Simultaneous quantification of metformin and glipizide in human plasma by high-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study

Development and Greenness Assessment of HPLC Method for Studying the Pharmacokinetics of Co-Administered Metformin and Papaya Extract

Foods with medical value have been proven to be beneficial, and they are extensively employed since they integrate two essential elements: food and medication. Accordingly, diabetic patients can benefit from papaya because the fruit is low in sugar and high in antioxidants. An RP-HPLC method was designed for studying the pharmacokinetics of metformin (MET) when concurrently administered with papaya extract. A mobile phase of 0.5 mM of KH2PO4 solution and methanol (65:35, v/v), pH = 5 ± 0.2 using aqueous phosphoric acid and NaOH, and guaifenesin (GUF) were used as an internal standard. To perform non-compartmental pharmacokinetic analysis, the Pharmacokinetic program (PK Solver) was used. The method's greenness was analyzed using two tools: the Analytical GREEnness calculator and the RGB additive color model. Taking papaya with MET improved the rate of absorption substantially (time for reaching maximum concentration (Tmax) significantly decreased by 75% while maximum plasma concentration (Cmax) increased by 7.33%). The extent of absorption reduced by 22.90%. Furthermore, the amount of medication distributed increased (30.83 L for MET concurrently used with papaya extract versus 24.25 L for MET used alone) and the clearance rate rose by roughly 13.50%. The results of the greenness assessment indicated that the method is environmentally friendly. Taking papaya with MET changed the pharmacokinetics of the drug dramatically. Hence, this combination will be particularly effective in maintaining quick blood glucose control.

Ecological HPLC method for analyzing an antidiabetic drug in real rat plasma samples and studying the effects of concurrently administered fenugreek extract on its pharmacokinetics

Currently, the total number of diabetic people worldwide is constantly increasing. Metformin (MET) is known to be a first-line antidiabetic drug with varied, wide-reaching applications. Concurrent administration of phytomedicines such as fenugreek extract with synthetic drugs is very common. It is reported that concomitant administration of fenugreek extract with metformin maintains lower blood glucose levels than metformin alone. In this work, an ecofriendly RP-HPLC method was established to study and compare the pharmacokinetics of metformin with and without the contemporary administration of fenugreek extract using rat as an animal model. In the developed method, a solvent mixture of 0.5 mM KH₂PO₄ solution : methanol (65 : 35, v/v) was used as a mobile phase and guaiphenesin was used as an internal standard. The plasma concentration–time curve was plotted, and non-compartmental pharmacokinetic analysis was performed using PKSolver. The results of the pharmacokinetic study showed that concurrent administration of fenugreek significantly increased the bioavailability of metformin and doubled the time required to reach the peak plasma concentration (T_max). Moreover, the volume of drug distribution decreased by about 70%, while its rate of clearance decreased by about 55.96%. Accordingly, the administration of fenugreek in combination with metformin significantly affected the pharmacokinetics of metformin, and this combination will be very useful in controlling blood glucose levels in diabetic patients. The greenness of the method was assessed using the Analytical Eco-Scale, Analytical Method Volume Intensity (AMVI), and National Environmental Method Index (NEMI), and all results affirmed that the method can be considered to be ecological.

The combination of fenugreek extract and metformin can be considered as an auspicious treatment for satisfactory diabetes control and minimizing the expected long-term complications of metformin.

Liquid chromatography tandem mass spectrometry for the simultaneous determination of metformin and pioglitazone in rat plasma: Application to pharmacokinetic and drug-drug interaction studies

