Nawab Sher

Analysis of metformin, glimepiride and pioglitazone in human serum and its application to pharmacokinetics

A robust method, for the chromatographic separation of three antidiabetic drugs viz metformin, pioglitazone and glimepiride using an isocratic reversed phase high-performance liquid chromatographic (HPLC) system having ultraviolet detection at 254 nm is presented in this paper. The method was developed in human serum and dosage formulation with high-quality chromatographic separation between the drug peaks by using a stainless steel analytical column Nucleosil, C18 (10 micron, 25 × 0.46 cm). The system was operated at room temperature using a mobile phase consisting of acetonitrile, phosphate buffer (pH 4.3) in the ratio of 60 : 40 v/v at a flow rate of 1 mL min−1. The parametric statistics, i.e., correlation coefficient of 0.999 was assessed for all the drugs having linearity over the tested concentration range (10 to 10 000 ng mL−1) in human serum. The accuracy and the relative standard deviations of samples for six replicate measurements were not less than 97% and greater than 2%, respectively. The proposed method was validated for selectivity, linearity, accuracy, and precision according to the International Conference on Harmonization (ICH). The method is applicable for the quality control of the mentioned drugs in raw material, bulk drug, and pharmaceutical formulations as well as in human serum.

Simultaneous determination of antihistamine anti-allergic drugs, cetirizine, domperidone, chlorphenamine maleate, loratadine, meclizine and buclizine in pharmaceutical formulations, human serum and pharmacokinetics application

This article describes a new, accurate and highly specific high performance liquid chromatographic method with UV detection (HPLC-UV) for the simultaneous determination of cetirizine HCl (CZ), chlorphenamine maleate (CPM), loratadine (LTD), domperidone (DP), buclizine (BZ) and meclizine (MZ) in pharmaceutical dosage form and human serum, involving pyridoxine (PYD) as the internal standard. The mobile phase consists of heptane sulphonic acid salt buffer and acetonitrile, drawn at a flow rate of 1.0 mL min−1 using a symmetry C18 column with UV detection at 230 nm. The intraday and inter-day precision measurements showed coefficients of variation always less than one. The calibration curve was tested in the range of 10–2150 ng mL−1 and the correlation coefficient of >0.9990 in all cases was obtained. The averages of the absolute and relative recoveries were found to be in the range of 98 to 102%. Up to six antihistamines were separated in the same chromatogram with good resolution. The proposed HPLC method has reasonable applications in pharmaceutical tablet dosage form and pharmacokinetics studies.

Development of New Method for Simultaneous Analysis of Piracetam and Levetiracetam in Pharmaceuticals and Biological Fluids: Application in Stability Studies

RP-HPLC ultraviolet detection simultaneous quantification of piracetam and levetiracetam has been developed and validated. The chromatography was obtained on a Nucleosil C18 column of 25 cm × 0.46 cm, 10 μm, dimension. The mobile phase was a (70 : 30 v/v) mixture of 0.1 g/L of triethylamine and acetonitrile. Smooth flow of mobile phase at 1 mL/min was set and 205 nm wavelength was selected. Results were evaluated through statistical parameters which qualify the method reproducibility and selectivity for the quantification of piracetam, levetiracetam, and their impurities hence proving stability-indicating properties. The proposed method is significantly important, permitting the separation of the main constituent piracetam from levetiracetam. Linear behavior was observed between 20 ng/mL and 10000 ng/mL for both drugs. The proposed method was checked in bulk drugs, dosage formulations, physiological condition, and clinical investigations and excellent outcome was witnessed.

New Method Development for Hydroxyzine Determination: Application in Stability Studies, Pharmaceutical Formulations, and Humane Serum

This article pertains to development and validation of a low cost, fast, sensitive, and accurate RP-HPLC method for quantitative analysis of HZ. A Hibar μBondapak C18 column as the stationary phase and acetonitrile:methanol:buffer (500:200:300) as the mobile phase were used to accomplish the separation, when drawn at a flow rate of 1.0 mL/min, with 235 nm as monitoring wavelength. Linearity was established by studying the drug over the concentration range of 10–10000 ng mL−1, correlation coefficient of r = 0.9993, drug recovery (97 to 102%), and high reproducibility in serum samples (less than 2.5% RSD) displayed excellent linearity, accuracy, and precision. Force degradation studies of the drug under various stress conditions (acid, base, oxidation, photo, and thermal) proved the stability indicating power of the method. Substantial method validation study was carried out inline with ICH guidelines and was applied successfully to quantify the amount of HZ in bulk, pharmaceutical formulations, and blood serum samples.

Determination of benzimidazoles in pharmaceuticals and human serum by high-performance liquid chromatography

ABSTRACT A liquid chromatographic method is described for the quantification of prednisolone, benzimidazoles, and preservatives using a C18 analytical column as stationary phase. The mobile phase was 30:70 methanol:pH 2.5 phosphate buffer at a flow rate of 1.0 mL min−1 with absorbance detection at 235 nm. The method was linear for concentrations ranged from 40–10,000 ng mL−1. Low values of coefficient of variance were obtained when samples were analyzed as replicates. Excellent recovery values were recorded in commercial products and fortified samples. International Conference of Harmonization protocols were employed to perform comprehensive method validation. The reported method has applications for pharmaceutical and serum samples.

