High Performance Liquid Chromatographic Assay of Verapamil Hydrochloride in Dosage Formsk

Abstract

A stability indicating high-performance liquid chromatographic (HPLC) method for determining verapamil hydrochloride in dosage forms is described. The assay affords baseline separation of the drug from its synthesis impurities and from photolytic degradation products, as well as from formulation excipients. The drug was extracted in 0.05 N hydrochloric acid, chromatographed on a C₁₈ reverse-phase column, eluted with methanol-water-acetic acid-triethylamine (55:44:1:0.1) and the effluent was detected at 280 nm. Linearity studies were carried out using peak height or peak area measurements and the detector response to the concentration of verapamil hydrochloride was confirmed. Excellent interlaboratory precision and recovery data were obtained by the spiked placebo method. This procedure was rapid and selective for the assay of the cardiotonic drug. Application of the method for the assay of verapamil hydrochloride in representative dosage forms is described.     

The Determination of Methenamine and its Salts in Tablet Dosage Forms Using Ion-Pair Extraction

Abstract

This paper reports a simple, accurate, reproducible, stability-indicating procedure which may be used to quantitatively determine methenamine base, methenamine mandelate or methenamine hippurate in tablet dosage forms. The procedure initially involves the separation of methenamine from the dosage form and from formaldehyde, the decomposition product, by a cartridge ion-pair extraction process. The methenamine may then be assayed by a number of methods. In this paper the methenamine was hydrolyzed to formaldehyde and the formaldehyde determined by the Nash procedure. The method compares favorably with the USP XXI procedure for methenamine tablets. Advantages of the procedure include the ability to use a single method for the base and salt forms of the drug and the potential application to stability and quality control studies of methenamine dosage forms.     

Simultaneous Determination of Hydrochlorothiazide and Propranolol Hydrochloride in Tablets by High-Performance Liquid Chromatography

Abstract

A simple and stability indicating HPLC procedure is described for the simultaneous determination of hydrochlorothiazide and propranolol hydrochloride in tablet formulations. Potential degradation products of both drugs and synthesis impurities of hydrochlorothiazide were separated, making the determination stability indicating for both drugs and selective for hydrochlorothiazide. All compounds were chromatographed on a cyanopropylsilane column, eluted with a 15:85 mixture of acetonitrile: 0.05 M ammonium phosphate (pH 3.0) and detected at 290 m. Excellent interlaboratory precision and recovery data were obtained. Linearity studies were carried out using peak area measurements. Detector response to the concentration of each drug was confirmed. The method was applied to dosage forms containing 25 mg of hydrochlorothiazide and 40 or 80 mg of propranolol hydrochloride.     

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.     

Monitoring of the degradation kinetics of diatrizoate sodium to its cytotoxic degradant using a stability‐indicating high‐performance liquid chromatographic method

The X‐ray diagnostic agent sodium diatrizoate (DTA) was studied for chemical degradation. The 3,5‐diamino derivative was found to be the alkaline and acidic degradation product. The 3,5‐diamino degradate is also the synthetic precursor of DTA and it is proved to have cytotoxic and mutagenic effects. A sensitive, selective and precise high‐performance liquid chromatographic stability‐indicating method for the determination of DTA in the presence of its acidic degradation product and in pharmaceutical formulation was developed and validated. Owing to the high toxicity of the degradation product, the kinetics of the acidic degradation process was monitored by the developed RP‐HPLC method. The reaction was found to follow pseudo‐first order kinetics. The kinetic parameters such as rate constant (K ) and half‐life (t _½) were calculated under different temperatures and acid concentrations; activation energy was estimated from the Arrhenius plot. The developed RP‐HPLC method depends on isocratic elution of a mobile phase composed of methanol–water (25:75 v /v; pH adjusted with phosphoric acid), and UV detection at 238 nm. The method showed good linearity over a concentration range of 2–100 μg/mL with mean percentage recovery of 100.04 ± 1.07. The selectivity of the proposed method was tested using laboratory‐prepared mixtures. The proposed method has been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives and the results were statistically compared with the official USP method. Validation of the proposed method was performed according to International Conference on Harmonization guidelines.     

