Enhanced LC-MS/MS analysis of alogliptin and pioglitazone in human plasma: Applied to a preliminary pharmacokinetic study

A physiologically-based quantitative systems pharmacology model for mechanistic understanding of the response to alogliptin and its application in patients with renal impairment

Alogliptin is a highly selective inhibitor of dipeptidyl peptidase-4 and primarily excreted as unchanged drug in the urine, and differences in clinical outcomes in renal impairment patients increase the risk of serious adverse reactions. In this study, we developed a comprehensive physiologically-based quantitative systematic pharmacology model of the alogliptin-glucose control system to predict plasma exposure and use glucose as a clinical endpoint to prospectively understand its therapeutic outcomes with varying renal function. Our model incorporates a PBPK model for alogliptin, DPP-4 activity described by receptor occupancy theory, and the crosstalk and feedback loops for GLP-1-GIP-glucagon, insulin, and glucose. Based on the optimization of renal function-dependent parameters, the model was extrapolated to different stages renal impairment patients. Ultimately our model adequately describes the pharmacokinetics of alogliptin, the progression of DPP-4 inhibition over time and the dynamics of the glucose control system components. The extrapolation results endorse the dose adjustment regimen of 12.5 mg once daily for moderate patients and 6.25 mg once daily for severe and ESRD patients, while providing additional reflections and insights. In clinical practice, our model could provide additional information on the in vivo fate of DPP4 inhibitors and key regulators of the glucose control system.

Thiazolidinediones: Recent Development in Analytical Methodologies

The instrumental analytical methods that have been developed and utilized for the determination of thiazolidinedione in bulk medications, formulations and biological fluids have been reviewed after an in-depth analysis of the literature published in a variety of analytical and pharmaceutical chemistry-related journals. The approaches covered by this research, which covers the years 2001-2022, include complex methods for analysis, chromatographic techniques and spectrometric analytical procedures. The mobile phase, flow rate, sample matrix, wavelength and other factors identified in the literature were just a few of the parameters used to evaluate thiazolidinediones. The present review focuses on the published analytical techniques for thiazolidinedione analysis that have been previously identified in the literature. The specified outcomes followed extensive learning, and the most recent advances in analytical methods for the identification of pioglitazone, pioglitazone HCl, rosiglitazone, rosiglitazone maleate and lobeglitazone were reviewed. Additionally, this article briefly discusses features of analytical discovery on thiazolidinediones, which will enable readers to access all discoveries in one place with precise outcomes.

An Effective Chromatographic Method for Simultaneous Quantification of Antidiabetic Drugs Alogliptin Benzoate and Pioglitazone HCl in Their Tablet Dosage Form: Implementation to In vitro Dissolution Studies and Uniformity of Dosage Unit

In patients with Type 2 diabetes, a combination of Alogliptin and Pioglitazone medications, together with diet and physical activity, are used to improve glycemic control. Eco-friendly, cost-effective, and precise stability-indicating RP-HPLC method was developed and validated for the identification and quantification of Alogliptin and Pioglitazone in their tablet dosage form, as well as implementation to in vitro dissolution studies and uniformity of dosage unit. Isocratic separation is conducted at ambient temperature on the InertSustain C18 Analytical Column (150 × 4.6 mm, 5 μm) using mobile phase comprising 50 mM of ammonium dihydrogen phosphate and 5.0 mM of heptane sulfonic acid:acetonitrile (45:55, v/v) at a flow rate of 1.3 mL/minute. Calibration curves are conducted in the linearity range of 1-40 μg/mL of Alogliptin and 2.5-75 μg/mL of Pioglitazone with a correlation value >0.9995 and satisfactory recovery findings between 99 and 100%. The degraded samples are analyzed under relevant stress conditions as acidity, alkalinity, thermal and oxidation. The active components in finished products were subjected to a content uniformity test, which showed that they achieved the declared claim's acceptance standards (85-115%). Comparative in vitro dissolution studies are performed for generic products Inhibazone 12.5/30 mg FCT and Inhibazone 25/15 mg FCT against innovator products Oseni 12.5/30 mg FCT and Oseni 25/15 mg FCT at suitable FDA dissolution medium and different USP dissolution media and the results are similar. The metrics of the designed method were assessed according to ICH requirements, and all metrics, such as system suitability, linearity, recovery, robustness, LOD, LOQ, specificity and precision, were found to be within required tolerances and no overlapping was found for degradation peaks. Thence, the method can be used in quality control for the analysis of raw material, bulk, finish and stability.

