnidipine (CIL) with chlorthalidone (CLT) and azilsartan medoxomil (AZL) are used for the treatment of hypertension. Numerous reverse-phase high-pressure liquid chromatography (RP-HPLC) and high-performance thin-layer chromatography (HPTLC) methods have been reported in the literature for the estimation of FDCs of CIL. But no HPTLC method has been reported yet for synchronous estimation of multiple FDCs of CIL to save time, organic solvent, and cost of analysis. In the recent scenario of green chemistry, the minimum usage of organic solvent in the development of the chromatographic method is highly desirable for the safety of the environment and analysts.

OBJECTIVE

Hence, a robust and green HPTLC method has been developed for the synchronous estimation of multiple FDCs of CIL using the analytical quality by design (AQbD) approach.

METHODS

The chemometric tool was applied for the identification of the critical method variables (CMVs) and critical analytical attributes (CAAs) for the HPTLC method development. The design of experiments (DoE) was applied for the response surface analysis of identified CMVs and CAAs using the Box-Behnken design. The analytical design space and control strategy was framed for the lifecycle management of the HPTLC method.

RESULTS

The chromatographic separation was performed using silica gel G60 F254 as the stationary phase and toluene-ethyl acetate-methanol (6.5 + 2 + 1.5, v/v) as the mobile phase. The method was validated as per the International Council for Harmonization Q2 (R1) guideline. The developed method was applied for the synchronous estimation of multiple FDCs of CIL, and results were found in compliance with labeled claims.

CONCLUSIONS

The developed HPTLC method can be used as a green, economical, and rapid analytical tool for routine analysis and quality control of multiple FDCs of CIL in the pharmaceutical industry.

HIGHLIGHTS

Development of a HPTLC method for synchronous estimation of multiple FDCs of CIL using the AQbD approach based on principles of chemometry and DoE. Application of the developed method for synchronous assay of multiple FDCs of CIL to save time, cost, and solvent for analysis.

Full spectrum and genetic algorithm-selected spectrum-based chemometric methods for simultaneous determination of azilsartan medoxomil, chlorthalidone, and azilsartan: Development, validation, and application on commercial dosage form

Five various chemometric methods were established for the simultaneous determination of azilsartan medoxomil (AZM) and chlorthalidone in the presence of azilsartan which is the core impurity of AZM. The full spectrum-based chemometric techniques, namely partial least squares (PLS), principal component regression, and artificial neural networks (ANN), were among the applied methods. Besides, the ANN and PLS were the other two methods that were extended by genetic algorithm procedure (GA-PLS and GA-ANN) as a wavelength selection procedure. The models were developed by applying a multilevel multifactor experimental design. The predictive power of the suggested models was evaluated through a validation set containing nine mixtures with different ratios of the three analytes. For the analysis of Edarbyclor® tablets, all the proposed procedures were applied and the best results were achieved in the case of ANN, GA-ANN, and GA-PLS methods. The findings of the three methods were revealed as the quantitative tool for the analysis of the three components without any intrusion from the co-formulated excipient and without prior separation procedures. Moreover, the GA impact on strengthening the predictive power of ANN- and PLS-based models was also highlighted.

Compound danshen dripping pills affect the pharmacokinetics of azisartan by regulating the expression of cytochrome P450 2B1, 2C6, and 2C11 in rats

Combination therapies of compound danshen dripping pill (CDDP) and Azilsartan (AZ) represent a promising treatment option in clinical practice in China, but there are no reports on drug-drug interactions between CDDP and AZ. This study investigated the effects of CDDP on the pharmacokinetics of AZ and clarified its potential mechanism. The pharmacokinetic profiles of oral administration of AZ (2 mg/kg) in Sprague-Dawley rats, with or without pre-treatment of CDDP (81, 405, 810 mg/kg/d for 7 d) were investigated using UPLC-MS/MS. The main pharmacokinetic parameters were calculated and compared. The MS analysis was performed in positive ionization mode. The purpose of chromatographic separation of AZ and the internal standard (IS, Valsartan) was finished on a Waters XBridge BEH C18 column (2.1 × 100 mm, 2.5 μm). The mobile phase was acetonitrile and 0.1 % formic acid-water with gradient elution at a flow rate of 0.4 mL/min. The mRNA and protein levels of CYP2B1, CYP2C6, and CYP2C11 in the rat liver were detected by qRT-PCR and western blot, respectively. The results indicated that low, medium and high doses of CDDP significantly increased the C_max (6.47 ± 2.28, 6.51 ± 1.99, 7.04 ± 1.31 vs. 3.30 ± 1.87) of AZ, compared with that in the AZ single-drug group (p<0.05). The AUC_0-t of AZ (47.77 ± 23.41, 50.69 ± 25.46, 54.50 ± 11.57 vs. 26.85 ± 16.79) tended to increase in combination with CDDP. The gene and protein expression levels of CYP2B1, CYP2C6, and CYP2C11 were significantly reduced in the rat liver by CDDP. CDDP may diminish the AZ metabolism in vivo by suppressing the expression of the CYP2B1, CYP2C6, and CYP2C11 enzymes. This observation suggested the occurrence of potential interactions between CDDP and AZ when clinically administered as combination therapy, which may require adjustment of the clinical dose of AZ.

