Complexation Based Voltammetric Determination of Pantoprazole Sodium in Pharmaceutical Formulations and Rabbit Plasma

Square wave adsorptive stripping voltammetric (SQWASV) method has been utilized to confirm and elucidate the possible complexation reaction between pantoprazole sodium and cobalt as a transition metal in Britton‐Robinson buffer (pH=7.0). The current signal due to the oxidation process was a function of the amount of pantoprazole sodium, pH of the medium, cobalt concentration and accumulation time at the electrode surface. The oxidation peak current has varied linearly with the concentration over the range of 0.1–9.0 nM. The limit of detection was found to be 0.04 nM. The validity of the method was successfully applied for the determination of pantoprazole sodium in pharmaceutical formulations with a pharmacokinetic study in rabbit plasma. The simplicity, rapidity, sensitivity and selectivity of this method make it a very attractive alternative to the other existing methods in the quality control laboratories.     

Analysis of Dexamethasone Acetate in Pharmaceutical Formulations by HPLC

Abstract

A rapid and effective high-pressure liquid chromatographic method has been developed for the quantitative determination of dexamethasone 21 acetate in pharmaceutical formulations. Sample preparation employs a simple extraction procedure and analysis is carried out on a reversephase chromatographic system using a LiChrosorb RP 18 column and a water-acetonitrile as mobile phase. The extraction procedure gives quantitative recovery and chromatographic results show that drug levels of as 0.1 ppm can be conveniently analyzed without significant background interferences.     

HPLC Determination of Ritodrine Hydrochloride in Pharmaceutical Formulations

A simple, rapid, and accurate HPLC method is described for the determination of ritodrine hydrochloride (RTH) in both pure form and pharmaceutical formulations. A Hypersil Shendon ODS column with a mobile phase of dibasic phosphate buffer and acetonitrile (75 : 25) and isoxsuprine hydrochloride were used as an internal standard. The flow rate was 1 mL min^–1 and the effluent was monitored at 270 nm pH 4.0. The calibration graph is linear in the range 2–30 g mL^–1. The proposed HPLC method has been successfully employed for the determination of RTH in Yutopar tablets and injection solutions.     

Simultaneous Estimation of Ceftazidime and Ceftizoxime in Pharmaceutical Formulations by HPLC Method

The aim of the present study was to develop a fast, sensitive and reliable method for rapid screening of cephalosporin injectable dosage forms namely ceftazidime and ceftizoxime to the detection of counterfeit and substandard drugs that might be illegally commercialized. Ceftazidime, ceftizoxime and cefixime (IS) were separated in a X-Terra RP-18 column (250 × 4.60 mm ID × 5 ??) and DAD detector set at 290 and 260 nm. The mobile phase consisted of a mixture of methanol:water 20:80 (v/v) at a flow rate of 1.0 mL min^?1. Additionally, in order to find the optimum pH value of separation the pK _a values of studied compounds were determined by using two different methodologies. Aqueous pK _a values of studied compounds have been determined by UV-spectrophotometry and liquid chromatography were used for the determination and direct characterization of the dissociation constants by using the dependence of the capacity factor on the pH of the mobile phase in 20% (v/v) methanol?Cwater binary mixture in which separation was performed. The pH of the mobile phase was adjusted with 25 mM H₃PO₄ to 3.2. The method was shown to be linear, sensible, accurate, and reproducible over the range of analysis and it can be used to pharmaceutical formulations containing a single active ingredient within a short analysis time.     

Simultaneous Determination of Bifonazole and Benzyl Alcohol in Pharmaceutical Formulations by Reverse-Phase HPLC

A simple, precise and sensitive reverse-phase high performance liquid chromatographic (RP-HPLC) method has been developed for the quantitation of bifonazole, an imidazole antifungal, simultaneously with benzyl alcohol, used as preservative, in pharmaceutical formulations. Method employed Zorbax Eclipse XDB-C18 (250×4.6 mm i.d., 5 m) column, methanol - ammonium acetate (pH 2; 65 mM) (65:35, v/v, pH^* 3.6) as mobile phase with flow rate of 1 mL min^–1 and variable UV detection at 220 and 252 nm. The proposed method was validated by testing its linearity, selectivity, recovery, repeatability, LOD/LOQ values and it was successfully employed for the determination of bifonazole and benzyl alcohol in pharmaceutical cream-based formulations.     

