Jithendra Chimakurthy

A sensitive, selective and rapid liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated for the simultaneous quantification of trace impurities, namely, 2‐isoniazid, 3‐isoniazid and isonicotinamide, in isoniazid active pharmaceutical ingredient (API) at parts‐per‐million (ppm) levels. Chromatographic separation was achieved within 6 min using a Zorbax SB Aq column maintained at 40°C. The mobile phase consisted of 10 mM ammonium formate buffer (pH 4.0, adjusted with formic acid) and 0.1% (v/v) formic acid in acetonitrile (48:52, v/v), delivered at a flow rate of 1.0 mL/min. The optimized conditions provided efficient separation, reproducible peak responses and stable ionization for all analytes. The method was validated in accordance with ICH Q2 guidelines with respect to specificity, accuracy, precision, linearity, range, detection limit and quantitation limit. The limits of detection and quantification were established at 0.8 and 2.5 ppm, respectively, demonstrating the high sensitivity of the method for trace impurity determination. The validated method was successfully applied to the analysis of isoniazid bulk drug samples and enabled consistent and accurate quantification of the impurities. The developed LC–MS/MS method is rapid, robust and suitable for routine quality control testing and regulatory impurity monitoring of isoniazid API.

The combination of avutometinib, a dual RAF/MEK inhibitor targeting the MAPK pathway, and defactinib, a selective focal adhesion kinase (FAK) inhibitor, represents a recently approved combination therapy for patients with KRAS‐mutated or KRIS‐mutated recurrent LGSOC (low‐grade serous ovarian cancers). A comprehensive review of the literature indicates that although clinical studies have demonstrated the therapeutic potential of this combination, limited information is available regarding simultaneous quantification in biological matrices. Therefore, the present study mainly focused on a rapid selective and specific LC–MS/MS method that was developed and fully validated for the estimation of avutometinib and defactinib in rat plasma. Chromatographic separation was achieved using a reverse phase Kinetex PS C18 2.1*50 mm, 3.5 um, 100A° column under gradient elution with 0.1% formic acid in water and 0.1% formic acid in acetonitrile as mobile phases. The flow rate was 0.6 mL/min, and glyburide was employed as the internal standard (IS). Mass spectrometric detection was performed using positive electrospray ionization mode and multiple reaction monitoring was applied for the quantitative analysis. Protein precipitation with acetonitrile was used for sample preparation. The method demonstrated an excellent linearity range of 1 ng/mL to 1000 ng/mL for both analytes ( r ² > 0.99). Intraday and interday accuracy and precision were observed to be within the acceptable regulatory limits for all quality control levels. Considering the limited availability of validated bioanalytical methods for this drug combination, the present work provides a robust and sensitive LC–MS/MS approach for the simultaneous quantification of avutometinib and defactinib. This validated method was successfully applied to a rat pharmacokinetic study following oral administration of both analytes.

Introduction: Erdafitinib is a pan‐FGFR tyrosine inhibitor approved for urothelial carcinoma, with growing interest in its broader anticancer applications. Accurate quantification in preclinical models is essential for understanding pharmacokinetics and optimizing therapeutic use. Developing a sensitive, economical bioanalytical method ensures reliable drug monitoring, supporting translational research and regulatory compliance in oncology drug development. Methods: Rat plasma samples were processed by protein precipitation, and analytes were separated on a reverse‐phase column using a gradient mobile phase. Detection employed LC‐MS/MS in positive ionization mode with multiple reaction monitoring (MRM), monitoring m / z 447.1 → 362.1 for erdafitinib and m / z 515.2 → 276.0 for internal standard. The total run time was 2.0 min. Results: The method demonstrated excellent linearity across 1.0–1000 ng/mL with a lower limit of quantification of 1.0 ng/mL. Precision was < 12% and accuracy within 100% ± 6% across the calibration range. The assay was validated according to US FDA M10 guidelines and successfully applied to pharmacokinetic studies in Sprague Dawley rats, enabling reliable plasma concentration profiling of erdafitinib. Conclusions: This validated LC‐MS/MS method provides a rapid, sensitive, and cost‐effective approach for erdafitinib quantification in preclinical plasma samples. Its application to pharmacokinetic studies supports drug development by enabling accurate assessment of exposure and disposition, thereby advancing pharmacological understanding and facilitating translation to clinical oncology research.

