A New stability indicating RP-HPLC method for the estimation of Gefitinib tablets using an ion pairing agent

Gefitinib is an anticancer drug used for the treatment of lung cancer, breast cancer and prostate cancer. A new stability indicating RP-HPLC method was proposed for the estimation of Gefitinib in pharmaceutical dosage forms (tablets). Shimadzu Model CBM-20A/20 Alite HPLC system with PDA detector and Agilent C18 column were used for the chromatographic study. Mobile phase mixture consisting of Tetra butyl ammonium hydrogen sulphate and Methanol in the ratio 50:50, v/v with a flow rate 0.8 mL/min was chosen for the chromatographic elution of Gefitinib (Detection wavelength 340 nm). The method was linear over the concentration range 0.1-80 mg/mL with linear regression equation, y = 70782x + 6171.6 (R² = 0.9999). The LOD and LOQ were found to be 0.2931 mg/mL and 0.8947 mg/mL respectively. Stress degradation studies were performed by exposing Gefitinib to various stress conditions and the method was validated as per ICH guidelines.

CHICKN: extraction of peptide chromatographic elution profiles from large scale mass spectrometry data by means of Wasserstein compressive hierarchical cluster analysis

Background The clustering of data produced by liquid chromatography coupled to mass spectrometry analyses (LC-MS data) has recently gained interest to extract meaningful chemical or biological patterns. However, recent instrumental pipelines deliver data which size, dimensionality and expected number of clusters are too large to be processed by classical machine learning algorithms, so that most of the state-of-the-art relies on single pass linkage-based algorithms. Results We propose a clustering algorithm that solves the powerful but computationally demanding kernel k-means objective function in a scalable way. As a result, it can process LC-MS data in an acceptable time on a multicore machine. To do so, we combine three essential features: a compressive data representation, Nyström approximation and a hierarchical strategy. In addition, we propose new kernels based on optimal transport, which interprets as intuitive similarity measures between chromatographic elution profiles. Conclusions Our method, referred to as CHICKN, is evaluated on proteomics data produced in our lab, as well as on benchmark data coming from the literature. From a computational viewpoint, it is particularly efficient on raw LC-MS data. From a data analysis viewpoint, it provides clusters which differ from those resulting from state-of-the-art methods, while achieving similar performances. This highlights the complementarity of differently principle algorithms to extract the best from complex LC-MS data.

DEVELOPMENT AND VALIDATION OF STABILITY INDICATING RP-UPLC METHOD FOR THE QUANTIFICATION OF BALOXAVIR MARBOXIL IN TABLET FORMULATION

Objective: Aim of the present work is to develop a simple, accurate and precise stability-indicating method for the quantification of baloxavir marboxil (BLMX) in tablet dosage form by UPLC. Methods: Chromatographic elution was processed through a HSS C18 (100 x 2.1 mm, 1.8 mm) reverse phase column and the mobile phase composition of buffer 0.1% orthophosphoric acid and acetonitrile in the ratio of 50:50 was processed through a column at a flow rate of 0.3 ml/min. Column oven temperature was maintained at 30 °C and the detection wavelength was processed at 240 nm. Results: Retention time of BLMX was found to be 0.87 min. Repeatability of the method was determined in the form of %RSD and the value was 0.2. The percentage mean recovery of the method was found to be 99.47%. LOD, LOQ values obtained from the regression equation of BLMX were 0.69 and 2.10 mg/ml, respectively. Regression equation and correlation coefficient values of BLMX were y = 16994x+7179.2 and 0.9996. Drug was subjected for acid, peroxide, photolytic, alkali, neutral and thermal degradation studies and the results shown that the percentage of degradation was found between 5.96% and 9.55%. Conclusion: Retention time and total run time of the drug was decreased and the developed method was simple and economical. So, the developed method can be adopted in industries as a regular quality control test for the quantification of BLMX.

Pharmacokinetics of metformin in the rat: assessment of the effect of hyperlipidemia and evidence for its metabolism to guanylurea

Metformin pharmacokinetics are highly dependent upon organic cationic transporters. There is evidence of a change in its renal clearance in hyperlipidemic obese patients, and no information on its metabolic fate. To study some of these aspects, the influence of poloxamer 407 (P407)-induced hyperlipidemia on metformin pharmacokinetics was assessed. Control and P407-treated adult male rats were administered 30 mg/kg metformin intravenously (i.v.). The pharmacokinetic assessments were performed at 2 time points, 36 and 108 h, following the intraperitoneal dose of P407 (1 g/kg). mRNA and protein expressions of cationic drug transporters were also measured. There was no evidence of a change in metformin pharmacokinetics after i.v. doses as a consequence of short-term hyperlipidemia, and a change in transporter mRNA but not protein expression was observed in the P407- treated rats 108 h after P407 injection. Urinary recovery of unchanged drug was high (>90%) but incomplete. Presumed metabolite peaks were detected in chromatograms of hepatocytes and microsomal protein spiked with metformin. Comparative chromatographic elution times and mass spectra suggested that one of the predominant metabolites was guanylurea. Hyperlipidemia by itself did not affect the pharmacokinetics of metformin. Guanylurea is a putative metabolite of metformin in rats.