Failure to attain and sustain long term glycemic control is an ongoing challenge in diabetes therapy. The trend to use a combined therapy and the risk of drug-drug interaction (DDI) are elevated and thus the need for sensitive analytical methods is of great significance. Herein, a simple, robust, and sensitive reverse phase high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (ESI-MS/MS) method for simultaneous determination of metformin (MET) and pioglitazone (PGT) in rat plasma using canagliflozin (CAN) as internal standards (IS) was developed and fully validated. Prior Chromatographic separation on an Agilent Eclipse Plus C18 (4.6 × 100 mm, 3.5 μm) using gradient mobile phase system consisting of ammonium formate pH 4.5 and acetonitrile at a flow rate of 0.5 mL min^-1, within a run time of 14 min, the antidiabetic drugs were extracted from rat plasma using acetonitrile-induced protein precipitation technique. Multiple reaction monitoring in positive ion mode was used for quantitation of precursor to production at m/z 130.1 → 71.0 & 60 for MET, 357.2 → 134.2 for PGT, and 462.16 → 191.1 for CAN. Method linearity was obeyed in the range of 1 to 5000 and 1 to 2500 ng mL^-1 for MET and PGT, respectively. The developed method was validated in terms of accuracy, precision, selectivity, recovery, matrix effects, and stability as per US-FDA bioanalytical guidelines and successfully applied to clinical pharmacokinetic and DDI studies with a single oral administration of target compounds. The peak plasma concentrations (C_max) and area under the concentration-time curve (AUC) of MET was significantly influenced by the concomitant administration of PGT at equal concentration and vice versa. PGT affected the absorption and elimination rate of MET via inhibition of organic cationic transporter (OCT). Molecular modeling study revealed the significant interaction of PGT with OCT. A potential DDI in type 2 diabetic patient receiving chronic treatment with MET and PGT deserves further attention and study to improve drug therapy and prevent adverse effects.

The role of mass spectrometry in studies of glycation processes and diabetes management

In the last decade, mass spectrometry has been widely employed in the study of diabetes. This was mainly due to the development of new, highly sensitive, and specific methods representing powerful tools to go deep into the biochemical and pathogenetic processes typical of the disease. The aim of this review is to give a panorama of the scientifically valid results obtained in this contest. The recent studies on glycation processes, in particular those devoted to the mechanism of production and to the reactivity of advanced glycation end products (AGEs, AGE peptides, glyoxal, methylglyoxal, dicarbonyl compounds) allowed to obtain a different view on short and long term complications of diabetes. These results have been employed in the research of effective markers and mass spectrometry represented a precious tool allowing the monitoring of diabetic nephropathy, cardiovascular complications, and gestational diabetes. The same approaches have been employed to monitor the non-insulinic diabetes pharmacological treatments, as well as in the discovery and characterization of antidiabetic agents from natural products. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 38:112-146, 2019.

Bioanalytical methods for the detection of antidiabetic drugs: a review

Type 2 diabetes mellitus, a disease which prevalence has been progressively increasing worldwide, is characterized by chronic hyperglycemia resulting from the combination of inappropriate insulin secretion and/or resistance to insulin action. If left uncontrolled, diabetes is associated with complications such as dysfunction and failure of various organs, and even premature death. Along with lifestyle-modification strategies, several classes of oral antidiabetic agents can be employed for glycemic control. Thus, therapeutic drug monitoring of these drugs is essential to maintain appropriate treatment. This review discusses the most frequently employed analytical techniques and sample preparation systems to obtain a reliable and trustworthy method to quantify antidiabetic drugs in biological matrices. An adequate choice of internal standard, ideal chromatography conditions and most suitable analytical detector are reported.

Simultaneous determination of glipizide and its four hydroxylated metabolites in human urine using LC-MS/MS and its application in urinary phenotype study

Cytochrome P450 (CYP) 2C9 and CYP2C19 genetic mutant could influence the plasma concentration of glipizide in human subjects, which refers to glipizide safety and adverse effects in clinic practice. A further study to investigate the relationship of the concentrations between glipizide and its metabolites in human with different CYP mutants was valuable. We firstly develop a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of glipizide and its hydroxylated metabolites in human urine. After simple protein precipitation with methanol including 4'-OH-tolbutamide and gliclazide (both are internal standards), the analytes were chromatographed on a reversed-phased column with a mobile phase of 0.1% formic acid in acetonitrile and 0.1% formic acid in water by a gradient elution. The ion transitions of the precursor to the product ion were principally protonated ions [M+H]⁺ at m/z 446.4→m/z 321.1 for glipizide, m/z 462.2→m/z 321.1 for the four hydroxylated forms of glipizide, m/z 287.2→m/z 188.0 for 4'-OH-tolbutamide, and m/z 324.1→m/z 127.1 for gliclazide. The method was linear over a concentration range of 0.02-20.0ng/mL. The intraday and inter-day variances were less than 9.9%, and accuracy was within ±6.8%. The method was successfully applied to the urinary phenotyping study in volunteers after a single oral administration of 5-mg glipizide tablet, and two new hydroxycyclohexyl metabolites of glipizide (OH-gp), 4-cis-OH-gp and 3-trans-OH-gp, were found in this study.