Fedratinib, a selective Janus kinase 2 (JAK2) inhibitor approved by the FDA for the treatment of myeloproliferative neoplasms, particularly myelofibrosis (MF), has clinical relevance. Despite this, no liquid chromatography–tandem mass spectrometry (LC–MS/MS) method has been reported for its quantification in biological matrices. This study aimed to develop and validate an LC–MS/MS method for quantifying fedratinib in mice plasma and assessing its pharmacokinetics. The method employed a Sciex 4500 triple quadrupole mass spectrometer with a Shimadzu LC system in positive ionization mode. Chromatographic separation was achieved using a Phenomenex Kinetex C18 column (2.1 × 50 mm, 5.0 μm) with a gradient mobile phase of 5 mM ammonium formate in 0.1% formic acid and acetonitrile at a flow rate of 0.8 mL/min. Telmisartan was used as the internal standard (IS). The method was validated in accordance with USFDA M10 bioanalytical guidelines. Fedratinib and IS were detected at m/z 525.5 → 468.9 and m/z 515.2 → 276.0, respectively. The assay demonstrated excellent sensitivity (LLOQ: 0.5 ng/mL), linearity (0.5 to 1000.0 ng/mL, r ² = 0.99), and accuracy (95.80–104.52%). Stability studies confirmed the analyte's integrity across multiple freeze–thaw cycles. The developed LC–MS/MS method is selective, sensitive, fully validated, and was successfully applied to pharmacokinetic studies.

Vactosertib, an inhibitor of transforming growth factor β‐receptor type‐1 (TGFBR1) effective in preventing tumor cell proliferation, is approved for treating various cancers by FDA. The literature revealed that no LC–MS/MS method was reported for the quantification of vactosertib. To develop a validated LC–MS/MS method for the quantification of vactosertib in rat plasma, vactosertib and cabozantinib (internal standard [IS]) were detected using Waters LC–MS/MS system in MRM positive ionization mode, with a mixture of 0.2% formic acid and acetonitrile (70:30, v/v) on an Agilent XDB C18 (50 × 2.1 mm, 5 μm) column at a flow rate of 0.8 mL/min. The method was validated in accordance with M10 bioanalytical method validation USFDA guidelines and applied for the determination of pharmacokinetic parameters in rat plasma. The analytes were detected at m/z 400.23 → 289.19 and m/z 502.13 → 323.07 for vactosertib, and IS, respectively. The method demonstrated a sensitivity of 1.0 ng/mL, linearity ranging from 1.0 to 1000.0 ng/mL, an r² of 0.999, accuracy ranged between 91.60% and 100.70%, and the drug was found to be stable across all freeze–thaw cycles. The results indicated that the method was selective, accurate, and validated for quantification of vactosertib in biological fluids and pharmacokinetic profiling of vactosertib.

Biopharmaceutical classification system (BCS) is an advanced tool used for classifying medicines based on dissolution, water solubility, and intestinal permeability, which affect the absorption of active pharmaceutical ingredients (API) from immediate-release solid oral forms. It is useful to the formulation researchers to develop novel dosage forms based on modernistic rather than experimental approaches. The current review focuses on the fundamentals, objectives, guidance of BCS, characteristics of BCS drugs, their importance and applications of BCS. This review explains the challenges in drug development in terms of solubility and in vivo disposition. In the current review, new strategies for improving BCS II drug solubility as well as biopharmaceutical drug disposition properties which are utilized throughout the early stages of drug development and commercialization are mainly discussed.

What is known and objective Depression is most important psychological problem that is much prevalent in women than men. Obesity and depression are the leading causes of both physical and mental disability and the link between these disorders had not explored well. The present study evaluated the link between the depression, Body mass index (BMI) and the components of metabolic syndrome (MetS) in subjects with, without insulin resistance. Methods A total of 150 subjects, vital and biochemical parameters were measured for eligible screened subjects in the trial of weight loss intervention at first visit. A self-reported Patient Health Questionnaire (PHQ-9) scale was used to assess the depression among the participants. The association of BMI and MetS components with risk of depression was analysed using multiple logistic regression analysis in subjects with and without insulin resistance. Results Obesity was associated with highly significant increase in risk of depression (OR = 13.01, 95% CI 4.40–38.49) as compared to overweight subjects. Female subjects with obesity had a greater risk for depression (β: 3.725, OR: 42.62, 95% CI: 5.74–316.3 and p < 0.0001) than male subjects (β: 1.922, OR: 6.83, 95% CI: 1.8–26 and p = 0.005), and it was statistically significant. There was no association between other models (IR and MetS) and depression in both genders (p < 0.05). What is new and conclusion The odds of depression was 42.62 times more in obese women and 6.83 time more in obese men compared to overweight subjects. Subjects those who are having ≥3 metabolic syndrome (MetS) components, increased the risk of depression by 0.75 times in women and 1.50 times in men. In view of these results of our study, we conclude that the body mass index is an individual strong predictor of depression whereas metabolic syndrome and insulin resistance had no significant association with depression.

In this study, the effect of EGb-761, the standardized extract of Ginkgo biloba at dose levels of 50, 100 and 200 mg/kg was investigated on experimental models of obsessive compulsive disorder such as quinpirole-induced compulsive checking in rats and marble burying behaviour in mice. Water maze test was used to evaluate the effect on spatial memory and the underlying mechanisms were predicted based on rat brain dopamine and serotonin levels. EGb-761 at 100 and 200 mg/kg showed significant improvement against quinpirole-induced compulsions. A protective effect on memory task was observed in EGb-761-treated rats. This could be attributed to the increase in serotonin and decrease in the dopamine levels. The protective effect of EGb-761 in the treatment of obsessive compulsive disorder is apparent through the performance in the open field and marble burying behaviour.