A Bioanalytical Method for Eliglustat Quantification in Rat Plasma

Bioanalytical Method Development, Validation and Stability Assessment of Xanthohumol in Rat Plasma

Xanthohumol (XH) a prenylated chalcone has diverse therapeutic effects against various diseases. In the present study, a bioanalytical method was developed for XH in rat plasma using reverse phase high performance liquid chromatography. The validation of the method was performed as per ICH M10 guidelines using curcumin as an internal standard. The Isocratic elution method was used with a run time of 10 min, wherein the mobile phase ratio 0.1% v/v OPA (A): Methanol (B) was 15:85 v/v at flow rate 0.8 mL/min and injection volume of 20 µL. The chromatograms of XH and curcumin was recorded at a wavelength of 370 nm. The retention time for XH and curcumin was 7.4 and 5.8 min, respectively. The spiked XH from plasma was extracted by the protein precipitation method. The developed method was linear with R² value of 0.9996 over a concentration range of 50-250 ng/mL along with LLOQ. The results of all the validation parameters are found to be within the accepted limits with %RSD value less than 2 and the percentage recovery was found to be greater than 95%. Based on the %RSD and percentage recovery results it was confirmed that the method was precise and accurate among the study replicates. LOD and LOQ values in plasma samples were found to be 8.49 ng/mL and 25.73 ng/mL, respectively. The stability studies like freeze thaw, short term and long-term stability studies were also performed, %RSD and percentage recovery of the XH from plasma samples were within the acceptable limits. Therefore, the developed bioanalytical method can be used effectively for estimation of XH in plasma samples.

Improvement in Bioavailability and Pharmacokinetic Characteristics of Efavirenz with Booster Dose of Ritonavir in PEGylated PAMAM G4 Dendrimers

Efavirenz (EFV) with a booster dose of ritonavir (RTV) (EFV-RTV) inhibits the metabolism of EFV and improves its bioavailability. However, inadequate organ perfusion with surface permeability glycoprotein (P-gp) efflux sustains the viable HIV. Hence, the present investigations were aimed to evaluate the pharmacokinetics and tissue distribution efficiency of EFV by encapsulating it into PEGyalated PAMAM (polyamidoamine) G4 dendrimers with a booster dose of RTV (PPG4ER). The entrapment efficiency of PEGylated PAMAM G4 dendrimers was found to be 94% and 92.12% for EFV and RTV respectively with a zeta potential of 0.277 mV. The pharmacokinetics and tissue distribution behavior of EFV within PPG4ER was determined by developing and validating a simple, sensitive, and reliable bioanalytical method of RP-HPLC. The developed bioanalytical method was very sensitive with a quantification limit of 18.5 ng/ml and 139.2 ng/ml for EFV and RTV, respectively. The comparative noncompartmental pharmacokinetic parameters of EFV were determined by administrating a single intraperitoneal dose of EFV, EFV-RTV, and PPG4ER to Wistar rats. The PPG4ER produced prolonged release of EFV with a mean residential time (MRT) of 24 h with C_max 7.68 µg/ml in plasma against EFV-RTV with MRT 11 h and C_max 3.633 µg/ml. The PPG4ER was also detected in viral reservoir tissues (lymph node and spleen) for 3-4 days, whereas free EFV and EFV-RTV were cleared within 72 h. The pharmacokinetic data including C_max, t_1/2, AUC_tot, and MRT were significantly improved in PPG4ER as compared with single EFV and EFV-RTV. This reveals that the PPG4ER has great potential to target the virus harbors tissues and improve bioavailability.

Target specific intracellular quantification of etoposide by quadrupole-time of flight based mass spectrometric method

Etoposide (ETP), a widely used chemotherapeutic agent has an intracellular target site of action. Unfortunately, the concentration of ETP in plasma does not properly reflect the concentration in its intracellular site of action. As per our knowledge, no reported bioanalytical method is available for intracellular quantification of ETP. In this research, we developed an LC-MS/MS method to quantitate ETP in intracellular compartments of MCF-7 cells. The Abcam nuclear extraction kit was used for extracting the nuclear and cytosolic protein from MCF-7 cells. The method showed excellent linearity in the 20-1000 ng/mL range. The intra and inter-day precision (%CV) including LLOQ were found to be in the range of 2.19-16.96% and 6.71-11.21%, respectively, with an accuracy of 86.87 to 110.37% and 93.03 to 100.50%, respectively. The concentration of ETP in nuclear and cytosolic fraction was successfully quantitated using the developed method. The developed method can be applied to understand the efficacy of different formulations based on the intracellular ETP concentration in vitro. It can be considered as a model method for quantification of other similar categories of drugs in their actual intracellular site of action after required optimization in the methodology.

Drug-Drug Interactions Of Amiodarone And Quinidine On The Pharmacokinetics Of Eliglustat In Rats

Background

Eliglustat, a new oral substrate-reduction therapy, was recently approved as a first-line therapy for Gaucher's disease type 1 (GD1) patients.

Purpose

The purpose of the present study was to develop and validate a simple UPLC-MS/MS method for the measurement of plasma-eliglustat concentration and to investigate the effects of amiodarone and quinidine on eliglustat metabolism in rats.

Methods

Eighteen rats were randomly divided into three groups (n=6): control (0.5% CMC-Na, group A), amiodarone (60 mg/kg, group B), and quinidine (100 mg/kg, group C). Thirty minutes later, 10 mg/kg eliglustat was orally administered to each rat and concentrations of eliglustat in the rats determined by our UPLC-MS/MS method.

Results

Amiodarone and quinidine increased the main pharmacokinetic parameters (AUC0→_t, AUC_0→∞, and C_max) of eliglustat significantly and decreased clearance obviously.

Conclusion

Amiodarone and quinidine can elevate eliglustat exposure and have an inhibitory effect on eliglustat metabolism. Clearly, appropriate pharmacological studies of eliglustat in patients treated with amiodarone or quinidine should be done in future.

Liquid chromatography-tandem mass spectrometric method for the quantification of eliglustat in rat plasma and the application in a pre-clinical study

Eliglustat is an oral substrate reduction therapy drug and has been approved as a first-line treatment for adults with Gaucher disease type 1 (GD 1). In the present study, we aimed to develop and establish an accurate and simple ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the measurement of eliglustat concentration in rat plasma. The goal of chromatographic separation of eliglustat and the internal standard (bosutinib) was finished on an Acquity BEH C18 (2.1 mm × 50 mm, 1.7 μm) column. Acetonitrile and 0.1% formic acid in water were employed as the mobile phase in a mode of gradient elution with the 0.40 mL/min flow rate. The detection was carried out on a XEVO TQ-S triple quadrupole tandem mass spectrometer coupled with electrospray ionization (ESI) interface in the positive-ion mode. Multiple reaction monitoring (MRM) was used to monitor the precursor-to-product ion transitions of m/z 405.4 → 84.1 for eliglustat and m/z 530.2 → 141.2 for bosutinib (IS), respectively. It was found that the linearity of the method in the range of 1-500 ng/mL was good for eliglustat. The values of intra- and inter-day accuracy and precision were all within the acceptance limits, and no matrix effect was found in this method. The current developed method was further performed to support in vivo pharmacokinetic study of eliglustat after oral treatment with 10 mg/kg eliglustat to rats.