Pregabalin and Tranexamic Acid Evaluation by Two Simple and Sensitive Spectrophotometric Methods

This paper demonstrates colorimetric visible spectrophotometric quantification methods for amino acid, namely, tranexamic acid and pregabalin. Both drugs contain the amino group, and when they are reacted with 2,4-dinitrophenol and 2,4,6-trinitrophenol, they give rise to yellow colored complexes showing absorption maximum at 418 nm and 425 nm, respectively, based on the Lewis acid base reaction. Detailed optimization process and stoichiometric studies were conducted along with investigation of thermodynamic features, that is, association constant and standard free energy changes. The method was linear over the concentration range of 0.02–200 µgmL−1 with correlation coefficient of more than 0.9990 in all of the cases. Limit of detection was in range from 0.0041 to 0.0094 µgmL−1 and limit of quantification was in the range from 0.0137 to 0.0302 µgmL−1. Excellent recovery in Placebo spiked samples indicated that there is no interference from common excipients. The analytical methods under proposal were successfully applied to determine tranexamic acid and pregabalin in commercial products. t-test and F ratio were evaluated without noticeable difference between the proposed and reference methods.

Kinetic and Thermodynamic Spectrophotometric Technique to Estimate Gabapentin in Pharmaceutical Formulations using Ninhydrin

BackgroundSimple and sensitive spectrophotometric method is described based on the reaction of drug (gabapentin) with ninhydrin in pure form and in pharmaceutical preparations.MethodsComplex formed during this reaction is measured at 575 nm as a function of time. Kinetic study involve initial-rate, rate-constant and fixed-time (80 minutes) procedures to determine the concentration of the drug.ResultsDrug was studied in the concentration range of 10-30 ?gmL-1 showing correlation coefficient 0.9997, 0.9970 and 0.9990 for initial rate, rate constant and fixed time respectively. Limit of detection (LOD) and limit of quantification (LOQ) was found to be 0.13 and 0.04 nana grams respectively. The variables affecting the reactions were optimized and the developed method was validated according to ICH guidelines.ConclusionThe proposed method has been efficiently applied to the estimation of gabapentin in pharmaceutical formulation with first-class recovery (98.3-101.4%). Thermodynamic parameters were studied i.e., association constants and standard free energy changes were determined by Benesi?Hildebrand equation while, Gibbs free energy change for the complex was also estimated.

Novel HPLC method for quantitative determination of cefazolin sodium in pharmaceutical formulations

This paper reports a validated high-performance liquid chromatography method which is rapid, highly specific, and accurate for determination of cefazolin sodium in injec table pharmaceutical formulations. Separation was carried out using a Hibar ® µBondapak ® C 18 column with a mobile phase consisting of an acetonitrile to monobasic sodium phosphate buffer ratio of 17:83 and a flow rate of 1.0 mL per minute, and monitoring at a wavelength of 254 nm. The calibration curve was linear, with a correlation coefficient .0.9995 in the range of 5-100 µg/mL. Drug recovery was 98.35%-100.86%, with a limit of detection of 12.92 ng/mL and a limit of quantification of 43.09 ng/mL. The drug was subjected to stress conditions of hydrolysis (acid, base, oxidation, and thermal degradation), where maximum degradation was observed. Forced degradation studies confirmed stability indicating power of this method, which was validated in accordance with International Conference on Harmonization guidelines and used successfully to quantify the amounts of cefazolin sodium in bulk injectable formulations

An Overview of Analytical Determination of Diltiazem, Cimetidine, Ranitidine, and Famotidine by UV Spectrophotometry and HPLC Technique

This review article recapitulates the analytical methods for the quantitative determinations of diltiazem and three H2 receptor antagonists (cimetidine, ranitidine, and famotidine) by one of the spectroscopic technique (UV spectrophotometery) and separation technique such as high-performance liquid chromatography (HPLC). The clinical and pharmaceutical analysis of these drugs requires effective analytical procedures for quality control, pharmaceutical dosage formulations, and biological fluids. An extensive survey of the literature published in various analytical and pharmaceutical chemistry-related journals has been compiled in its review. A synopsis of reported spectrophotometric and high-performance liquid chromatographic methods for individual drug is integrated. This appraisal illustrates that majority of the HPLC methods reviewed are based on the quantitative analysis of drugs in biological fluids, and they are appropriate for therapeutic drug monitoring purpose.

Dual Wavelength RP-HPLC Method for Simultaneous Determination of Two Antispasmodic Drugs: An Application in Pharmaceutical and Human Serum

A reverse phase stability indicating HPLC method for simultaneous determination of two antispasmodic drugs in pharmaceutical parenteral dosage forms (injectable) and in serum has been developed and validated. Mobile phase ingredients consist of Acetonitrile : buffer : sulfuric acid 0.1 M (50 : 50 : 0.3 v/v/v), at flow rate 1.0 mL/min using a Hibar μBondapak ODS C18 column monitored at dual wavelength of 266 nm and 205 nm for phloroglucinol and trimethylphloroglucinol, respectively. The drugs were subjected to stress conditions of hydrolysis (oxidation, base, acid, and thermal degradation). Oxidation degraded the molecule drastically while there was not so much significant effect of other stress conditions. The calibration curve was linear with a correlation coefficient of 0.9999 and 0.9992 for PG and TMP, respectively. The drug recoveries fall in the range of 98.56% and 101.24% with 10 pg/mL and 33 pg/mL limit of detection and limit of quantification for both phloroglucinol and trimethylphloroglucinol. The method was validated in accordance with ICH guidelines and was applied successfully to quantify the amount of trimethylphloroglucinol and phloroglucinol in bulk, injectable form and physiological fluid. Forced degradation studies proved the stability indicating abilities of the method.