Determination of ergocalciferol in human plasma after Diels-Alder derivatization by LC-MS/MS and its application to a bioequivalence study.

An accurate, sensitive and selective method is developed for determination of ergocalciferol (vitamin D) in human plasma using LC-MS/MS. After liquid-liquid extraction with hexane, ergocalciferol was derivatized by reacting with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), a strong dienophile based on Diels-Alder reaction. Ergocalciferol and its deuterated internal standard, ergocalciferol-d6, were analyzed on X Select CSH C (100 mm×4.

Pullulan based oral thin film formulation of zolmitriptan: Development and optimization using factorial design.

The goal of study was to formulate and characterize pullulan based oral thin film (OTF) of zolmitriptan by solvent casting method. Based on preliminary trials, glass, PEG 400 and sucralose were selected as casting surface, water-miscible plasticizer and sweetener for OTF, respectively. A 3 factorial design was used to study the effect of amount of PEG 400 (X) and sucralose (X) as independent variables on tensile strength (Y), elasticity (Y), % in-vitro drug release in phosphate buffer of pH 6.

High-sensitivity simultaneous liquid chromatography-tandem mass spectrometry assay of ethinyl estradiol and levonorgestrel in human plasma.

A sensitive and simultaneous liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of ethinyl estradiol and levonorgestrel. The analytes were extracted with methyl-tert-butyl ether: n-hexane (50:50, v/v) solvent mixture, followed by dansyl derivatization. The chromatographic separation was performed on a Kinetex C (50 mm×4.

Development and optimization of modified release IPN macromolecules of oxcarbazepine using natural polymers.

The study shows development and optimization of modified release interpenetrating polymer network (IPN) macromolecules (beads) of oxcarbazepine using sodium alginate-egg albumin prepared by ionotropic gelation method and CaCl2 as a cross-linker. Independent variables were identified based on preliminary study of investigation. The effect of amount of both polymers on drug entrapment efficiency (DEE,%), bead size (μm) and cumulative drug release at 8 h (Q8h, %) were optimized using 3(2) factorial design.

Chromatographic separation of (E)- and (Z)-isomers of entacapone and their simultaneous quantitation in human plasma by LC-ESI-MS/MS.

A selective, sensitive and high throughput liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) method has been developed and validated for the chromatographic separation and quantitation of (E)-entacapone and (Z)-entacapone in human plasma. Sample clean-up involved liquid-liquid extraction (LLE) of both the isomers and carbamazepine used as internal standard from 500microL of human plasma. Both the analytes were chromatographically separated with a resolution factor of 3.

Isolation of Moraxella bovis from frozen bovine semen and determination of microbial load.

In the present study, isolation of Moraxella bovis was done from the microbiological examination of frozen semen straws from clinically healthy twelve Jersey and one Jersey-cross bull supplied by a semen laboratory. The organism was identified on the basis of colonial morphology and biochemical characteristics. Further, viable cell count of the bacterium was studied in detail in the semen sample.