Quantitative measurement of pioglitazone in neoplastic and normal tissues by AP-MALDI mass spectrometry imaging

Pioglitazone is a Peroxisome Proliferator-Activated Receptor (PPAR) agonist of the thiazolidinedione class of compounds with promising anticancer activity. An innovative quantitative mass spectrometry imaging (MSI) method and a HPLC-UV method were developed and validated to investigate its distribution in tumor and liver tissues. The MSI method is based on stable isotope normalization and resulted highly specific and sensitive (0.2 pmol/spot). The correct identification of the drug ion signal is confirmed by MS/MS analysis on tissue. The method shows an optimal lateral resolution (25 μm) relying on the ionization efficiency and fine laser diameter of the atmospheric pressure MALDI source. The HPLC-UV method is simple and straightforward involving quick protein precipitation and shows good sensitivity (50ng/sample) using a small starting volume of biological sample. Thus, it is applicable to samples obtained from both preclinical models and clinical surgical procedures. MSI and HPLC-UV assays were validated assessing linearity, intra- and inter-day precision and accuracy, limit of quantification, selectivity and recovery. These are the first methods developed and validated for the analysis of pioglitazone in tissues, and they were applied successfully to myxoid liposarcoma xenograft-bearing mice, which received clinically relevant drug doses. Pioglitazone was measured by either method in sections of tumor and liver 2, 6 and 24 h post-treatment. Drug distribution was relatively homogeneous.

Hantzsch Condensation Reaction as a Spectrofluorometric Method for Determination of Alogliptin, an Anti-diabetic Drug, in Pure, Tablet, Human, and rat plasma

To analyze alogliptin in its pharmaceutical dosage forms and human plasma, a sensitive, inexpensive, simple, and precise spectrofluorimetric method was developed and tested. Also, this method was used to investigate the drug pharmacokinetic behavior in the blood of rats. It is based on the Hantzsch reaction, which produces yellowish luminous products that can be detected spectrofluorometrically at 480 and 415 nm, emission, and excitation, respectively, when the primary amine group in the examined drug reacts with acetylacetone and formaldehyde. Several experimental parameters that affect the reaction product's development and stability were explored and improved. The curve of fluorescence and concentration for alogliptin was linear in the concentration range of 0.05-3.60 μg ml^-1 . According to ICH criteria, the proposed approach was validated. The method was successfully utilized to evaluate the examined drug in dose formulations and spiked human plasma with high accuracy.

Development and validation of a sensitive LC-MS/MS method for pioglitazone: application towards pharmacokinetic and tissue distribution study in rats

In the present study, a sensitive LC-MS/MS method was developed and validated to measure pioglitazone (PGZ) concentrations in rat plasma and tissues. The chromatographic separation was achieved by using a YMC Pro C₁₈ column (100 mm × 4.6 mm, 3μ) with a mobile phase consisting of formic acid (0.1% v/v) and acetonitrile (5 : 95) at a flow rate of 0.7 mL min⁻¹ and injection volume of 10 μL (IS: rosiglitazone). Mass spectrometric detection was done using triple quadrupole mass spectrometry using the ESI interface operating in a positive ionization mode. The developed method was validated over a linearity range of 1–500 ng mL⁻¹ with detection and a lower quantification limit of 0.5 ng mL⁻¹ and 1 ng mL⁻¹. The method accuracy ranged from 95.89–98.78% (inter-day) & 93.39–97.68% (intra-day) with a precision range of 6.09–8.12% for inter-day & 7.55–9.87% for intra-day, respectively. The PGZ shows the highest C_max of 495.03 ng mL⁻¹ in plasma and the lowest C_max, 24.50 ± 2.71 ng mL⁻¹ in bone. The maximum T_max of 5.00 ± 0.49 h was observed in bone and a minimum of 1.01 ± 0.05 h in plasma. The AUC_{(0–24 h and 0–∞)} values are highest in plasma (1056.58 ± 65.78 & 1069.38 ± 77.50 ng h⁻¹ mL⁻¹) and lowest in brain (166.93 ± 15.70 &167.12 ± 16.77 ng h⁻¹ mL⁻¹), and the T_1/2 was highest in plasma (5.62 ± 0.74 h) and lowest in kidney (2.78 ± 0.19). The developed method was successfully used to measure the PGZ pharmacokinetic and tissue distribution. Further, the developed method could be utilized for validating target organ (adipose tissue) specific delivery of PGZ (nano-formulations) in addition to conventional dosage forms.