A Stability-Indicating Simultaneous Analysis of Acetaminophen and Hydrocodone Bitartrate in Tablets Formulation by HPLC

Abstract

A rapid, simple, stability indicating, reversed phase high-performance liquid chromotographic (HPLC) method is presented here for direct and simultaneous quantitation of Acetaminophen and Hydrocodone Bitartrate in tablets dosage form at a ratio of 100:1. This procedure not only separated the two active components but also separated known impurity and degradation product of acetaminophen, p-aminophenol and p-chloroacetanilide. The method described here also separates other opiates, codeine sulfate and hydromorphone. In this procedure a radial pak cartridge packed with chemically bonded octadecylsilane (C18, 4 micron) as a stationary phase and (16:84) acetonitrile with phosphate buffer (pH 3.3) as the mobile phase were utilized. Detection was made with a uv-spectrophotometer at 215 nm. Quantitation was performed by peak height and external standard method. The average recovery at 100% label claim and the relative standard deviation of the two respective components, acetaminophen and hydrocodone were: 99.03%, 1.29% and 98.78%, 0.3%.     

Development and validation of HPLC method for simultaneous estimation of piperine and guggulsterones in compound Unani formulation (tablets) and a nanoreservoir system

An attempt has been made to develop and validate a simultaneous HPLC method for novel approach of drug release via oil‐in‐water (o/w) nanoemulsion formulation and Habb‐e‐Khardal Unani tablet containing piperine and guggul sterones E and Z as main ingredients. Nanoemulsion was prepared by titration method using sefsol‐218 as an oily phase, cremophor‐EL as a surfactant, transcutol as a co‐surfactant and distilled water as an aqueous phase. The formulation was optimized on the basis of thermodynamic stability and dispersibilty test. The nanoformulation was evaluated for particle size, surface morphology, electrical conductivity and viscosity determination. The in vitro dissolution was carried out by dialysis bag method. Drugs were quantified using an HPLC method developed in‐house with a C₁₈ column as stationary phase and acetonitrile and water as mobile phase at λ_max of 240 nm. The optimized formulation showed higher drug release, lower droplet size and less viscosity as compared with the conventional Habb‐e‐Khardal Unani tablet. The present study illustrated the potential of nanoemulsion dosage form in improving biopharmaceutic performance of piperine and guggul sterone. The HPLC method was also found to be quite sufficient for the routine quality control of formulations containing piperine and guggul sterone E and Z as ingredients and also for in vitro drug release studies. Copyright © 2011 John Wiley & Sons, Ltd.     

The Identification of Drugs of Abuse in Urine Using Reverse Phase High Pressure Liquid Chromatography

Abstract

A rapid, isocratic HPLC procedure for the identification of drugs of abuse in urine is described. The procedure utilizes a reverse phase μC₁₈ column, a methanol/water mobile phase, buffered to pH 7.5, and a UV detector operating at 254 nm. Using indole as an external standard, 13 common drugs of abuse can be differentiated in less than 15 minutes. Nine different drugs of abuse were identified in actual drug screen urine samples, confirming TLC results. Reproducibility and quantitative capabilities of this method were also demonstrated. Due to apparent interferences from drug metabolites this method must at present be used in conjunction with another established method such as TLC or GC for positive drug identification.     

Stability‐indicating chromatographic methods for determination of flecainide acetate in the presence of its degradation products; isolation and identification of two of its impurities

