Improved High Performance Liquid Chromatographic Method for the Determination of Some Corticosteroids

Abstract

A simple, selective and accurate high performance liquid chromatographic method for the determination of some pharmaceutically important corticosteroids has been developed. the suggested method uses a ultrasphere ODS column with acetonitrile-phosphate buffer (pH 8) as a mobile phase.

The mean percentage recovery ranged from 97.9 to 99.7, the proposed method was applied to the determination of the studied corticosteroids pro in some dosage forms. the statistical analysis of the results obtained were compared favourably with those given with the official method.     

High Performance Liquid Chromatographic Analysis of Penicillin V Solid Dosage Forms

Abstract

An isocratic high performance liquid chromatographic (HPLC) method for the determination of Penicillin V in solid dosage forms is described. A reverse phase RP-8 column and a mobile phase of 52% methanol in 0.05 M phosphate buffer (pH 3.3) were employed. Detection was effected at 254 nm. The results obtained are compared with those from the iodometric method.     

Determination of Pyridostigmine in Human Plasma by High-Performance Liquid Chromatography

Abstract

An easy to perform, specific, reproducible and sensitive high performance liquid chromatographic (HPLC) method to measure pyridostigmine concentration in human plasma was developed and validated. Sample clean-up consists of ion-pair extraction into dichloromethane in the presence of neostigmine as internal standard, followed by back extraction into an aqueous phase. Mean recovery of 110% (with a standard deviation of 10%) was determined for concentrations of 5 – 100 ng/ml. Chromatography on a 125·4 mm CN-propyl column using a mobile phase composed of 10% acetonitrile in 3.5×10^?4M NaH₂PO₄ and UV detection at 270 nm, yields clean chromatograms without any interferences from endogenous plasma components. Using 1 ml plasma samples the method has a limit of detection (LD) of 3 ng/ml, with %CV (precision) and bias (accuracy) ≥ 10% for concentrations in the range of 0–100 ng/ml. The method is being used in human pharmacokinetic studies of oral dosage forms of pyridostigmine.     

High Performance Liquid Chromatographic Determination of Flurbiprofen in Pharmaceutical Dosage Forms

Abstract

A rapid, specific and reliable high performance liquid chromatographic assay of flurbiprofen in dosage forms has been developed. Reversed-phase chromatography was conducted using a mobile phase of 0.05 M ammonium acetate and acetonitrile, (40% v/v) PH 5.2 and detection at λ 247 nm. The recovery and coefficient of variation from six placebo tablets spiked with 100 mg of flurbiprofen were 100.1% and 0.4% respectively. Replicate regression analyses of three standard plots in the concentration range 0.5 - 9 mcg/ml obtained on three different days gave a correlation coefficient (0.99996) and the coefficient of variation of the slopes 0.159%. The assay was precise within day and between days as indicated by ANOVA test. It is suggested that the proposed HPLC method should be used for routine quality control and dosage form assay of flurbiprofen.     

Quantitation of Terbutaline Sulfate in Pharmaceutical Dosage Forms Using High Performance Liquid Chromatography

Abstract

A stability-indicating reverse phase high-performance liquid chromatography method has been developed to quantify terbutaline sulfate in pharmaceutical dosage forms. The method is accurate and precise with percent relative standard deviations based on 6 readings of 0.6 with an internal standard (salicylic acid) and 0.8 without an internal standard. The results are in excellent agreement with the USP-NF method. A decomposed sample gave 49.4% results with the developed method versus 71.3% with the USP-NF method.     

A HPLC Method for the Determination of Butaperazine in Solutions,Tablets, Plasma and Bile

Abstract

A specific HPLC method for the determination of the antipsychotic drug butaperazine (B) in solutions, tablets, plasma and bile has been developed. The instrument used was a Waters HPLC equipped with a Model 440 Spectrometer and a μ-Bondapak-NH₂ column. The mobile phase, chloroform-methanol (100:3.5) was pumped at a rate of 1.5 ml per minute. Ultraviolet absorbance at a wave length of 280 nm was used for detection. The procedure involved the extraction of the drug from the dosage forms with chloroform and from plasma and bile with hexaneisopropanol (9:1). Hydrocortisone acetate was used as the internal standard. Retention times of 2.4 and 3.9 minutes were obtained for the internal standard and B respectively. Analytical calibration yielded a linear relationship from 0.1–25 μg per ml, with r² value of 0.99. The percentage recovery of B averaged 99% from the dosage forms and 94% from the biological fluids. An improvement in the method for determining B in bile and plasma was later developed. It involved the use of a different mobile phase and detecting the drug fluorometrically.     

