Simultaneous determination of tramadol and paracetamol in human plasma using LC-MS/MS and application in bioequivalence study of -fixed-dose combination.

The study aimed to develop a sensitive and high-throughput liquid chromatography coupled with tandem mass spectrometry method to quantify concentrations of tramadol and paracetamol simultaneously in human plasma. Sample preparation involved single-step protein precipitation using methanol and two deuterated internal standards, tramadol D6 and paracetamol D4. Agilent Poroshell 120 EC-C18 (100 × 2.

Simple and high sample throughput LC/ESI-MS/MS method for bioequivalence study of prazosin, a drug with risk of orthostatic hypotension.

Objective: The study aimed to develop a rapid, simple and sensitive LC/ESI-MS/MS method to measure prazosin concentration in human plasma and apply bedside sampling in bioequivalence study of two prazosin tablets to resolve the adverse effect of orthostatic hypotension.

Significance: The LC/ESI-MS/MS prazosin method was highly sensitive and selective. Bedside sampling reduced the orthostatic hypotension incidence and subject dropout rate.

Fast and Sensitive HPLC-ESI-MS/MS Method for Etoricoxib Quantification in Human Plasma and Application to Bioequivalence Study.

Etoricoxib is a non-steroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation. The objective of the current study was to develop a sensitive, fast and high-throughput HPLC-ESI-MS/MS method to measure etoricoxib levels in human plasma using a one-step methanol protein precipitation technique. A tandem mass spectrometer equipped with an electrospray ionization (ESI) source operated in a positive mode and multiple reaction monitoring (MRM) were used for data collection.

Healing Enhancement Assessment of Thermosensitive in Situ Gelling Formulation Containing Metronidazole and Diclofenac Potassium for Ligature-induced Periodontitis in Rats.

Objectives: We sought to investigate the healing efficacy of thermosensitive in situ gelling formulation containing metronidazole and diclofenac potassium on ligature-induced periodontitis (LIP) in rats.

Methods: We used 30 adult male Sprague-Dawley rats; 24 rats were subjected to LIP, while the remaining six rats were used as control. The 24 rats with LIP were subdivided into four groups of six rats each.

Sample preparation and quantification of polar drug, allopurinol, in human plasma using LCMSMS.

A fast, selective and reproducible LC-MS/MS method with simple sample preparation was developed and validated for a polar compound, allopurinol in human plasma, using acyclovir as internal standard (IS). Chromatographic separation was achieved using Agilent Poroshell 120 EC-C (100 × 2.1 mmID, 2.

Fast Melt Cocoa Butter Tablet: Effect of Waxes, Starch, and PEG 6000 on Physical Properties of the Preparation.

A fast melt tablet (FMT) is well regarded as an alternative delivery system that might help resolve a patient's non-compliance issue. The main objective of this study was to develop a cocoa butter-based FMT. Additives, namely 5-15% of PEG 6000, beeswax, paraffin wax, and corn starch, were incorporated into the cocoa butter-based FMT to study the effects of these additives with the physical characteristic of a cocoa butter FMT.

Development of stability-indicating HPLC-UV method and oxidative degradation kinetic study of montelukast in chewable tablet formulation.

A simple and sensitive stability-indicating HPLC-UV method was developed and validated for the determination of montelukast in the development of chewable tablet formulation. Chromatographic separation was achieved using Atlantis® T3 3µm C18 (4.6mmID X 10cm) analytical column.

Simultaneous determination of duloxetine and 4-hydroxy duloxetine glucuronide in human plasma and back-conversion study.

To develop an LC-MS/MS method for simultaneous determination of duloxetine and its metabolite, 4-hydroxy duloxetine glucuronide (4HDG) in human plasma and to investigate the potential back-conversion of 4HDG to duloxetine using stability study. The LC-MS/MS method was validated according to the EMA and USFDA Bioanalytical Method Validation Guidelines and applied to pilot bioequivalence study. The method validation results were within the acceptance limits.

