Development and validation of LC/MS/MS method for the simultaneous determination of montelukast, gliclazide, and nifedipine and its application to a pharmacokinetic study

Gliclazide in Binary and Ternary Systems Improves Physicochemical Properties, Bioactivity, and Antioxidant Activity

The poor solubility of the antidiabetic drug gliclazide (Glc) is due to its hydrophobic nature. This research is aimed at improving Glc's solubility and drug release profile, as well as at investigating additional benefits such as bioactivity and antioxidant activity, by forming binary complexes with HPβCD at different w/w ratios (1 : 1, 1 : 2.5, 1 : 4, and 1 : 9) and ternary complexes with HPβCD and Tryp at 1 : 1 : 1, 1 : 1 : 0.27, 1 : 2.5 : 0.27, 1 : 3.6 : 3.6, 1 : 4 : 1, and 1 : 9 : 1, respectively. Complexes were prepared by the physical mixing (PM) and solvent evaporation (SE) methods. The prepared inclusion complexes were meticulously characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra. To verify our findings, the inclusion complexes were evaluated by equilibrium solubility, in vitro drug release profile, kinetic models, and antidiabetic and antioxidant activities in animal models. Our results demonstrated that the solubility and drug release profile were found to be enhanced through binary as well as ternary complexes. Notably, ternary complexes with a ratio of 1 : 9 : 1 showed the highest solubility and drug release profile compared to all other preparations. Data on antioxidant activity indicated that the ternary complex had the higher total antioxidant status (TAS), superoxide dismutase (SOD), and catalase (CAT) activity than the binary complex and Glc alone, in contrast to the diabetic group. In vivo antidiabetic activity data revealed a high percentage reduction in the blood glucose level by ternary complexes (49-52%) compared to the binary complexes (45-46%; p ≤ 0.05). HPβCD and Tryp provide a new platform for overcoming the challenges associated with poorly soluble Glc by providing greater complexing and solubilizing capabilities and imparting ancillary benefits to improve the drug's antidiabetic and antioxidant activities.

Development of LC-MS/MS method and application to bioequivalence study of a light sensitive drug montelukast

OBJECTIVE

The aim of the study was to develop a simple, highthroughput and sensitive LC-MS/MS method and apply to a bioequivalence study of montelukast, a light sensitive drug.

METHOD

The effects of organic modifiers in mobile phase, protein precipitation agent to plasma sample ratio, and light on montelukast stability in unprocessed and processed human plasma, were evaluated. Validation was conducted in accordance with European Medicines Agency Guideline on bioanalytical method validation.

RESULTS

No interference peak was observed when acetonitrile was used as an organic modifier. Acetonitrile to plasma ratio of 4:1 produced clean plasma sample. Approximately 3 % of cis isomer was detected in unprocessed plasma samples while 21 % of cis isomer was detected in processed plasma samples after exposing to fluorescent light for 24h. The standard calibration curve was linear over 3.00-1200.00 ng/mL. All method validation parameters were within the acceptance criteria.

CONCLUSION

The validated method was successfully applied to a bioequivalence study of two montelukast formulations involving 24 healthy Malaysian volunteers. The light stability of a light sensitive drug in unprocessed and processed human plasma samples should be studied prior to pharmacokinetic/bioequivalence studies. Measures could then be taken to protect the analyte in human plasma from light degradation.

A simple and sensitive HPLC-MS/MS assay for the quantitation of montelukast in cell-based systems in vitro pulmonary drug permeability study

Montelukast is a potent and selective antagonist of the cysteinyl leukotriene receptor 1 subtype (CysLT1) and widely used in the form of oral tablets and granules for asthma prophylaxis and treatment. Recently, due to the pulmonary inhaled administration can limit montelukast distribution in the systemic circulation, avoid the first-pass metabolism and have better therapeutic effects in respiratory disease treatment, explore alternative routes of administration, like delivery of montelukast via an inhaled, is a new research trend for montelukast. The aim of the current study was to develop and validate a simple, accurate, highly sensitive and selective liquid chromatography-tandem mass spectrometry method (LC-MS/MS) for determination of montelukast in an in vitro cell-based pulmonary pharmacokinetics system model, which can be used to be a better understanding the fate of inhaled montelukast in the lungs. In this study, montelukast was extracted by protein precipitation with acetonitrile containing labeled montelukast. The chromatography was performed on an Agilent Eclipse plus C8 column (4.6 mm × 100 mm, 3.5 μm, Darmstadt, Germany) operating at 35 ◦C. The mobile phase consisted of acetonitrile: 20 mM ammonium formate buffer (80: 20, v/v), was delivered at a flow rate of 0.5 mL/min. montelukast and the internal standard were both eluted at 4.2 min. A linear (1/x²) relationship was used to perform the calibration over an analytical range from 0.5 to 600 ng/mL. The intra- and inter-batch precision expressed as CV for four QC samples including LLOQ range from 1.14 % to 6.25 %. The intra- and inter-batch accuracy for four concentrations of montelukast were in the range of 95.19%-104.1%. All the values for accuracy and precision were within the acceptance range. The method met all the bioanalytical method validation requirements by ICH and was suitable for the assay of montelukast which in the in vitro cell-based pulmonary pharmacokinetics system model.

