A Stability Indicating High Performance Liquid Chromatographic Assay of Isradipine in Pharmaceutical Preparations

Abstract

A high performance liquid chromatographic procedure has been developed for the assay of isradipine in bulk form and tablet and capsule pharmaceutical preparations. The separation is achieved within 20 min on an octadecylsilane column at ambient temperature with a mobile phase of 60:40 v/v methanol - water, a flow rate of 1 mL/min, and detection at 325 nm. Degradation studies showed no peak interference between isradipine and degradation products. It was also determined that the excipients in the commercial tablet and capsule preparations did not interfere with the assay. The method was linear in the range 10–60 μg/mL with accuracy and precision in the 0.40 - 1.53% range.     

High Performance Liquid Chromatographic Assay of Hydromorphone Hydrochloride Injection

Abstract

A stability indicating high performance liquid chromatographic (HPLC) method for determining hydromorphone hydrochloride in dosage forms is described. The drug was chromatographed on a C₁₈ reverse phase column, using a mobile phase consisting of sodium lauryl sulfate, acetic acid, acetonitrile and water, and detected at 280 nm. Linearity of detector response to the concentration was confirmed. The procedure showed excellent reproducibility and gave quantitative recoveries of the drug from spiked placebos. Photodegraded samples of the dosage form, were assayed by the HPLC procedure and the current USP spectrophotometric procedure. Comparison of the results showed that the USP procedure is only partially stability indicating.     

High Performance Liquid Chromatographic Determination of Sertraline in Presence of Its Degradation Product

A simple, stability – indicating, reversed phase liquid chromatographic method has been developed for the determination of sertraline in the presence of its oxidative degradation product. Reversed phase chromatography was conducted using a phenyl (250 × 4.6 mm id) stainless steel column at ambient temperature with UV-detection at 226 nm. A mobile phase consisting of potassium dihydrogen phosphate buffer: acetonitrile (50:50, v/v) adjusted to pH 4.5 with phosphoric acid, has been used for the separation of sertraline and its oxidative degradation product at a flow rate of 1 ml/min. The calibration curve was rectilinear over the concentration range of 1–20 μg/ml with a detection limit (LOD) of 0.09 μg/ml, and quantification limit (LOQ) of 0.27 μg/ml. The proposed method was successfully applied for the analysis of sertraline in its tablets, with mean % recoveries of 100.17 ± 0.62 for sertraline in pure form and 100.14 ± 0.68, 100.29 ± .77, and 100.06 ± 0.67 for seserine®, serlift®, and sirto® tablets, respectively. The obtained results were favorably compared with those obtained by a reference method. The drug was exposed to forced alkaline, acidic, hydrolytic, and oxidative degradation according to the ICH Guidelines. Moreover, the method was utilized to investigate the kinetics of the photoinduced oxidative degradation of the drug. The first-order rate constant, half-life time, and activation energy of the degradation reaction were calculated.     

A Rapid High Pressure Liquid Chromatographic Assay of Benoxaprofen in Plasma

Abstract

A rapid high-performance liquid chromatographic assay for the determination of the anti-inflammatory drug benoxaprofen in human plasma, is described. Plasma samples of 1.0 ml, to which benoxaprofen, and warfarin as an internal standard, had been added, were extracted with ether under acidic conditions. The samples were analyzed on a MicroPak CN-10 column using 25% acetonitrile in water (pH 2.5 with phosphoric acid). Detection was made on a variable wavelength UV absorbance detector at 309 nm.

Samples containing 0.5–10 μg benoxaprofen gave a mean extraction recovery from control plasma of 90.6 ± 6.8% (n=18). Stability tests have shown that benoxaprofen in plasma is stable for at least two weeks after freezing.     

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.     