Enantiospecific HPLC and CE Methods for Separation and Determination of S-Darifenacin in Pharmaceutical Formulations

Two separation techniques were developed for the determination of S-(−)darifenacin (DAR) in the presence of its R-(+) isomer: The first method is high performance liquid chromatography (HPLC) and the second is capillary electrophoresis (CE). Chiral separation for chromatographic HPLC method development was carried out for S-DAR on Daicel CROWNPAK CR (+) (5 μm, 4.0 × 150 mm) column which contains (3,3-diphenyl-1,1-binaphthyl)-crown-6 coated onto a 5.5 μm silica support. The mobile phase system was aqueous acidic 70 % HClO₄ (pH 2.5): methanol in the proportion of 90:10 v/v. This current mobile phase was delivered at flow rate 0.8 mL min⁻¹ using UV detector adjusted at 286 nm. In CE method, the enantiomers were separated using 50 μm inner diameter fused-silica capillary cut to total lengths of 31.2 cm using 50 mM phosphate buffer as background electrolyte adjusted to pH 2.5 by triethanolamine. A wide range of cyclodextrins (CDs) were used such as highly sulfated α, γ CDs, hydroxyl propyl-β-CD and sulfobutyl ether-β-CD as chiral selectors. The effects of chiral additives regarding its concentration and content of organic modifier on the enantioseparation were investigated. Linear concentration ranges were from 2.5 to 50 and 40 to 300 μg mL⁻¹ with detection limits 0.67 and 12.28 μg mL⁻¹ for chromatographic HPLC and electrophoretic CE methods, respectively. The two methods were validated according to ICH guidelines with respect to linearity, accuracy, precision, LOQ, LOD and robustness. The suggested methods are suitable for separation and quantitation of S-DAR in tablets.

     

Validation of UV Spectrophotometric Method for Fexofenadine Hydrochloride in Pharmaceutical Formulations and Comparison with HPLC

Abstract

A simple, reproducible, accurate, and effective spectrophotometric method was developed and validated for the quantitation of the antihistamine fexofenadine in capsules and coated tablets. Ethanol was used as solvent and the absorbance at the wavelength of 220 nm was employed to the quantitation of the drug. The method validation was fulfilled through the evaluation of the analytical parameters of linearity, precision, accuracy, limits of detection, and quantitation and specificity. The method was linear (r=0.9999) at concentrations ranging from 8.0 to 20.0 µg ml^?1, precise (RSD intra‐day=0.29; 0.18; 0.39; RSD inter‐day=0.12 for capsules and RSD intra‐day=0.13; 0.16; 0.13; RSD inter‐day=0.13 for coated tablets), accurate (percentage recovery=99.97% for capsules and 100.51% for tablets), sensitive (limits of detection and quantitation of 0.10 and 0.29 µg ml^?1, respectively) and specific. The method was compared to a high performance liquid chromatography (HPLC) method, which was previously developed to the same drug. The results showed no significant difference between the methods in fexofenadine hydrochloride quantitation.     

Simultaneous Determination of Atenolol,Rosuvastatin, Spironolactone,Glibenclamide and Naproxen Sodium in Pharmaceutical Formulations and Human Plasma by RP‐HPLC

A rapid and sensitive high‐performance liquid chromatographic method was developed and validated for the simultaneous determination and quantification of atenolol, rosuvastatin, spirnolactone, glibenclamide and naproxen sodium in bulk drugs, pharmaceutical formulations and in human plasma in the presence of internal standard (flurbiprofen). Chromatograms were developed with methanol and water (80:20, v/v) solvent system on a Purospher start, C₁₈ (5 μm, 250 × 4.6 mm) column and pH was adjusted to 3.40 with ortho‐phosphoric acid. Mobile phase was pumped with a flow rate of 0.90 mL/minute with 235 nm UV detection. Standard curves were linear over the concentration range 0.25‐30 μg/mL^?1. The coefficients of variation (C.V.%), were < 3% and LOD and LOQ were <0.0154 & 0.06 for inter‐ and intra‐day, respectively. The method was applied to drug interaction studies of atenolol with rosuvastatin, spironolactone, glibenclamide and naproxen to illustrate the scope and application of the methods to manage four different therapeutic classes of drugs, as they are co‐administered.     

Quantitative Analysis of Meclizine in Tablet Formulations by HPLC

Abstract

A simple, rapid and precise high-performance liquid chromatographic assay of meclizine in tablets has been developed. Reversed-phase chromatography was conducted using a mobile phase of acetonitrile and water (30% V/V) and detection at 230 nm. The recovery and coefficient of variation from six placebo tablets containing 25 mg of meclizine were 100.5% and 0.84%, respectively. Replicate regression analyses of three standard plots in the concentration range of 1–12 mcg/ml obtained on three different days gave a correlation coefficient >0.998 and the coefficient of variation of the slopes <1%. The assay was precise within day and between days as indicated by ANOVA test. The recoveries from 10 replicate tablets of the two different commercial meclizine brands were 98.5 and 100.7% of the label amount and their coefficients of variation were 1.16 and 1.71%.     

Determination of Nabumetone and Its Major Metabolite in Plasma and Tablet Formulations by Reverse-Phase HPLC

Abstract

A high performance liquid chromatographic procedure is presented for the determination of nabumetone in pharmaceutical tablets and in plasma. An aliquot of the sample is dissolved in 50% acetonitrile (ACN) containing 4-methoxyacetophenone as an internal standard and chromatographed on a Supelcosil LC-8 (5μ) (150 mm × 4.6 mm i.d.) column. The mobile phase was a mixture of acetonitrile (500 mL), triethylamine (1.5 mL) and glacial acetic acid (8 mL) diluted to 1000 mL, with distilled deionized water. The detection was carried at 270 nm. The method was tested for linearity, recovery and specificity.     