Rapid Quantitation of Verapamil in Plasma by High-Performance Liquid Chromatography

Abstract

A simple and sensitive liquid chromatographic assay procedure using a fluorescence detector for the quantitative determination of verapamil in plasma without extraction was developed. After precipitating the protein with acetonitrile, the resulting supernatant liquid was injected onto the column for analysis. Chromatographic separation was achieved on C₁₈ reversed phase column and the eluting solvent was the isocratic mixture of methanol, acetonitrile and pH 3.0 glycine buffer (1:4:5). With this mobile phase the drug and its internal standard were well separated from the interference of the plasma sample. The average recovery of verapamil from 3 replicate samples of different concentration (100–600 ng/mL) were 95.5 ± 5.68%. The minimum amount of verapamil detectable by this method was 40 ng/mL of sample. The elimination half-life (β-phase) of this drug in rabbits was found to be 3.7 hours.     

High Performance Liquid Chromatograph 1C Method for Determination of Mifobate in Rat Feed

Abstract

A high performance liquid Chromatographie (HPLC) method is described for the quantitative determination of Mifobate (SR-202) in rat feed. Mifobate is extracted in acetone and isolated from other extractants on a Waters Sep-pak® C₁₈ disposable pre-column. The extracted drug and internal standard are chromatographed on a μBondapak? C₁₈ reverse phase column with a mobile phase consisting of water and acetonitrile (55:45, v/v). The eluent is monitored at 225 nm.

The method provided a 101.56 ± 5.1% mean recovery of Mifobate from spiked feed samples ranging in the 22.24 to 433.04 mg/kg concentration range. Standard curves bracketing this concentration range had linear coefficients greater than 0.9998. The average relative standard deviation (%) for the entire concentration range was 4.2%. The critical steps and precision of the method were also evaluated.     

Determination of Some Penicillin Derivativies Using High Performance Liquid Chromatography

Abstract

A rapid, precise and selective method is described for determination of penicillin derivatives. Penicillin derivatives are separated from closely related degradation products by high performance liquid chromatography at ambient temperature using 10cm column packed with 5um Nucleosil RP₁₈ and buffered aqueous acetonitrile as mobile phase. The eluate is monitored at 254nm. The procedure is suitable for determination of 8 penicillin derivatives either in raw material or phamaceutical dosage forms.     

Determination of Flurbiprofen in Dosage form and in Biological Fluids by High Performance Liquid Chromatography

Abstract

A high performance liquid chromatograpy method is described for the determination of flurbiprofen in both dosage form and in biological fluids (urine and plasma) using fluorescence detection. The method for dosage forms involves grinding of a 100 mg tablet, suspension in methanol, filtration and adjusting to the appropriate concentration and 10 ul is injected onto the column. In the case of biological fluids a series of standard solutions were prepared in 0.IN sodium hydroxide and a known amount was added to 1 ml of serum or urine which was then acidified, extracted with ethylacetate, evaporated and the residue was then dissolved in a known volume of the mobile phase. Complete separation of the drug was achieved in about 6.5 minutes under the used conditions.     

Sensitive High-Performance Liquid Chromatographic Determination of Mebeverine in Plasma Using Fluorescence Detection

Abstract

A sensitive high-performance liquid chromatographic (HPLC) method for mebeverine (MB) determination in plasma is described. Sample preparation involves extraction of MB and Ibuprofen (internal standard) from 0.5 ml plasma. The analysis is carried out on reversed-phase chromatographic system using U-Bondapack C₁₈ column with a mobile phase consisting of water: acetonitrile:acetic acid (59:40:1) mixture. The effluent was monitored using a fluoremetric detection at excitation and emission wave lengths 270 and 362 nm, respectively. The method gave accurate, precise and reproducible results with high sensitivity. The within-day coefficients of variation ranged from 2.5 to 6.1% and between-days from 7.5 to 13.5% at four different concentrations. Injection-volumes containing as small amount of MB as 0.5 ng in plasma was detected. This method was applied to a bioavailability study with a single 10 mg/kg oral dose in two rabbits.     