High Pressure Liquid Chromatographic Assay for Salicylic Acid and its Metabolites in Rat Urine

Abstract

An HPLC method for the determination of salicylic acid (SA), gentisic acid (GA), salicyluric acid (SU), and salicyl acyl glucuronide (SAG) in rat urine was developed. The method consisted of extracting SA, GA, and SU from acidified urine into 50:50 mixture of ethyl acetate and butyl chloride. Salicyl acyl glucuronide was extracted from neutral urine after conversion to salicyl hydroxamic acid with hydroxylamine. Salicyl phenolic glucuronide was estimated indirectly as the difference between total salicylate and sum of the four constituents mentioned above. Chromatographic separation was done on a C₁₈ column with U.V. detection at 310 nm using a mobile phase consisting of 5–10% acetonitrile in 3% glacial acetic acid. The extraction recovery of these compounds from spiked urine ranged from 90–108%. The detection limits were 10 μg/ml for GA, SU and SA, and 2.5 μg/ml for SHA. The method was applied to the study of salicylic acid metabolism in the rat.     

Gas Liquid Chromatographic Determination of Promethazine Hydrochloride in Polyethylene Glycol Suppositories Using the Hall's Electrolytic Conductivity Detector

Abstract

A gas liquid chromatographic method using the Hall's electrolytic conductivity detector is described for the determination of promethazine hydrochloride in polyethylene glycol suppositories. This method is capable of distinguishing the intact drug from its thermal degradation products. A linear relationship between peak height ratio (promethazine/promazine) and promethazine hydrochloride concentration is found up to a concentration of 600 μg/ml. In the presence and absence of polyethylene glycol vehicle the recovery of promethazine hydrochloride is found to be 100.2 and 99.7 percent respectively. The percent coefficient of variation is 0.62 and 0.94 in the absence and presence of polyethylene glycol vehicle.     

Validated Stability-Indicating Chromatographic Methods for the Determination of Veralipride in Presence of Its Degradation Products

Two sensitive and selective chromatographic methods were developed and validated for determination of veralipride in presence of its degradation products. Forced degradation studies were performed, using HCl, NaOH and 3% H₂O₂. The first method is based on thin-layer chromatographic separation of the intact drug spot from its degradation, followed by densitometric measurements. The second method is based on isocratic liquid chromatographic separation of the studied drug from its degradation on a reversed phase C₁₈ column. The proposed LC method was utilized to investigate the kinetics of alkaline degradation process of the selected drug at different temperatures.     

High Pressure Liquid Chromatographic Assay of Cefamandole in Serum Following Intravenous and Intraperitoneal Administration

Abstract

Following cesarean section 102 women were treated with cefamandole by either perioperative intravenous administration or intraperitoneal irrigation. High-pressure liquid chromatographic (HPLC) methods for the quantitation of the low serum levels of cefamandole following intraperitoneal lavage were developed. The antibiotic was assayed in the serum using a standard microbiological assay and two types of reverse phase column technology for HPLC. The two HPLC systems were almost identical in performance. Both HPLC methods were at least 10-fold more sensitive than the microbiological assay. The correlation between the three methods was 0.9739. The half-life of cefamandole was 37 min, which was not significantly different from the half-life of the drug in serum of non-pregnant women. The peak serum levels were 47.6 ± 36.8 μg/ml and 1.98 ± 1.5 μg/ml for the intravenous and intraperitoneal methods of administration, respectively.     

High Pressure Liquid Chromatographic Determination of Isoniazid and Acetylisoniazid in Human Plasma

Abstract

A quantitative high pressure liquid chromatographic (HPLC) assay has been developed for the determination of isoniazid (INH) and acetylisoniazid (ACINH) in human plasma. Plasma samples were taken from a patient after oral administration of INH (with proven tuberculosis infection). A C₁₈ reversed phase radial compression column was used to separate INH and ACINH from other plasma components. The analysis takes 10 minutes per sample and the lower limit of detection for each compound is 0.10 ug/ml plasma.     

High Pressure Liquid Chromatographic Determination of Mecillinam in Human Plasma and Urine

Abstract

A simple, specific, rapid and sensitive method for the analysis of mecillinam in plasma and urine using high pressure liquid chromatography is described. The assay is performed by direct injection of a plasma protein free supernatant or a dilution of urine. A μBondapak phenyl column with an eluting solvent of 16% CH₃CN-0.2% H₃PO₄ was used, with UV detection of the effluent at 220 nm. Desacetyl-cephalothin was used as the internal standard and quantitation was based on peak height ratio of mecillinam to that of the internal standard. The lowest concentration detectable without extraction was 0.25 μg/ml for plasma and 8.9 μg/ml for urine. No interference from plasma and urine was noted.     