Development of Certain Protein Kinase Inhibitors with the Components from Traditional Chinese Medicine

Traditional Chinese medicines (TCMs) have been used in China for more than two thousand years, and some of them have been confirmed to be effective in cancer treatment. Protein kinases play critical roles in control of cell growth, proliferation, migration, survival, and angiogenesis and mediate their biological effects through their catalytic activity. In recent years, numerous protein kinase inhibitors have been developed and are being used clinically. Anticancer TCMs represent a large class of bioactive substances, and some of them display anticancer activity via inhibiting protein kinases to affect the phosphoinositide 3-kinase, serine/threonine-specific protein kinases, pechanistic target of rapamycin (PI3K/AKT/mTOR), P38, mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK) pathways. In the present article, we comprehensively reviewed several components isolated from anticancer TCMs that exhibited significantly inhibitory activity toward a range of protein kinases. These components, which belong to diverse structural classes, are reviewed herein, based upon the kinases that they inhibit. The prospects and problems in development of the anticancer TCMs are also discussed.

Simultaneous Quantification of Antidiabetic Agents in Human Plasma by a UPLC-QToF-MS Method

An ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry method for the simultaneous quantification of chlorpropamide, glibenclamide, gliclazide, glimepiride, metformin, nateglinide, pioglitazone, rosiglitazone, and vildagliptin in human plasma was developed and validated, using isoniazid and sulfaquinoxaline as internal standards. Following plasma protein precipitation using acetonitrile with 1% formic acid, chromatographic separation was performed on a cyano column using gradient elution with water and acetonitrile, both containing 0.1% formic acid. Detection was performed in a quadrupole time-of-flight analyzer, using electrospray ionization operated in the positive mode. Data from validation studies demonstrated that the new method is highly sensitive, selective, precise (RSD < 10%), accurate (RE < 12%), linear (r > 0.99), free of matrix and has no residual effects. The developed method was successfully applied to volunteers' plasma samples. Hence, this method was demonstrated to be appropriate for clinical monitoring of antidiabetic agents.

LC-MS/MS analysis of metformin, saxagliptin and 5-hydroxy saxagliptin in human plasma and its pharmacokinetic study with a fixed-dose formulation in healthy Indian subjects

A specific and rapid liquid chromatography-tandem mass spectrometry method is proposed for the simultaneous determination of metformin (MET), saxagliptin (SAXA) and its active metabolite, 5-hydroxy saxagliptin (5-OH SAXA) in human plasma. Sample preparation was accomplished from 50 μL plasma sample by solid-phase extraction using sodium dodecyl sulfate as an ion-pair reagent. Reversed-phase chromatographic resolution of analytes was possible within 3.5 min on ACE 5CN (150 × 4.6 mm, 5 μm) column using acetonitrile and10.0 mm ammonium formate buffer, pH 5.0 (80:20, v/v) as the mobile phase. Triple quadrupole mass spectrometric detection was performed using electrospray ionization in the positive ionization mode. The calibration curves showed good linearity (r²  ≥ 0.9992) over the established concentration range with limit of quantification of 1.50, 0.10 and 0.20 ng/mL for MET, SAXA and 5-OH SAXA respectively. The extraction recoveries obtained from spiked plasma samples were highly consistent for MET (75.12-77.84%), SAXA (85.90-87.84%) and 5-OH SAXA (80.32-82.69%) across quality controls. The validated method was successfully applied to a bioequivalence study with a fixed-dose formulation consisting of 5 mg SAXA and 500 mg MET in 18 healthy subjects. The reproducibility of the assay was demonstrated by reanalysis of 87 incurred samples.