Simple and fast LC-MS/MS method for quantification of terazosin in human plasma and application to bioequivalence study.

A simple, fast and sensitive LC-MS/MS method was developed to quantify terazosin in human plasma. The mobile phase consisted of acetonitrile-0.1% (v/v) formic acid (70:30, v/v).

Development of LC-MS/MS method and application to bioequivalence study of a light sensitive drug montelukast.

Objective: The aim of the study was to develop a simple, highthroughput and sensitive LC-MS/MS method and apply to a bioequivalence study of montelukast, a light sensitive drug.

Method: The effects of organic modifiers in mobile phase, protein precipitation agent to plasma sample ratio, and light on montelukast stability in unprocessed and processed human plasma, were evaluated. Validation was conducted in accordance with European Medicines Agency Guideline on bioanalytical method validation.

Simple and rapid LC-MS/MS method for simultaneous determination of flavoxate and 3-methyl-flavone-8-carboxylic acid in human plasma: Application to a bioequivalence study.

A simple, rapid, sensitive, and reproducible LC-MS/MS method was developed for simultaneous quantification of flavoxate and 3-methyl-flavone-8-carboxylic (MFCA) in human plasma, using diphenhydramine HCl as internal standard (IS). The chromatographic separation was achieved using Agilent Poroshell 120 EC-C18 - Fast LC column (100 × 2.1mmID, 2.

Simple and rapid LC-MS/MS method for determination of sitagliptin in human plasma and application to bioequivalence study.

A simple, rapid, sensitive, and reproducible liquid chromatography-tandem mass spectrometry method was developed to determine sitagliptin in human plasma. Diphenhydramine HCl was used as internal standard (IS). The chromatographic separation was achieved using Agilent Poroshell 120 EC-C18 - Fast LC column (100 × 2.

Effect of Hydrophilic Polymers on Complexation Efficiency of Cyclodextrins in Enhancing Solubility and Release of Diflunisal.

The effects of three hydrophilic polymers, namely, carboxymethyl cellulose sodium (CMC-Na), polyvinyl alcohol (PVA) and poloxamer-188 (PXM-188) on the solubility and dissolution of diflunisal (DIF) in complexation with β-cyclodextrin (βCD) or hydroxypropyl β-cyclodextrin (HPβCD), were investigated. The kneading method was used at different drug to cyclodextrin weight ratios. Increases in solubility and drug release were observed with the DIF/βCD and DIF/HPβCD complexes.

Stability indicating HPLC method for simultaneous quantification of sildenafil citrate and dapoxetine hydrochloride in Pharmaceutical products.

A stability-indicating HPLC-UV method for the simultaneous determination of sildenafil citrate and dapoxetine hydrochloride in solution and tablet was developed. The mobile phase was comprised of acetonitrile and 0.2M ammonium acetate buffer.

RELEASE AND MUCOADHESION PROPERTIES OF DICLOFENAC MATRIX TABLETS FROM NATURAL AND SYNTHETIC POLYMER BLENDS.

The delayed release and mucoadhesive properties of Cedrela gum and hydroxypropylmethylcellulose blend in diclofenac sodium tablet formulations were evaluated. Tablets were prepared by direct compression and the crushing strength and detachment force were found to increase from 74.49 ± 1.

Characterisation of Physicochemical Properties of Propionylated Corn Starch and Its Application as Stabiliser.

A series of propionylated starches with different degrees of substitution (DS) was synthesised and their physicochemical properties and application as a stabiliser were investigated. Starch propionates with moderate DS were prepared by esterification of native corn starch with propionic anhydride. By varying the reaction times of the esterification process, twelve starch propionates with DS of 0.

Investigation on the effect of polymer and starch on the tablet properties of lyophilized orally disintegrating tablet.

Orally disintegrating tablet (ODT) is a user friendly and convenient dosage form. The study aimed to investigate the effect of polymers and wheat starch on the tablet properties of lyophilized ODT, with dapoxetine as model drug. Three polymers (hydroxypropylmethyl cellulose, carbopol 934P and Eudragit EPO) and wheat starch were used as matrix forming materials in preparation of lyophilized ODT.