Spectrophotometric Determination of Methotrexate and in Pharmaceutical Formulations

Abstract

Methotrexate, 4-amino-10-methyl folic acid, is one of the drugs belonging to the folic acid antagonists that is widely used for the treatment of cancer and psoriasis ^{1, 2}     

Determination of Cinnarizine in Pure and Pharmaceutical Formulations

Two simple, rapid and sensitive extractive spectrophotometric methods have been developed for the assay of cinnarizine (CNR) in pure and pharmaceutical formulations. The methods are based on the formation of chloroform soluble ion‐association complexes of CNR with thymol blue (TB) and with cresol red (CR) inNaOAc‐AcOH buffer of pH 3.6 for TB and in KCl‐HCl buffer of pH 1.6 for CR with absorption maxima at 405 nm and at 403 nm for TB and CR, respectively. Reaction conditions were optimized to obtain the maximum color intensity. The systems obeyed Beer's law in the range of 0.6–15.8 and 0.8–16.6 μg mL^?1 for TB and CR, respectively. Various analytical parameters have been evaluated and the results have been validated by statistical data.     

UV Densitometric HPTLC Method for Analysis of Nitrazepam in Pharmaceutical Formulations

JPC – Journal of Planar Chromatography – Modern TLC - A UV densitometric high-performance thin-layer chromatographic (HPTLC) method for analysis of nitrazepam in pharmaceutical...     

Colorimetric Estimation of Melatonin in Pharmaceutical Formulations

 Three simple and sensitive colorimetric methods (A–C) for the determination of melatonin in bulk samples and in pharmaceutical formulations are described. They are based on the formation of coloured species by reaction of ninhydrin with the drug (method A, λ_max 397 nm) by oxidation of the indol moiety in melatonin with potassium persulphate (method B, λ_max 450 nm) or by reduction of osmium (VIII) (method C, λ_max 516 nm). Regression analysis of Beer-Lambert plots showed good correlations in concentration ranges between 0.8–14.2, 70.0–140.0 and 2.0–40.0 μg/mL for methods A, B and C, respectively. The molar absorptivity, Sandell sensitivity and detection limit were calculated. For more accurate analysis, Ringbom optimum concentration ranges were calculated. The validity of the proposed methods was tested by analysing pharmaceutical formulations containing melatonin. The relative standard deviations were ≤ 0.95% with recoveries 99.0–101.33%. Received October 20, 1999. Revision February 10, 1999.     

FT-IR Spectrophotometric Analysis of Ascorbic Acid and Biotin and their Pharmaceutical Formulations

Abstract

Fourier transform–infrared (FT-IR) spectrometry was used for the rapid, direct measurement of ascorbic acid (vitamin C) and biotin (vitamin H) in different pharmaceutical products. Conventional KBr spectra were compared for the best determination of active substances in drug preparations. The Beer–Lambert law and chemometric approaches were applied in data processing.     

Simultaneous Identification and Quantitative Analysis of Eight Cephalosporins in Pharmaceutical Formulations by TLC-Densitometry

JPC – Journal of Planar Chromatography – Modern TLC - A rapid, accurate, and sensitive densitometric TLC method has been established and validated for simultaneous analysis of eight...     

High Performance Liquid Chromatographic Analysis of Rifampin and Related Impurities in Pharmaceutical Formulations

Abstract

High pressure liquid chromatography was employed for the assay of rifampin in capsules. A reverse phase RP-2 column and a mobile phase of 48% methanol, 5% tetrahydrofuran and 47% 0.05 M ammonium formate (pH 7.3) were used with detection at 254 nm. Rifampin was separated from all its major degradation products and quantitated.     

Spectrophotometric Determination of Lisinopril in Pure and Pharmaceutical Formulations

An accurate, simple, fast, and cheap spectrophotometric method has been developed for the determination of lisinopril in pharmaceutical pure and dosage forms. The method is based on the reaction of ninhydrin with primary amine present in the lisinopril in the presence of DMF. This reaction produces a greenish blue colored product which absorbs maximally at 600 nm. Beer's law was obeyed in the range of 10–150 μg/mL with molar absorptivity of 4.083 × 10³ L mole^?1 cm^?1. The effects of variables such as temperature, heating time, concentration of color producing reagent, and stability of color were investigated to optimize the procedure. The results are validated statistically. The proposed method was applied to commercially available tablets, and the results were statistically compared with the official potentiometric method.     

HPLC Determination of Carbendazim in Formulations

Abstract

A rapid high performance liquid chromatographic method has been developed to determine Carbendazim (methyl 2-benzimidazole carbamate) in formulations using reverse phase μ Bondapak C₁₈ column and ultraviolet detection. The sample is extracted from formulations with methanol, carbaryl is used as an internal standard. Absorbance is measured at 254 nm and the compound is quantitated by peak height ratios. The method is simple and recoveries averaged between 91–93%.