The developed method was investigated for target and off-target distribution of pioglitazone and could be applied to validate the site-specific delivery systems.

Salting-out induced liquid-liquid microextraction for alogliptin benzoate determination in human plasma by HPLC/UV

Salting-out induced liquid–liquid microextraction method has been developed for plasma sample treatment before determination of alogliptin by high performance liquid chromatography with UV detection. Several parameters were optimized to achieve maximum enrichment, including type of extractant, volume of extractant, type of anion, type of cation, salt amount and pH. The optimum conditions were attained using 500 µL of acetonitrile, added to 1 mL of aqueous sample containing 250 mg of sodium chloride at pH 12. An RP-HPLC method was developed and validated according to the International Conference on Harmonization guidelines M10. The method was linear in the concentration range of 0.1 to 50 µg/mL (correlation coefficient = 0.997). The limit of detection was 0.019 µg/mL and limit of quantitation was 0.06 µg/mL. The method was accurate and precise with an average % recovery of 99.7% and a % relative standard deviation ranging between 1.5 and 2.5. These results showed that the salting-out induced liquid–liquid microextraction methods could be better than other sample preparation protocols in terms of sensitivity, easiness, solvent consumption and waste reduction.

Simultaneous Determination of Alogliptin, Linagliptin, Saxagliptin, and Sitagliptin in Bulk Drug and Formulation by UPLC Q-TOF-MS

Background:

A simple and sensitive Ultra Performance Liquid Chromatography-Mass Spectrometry method was developed and validated to measure the concentrations of Alogliptin (ALO), Linagliptin (LIN), Saxagliptin (SAX), and Sitagliptin (SIT) using Pioglitazone (PIO) as an internal standard.

Methods:

Chromatographic separation of six gliptins was achieved on a C-18 column (100×2.1 mm, 2.7 μm) using a mobile phase consisting of formic acid in water, 0.1%v/v: acetonitrile in gradient elution. Electrospray ionization (ESI) source was operated in the positive ion mode. Targeted MS/MS mode on a QTOF MS was used to quantify the drug utilizing the transitions of 340.1(m/z), 473.2 (m/z), 316.2 (m/z), 408.1 (m/z), and 357.1 (m/z) for ALO, LIN, SAX, SIT and PIO respectively.

Results:

As per ICH Q2R1 guidelines, a detailed validation of the method was carried out and the standard curves were found to be linear over the concentration ranges of 1516.0-4548.1 ng mL-1, 519.8- 1559.4 ng mL-1, 1531.4-4594.3 ng mL-1and 1519.6-4558.8 ng mL-1 for ALO, LIN, SAX and SIT respectively. Precision and accuracy results were within the acceptable limits. The mean recovery was found to be 98.8 _ 0.76 % (GEM), 102.2 _ 1.59 % (LIN), 95.3 _ 2.74 % (SAX) and 99.2 _ 1.75 % (SIT) respectively.

Conclusions:

The optimized validated UPLC QTOF-MS/MS method offered the advantage of shorter analytical times and higher sensitivity and selectivity. The optimized method is suitable for application in quantitative analysis of pharmaceutical dosage forms for QC laboratory.