Simultaneous quantification of sildenafil and N-desmethyl sildenafil in human plasma by UFLC coupled with ESI-MS/MS and pharmacokinetic and bioequivalence studies in Malay population.

A simple, rapid, specific and reliable UFLC coupled with ESI-MSMS assay method to simultaneously quantify sildenafil and N-desmethyl sildenafil, with loperamide as internal standard, was developed. Chromatographic separation was performed on a Thermo Scientific Accucore C18 column with an isocratic mobile phase composed of 0.1% v/v formic acid in purified water-methanol (20:80, v/v), at a flow rate of 0.

Stability indicating HPLC-UV method for detection of curcumin in Curcuma longa extract and emulsion formulation.

A stability-indicating HPLC-UV method for the determination of curcumin in Curcuma longa extract and emulsion was developed. The system suitability parameters, theoretical plates (N), tailing factor (T), capacity factor (K'), height equivalent of a theoretical plate (H) and resolution (Rs) were calculated. Stress degradation studies (acid, base, oxidation, heat and UV light) of curcumin were performed in emulsion.

Identification of phases of various oil, surfactant/ co-surfactants and water system by ternary phase diagram.

The objective of this study was to select appropriate surfactants or blends of surfactants and oil to study the ternary phase diagram behavior and identify various phases obtained from the oil and surfactant/surfactant mixture combinations of different HLB. The phases include conventional emulsion, gel/viscous and transparent/translucent microemulsion. Pseudoternary phase diagrams of water, oil and S/Smix of various HLB values range of 9.

Stability indicating HPLC-UV method for determination of dapoxetine HCl in pharmaceutical product.

A stability-indicating HPLC-UV method for the determination of dapoxetine hydrochloride in solution and pharmaceutical product was developed. The mobile phase was composed of acetonitrile and 0.2 M ammonium acetate buffer at 50 : 50 ratio.

Effect of deprotenizing agent and quantification of donepezil hydrochloride in human plasma.

The effect of deprotenizing agents on recovery of donepezil hydrochloride in the development of a simple, rapid, selective and sensitive high performance liquid chromatography method for quantification of donepezil hydrochloride in human plasma was described. The deprotenizing agents were comprised of, perchloric acid, methanol, acetonitrile, chloroform and their mixtures. The chromatographic separation was carried out using reversed phase C18 column (Agilent Eclipse Plus C18) with UV detection at 268 nm.

Improved protein deproteinization method for the determination of meloxicam in human plasma and application in pharmacokinetic study.

A simple, rapid, specific and reliable high-performance liquid chromatographic assay of meloxicam in human plasma has been developed using a C18 reversed-phase analytical column. Reversed-phase chromatography was conducted using a mobile phase of 0.02 potassium dihydrogen phosphate (adjusted to pH 2.

Randomized two-way cross-over bioequivalence study of two amoxicillin formulations and inter-ethnicity pharmacokinetic variation in healthy Malay volunteers.

The objectives of this study were to develop a new deproteinization method to extract amoxicillin from human plasma and evaluate the inter-ethnic variation of amoxicillin pharmacokinetics in healthy Malay volunteers. A single-dose, randomized, fasting, two-period, two-treatment, two-sequence crossover, open-label bioequivalence study was conducted in 18 healthy Malay adult male volunteers, with one week washout period. The drug concentration in the sample was analyzed using high-performance liquid chromatography (UV-vis HPLC).

Taste-masked and affordable donepezil hydrochloride orally disintegrating tablet as promising solution for non-compliance in Alzheimer's disease patients.

Context: Manufacturing process and superdisintegrants used in orally disintegrating tablet (ODT) formulation are often time discussed. However, the effect of suitable filler for ODT formulation is not explored thoroughly.

Objective: The aim of this study was to develop a novel taste masked and affordable donepezil hydrochloride ODT with fast disintegration time and stable to improve medication compliance of Alzheimer's disease patient.