Development and validation of LC-MS/MS method for quantification of novel PP2A – β-catenin signalling inhibitor, S011-2111 in mice plasma: Application to its preclinical pharmacokinetic studies

Preclinical pharmacokinetic exploration of a novel osteoporotic quinazolinone-benzopyran-indole hybrid (S019-0385) using LC-MS/MS

1. The current investigation was to develop and validate the LC-MS/MS method in order to analyse the various pharmacokinetic parameters of S019-0385. A sensitive, selective, and robust LC-MS/MS approach was established and validated for measuring S019-0385 in female mice plasma and tissue, using optimal multiple reaction monitoring (MRM) transition m/z 488.25/329.12 on positive mode. On a Waters Symmetry Shield C18 column, the analyte was separated using acetonitrile and deionised water with formic acid within 6 min at 0.7 mL/min. Linearity (R2 ≥ 0.99) was observed across 0.195-100 ng/mL concentration range using linear least-squares regression.2. Blood-to-plasma ratio and plasma protein drug binding (%) in mice and human was assessed and found to be less than 1 and >83%, respectively. Absolute bioavailability (%F) of S019-0385 in female Swiss mice was exhibited to be 6.90%. Percent dose excreted S019-0385 in unchanged form through urine and faecal was found to be less than 2% and 0.5%, respectively.3. Following oral administration at 5 mg/kg, the concentration of S019-0385 in tissue distribution was found to be in the order of C small intestine > C bone > C lung > C spleen > C kidney > C liver > C heart > C brain.

Approaches to minimize the effects of P-glycoprotein in drug transport: A review

P-glycoprotein (P-gp) is a transporter protein that is come under the ATP binding cassette family of proteins. It is situated on the surface of the intestine epithelium, where P-gp substrate binds to the transporter and is pumped into the intestine lumen by the ATP-driven energy-dependent process. In this review, we summarize the role of the P-gp efflux transporter situated on the intestine, the clinical importance of P-gp related drug interactions, and approaches to minimize the effect of P-gp in drug transport. This review also focuses on the impact of P-gp on the bioavailability of the orally administered drug. Many drug's oral bioavailabilities can improve by concomitant use of P-gp inhibitors. Multidrug resistance are reduced by using some naturally occurring compounds obtained from plants and several synthetic P-gp inhibitors. Formulation strategies, one of the most important approaches to mimic the P-gp transporter's action, finally enhancing the oral bioavailability of the drug by inhibiting its P-gp efflux. Vitamin E TPGS, Gelucire 44/14 and other pharmaceutical/formulation excipients inhibit the P-gp efflux. A prodrug approach might be a useful strategy to overcome drug resistance. Prodrug helps to enhance the solubility or alter the pharmacokinetic properties but does not diminish the pharmacological action.

Simultaneous quantification of five biomarkers in ethanolic extract ofCassia occidentalisLinn. stem using liquid chromatography tandem mass spectrometry: application to its pharmacokinetic studies

Cassia occidentalis L. stem extract is used as a purgative, febrifuge, and diuretic, and in the treatment of flu, fever, fracture and bone diseases. Pharmacological studies prove the osteogenic and antiresorptive effects of Cassia occidentalis L. ethanolic extract (COEE), which may be due to apigenin, apigenin-6-C-glucopyranoside, luteolin, 3′,4′,7-trihydroxyflavone and emodin. The objectives of this study was to develop a selective and sensitive LC-MS/MS method and validate for the simultaneous determination of the above five biomarkers in rat plasma after oral administration of COEE at a dose of 500 mg kg⁻¹. The analytes were separated on a Phenomenex Luna C18 column (4.6 × 150 mm, 3.0 μm) with an isocratic mobile phase consisting of methanol-10 mM ammonium acetate buffer (95 : 05, v/v). Run time was for 5.5 min with LLOQ of 1 ng mL⁻¹ for all the analytes. The mass spectrometer was operating in negative ionization mode for quantification of the analytes. The calibration curves were linear (r² > 0.99) for all the analytes. The intra- and inter-day precisions were less than 8.17% and the relative error was between −8.57% and 7.28%. Analytes were rapidly absorbed in the oral pharmacokinetic study. The biomarkers were stable in simulated gastric and intestinal fluids but underwent metabolism in rat liver microsomes. This is the first report on in vivo oral pharmacokinetics and in vitro stability studies of osteogenic compounds present in COEE. These results will be helpful for further understanding of pharmacodynamic behaviour of COEE and the bioanalytical method will be useful for further preclinical/clinical trials.

Liquid chromatography tandem mass spectrometry was used to develop a bioanalytical method for simultaneous quantification of five biomarkers of Cassia occidentalis L. ethanolic extract to use in oral pharmacokinetics and in vitro stability studies.