In this work, two stability‐indicating chromatographic methods have been developed and validated for determination of flecainide acetate (an antiarrhythmic drug) in the presence of its degradation products (flecainide impurities; B and D). Flecainide acetate was subjected to a stress stability study including acid, alkali, oxidative, photolytic and thermal degradation. The suggested chromatographic methods included the use of thin layer chromatography (TLC‐densitometry) and high‐performance liquid chromatography (HPLC). The TLC method employed aluminum TLC plates precoated with silica gel G.F₂₅₄ as the stationary phase and methanol–ethyl acetate–33% ammonia (3:7:0.3, by volume) as the mobile phase. The chromatograms were scanned at 290 nm and visualized in daylight by the aid of iodine vapor. The developed HPLC method used a RP‐C₁₈ column with isocratic elution. Separation was achieved using a mobile phase composed of phosphate buffer pH 3.3–acetonitrile–triethylamine (53:47:0.03, by volume) at a flow rate of 1.0 mL/min and UV detection at 292 nm. Factors affecting the efficiency of HPLC method have been studied carefully to reach the optimum conditions for separation. The developed methods were validated according to the International Conference on Harmonization guidelines and were applied for bulk powder and dosage form. Copyright © 2016 John Wiley & Sons, Ltd.     

Determination of Diphenoxylate Hydrochloride and Atropine Sulphate in Tablet Formulations by Reversed - Phase HPLC

Abstract

The official compendial USP method for the determination of Diphenoxylate HCI (DPHCI) and Atropine Sulphate (ATSO₄) involves extensive sample manipulation followed by non-aqueous titration for (DPHCI) and gas chromatography for (ATSO₄). Furthermore, the assay for individual tablets (content uniformity) is not specific. The proposed HPLC methodology offers substantial improvement in sensitivity, specificity and speed. The method provides simultaneous separation with minimum sample manipulation. The total elution time is less than ten minutes. The accuracy of the method was validated by comparing the results with those obtained by applying the USP XX method on commercial tablets. The specificity of the method was confirmed by the results of content uniformity of DPHCI which were more accurate than those obtained by the USP method.     

Determination of Naloxone Hydrochloride in Dosage form by High-Performance Liquid Chromatography

Abstract

A new, sensitive and rapid method for the determination of naloxone hydrochloride as drug in dosage entity and form using HPLC has been developed. Authentic naloxone hydrochloride was used to establish a calibration curve. A linear relationship was obtained for concentrations ranging from 10 μg/ml to 50 μg/ml. The column used was C₁₈, Micropak MCH-10 (monomeric) and the mobile phase was acetonitrile : 0.01 M KH₂PO₄ (70 : 30) at a flow rate of 2 ml/min. Retention time for naloxone hydrochloride was 3.3 minutes. The proposed method has been proved accurate and precise compared to other pharmacopoeia methods of assay for naloxone hydrochloride.     

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.     

The Determination of Sodium Monofluoroacetate (Compound 1080) in Formulation and Technical Samples by High Pressure Liquid Chromatography

Abstract

A high pressure liquid chromatographic (HPLC) procedure was developed for the determination of sodium monofluoroacetate (Compound 1080). The procedure utilized an amine (NH₂) bonded column for the reverse phase determination of sodium monofluoroacetate in formulation and technical samples.     

High Performance Liquid Chromatographic Method for Quantitation of a New Antidiabetic Agent in Plasma

Abstract

An HPLC procedure for the detection and quantitation of a new antidiabetic agent, N-(trans-4-isopropylcyclohexylcarbonyl)-D-phenylalanine (A4166), in dog plasma was developed. The drug and internal standard were extracted from plasma using a reversed phase C₁₈ extraction column (Sep-pak). Separation was accomplished on a ERC-ODS-1161 reversed-phase column with a mobile phase of acetonitrile/0.1M phosphate buffer, pH 6.6 (30/70). Quantitation was achieved by monitoring the ultraviolet absorbance at 210 nm. A linear relationship between concentration and peak height ratio (A4166/internal standard) was obtained. The method has been successfully used for analysis of plasma samples from beagle dogs following oral administration of A4166.     

Carbamazepine: Stability Indicating HPLC Assay Method

Abstract

The present research work discusses the development of a stability indicating HPLC assay method for Carbamazepine as a bulk drug and from formulations. The mobile phase selected was acetonitrile, methanol, and water (10:60:40 v/v/v, respectively. The calibration curve of the drug was linear in the range of 1.0–20 µg/ml. The system precision and the method precision studies were carried out with an RSD of 0.969 and 1.40, respectively. The limit of detection and quantitation were 85.5 and 285 ng, respectively. The mean percent recovery was found to be 100.22%. The developed assay method was found to be accurate, precise and specific.     

