HPLC determination of phenylpropanolamine in pharmaceutical OTC preparations

A convenient HPLC method to determine phenylpropanolamine (PPA) in addition to phenylephrine (PE) and chlorpheniramine (CPA) in commercially available over-the-counter (OTC) preparations has been developed. Sample solutions were prepared by dilution with water or methanol followed by filtration and direct injection into the HPLC system. The mobile phase was a mixture of methanol-acetonitrile-acetic acid (0.1 M)-triethylamine (20:20:60:0.6, v/v/v/v) containing sodium heptanesulfonate (0.5 mM) as an ion pair. The separation was achieved on a reversed-phase ODS column with detection wavelength set at 254 nm. The compounds showed good linearity in the range 2.5-1000 micro M with detection limits ranged from 0.13 to 0.48 micro M. PE, caffeine and CPA were well separated when present together with PPA. The method was applied to the determination of PPA in pharmaceutical preparations including hard and soft capsules.     

Determination of volatile residual solvents in pharmaceutical products by headspace liquid-phase microextraction gas chromatography-flame ionization detector

This paper demonstrates headspace liquid-phase microextraction (HS-LPME) as used for the determination of volatile residual solvents in pharmaceutical products. This method is based on headspace liquid-phase microextraction capillary column gas chromatography. Under optimum conditions, the linerary of the method ranged from 1 to 1,000 mg l⁻¹. The limits of detection are 0.2–2.0 mg l⁻¹ and relative standard deviations (RSD) for most of the volatile solvents were below 10%. This novel method is applied to the analysis of volatile residual solvents in pharmaceutical products with satisfactory results.     

Stability indicating methods for the determination of some anti-fungal agents using densitometric and RP-HPLC methods

Two chromatographic methods were developed for the determination of some anti-fungal drugs in the presence of either their degradation products or cortisone derivatives. The densitometric method determined mixtures of each of ketoconazole (KT), clotrimazole (CL), miconazole nitrate (MN) and econazole nitrate (EN) with the degradation products of each one. Mixtures of MN with hydrocortisone (HC) and of EN with triamcinolone acetonide (TA) were also successfully separated and determined by this technique. For KT and CL, a mixture of methanol:water:triethylamine (70:28:2 v/v) was used as a developing system and the spots were scanned at 243 nm and 220 nm for KT and CL, respectively. For MN and EN, a mixture of hexane:isopropyl alcohol:triethylamine (80:17:3 v/v) was used as a developing system and the spots were scanned at 225 nm for both drugs. The HPLC method determined mixtures of CL or EN with their degradation products which were separated and quantified on a Zorbax C8 column. Elution was carried out using methanol:phosphate buffer pH 2.5 (65:35 v/v) as a mobile phase at a flow rate of 1.5 ml/min and UV detection at 220 nm for CL. For EN, a mixture of methanol:water containing 0.06 ml triethylamine pH 10 (75:25 v/v) was used as a mobile phase at a flow rate of 1.5 ml/min and UV detection at 225 nm. The methods were also used to separate mixtures of CL with betamethasone dipropionate (BD) and EN with TA in a laboratory prepared mixture and in pharmaceutical preparations. The methods were sensitive, precise and applicable for determination of the drugs in pharmaceutical dosage forms.     

Development and validation of a stability-indicating LC method for the assay of adapalene in bulk drug and pharmaceutical formulations

A simple and sensitive reverse phase HPLC method for the determination of adapalene (ADP) in bulk drug samples and pharmaceutical formulations has been developed and validated. The separation of ADP was achieved on an Inertsil ODS-3V (5 ??m, 15 cm ± 4.6 mm i.d.) column using UV detector at 230 nm. The mobile phase consisted of ammonium acetate (25 mM, pH 3.0), methanol and tetrahydrofuran (18: 42: 40 v/v). The linear range of detection was 2?C200 ??g/mL (R = 0.9991). Intra- and inter-day assay relative standard deviation values were less than 0.5%. The method has been successfully applied to the determination of ADP in pharmaceutical preparations. The excipients commonly present in formulations did not interfere with the assay of ADP. Analytical parameters were calculated and complete statistical evaluation was performed.     

Analysis of metformin dosage formulations by capillary electrophoresis at nano scale detection

An inexpensive, rapid and reproducible capillary electrophoretic method has been developed and validated for the determination of metformin in pharmaceutical preparations. The method was developed utilizing a fused silica capillary (60 cm x 50 microm I.D.), phosphate buffer (50 mM, 3.0 pH)-acetonitrile (95:5, v/v) as background electrolyte (BGE), 20 kV applied voltage with UV detection at 254 nm and at a working temperature of 23 +/- 1 degrees C. Linearity was observed in the concentration range from 100 ng/L to 5 microg/L, with a correlation coefficient (R2) of 0.9998. The limits of detection and quantification achieved were 60 and 100 ng/mL, respectively. The recovery of metformin from pharmaceutical preparations was 99.1%. These validation parameters demonstrate the precision of the method and its suitability for the determination of metformin in pharmaceutical tablet formulations.     