Spectrofluorometric determination of alogliptin an antidiabetic drug in pure and tablet form using fluorescamine, a fluorogenic agent: application to content uniformity test

Alogliptin is an antidiabetic drug that belongs to a group called dipeptidyl peptidase-4 enzyme inhibitors. As the drug contains a primary amino group in its structure, it readily reacts with fluorescamine in slightly alkaline medium (borate buffer, pH 8.8) to form a highly fluorescent product. Emission of this product was measured at 477 nm (λ_ex = 387 nm). The linear range between the fluorescence intensity and the drug concentration was 0.1-0.5 μg ml^-1 with a good correlation coefficient (0.9986). Limits of detection and quantitation were 22 and 72 ng ml^-1 , respectively. Guidelines of the International Conference for Harmonisation were followed to validate the developed method with acceptable results. Alogliptin content was determined successfully in its commercial dosage form using the fluorescamine method with good recovery (98.60-101.26%). The method has excellent levels of accuracy and precision compared with the reported method as assessed using Student's t-test and Fisher's exact test. The method was applied successfully for the content uniformity test with high recovery and low relative standard deviation.

Simultaneous Determination of Alogliptin and Pioglitazone in Human Plasma by a Novel LC-MS/MS Method

Background:

A combination of alogliptin and pioglitazone is well tolerated. It does not increase the risk of hypoglycemia. In order to study the bioavailability of aloglipitn in the presence of pioglitazone, it is essential to have a method that can simultaneously detect both in human plasma. A protein precipitation-based method was used to determine alogliptin and pioglitazone simultaneously in human plasma. Protein precipitation causes ion suppression or enhancement in detection methods when compared to other methods.

Objective:

To simultaneously quantify alogliptin and pioglitazone in human plasma by LC-MS/MS based method.

Methods:

LC-MS/MS method for the simultaneous determination of pioglitazone and alogliptin in human plasma using stable isotope labelled compounds internal standards. The simple and one step solid phase extraction (SPE) was employed to extract the analytes from plasma. The extracted samples were separated on a C18 column by using a 25:75 (v/v) mixture of acetonitrile and 5 mM ammonium formate as the mobile phase at a flow rate of 0.5 mL/min.

Results:

The calibration curves obtained were linear (r2= 0.99) over the concentration range of 12.0- 2438.0 ng/mL for pioglitazone and 1.0-202.0 ng/mL for alogliptin. The results of the intra- and interday precision and accuracy studies were found to be within the acceptable limits. The analytes were stable under different stability conditions. All the validation results were found to be within the acceptable limits. The total analytical run time was 3.0 min. There was no interference from plasma matrices.

Conclusion:

The developed method is precise and adequately sensitive for detection and quantification of analytes. Thus, the method can be useful for bioavailability and bioequivalence (BA/BE) studies and routine therapeutic drug monitoring with the desired precision and accuracy.

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.

Repositioning of Omarigliptin as a once-weekly intranasal Anti-parkinsonian Agent

Drug repositioning is a revolution breakthrough of drug discovery that presents outstanding privilege with already safer agents by scanning the existing candidates as therapeutic switching or repurposing for marketed drugs. Sitagliptin, vildagliptin, saxagliptin & linagliptin showed antioxidant and neurorestorative effects in previous studies linked to DPP-4 inhibition. Literature showed that gliptins did not cross the blood brain barrier (BBB) while omarigliptin was the first gliptin that crossed it successfully in the present work. LC-MS/MS determination of once-weekly anti-diabetic DPP-4 inhibitors; omarigliptin & trelagliptin in plasma and brain tissue was employed after 2 h of oral administration to rats. The brain/plasma concentration ratio was used to deduce the penetration power through the BBB. Results showed that only omarigliptin crossed the BBB due to its low molecular weight & lipophilic properties suggesting its repositioning as antiparkinsonian agent. The results of BBB crossing will be of interest for researchers interested in Parkinson's disease. A novel intranasal formulation was developed using sodium lauryl sulphate surfactant to solubilize the lipophilic omarigliptin with penetration enhancing & antimicrobial properties. Intranasal administration showed enhanced brain/plasma ratio by 3.3 folds compared to the oral group accompanied with 2.6 folds increase in brain glucagon-like peptide-1 concentration compared to the control group.