Stability Indicating Hplc Method for the Determination of Sparfloxacin (Spar)

ABSTRACT

A rapid, sensitive and stability indicating method for the determination of sparfloxacin (SPAR) by RP - HPLC has been developed on a Merck RP - Select B (5 μm; 12.5 cm x 4.0 mm) column using a mobile phase of water: acetonitrile: triethylamine (80 : 20 : 0.2 v/v) pH of which was adjusted to 2.6 with orthrophosphoric acid. The flow rate was 1 ml / min. and the detection was carried out at 304 nm using Waters 486 variable wavelength detector. The retention time for SPAR was 7.2 min. Linearity range was from 8 - 1000 ppm. The method showed good precision and accuracy when applied to two brands of tablets containing SPAR. In alkaline media SPAR is stable where as it undergoes degradation in acidic and oxidising conditions generating different degradation products the nature of which is required to be established. The proposed method nicely separates the degraded products from SPAR and hence can be used as stability indicating method for the assay of SPAR.     

A Study On Air Pollution by Asphalt Fumes

Abstract

A TLC/HPLC procedure for the determination of polycyclic aromatic hydrocarbons (PAH), occuring in asphalt fumes (adsorbed on particular matter), is described. The method is based on extraction of asphalt fume particles, collected on glass fibre filters, using CCK₄. Following a clean up step by the aid of a TLC procedure on Al₂ O₃ thinlayer plates, using a mixture of cyclohexane/acetone/ether as the mobile phase. Under UV-light, occuring PAH are indicated as fluorescent spots. A separation of the collected PAH into individual components and their identification is performed by the aid of a HPLC procedure. Futher-more, an approach was made to verify the separated PAH by their fluorescence spectra and their mass spectra.     

Aflatoxin Analysis by Reverse Phase HPLC Using Post-Column Derivatization for Enhancement of Fluorescence

Abstract

The application of a technique for the determination of aflatoxins by reverse phase HPLC and fluorescence detection incorporating post-column derivatization with iodine, is described. The procedure proved to be extremely sensitive and reproducible. Chromatograms of extracts from maize, peanut butter, sorghum malt and duckling mash are presented illustrating the value of the procedure for confirming the presence of aflatoxins B₁ and G₁.     

Use of Alkaline Degradation for the Analysis of Dihydrotriazines via High Pressure Liquid Chromatography

Abstract

An HPLC method is described for the determination of 4,6-diamino-1,2-dihydro-2,2-dimethyl-1-(3′,4′-dichlorobenzyloxy)-1,3,5-triazine hydrochloride (WR 38839). The procedure required the isomerization of the drug sample by alkaline treatment with sodium hydroxide, as the parent compound was retained by the column. The reaction product of the drug was analyzed by HPLC using a strong cation exchange resin as the stationary phase and glycine buffer, pH 10.4 as the mobile phase. The product was isolated and identified by TLC, UV, IR, mass spectroscopy and elemental analysis. The postulated mechanism indicates that this would be a general analytical method for dihydrotriazine compounds. This technique, developed for the assay of the dihydrotriazine in an aqueous system, was successfully applied to rat urine samples spiked with the drug.     

Quantitation Of The Local Anesthetic Dibucaine With Gas Chromatography / Mass Spectrometry

Abstract

A chemical ionization and an electron impact GC/MS assaying approach is presented for determining dibucaine concentrations in biological fluids. Both use deuterium-labeled drug as the internal standard and rely on the same sample extraction and sample preparation procedure. Under chemical ionization conditions (CH₄), the assaying limits are in the range of 1–80 ng/ml of serum. Under electron impact conditions, the analytical range is 20–800 ng/ml. The chemical ionization procedure has been found suitable for monitoring drug levels in man. One volunteer, who received a single 5-mg oral dose, showed peak serum drug concentrations of 23 ng/ml attained 2 hr after drug administration. The biologic half-life (ß phase) was 11 hr.