Validated stability indicating liquid chromatographic determination of ebastine in pharmaceuticals after pre column derivatization: Application to tablets and content uniformity testing

An accurate, simple, sensitive and selective reversed phase liquid chromatographic method has been developed for the determination of ebastine in its pharmaceutical preparations. The proposed method depends on the complexation ability of the studied drug with Zn²⁺ ions. Reversed phase chromatography was conducted using an ODS C18 (150 × 4.6 mm id) stainless steel column at ambient temperature with UV-detection at 260 nm. A mobile phase containing 0.025%w/v Zn²⁺ in a mixture of (acetonitril/methanol; 1/4) and Britton Robinson buffer (65:35, v/v) adjusted to pH 4.2, has been used for the determination of ebastine at a flow rate of 1 ml/min. The calibration curve was rectilinear over the concentration range of 0.3 - 6.0 μg/ml with a detection limit (LOD) of 0.13 μg/ml, and quantification limit (LOQ) of 0.26 μg/ml. The proposed method was successfully applied for the analysis of ebastine in its dosage forms, the obtained results were favorably compared with those obtained by a comparison method. Furthermore, content uniformity testing of the studied pharmaceutical formulations was also conducted. The composition of the complex as well as its stability constant was also investigated. Moreover, the proposed method was found to be a stability indicating one and was utilized to investigate the kinetics of alkaline and ultraviolet induced degradation of the drug. The first-order rate constant and half life of the degradation products were calculated.     

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.     

Spectrophotometric determination of clotrimazole in bulk drug and dosage forms

A simple, specific, rapid and sensitive spectrophotometric method has been developed for the assay of clotrimazole, in bulk drug and its pharmaceutical preparations. This method is based on the ion-pair complex reaction of clotrimazole and methyl orange in aqueous methanol, and in the presence of citric acid. The chromogen, being extractable with chloroform, could be measured quantitatively at 422 nm. All variables were studied to optimize the reaction conditions. Regression analysis of beer's plot showed good correlation in a general concentration range of 2-14 mu/ml. The proposed method has been successfully applied for the analysis of the bulk drug and its dosage forms such as powder, vaginal tablets, topical solution and creams. No interference was observed from betamethasone dipropionate (Lotriderm cream) or dexamethasone acetate and azidamphenicol (Baycuten cream) or other common pharmaceutical adjuvants. In addition, this method was also found to be specific for the analysis of clotrimazole in the presence of its hydrolytic products as well as imidazole, as a possible impurity.     

Validated RP-HPLC method for determination of permethrin in bulk and topical preparations using UV-vis detector

An isocratic reversed-phase high-performance liquid chromatographic method for the estimation of permethrin in raw materials and pharmaceutical topical preparations has been devised and validated. The chromatographic analysis was performed on a 5 μm particle C-18 Nucleosil (Macherey-Nagel, Germany) column (250 × 4.6 mm). Mobile phase consisted of methanol and 0.025 mM Phosphoric acid (85:15 v/v) at a flow rate of 1.5 mL/min. UV detection was performed at 272 nm and peaks were identified with retention times as compared with standards. The limit of detection was 1.782 μg/mL, while limit of quantitation was 48.0 μg/mL. The calibration was linear in a concentration range of 48.0-5000 μg/mL with correlation coefficient of 0.999978. Regression equation was absorbance =2833.23 × concentration(μg/mL) + 19.1045 with variance of the response variable, S(yx)(2), calculated to be 1.75328 (six degrees of freedom). The method was validated as per ICH guidelines and USP requirements and found advantageous for the routine analysis of the drug in pharmaceutical formulations and in pharmaceutical investigations involving permethrin.     

Volatile flavour constituent patterns of Terras Madeirenses red wines extracted by dynamic headspace solid-phase microextraction

A suitable analytical procedure based on static headspace solid-phase microextraction (SPME) followed by thermal desorption gas chromatography-ion trap mass spectrometry detection (GC-(ITD)MS), was developed and applied for the qualitative and semi-quantitative analysis of volatile components of Portuguese Terras Madeirenses red wines. The headspace SPME method was optimised in terms of fibre coating, extraction time, and extraction temperature. The performance of three commercially available SPME fibres, viz. 100 mum polydimethylsiloxane; 85 mum polyacrylate, PA; and 50/30 mum divinylbenzene/carboxen on polydimethylsiloxane, was evaluated and compared. The highest amounts extracted, in terms of the maximum signal recorded for the total volatile composition, were obtained with a PA coating fibre at 30 degrees C during an extraction time of 60 min with a constant stirring at 750 rpm, after saturation of the sample with NaCl (30%, w/v). More than sixty volatile compounds, belonging to different biosynthetic pathways, have been identified, including fatty acid ethyl esters, higher alcohols, fatty acids, higher alcohol acetates, isoamyl esters, carbonyl compounds, and monoterpenols/C(13)-norisoprenoids.     

