Quantification of rosiglitazone in rat plasma and tissues via LC-MS/MS - method development, validation, and its application in pharmacokinetic and tissue distribution studies

A bioanalytical method for the quantification of rosiglitazone on rat plasma and tissues (adipose tissue, heart, brain, bone, and kidney) using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed and validated. Chromatographic separation was achieved on Gemini C₁₈ column (50mm x 4.6mm, 3μm) using mobile phase consists of 10mM ammonium formate (pH 4.0) and acetonitrile (10:90, v/v) at a flow rate of 0.8 mL/min and injection volume of 10μL (Internal standard - Pioglitazone). LC-MS detection was performed with multiple reaction monitoring mode (MRM) using target ions at m/z→358.0 and m/z → 357.67 for rosiglitazone and pioglitazone (IS) respectively. The calibration curve showed a good correlation coefficient (r² ) over the concentration range of 1-10000 ng/mL. The mean percentage recoveries of rosiglitazone were found to be over the range of 92.54-96.64 % with detection and lower quantification limit of 0.6 ng/mL and 1.0 ng/mL, respectively. The developed method was validated as per USFDA guidelines and successfully utilized to measure rosiglitazone in plasma and tissue samples. Further, the developed method can be utilized for validating specific organ targeting delivery systems of rosiglitazone in addition to conventional dosage forms.

Quality by Design (Qbd) Approach to Develop HPLC Method for Estimation of Gliclazide and its Impurity (Gliclazide Impurity A) in Bulk Drug

Background:

Gliclazide Impurity A (GI-A) is one of the gliclazide impurities, as described in the European Pharmacopoeia.

Objective:

The objective of this study was to develop and validate simple, robust and accurate Reverse- Phase High-Performance Liquid Chromatography (RP-HPLC) method for estimation of gliclazide along with GI-A in bulk by optimising chromatographic parameters using Box Behnken design in response surface methodology.

Methods & Results:

Box Behnken design was employed for optimizing flow rate, injection volume and strength of the buffer in order to minimize retention time of both gliclazide and GI-A. The optimized strength of orthophosphoric acid buffer in a mixture of Acetonitrile (50:50 v/v), flow rate and injection volume were found to be 25mM, 1mL/min, 20 µL respectively. Linearity was observed in concentration range of 25-150 µg/mL (r2=0.999). The retention time of gliclazide and GI-A was found to be 5.799 minutes and 3.819 minutes, respectively. The limit of detection for Gliclazide and GI-A was found to be 0.0066, and 0.0075 µg/mL and the limit of quantification limit was found to be 0.0202, 0.0228 µg/mL, respectively. The developed method was validated as per the ICH guidelines.

Conclusion:

The proposed method is useful for best analysis of Gliclazide and GI-A in pharmaceutical dosage forms. QbD approach was found to be an effective tool for optimising chromatographic conditions of the proposed method.

Rapid, Validated UPLC-MS/MS Method for Determination of Glibenclamide in Rat Plasma

Quick and specific bioanalytical methods are required for analyzing drugs in biological samples. A simple, quick, sensitive, and specific UPLC-MS/MS method was developed and validated for glibenclamide determination in plasma samples. The plasma samples were processed by protein precipitation technique. Glimepiride was used as internal standard (IS). Glibenclamide and glimepiride were eluted on C18 column (Acquity UPLC®BEH). Mobile phase consisting of acetonitrile (0.1% formic acid) and water (0.1% formic acid) was pumped in binary gradient mode at flow rate of 150 μL/min. Glibenclamide and IS elution time was about 1.0 min, and total run time was 2.0 min. The mass spectrometer (triple-quadrupole) was operated in positive electrospray ionization mode. Sodium adducts [M + Na]+ of glibenclamide and IS were monitored in MRM mode. A linear calibration curve was obtained in the range of 10-1280 ng/mL, with regression equation Y = 0.0076 X – 0.0165 and linear regression coefficient r2 = 0.999. Lower limit of quantitation was 10 ng/mL. Accuracy of the method at LQC, MQC, and HQC was 109.7% (± 6.7), 93.6% (± 0.4), and 99.3% (± 1.9), respectively. The coefficient of variation for precision at all QC concentrations was less than 6%. Recovery at LLQC, MQC, and HQC was 104.2% (± 4.9), 100.6% (± 0.9), and 102.9% (± 5.8), respectively. The method was successfully implemented for pharmacokinetic investigations (in-house data).

Active bioparticle manipulation in microfluidic systems

The motion of bioparticles in a microfluidic environment can be actively controlled using several tuneable mechanisms, including hydrodynamic, electrophoresis, dielectrophoresis, magnetophoresis, acoustophoresis, thermophoresis and optical forces.