Simultaneous High Performance Liquid Chromatographic Determination of Amitriptyline Hydrochloride and Perphenazine in Tablet Formulations

Abstract

A rapid, precise, and accurate high performance liquid chromatographic procedure is presented for the simultaneous determination of amitriptyline hydrochloride and perphenazine in two component tablet formulations. The related compounds of amitriptyline hydrochloride were separated, making the determination specific for amitriptyline hydrochloride and perphenazine. The method was used for the assay and content uniformity for three commercial products. The mobile phase was 0.02 M ammonium acetate in aceto-nitrile: methanol: water (45:15:40) solution and the pH was adjusted to 5.0 by acetic acid. The column was a supelcosil (5 μm) LC-8-DB (250 mm × 4.6 mm i. d). The method was tested for linearity, recovery, and specificity.     

Simple Thin-Layer Chromatographic Method for Analysis of Ranitidine in its Pharmaceutical Formulations: Application to the Analysis of Photolytic Degradation Products

JPC – Journal of Planar Chromatography – Modern TLC - Thin-layer chromatography and high-performance thin-layer chromatography have been used for analysis of ranitidine hydrochloride...     

盐酸异丙嗪的微波增敏方波伏安法测定

以玻碳电极作工作电极,在微波作用下用循环伏安法和方波伏安法研究了盐酸异丙嗪的电化学特性,结果表明微波可以增大峰电流,并应用于盐酸异丙嗪的检测,建立了一种新的检测盐酸异丙嗪的电化学方法.在最佳实验条件下,无微波作用时用方波伏安法检测盐酸异丙嗪,其响应电流与盐酸异丙嗪的浓度在4.0×10-6 ～1.0×10-4 mol/L范围呈线性关系(r=0.998 2,n=7),线性回归方程为I(A)=0.040 3c(mol/L)+5.0×10-7,检出限为4.0×10-7 mol/L;在微波作用下用方波伏安法检测盐酸异丙嗪,其响应电流与盐酸异丙嗪的浓度在4.0×10-6 ～1.0×10-4 mol/L范围有很好的线性关系(r=0.999 1,n=7),线性回归方程为I(A)=0.045 7c(mol/L)+6.0×10-7,检出限为2.0×10-7 mol/L.在4.0×10-6 ～1.0×10-4 mol/L范围微波增敏的峰电流与无微波条件下峰电流的比值平均值为1.22.该方法用于盐酸异丙嗪片的测定,结果满意.     

High Pressure Liquid Chromatographic Determination of Parabens in Pharmaceutical Preparations Containing Hydroxyquinolines

Abstract

A high pressure liquid chromatographic (HPLC) procedure for the analysis of methyl paraben (MP) and propyl paraben (PP) in pharmaceutical preparations containing a halogenated hydroxyquinoline (HHQ) is described. The method involves a separation of the phenolic constituents, MP, PP and HHQ with a Bio-Rad AG 1–X8 anion exchange resin, elution of the phenols with methanol after acidification and a reverse phase HPLC separation of the parabens using methanol-pH 6.5 buffer (60/40) mobile phase, a 30 cm × 3.9 mm (i.d.) column packed with Waters μBondapak C₁₈ packing and a guard column packed with Waters Bondapak C₁₈/Corasil packing. Recovery, precision, specificity and interference data along with the application of the proposed method for some commercial formulations both with and without a hydroxyquinoline are described.     