LC-tandem mass spectrometry method for the simultaneous determination of metformin and sitagliptin in human plasma after ion-pair solid phase extraction

A reversed-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method was established for simultaneous determination of two oral hypoglycemic drugs metformin (MET) and sitagliptin (STG) in human plasma. The analytes were extracted from 50μL human plasma by ion-pair solid phase extraction using sodium lauryl sulphate on Phenomenex Strata-X (30mg/1mL) cartridges. The chromatographic separation was accomplished on XSelect HSS CN (150×4.6mm, 5μm) column using mobile phase consisting of methanol-8.0mM ammonium formate in water, pH 4.5 (80:20, v/v) under isocratic condition. Tandem MS detection was performed on a triple quadrupole spectrometer equipped with an electrospray ionization source, operated in the positive mode. Multiple reaction monitoring (MRM) was used to quantify the analytes following transitions, m/z 130.1→60.1 and m/z 408.3→235.1 for MET and STG respectively. The method displayed acceptable linearity in the concentration range of 4.00-3200ng/mL for MET and 1.00-800ng/mL for STG. The intra-batch and inter-batch precisions were ≤5.1% and accuracy ranged from 96.5 to 103.3% for both the drugs. The mean recovery of MET and STG obtained from spiked plasma samples was 82.5% and 90.4% respectively with minimal matrix interference. Both the drugs were found to be stable under all mandatory storage conditions. The validated method was successfully applied to a clinical pharmacokinetic study for a fixed-dose tablet formulation containing 500mg MET and 50mg STG in 16 healthy volunteers.

Recent advances in the use of metformin: can treating diabetes prevent breast cancer?

There is substantial epidemiological evidence pointing to an increased incidence of breast cancer and morbidity in obese, prediabetic, and diabetic patients. In vitro studies strongly support metformin, a diabetic medication, in breast cancer therapy. Although metformin has been heralded as an exciting new breast cancer treatment, the principal consideration is whether metformin can be used as a generic treatment for all breast cancer types. Importantly, will metformin be useful as an inexpensive therapy for patients with comorbidity of diabetes and breast cancer? In general, meta-analyses of clinical trial data from retrospective studies in which metformin treatment has been used for patients with diabetes and breast cancer have a positive trend; nevertheless, the supporting clinical data outcomes remain inconclusive. The heterogeneity of breast cancer, confounded by comorbidity of disease in the elderly population, makes it difficult to determine the actual benefits of metformin therapy. Despite the questionable evidence available from observational clinical studies and meta-analyses, randomized phases I-III clinical trials are ongoing to test the efficacy of metformin for breast cancer. This special issue review will focus on recent research, highlighting in vitro research and retrospective observational clinical studies and current clinical trials on metformin action in breast cancer.

Quality by Design Approach for the Development and Validation of Glipizide, an Antidiabetic Drug, by RP-UPLC with Application to Formulated Forms and Urine

Quality by design (QbD) refers to the achievement of certain predictable quality with desired and predetermined specifications. The objective of this study was to develop and demonstrate an integrated multivariate approach to develop and quantify the constituent concentrations of glipizide (GPZ) drug in its pure and tablet forms. The method was developed using Zorbax Extend C-18 (50 mm × 4.6 mm × 1.8 μm) column with mobile phase consisting of a mixture of phosphate buffer of pH 3.5 and acetonitrile (60 : 40 v/v). The method fulfilled validation criteria and was shown to be sensitive, with limits of detection (LOD) and quantitation (LOQ) of 0.001 and 0.005 μg mL−1, respectively. The percentage relative standard deviations for robustness and ruggedness were observed within the range of 0.1 and 0.99. The calibration graph was linear in the range of 0.005–300 μg mL−1. The applicability of the method was shown by the analysis of formulated drug and spiked urine samples. The proposed method can be used for routine analysis in quality control laboratories for its bulk and formulated product, and this is the first UPLC method reported for the assay of GPZ in bulk, formulated form and urine.