Azilsartan medoxomil

Azilsartan is used for treatment of the high blood pressure (hypertension). Reducing high blood pressure enables avoid strokes, heart attacks and problems of kidneys. Azilsartan comes under the name angiotensin receptor blocker (ARBs) as a class of drugs. It acts by relaxing blood vessels to make it easier for blood to flow. Azilsartan Medoxomil's a comprehensive profile containing the description, formulae, Elemental Analysis, Uses and application. Furthermore, methods and schemes are outlined for the preparation of the drug substance. The physical properties of the medication include constant of ionization, solubility, X-ray powder diffraction pattern, differential scanning calorimetry, thermal conduct and spectroscopic studies are investigated. The methods employed in bulk medicines and/or in pharmaceutical formulations to analyze the drug substance include spectrophotometric, electrochemical and the chromatographic methods. Other studies on this drug substance include drug stability, Pharmaceutical Applications, Mechanism of Action, Pharmacodynamics, and a Dosing Information are reviewed. At the end of this profile, there are more than sixty references were listed.

Azilsartan ameliorates apoptosis of dopaminergic neurons and rescues characteristic parkinsonian behaviors in a rat model of Parkinson's disease

Loss of dopaminergic neurons within the substantia nigra (SN) is a pathological hallmark of Parkinsons disease (PD), which leads to the onset of motor symptoms. Previously, our in vitro studies revealed that Angiotensin II (Ang II) induced apoptosis of dopaminergic neurons through its type 1 receptor (AT1R), but these findings needed to be confirmed via animal experiments. Here, using a rotenone-induced rat model of PD, we observed an overactivation of Ang II/AT1R axis in the SN, since Ang II level and AT1R expression were markedly increased. Furthermore, we provided in vivo evidence that Ang II directly elicited apoptosis of dopaminergic neurons via activation of AT1R in the SN of rats. More importantly, we showed for the first time that oral administration of azilsartan, a newly developed AT1R blocker approved by the U.S. Food and Drug Administration for hypertension treatment, rescued the apoptosis of dopaminergic neurons and relieved the characteristic parkinsonian symptoms in PD rats. These results support the application of AT1R blockers in PD therapy, and strengthen the notion that many therapeutic agents may possess pleiotropic action in addition to their main applications.

The simultaneous UPLC-MS/MS determination of emerging drug combination; candesartan and chlorthalidone in human plasma and its application

A novel, precise, sensitive and accurate ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed for the simultaneous determination of a novel drug combination, candesartan (CAN) and chlorthalidone (CHL), in human plasma. Chromatographic separation was achieved on Waters Acquity UPLC BEH C₁₈ (50 × 2.1 mm, 1.7 μm). Mobile phase consisting of 1 mm ammonium acetate in water-acetonitrile (20:80 v/v) was used. The total chromatographic runtime was 1.9 min with retention times for CAN and CHL at 0.7 and 1.1 min respectively. Ionization and detection of analytes and internal standards was performed on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring and negative ionization mode. Quantitation was done to monitor protonated precursor → product ion transition of m/z 439.2 → 309.0 for CAN, 337.0 → 189.8 for CHL and 443.2 → 312.1 for candesartan D4 and 341.0 → 189.8 for chlorthalidone D4. The method was validated over a wide dynamic concentration range of 2.0-540.0 ng/mL for candesartan and 1.0-180.0 ng/mL for chlorthalidone. The validated method was successfully applied for the assay of CAN and CHL in healthy volunteers.

