Development and Validation of a Rapid Analytical Method for the Simultaneous Quantification of Metabolic Syndrome Drugs by HPLC-DAD Chromatography

Worldwide, 25% of the population suffers from metabolic syndrome (MetS). The treatment of patients with MetS regularly includes drugs prescribed simultaneously to treat several disorders that manifest at the same time, such as hypercholesterolemia, arterial hypertension, and diabetes. To the authors’ best knowledge, there is no previous published analytical method for the simultaneous quantification of drugs used in the treatment of these diseases. In the present study, a rapid high-performance liquid chromatography with a diode-array detector HPLC-DAD methodology was developed for simultaneous quantification of carvedilol (CVD), telmisartan (TEL), bezafibrate (BZT), gliclazide (GZD), and glimepiride (GMP) in bulk and pharmaceutical form. The chromatographic separation of the five pharmaceuticals was achieved on a Hypersil GOLD C18 Selectivity (5 µm, 150 × 4.60 mm2) using a mobile phase of acetonitrile (50%) and 0.02 M KH2PO4, pH 3 (50%) at a flow rate of 1 mL/min and at 25 °C. The total separation time was 9 min. The analytical method was validated following the International Conference on Harmonization guidelines. A reproducible method was obtained with acceptable limits of detection (LOD) and quantification (LOQ) for CVD (0.012 and 0.035 μg mL−1), TEL (0.103 and 0.313 μg mL−1), BZT (0.025 and 0.076 μg mL−1), GZD (0.039 and 0.117 μg mL−1), and GMP (0.064 and 0.127 μg mL−1). The validated method allowed the determination of these drugs in commercial pharmaceutical products both individually and simultaneously. The present method was found to be suitable for simultaneous quantification of the five drugs that are most commonly used in the simultaneous treatment of the metabolic syndrome.

A Versatile Stability-indicating Liquid Chromatographic Method for the Simultaneous Determination of Atenolol, Hydrochlorothiazide and Chlorthalidone

Background:

Atenolol is a selective beta 1 blocker that can be used alone or in combination with hydrochlorothiazide or with chlorthalidone for the treatment of hypertension and prevention from a heart attack.

Objective:

The main target of this work was to improve modern, easy, accurate and selective liquid chromatographic method (RP-HPLC) for the determination of these drugs in the presence of their degradation products. These methods can be used as analytical gadgets in quality control laboratories for a routine examination.

Methods:

In this method, the separation was accomplished through an Inertsil® ODS-3V C18 column (250 mm x 4.6 mm, 5 μm), the mobile phase used was 25 mM aqueous potassium dihydrogen orthophosphate solution adjusted to pH 6.8 by using 0.1M sodium hydroxide and acetonitrile (77 : 23, v/v), the flow rate used was 1 ml/min and detection was achieved at 235 nm using UV.

Results:

All peaks were sharp and well separated, the retention times were atenolol degradation (ATN Deg.) 2.311 min, atenolol (ATN) 2.580 min, hydrochlorothiazide degradation (HCT Deg.) 5.890 min, hydrochlorothiazide (HCT) 7.016 min, chlorthalidone degradation CTD Deg 8.018 min and chlorthalidone (CTD) 14.972 min. Linearity was obtained and the range of concentrations was 20- 160 μg/ml for atenolol, 10-80 μg/ml for hydrochlorothiazide and 10-80 μg/ml for chlorthalidone. According to ICH guidelines, method validation was accomplished, these methods include linearity, accuracy, selectivity, precision and robustness.

Conclusion:

The optimized method demonstrated to be specific, robust and accurate for the quality control of the cited drugs in pharmaceutical dosage forms.

Spironolactone voltammetric determination on renewable amalgam film electrode

In this study a new high sensitive method of spironolactone (SP) determination is proposed using voltammetric technique. As the working electrode amalgam film silver based electrode (Hg(Ag)FE) was applied, that resulted in obtaining low limit of spironolactone detection, ex. for the preconcentration time 45 s obtained detection limit was 4.7·10^-9 mol L^-1 (1.96·10^-6 g L^-1). The linear response of spironolactone signal on mercury film electrode was obtained in the range of concentration from 15·10^-9 to 3.0·10^-6 mol L^-1 and the obtained repeatability measured as RSD was very good, with the value of 2.0% (n = 5; concentration 0.5·10^-6 mol L^-1). The proposed method was successfully applied and validated by studying the recovery in commercially available pharmaceutical formulations containing known amount of spironolactone.

Determination of rosuvastatin at picogram level in serum by fluorimetric derivatization with 9-anthryldiazomethane using HPLC

For the first time, a carboxyl group derivatization assay has been developed and validated for the determination of the cholesterol-lowering drug rosuvastatin in human serum at picogram level by high-performance liquid chromatography with fluorescence detection. The assay procedure involved a simple one-step liquid-liquid extraction of rosuvastatin with lovastatin as internal standard from serum with an ethyl acetate-methyl tertiary buthyl ether (1:1) mixture. After pre-column derivatization with 9-anthryldiazomethane at room temperature for one hour, the reaction mixture was injected onto a Phenomenex, Synergi C18 column (250 × 4.6 mm, 4 µ i.d.). The analytes were separated with a mobile phase composed of acetonitrile-water in gradient elution mode and detected at λ(em) = 410 nm, exciting at 366 nm. Calibration curves were constructed in concentration range of 0.01-20.0 ng/mL and limit of detection and limit of quantification values were found to be 0.68 and 2.30 pg/mL, respectively. To test suitability of the developed methods for clinic use, the pharmacokinetics of rosuvastatin were investigated after oral administration of a 20 mg rosuvastatin film tablet to a healthy volunteer and maximum plasma concentration, time to reach that concentration and elimination half life were found to be 17.5 ng/mL, 3.5 h and 18.09 h, respectively.