High Performance Liquid Chromatographic Assay of Phenacemide in Tablets

Abstract

A rapid, specific and reliable high-performance liquid chromatographic assay of phenacemide in tablets has been developed. Reversed-phase chromatography was conducted using a mobile phase of acetonitrile and acetate buffer, pH 4.2 (50% V/V) and detection at 254 nm. The recovery and coefficient of variation from six placebo samples of 100 mg were 100.2% and 0.57%, respectively. The percent recovery of 10 replicate commercial tablets was 101.1% of the label amount and its coefficient of variation was 0.95%. Regression analyses of three standard plots in the concentration range of 15-150 μ g/ml obtained on three different days gave a correlation coefficient > 0.999 and the coefficient of variation for their slopes <2%. The HPLC method is rapid as it takes - 1 hour to analyze six commercial tablets compared with 6 hours consumed by the USP method. The assay was precise within day and between days as indicated by ANOVA test.     

Application of High Pressure Liquid Chromatography to the Determination of Diastereoisomer in Methylphenidate Hydrochloride

Abstract

A procedure for the quantitative analysis of the diastereoisomer in methylphenidate hydrochloride is described. The method is based on a high pressure liquid chromatographic separation of the isomers on a Sil-X column with a mobile phase containing ethanol, cyclohexane, chloroform and ammonium hydroxide. The method is simple, precise and accurate and has a limit of detection of 0.1% of the diastereoisomer in the drug substance.     

Stability-Indicating Method for the Determination of Hydrochlorothiazide,Benzydamine Hydrochloride and Clonazepam in the Presence of Their Degradation Products

Abstract

Spectrophotometric, colorimetric and densitometric methods for the determination of hydrochlorothiazide, benzydamine hydrochloride and clonazepam in the presence of their degradation products are described. Hydrochlorothiazide was determined in the presence of its degradation products methoxyhydrothiazide, hydroxyhydrothiazide and 5-chloro-2,4-disulfonamidoaniline applying the first and second derivative spectrophotometer at 278.8 nm and 254.4 nm, respectively, while benzydamine hydrochloride was determined in the presence of its toxic photodegradation products 5-hydroxybenzydamine and 2-B-dimethylaminopropyl-l-benzylindalolin-3-one colorimetrically using the acid dye bromophenol red and measuring the absorbance of the chloroform solution of the ion-pair formed at 425nm. Clonazepam was determined densitometrically in the presence of its degradation products carbostyril and 2-amino-2-chloro-5-nitrobenzophenone. The suggested methods determine hydrochlorothiazide, benzydamine hydrochloride and clonazepam in the presence of degradation products with mean accuracies of 99.57±0.51%, 100.04±0.41%, 100.03±0.21% and 99.84±0.34%, respectively. The proposed methods are suitable for stability testing in bulk powder and in pharmaceutical preparations.     

Spectrophotometric Determination Of Rifampin in the Presence of its Degradation Products in Pharmaceutical Preparations

Abstract

The determination of rifampin in the presence of its main degradation products, 3-formyl rifampin and rifampin quinone using two spectrophotometric methods is described. Both Glenn's method and first derivative spectrophotometry were successfully adopted. No preliminary separation steps were required in either cases. Both methods gave accurate and reproducible results for the determination of the drug in dosage forms. The percentage recoveries ranged from 99.33% ±0.63 to 100.2% ± 0.44. The proposed methods are more simple, rapid than other existing methods and can be readily adopted in control laboratory.     

A New High Performance Liquid Chromatographic Assay for Fluspirilene in Dosage Forms

Abstract

A new method for the assay of fluspirilene (R 6218) in dosage forms using HPLC has been developed. The instrument used had a low volume positive displacement pump, a universal injector, a single wavelength (254 nm) detector, and a data module. The column was stainless steel 30 cm × 4 mm i.d. packed with microparticulate silica. The mobile phase consisted of equal volumes of chloroform and methanol at a flow rate of 1 ml per min. A linear relationship (r = 0.999) was obtained between peak area and concentration of fluspirilene in the range 10–200 μg per ml; no internal standard was used. Fluspirilene was extracted from injectable aqueous suspensions by membrane filtration, drying and dissolution in chloroform-methanol (1:1). Results of assaying fluspirilene in two commercial injectable suspensions by this method were 99.73 and 99.78% of labelled amount.