High Performance Liquid Chromatographic Determination of Pirenzepine Dihydrochloride in Its Pharmaceutical Formulation

Abstract

A high-performance liquid chromatographic procedure for the determination of pirenzepine dihydrochloride as a bulk material and in its tablet dosage form (Gastrozepin^R) is presented. Normal phase liquid chromatography has been performed on a Micro-pack Si-10 column using ammonium hydroxide (28–30% NH₃) in methanol (0.75: 99.25% v/v) as mobile phase at a flow rate of 2 ml/min. Clobazam has been used as internal standard with retention times of 1.9 and 2.8 minutes for clobazam and pirenzepine dihydrochloride, respectively at 254 nm. Analytical calibration yields a linear relationship between 5 and 25 μg/ml, with correlation coefficient of 0.999. Tablets each labelled to contain 25 mg pirenzepine dihydrochloride give mean percentage found of 99.98 ± 0.4. A plot of logarithm of concentration against time for a solution in 6 N hydrochloric acid gives a straight line with a slope of - 0.197 day^?1. The proposed method is, therefore, a stability indicating method.     

Determination of Atenolol and Its Related Compounds by Ion Pair High Performance Liquid Chromatography

Abstract

A rapid, simple, accurate, and stability-indicating ion pair high performance liquid chromatography (IP HPLC) procedure is presented for the determination of atenolol in pharmaceutical tablets. The related compounds of atenolol were separated, making the determination specific for atenolol. An aliquot of the sample is dissolved in methanol containing N-butyryl-4-aminophenol as an internal standard and chromatographed on a supelcosil LC-8-DB (5μ) (25Omm × 4.6mm i.d.) column using 1.0 mM ammonium acetate and 2.0 mM octanesulfonic acid sodium salt in acetonitrile: water (25:75) solution adjusted to pH 3.5 with glacial acetic acid as the mobile phase. The detection was carried at 225 nm. The relative standard deviations are less than 1.0% for the two commercial products analyzed. The method was tested for linearity, recovery, and specificity.     

Quick and Simple Determination of Dihydroergotamine by High-Performance Liquid Chromatography

Abstract

A simple and rapid liquid chromatographic assay method using a fluorescence detector for quantitation of dihydroergotamine in plasma without extraction was developed. After precipitating the protein with acetonitrile, the supernatant liquid was directly injected for analysis. Chromatographic separation was achieved on C₁₈ reversed phase column and the mobile phase was the isocratic mixture of methanol, acetonitrile and glycine buffer (0.5:3.5:6.0). With this eluting solvent the drug and its internal standard were well separated from the interference of the plasma sample. The average recovery of dihydroergotamine from 6 replicate samples of different concentrations (5-30 ng/ml) were 92.2 ± 3.37%. The minimum amount of dihydroergotamine detectable by this method was 2 ng/ml of sample.     

Determination of Tetracycline and Related Compounds by High-Performance Liquid Chromatography

Abstract

An isocratic high-performance liquid chromatography method for the determination of tetracycline and its related compounds is described. The method uses a reverse phase (C₁₈) column, a modified acetonitrile/water mobile phase, and banzoic acid as the internal standard. Elution of all compounds of interest is complete within seven minutes. Results are presented for thirteen commercial capsule formulations and are compared with results by microbiological assay and thin-layer chromatographic methods.     