Synthesis and characterization of a molecularly imprinted polymer (MIP) for solid-phase extraction of the antidiabetic gliclazide from human plasma

Gliclazide is a sulfonylurea frequently prescribed for the management of type 2 diabetes mellitus in elderly patients and for patients with chronic renal or hepatic diseases. Even though it is considered a safer alternative, the drug can provoke side effects in some patients, especially hypoglycemia, due to the high interindividual variability. Therefore, the quantification of gliclazide in biological samples is usually recommended in order to assure efficacy and safety of the pharmacotherapy. However, due to the complexity of biological matrices, therapeutic monitoring can be very challenging, especially in the sample preparation step. For that reason, the synthesis and characterization of a novel and selective molecularly imprinted polymer (MIP) was proposed to be employed as sorbent for the extraction of gliclazide from human plasma samples by a molecularly imprinted solid-phase extraction (MISPE) procedure. Synthesis conditions were optimized (monomer, crosslinker and porogen) and the polymer was characterized for its morphological, physicochemical and stability properties. The influence of drug concentration, solvent composition and pH on the coefficient of distribution (K_d) and imprinting factor (IF) were studied, as well as repeatability between batches and selectivity. A bioanalytical method was developed applying the developed MIP as sorbent in solid phase extraction and liquid chromatography using a Poroshell 120 C18 (100 × 4.6 mm, 4 μm) column, acetonitrile and 10 mM potassium phosphate buffer pH 3.0 (50:50) at a flow-rate of 1.2 mL/min as mobile phase, temperature of 30 °C, injection volume of 40 μL and detection at 230 nm. The best reaction yield, extraction capacity, and selectivity was obtained using 2-hydroxyethyl methacrylate (2-HEMA), ethyleneglycol dimethacrylate (EGDMA) and acetonitrile. The optimized MIP showed coefficient of distribution (K_d) of 59.85 μg/g, imprinting factor (IF) of 1.60, and selectivity for gliclazide and other sulfonylureas compared to possible concurrent drugs. The developed method by MISPE-HPLC-UV showed to be appropriate to determine gliclazide in human plasma samples.

Screening of herbal medicines for potential allopathic antidiabetic adulterants: An analytical study

Background:

There are several reports worldwide on adulteration of herbal medicines (HMs) with allopathic drugs. In India, only a few studies have reported adulteration of HMs with antidiabetics and there are no systematic studies.

Aims:

To develop a rapid and validated method for detection of allopathic antidiabetic adulterants and to explore the extent of adulteration in HMs sold in South India.

Materials and Methods:

Standards and solvents were purchased from Sigma-Aldrich. Different brands of antidiabetic HM samples with manufacturing licenses were procured from dispensaries. Spiked drug free psyllium husk as solid and flask seed oil as liquid herbal matrices were used for method development. The spiked matrices with different concentrations were extracted with methanol and subjected to centrifugation. The supernatant was collected and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Isocratic elution was carried on a C18 column with 0.1% (v/v) formic acid:methanol (3:7, v/v) as a mobile phase. All drugs were monitored for two ion products in positive electrospray ionization mode using multiple reaction monitoring scans.

Results:

The retention time was 9 min. Limit of detection is 10 Pictograms (pg) for all analytes except for metformin, which was 370 pg. Recoveries of analytes range from 96% to 117%. Forty different brands of antidiabetic HMs were analyzed. Adulterant peaks were not observed in the mass chromatograms of HMs.

Conclusions:

A single-run method was developed by LC-MS/MS for the detection of proposed antidiabetics in HMs from licensed manufacturing units and online sold HMs across herbal dispensaries in Puducherry union territory, India. None of the HMs was found to be adulterated with proposed allopathic antidiabetic adulterants.

Liquid chromatography-tandem mass spectrometry method for the quantification of a potent H3 receptor antagonist conessine in serum and its application to pharmacokinetic studies

Conessine, a steroidal alkaloid obtained from the bark and seeds of the plant species of Apocynaceae family, elicits a histamine antagonistic action, selectively for the H₃ histaminergic receptors. This alkaloid is used mainly for the treatment of dysentery and helminthic disorders. For the quantification of conessine in serum, a liquid chromatography-tandem mass spectrometry method was developed. Chromatographic separation was achieved on a Zorbax SB-CN column (100 × 4.6 mm, 3.5 µm), and a mobile phase consisting of 90% methanol in aqueous ammonium acetate buffer (pH 3.5) with 0.1% (v/v) formic acid at an isocratic flow rate of 0.6 ml/min at 40℃ provides efficiency in separation. A volume of 40 µl was injected each time and the run time for each sample was 5 min. Phenacetin (internal standard) was added to 50 µl of serum sample prior to liquid-liquid extraction using 3% isopropanol in n-hexane. The detection was performed on a 5500 QTRAP mass spectrometer by multiple reaction monitoring mode via electrospray ionization source. The multiple reaction monitoring of conessine and IS was m/ z 357.4 to m/ z 312.1 and m/ z 180.1 to m/ z 138.1, respectively. The method that showed selectivity and linearity in the range of 1-200 ng/ml was validated in terms of sensitivity, accuracy, precision and stability. The detection and quantitation limits were recognized at 0.1 and 1 ng/ml, respectively. The intra- and inter-day precision and accuracy fulfils the acceptance criteria. Applying the method to the pharmacokinetic studies in rats, conessine showed a peak serum concentration at 2 h post oral dose with a good bioavailability of 71.28 ± 4.65%.