Evaluation of the impact of 16-dehydropregnenolone on the activity and expression of rat hepatic cytochrome P450 enzymes

16-dehydropregnenolone (DHP) is a promising novel antihyperlipidemic agent developed and patented by Central Drug Research Institute (CDRI), India. The purpose of the present study was to investigate whether DHP influences the activities and mRNA expression of hepatic drug-metabolizing cytochrome P450 (CYP) enzymes (CYP1A2, CYP2C11, CYP2D2, CYP2E1 and CYP3A1) in Sprague-Dawley (SD) rats. A cocktail suspension of CYP probe substrates which contained caffeine (CYP1A2), tolbutamide (CYP2C11), dextromethorphan (CYP2D2), chlorzoxazone (CYP2E1) and dapsone (CYP3A1) was administered orally on eighth- or fifteenth-day to rats pre-treated with DHP intragastrically at a dose of 36 and 72mg/kg for one week and two weeks. The concentrations of probe drugs in plasma were estimated by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Alongside, the effect of DHP on CYPs activity and mRNA expression levels were assayed in isolated rat liver microsomes and by real-time reverse transcription-polymerase chain reaction (RT-PCR), respectively. DHP had significant inducing effects on CYP1A2, 2C11, 2D2 and 2E1 with no effect on CYP3A1 in dose- and time-dependent manner, as revealed from the pharmacokinetic profiles of the probe drugs in rats. In-vitro microsomal activities and mRNA expression results were in good agreement with the in-vivo pharmacokinetic results. Collectively, the results unveiled that DHP is an inducer of rat hepatic CYP enzymes. Hence, intense attention should be paid when DHP is co-administered with drugs metabolized by CYP1A2, 2C11, 2D2 and 2E1, which might result in drug-drug interactions and therapeutic failure.

Plasma pharmacokinetics, bioavailability and tissue distribution of agnuside following peroral and intravenous administration in mice using liquid chromatography tandem mass spectrometry

Agnuside (AGN), an iridoid glycoside, is the chemotaxonomic marker of the genus Vitex which has gained enormous attention by virtue of its potential health benefits. Regardless of claiming many therapeutic applications reports demonstrating its pharmacokinetics or quantification in biomatrices are lacking. This is the first report which presents a sensitive liquid chromatography coupled to a tandem mass spectrometry (LC-MS/MS) method for the quantification of AGN in mice plasma and various tissues (including liver, intestine, spleen, kidney, heart, lungs and brain). AGN was extracted from the biological samples using protein precipitation followed by liquid-liquid extraction and the separation was achieved on C18 reversed phase column with a mobile phase consisted of 0.1% formic acid in acetonitrile-0.1% formic acid in triple distilled water (92:8, v/v) at a flow rate of 0.7mL/min. The MS/MS detection was performed by electrospray ionization (ESI) using multiple reaction monitoring (MRM) in negative scan mode. The bioanalytical method was found linear over the concentration range of 1-4000ng/mL for plasma and tissue homogenates (r(2)≥0.990). The lower limit of quantitation (LLOQ) for all matrices was 1ng/mL. Intra-day and inter-day variance and accuracy ranged from 90 to 110% and 1-10%, respectively. Matrix effect and recoveries were well within the satisfactory limits. The validated method was applied successfully to measure AGN concentrations in plasma and tissues following intravenous (i.v.) and peroral (p.o.) administration to mice. Maximal AGN concentrations in plasma and tissues were reached within 30-45min. The mean absolute bioavailability (%F) of AGN was∼0.7%. After oral administration, AGN was most abundant in intestine, followed by kidney, liver, spleen, brain, lungs and heart. The identified target tissues of AGN may help in understanding its pharmacological action in vivo.

A liquid chromatography-tandem mass spectrometry method for the quantitation of actarit in rabbit plasma: application to pharmacokinetics and metabolic stability

Actarit (ATR), 4-acetylaminophenylacetic acid is an orally effective disease-modifying anti-rheumatic drug widely prescribed for the treatment of rheumatoid arthritis. The present study demonstrates the first report on a selective and sensitive liquid chromatography-tandem mass spectrometry method for the quantification of ATR in rabbit plasma using p-coumaric acid as an internal standard (IS). Following liquid-liquid extraction, chromatographic separation of the reconstituted samples was achieved isocratically on a Syncronis-C18 column with a mobile phase consisting of aqueous ammonium acetate (10 mM, pH 4)- methanol and acetonitrile mixture (8 : 92, v/v) at a flow rate of 0.6 ml/min. ATR and IS were detected using electrospray ionization operated in negative multiple reaction monitoring mode. The calibration curve was linear (r(2)  ≥ 0.990) over the concentration range of 1-4000 ng/ml with a lower limit of quantitation of 1 ng/ml. The mean extraction recovery of ATR and IS from rabbit plasma was greater than 85%. The method complied well with US Food and Drug Administration guidelines for selectivity, sensitivity, accuracy, precision, matrix effect, dilution integrity, carry-over effect and stability. The method was successfully applied to in vitro metabolic stability (using rabbit liver microsomes) and in vivo pharmacokinetic study after oral administration of ATR at a dose of 10 mg/kg in New Zealand rabbits. Copyright © 2015 John Wiley & Sons, Ltd.