High Performance Liquid Chromatographic Determination of Amiodarone in Plasma and Tissues

Abstract

A simple and rapid high-performance liquid chromatographic (HPLC) method for the determination of amiodarone (AD) in plasma and tissues was developed. The method involved deproteinization of plasma or homogenized tissue with acetonitrile containing an internal standard (N-Cetylpyridinium chloride) followed by reversed phase chromatography using μ bondapack C₁₈ column (10μm) with a mobile phase consisting of acetonitrile - methanol - sodium dihydrogen phosphate buffer (70:10:20%, v/v), the pH adjusted to 4.0 and pumped at flow rate of 1.0 ml/min. The column effluent was monitored at 242 nm. A linear relationship was obtained between peak height ratios (drug to internal standard) versus drug levels over the concentration range of 50–750 ng/ml. The detection limit of AD in plasma and tissues by this method was 20 ng/ml.     

High-Performance Liquid Chromatographic Assay for Chlorquine and its Two Major Metabolites,Desethylchloroquine and Bidesethylchloroquine in Biological Fluids

Abstract

A high-performance liquid chromatography (HPLC) method for the determination of chloroquine and its two major metabolites in biological fluids is described. Hydroxychloroquine is used as an internal standard (I.S.). Drug, metabolites and I.S. were extracted as bases with diethyl ether by a single step procedure. After drying and evaporation of the organic phase, the residue was dissolved into the mobile phase and injected into the chromatographic system. Separation was performed using a normal phase column (Inertsil sill with mixture of acetonitrile, methanol and ammonia as mobile phase. The detection was carried out by fluorescence measurement : excitation wavelength was set at 325 nm and emission at 380 nm. The limit of detection was near 3.7 ng ml^?1 for chloroquine and metabolites. No chromatographic interference could be detected by endogenous compounds or other antimalarial drugs. Because of the good accuracy of the method, concentrations were determinated with a relative standard deviation lower than 7% at the 25 ng ml^?l level for all substances.

An excellent precision was obtained over the range of concentrations tested, 25–1000ng ml^?l. This method can be applied to therapeutic, pharmacokinetic and epidemial studies.     

Simultaneous Quantitative Determination of Codeine Phosphate,Chlorpheniramine Maleate Phenylephrine Hydrochloride and Acetaminophen in Pharmaceutical Dosage Forms Using Thin Layer Chromatography Densitometry

Abstract

A simple and specific method for the analysis of codeine phosphate, chlorpheniramine maleate, phenylephrine hydrochloride and acetaminophen in pharmaceutical dosage forms was developed. The procedure consists of direct application of diluted liquid dosage forms and the solutions of solid dosage forms on silica gel plates. The mobile phase for development consisted of n-butanol-methanol-toluene-water and acetic acid. The separated components were measured quantitatively by densitometry. Linearity, reproducibility and percentage recovery of active ingredients from dosage forms were calculated.     

Determination of Apomorphine in Tablets Using High Performance Liquid Chromatography with Electrochemical Detection

Abstract

A rapid and selective method using high performance liquid chromatography with electrochemical detection is described for the determination of apomorphine in tablets. Tablet mixes were dissolved in a standard volume of mobile phase containing the internal standard, N-n-propylnorapomorphine. Separation was achieved on a μ-phenyl column using methanol-acetonitrile-0.05M KH₂PO₄ (5:15:80) as mobile phase. The eluted compounds were detected with a sandwich-type electrochemical detector employing a glassy carbon working electrode and operated at 0.5V. Satisfactory accuracy and precision were obtained during analyses of tablets containing apomorphine.     

Improved and Rapid Liquid Chromatographic Determination of Indomethacin in Serum

Abstract

A rapid, specific and sensitive reversed-phase liquid chromatographic (LC) assay for the quantitative determination of indomethacin in serum without extraction was developed. Chromatographic separation using flunixin meglumine as the internal standard was achieved on octadecylsilane-coated particles with a mobile phase of 0.15 M acetate buffer pH 3.0 (50% v/v), acetonitrile (30% v/v) and methanol (20% v/v). The recovery of indomethacin from serum samples in the concentration range of 0.1-25 μg/ml was 95.5 ± 5.8% and as little as 100 ng/ml of indomethacin in serum samples can be quantitated by this procedure. A serum level versus time profile of dog with intravenously administered indomethacin demonstrated the applicability of the assay.