Determination of serum sulphonylureas by high-performance liquid chromatography with fluorimetric detection

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.

Application of monolithic column in quantification of gliclazide in human plasma by liquid chromatography

A simple, rapid and sensitive isocratic reversed phase HPLC method with UV detection using a monolithic column has been developed and validated for the determination of gliclazide in human plasma. The assay enables the measurement of gliclazide for therapeutic drug monitoring with a minimum quantification limit of 10ngml(-1). The method involves simple, one-step extraction procedure and analytical recovery was complete. The separation was carried out in reversed-phase conditions using a Chromolith Performance (RP-18e, 100mmx4.6mm) column with an isocratic mobile phase consisting of 0.01M disodium hydrogen phosphate buffer-acetonitrile (52:48, v/v) adjusted to pH 4.0. The wavelength was set at 230nm. The calibration curve was linear over the concentration range 10-5000ngml(-1). The coefficients of variation for inter-day and intra-day assay were found to be less than 6.0%.

Spectrophotometric determination of gliclazide in pharmaceuticals and biological fluids through ternary complex formation with eosin and palladium (II)

A simple and sensitive spectrophotometric method has been developed for the determination of gliclazide (GLZ) in pharmaceutical formulations and biological fluids. The proposed method is based upon the formation of a ternary complex between palladium (II), eosin and GLZ in the presence of methyl cellulose as a surfactant and acetate buffer of pH 4.5. The ternary complex showed an absorption maximum at 550 nm. The solution of ternary complex obeyed Beer's law over the concentration range of 0.5-4 microg ml(-1) with minimum detectability (S/N = 2) of 0.05 microg ml(-1) (1.545 x 10(-7) M). The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. The proposed method was successfully applied to the analysis of commercial tablets. The results obtained were in good agreement with those obtained using the official or reference spectrophotometric method. The proposed method was further applied to spiked human urine and plasma, the percentage recoveries were 97.84 +/- 0.72 and 97.43 +/- 0.83, respectively, (n = 4). A proposal of the reaction pathway was presented.

Systematic toxicological analysis procedures for acidic drugs and/or metabolites relevant to clinical and forensic toxicology and/or doping control

This paper reviews systematic toxicological analysis (STA) procedures for acidic drugs and/or metabolites relevant to clinical and forensic toxicology or doping control using gas chromatography, gas chromatography-mass spectrometry, liquid chromatography, thin-layer chromatography and capillary electrophoresis. Papers from 1992 to 1998 have been taken into consideration. Screening procedures in biosamples (whole blood, plasma, serum, urine, vitreous humor, brain, liver or hair) of humans or animals (horse, or rat) are included for the following drug classes: angiotensin-converting enzyme (ACE) inhibitors and angiotensin II (AT-II) blockers, anticoagulants of the 4-hydroxy coumarin type, barbiturates, dihydropyridine calcium channel blockers (calcium antagonists), diuretics, hypoglycemic sulfonylureas and non-steroidal anti-inflammatory drugs (NSAIDs). Methods for confirmation of preliminary results obtained by screening procedures using immunoassay or chromatographic techniques are also included. Furthermore, procedures for the simultaneous detection of several drug classes are reviewed. The toxicological question to be answered and the consequences for the choice of an adequate method, the sample preparation and the chromatography itself are discussed. The basic information about the biosample assayed, work-up, separation column, mobile phase or separation buffer, detection mode and validation data of each procedure is summarized in 16 tables. They are arranged according to the drug class and the analytical method. Examples of typical applications are presented. Finally, STA procedures are reviewed and described allowing simultaneous screening for different (acidic) drug classes.

The mode of action and clinical pharmacology of gliclazide: a review

Gliclazide is a sulphonylurea drug with an intermediate half-life of around 11 hours. It is extensively metabolised, and renal clearance accounts for only 4% of total drug clearance. The molecule contains an azabicyclo-octyl group which confers special properties on the basic sulphonylurea moiety. Gliclazide stimulates insulin secretion through the beta cell sulphonylurea receptor, and possibly through a direct effect on intracellular calcium transport. It specifically improves the abnormal first phase insulin release in type 2 diabetes, and also has an effect on the second phase. This pattern of insulin release is thought to explain the lower incidence of hypoglycaemic episodes and weight gain compared with some other sulphonylureas. There is also a reduction in hepatic glucose production and improvement in glucose clearance, without changes in insulin receptors. This suggests a possible post-receptor effect on insulin action, perhaps by stimulation of hepatic fructose-2,6-bisphosphatase and muscle glycogen synthase. Gliclazide reduces platelet adhesion, aggregation and hyperactivity and increases fibrinolysis. These actions, thought to be independent of its hypoglycaemic activity, may make gliclazide useful in halting the progression of diabetic microangiopathy.