Development and validation of an LC-MS/MS method for the simultaneous quantification of seven constituents in rat plasma and application in a pharmacokinetic study of the Zaoren Anshen prescription

A sensitive, specific and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of seven constituents of the Zaoren Anshen prescription (ZAP) in rat plasma after oral administration of the ZAP: spinosin, salvianic acid A, 6'''-feruloylspinosin, protocatechualdehyde, salvianolic acid B, schisandrin and deoxyschisandrin. The plasma samples and the internal standard (IS) sulfamethoxazole were extracted using acetonitrile. Chromatographic separation was performed with an Agilent HC-C₁₈ column using a gradient elution profile and a mobile phase consisting of 0.01% formic acid in water (A) and acetonitrile (B). The analytes were quantified simultaneously in a single run using an ion trap mass spectrometer operated in the multiple reaction monitoring mode and electrospray ion-source polarity in the positive and negative modes. The calibration curves for spinosin, salvianic acid A, 6'''-feruloylspinosin, protocatechualdehyde, salvianolic acid B, schisandrin and deoxyschisandrin were linear over the concentration ranges of 2.90-1160, 2.50-1000, 1.80-720, 0.65-260, 2.50-1000, 8.00-1600 and 1.30-520 ng/mL, respectively. The intra- and inter-day precisions in terms of relative standard deviation were <18.9%, and the accuracies in terms of relative error were within ±14.2%. Consequently, the proposed method was successfully applied to the pharmacokinetic analysis of these seven major active compounds in rats administered ZAP. These results will facilitate research aiming to predict the effectiveness of the optimal dose of ZAP and might be beneficial for the therapeutic use of ZAP in the clinical setting.

Transfer of Montelukast into Human Milk During Lactation

AIM

The aim of this study was to determine levels of montelukast in human milk and to develop a simple, sensitive analytical method using mass spectrometry.

METHODS

Milk samples were collected from seven breastfeeding mothers, age 26-35 years, at 0, 1, 2, 4, 8, and 12 hours after oral ingestion of 10 mg montelukast. The samples were analyzed using a new Liquid Chromatography-Tandem Mass Spectrometry method. Area under the milk concentration time curve from zero to the time of the last sample (12 hours) was estimated by the linear trapezoidal rule.

RESULTS

Average montelukast levels (C_avg) in milk were 5.3 ng/mL, and the relative infant dose was 0.68% of the maternal dose. The maximum concentration (C_max) observed at 4 hours (Tmax) was 9.7 ng/mL.

CONCLUSION

The exposure to the infant seems to be very low, far below therapeutic ranges in an infant. Our data suggest that montelukast is probably safe to use in a breastfeeding mother.

Investigation of the bioequivalence of montelukast chewable tablets after a single oral administration using a validated LC-MS/MS method

Background

Montelukast (MT) is a leukotriene D4 antagonist. It is an effective and safe medicine for the prophylaxis and treatment of chronic asthma. It is also used to prevent acute exercise-induced bronchoconstriction and as a symptomatic relief of seasonal allergic rhinitis and perennial allergic rhinitis.

Objective

The aim of this study was to evaluate the bioequivalence (BE) of two drug products: generic MT 5 mg chewable tablets versus the branded drug Singulair^® pediatric 5 mg chewable tablets among Mediterranean volunteers.

Methods

An open-label, randomized two-period crossover BE design was conducted in 32 healthy male volunteers with a 9-day washout period between doses and under fasting conditions. The drug concentrations in plasma were quantified by using a newly developed and fully validated liquid chromatography tandem mass spectrometry method, and the pharmacokinetic parameters were calculated using a non-compartmental model. The ratio for generic/branded tablets using geometric least squares means was calculated for both the MT products.

Results

The relationship between concentration and peak area ratio was found to be linear within the range 6.098–365.855 ng/mL. The correlation coefficient (R²) was always greater than 0.99 during the course of the validation. Statistical comparison of the main pharmacokinetic parameters showed no significant difference between the generic and branded products. The point estimates (ratios of geometric means) were 101.2%, 101.6%, and 98.11% for area under the curve (AUC)_0→last, AUC_0→inf, and C_max, respectively. The 90% confidence intervals were within the predefined limits of 80.00%–125.00% as specified by the US Food and Drug Administration and European Medicines Agency for BE studies.

Conclusion

Broncast^® pediatric chewable tablets (5 mg/tablet) are bioequivalent to Singulair^® pediatric chewable tablets (5 mg/tablet), with a similar safety profile. This suggests that these two formulations can be considered interchangeable in clinical practice.