Comparison of CZE, open-tubular CEC and non-aqueous CE coupled to electrospray MS for impurity profiling of drugs

Open-tubular CEC and non-aqueous CE (NACE) methods were developed for the analysis of six pharmaceutical compounds and their respective process-related impurities, comprising 22 analytes in total with a range of functional groups and lipophilicities. These methods were assessed for orthogonality of analyte separation with respect to existing CZE-ESI-MS and HPLC-ESI-MS methods, in order to complement a generic analytical strategy for impurity profiling of pharmaceutical compounds. Open-tubular CEC, using etched and chemically modified capillaries, induced weak reversed-phase-type interactions between some of the analytes and the bonded phases (0.811相似文献   

顶空气相色谱法测定化妆品中15种挥发性有机溶剂残留

建立了化妆品中15种挥发性有机溶剂残留的顶空气相色谱测定方法。样品经60 ℃、30 min静态顶空后,采用气相色谱-氢火焰离子化检测器进行检测,外标法定量。加标回收试验结果表明: 15种挥发性有机溶剂残留平均回收率为62.8%～116%,相对标准偏差均小于5%。方法的检出限为0.09～0.68 mg/kg。该方法可有效克服基体干扰,一次进样可同时分离和测定化妆品中15种挥发性有机溶剂,准确灵敏,简单快速,适用于化妆品中挥发性有机溶剂残留的检测。     

Determination of repaglinide in pharmaceutical formulations by HPLC with UV detection.

A simple, precise and rapid RP-HPLC method was developed for the determination of repaglinide in pharmaceutical dosage forms. The method was carried out on a Shim-pack, RP-C18 column using a mixture of methanol: 0.1% v/v triethylamine (pH adjusted to 7 with orthophosphoric acid) and detection was done at 235 nm using nimesulide as internal standard. The linearity range was 0.1 to 0.5 microg/ml. The intra-day and inter-day precision were in the range of 0.48 to 1.01 and 0.15 to 1.15, respectively.     

Highly sensitive determination and validation of gabapentin in pharmaceutical preparations by HPLC with 4-fluoro-7-nitrobenzofurazan derivatization and fluorescence detection

A sensitive HPLC method with pre-column fluorescence derivatization using 4-Fluoro-7-Nitrobenzofurazan (NBD-F) has been developed for the determination of gabapentin in pharmaceutical preparations. The method is based on the derivatization of gabapentin with (NBD-F) in borate buffer of pH 9.5 to yield a yellow, fluorescent product. The HPLC separation was achieved on a Inertsil C(18) column (250 mm × 4.6 mm) using a mobile phase of methanol water (80:20, v/v) solvent system at 1.2 mL/min flow rate. Mexiletine was used as the internal standard. The fluorometric detector was operated at 458 nm (excitation) and 521 nm (emission). The assay was linear over the concentration range of 5 50 ng/mL. The method was validated for specificity, linearity, limit of detection, limit of quantification, precision, accuracy, robustness. Moreover, the method was found to be sensitive with a low limit of detection (0.85 ng/mL) and limit of quantitation (2.55 ng/mL). The results of the developed procedure for gabapentin content in capsules were compared with those by the official method (USP 32). Statistical analysis by t- and F-tests, showed no significant difference at 95 confidence level between the two proposed methods.     

Stability indicating method for the determination of paracetamol in its pharmaceutical preparations by TLC densitometric method

Simple, sensitive and accurate thin layer procedure was described for a quantitative determination of paracetamol in its bulk powder and in its pharmaceutical dosage forms in the presence of its degradation product. The method consists of dissolving the drug in methanol and then spotting the solution on a thin layer of silica gel G254. Paracetamol was separated on silica gel using the mixture of the mobile phase, ethyl acetate: benzene: acetic acid in a ratio (1:1:0.05 v/v/v).Absorbance measurements (detection of reflectance) of the separated drug were carried out at 250 nm. Calibration curves were established in the concentration range of 5–20 mcg/spot for paracetamol. Quantitation is achieved by comparing the area under the peaks obtained from scanning the thin layer chromatographic plates in a spectrodensitometer. The method has been successfully applied to pharmaceutical preparations (capsules) and the results obtained were statistically compared with those obtained by applying the reference method.     

High-Performance Liquid Chromatographic Method for the Simultaneous Determination of Four Flavonols in Food Supplements and Pharmaceutical Formulations

A method using high-performance liquid chromatography with diode array detection (HPLC-DAD) as a powerful separation technique has been developed for the simultaneous determination of the four flavonols rutin, quercetin, kaempferol and isorhamnetin in food supplements and pharmaceutical formulations. The chromatographic separation was achieved in 36?min using a Symmetry C₁₈ column (250?×?3?mm; 5?µm) as the stationary phase and a mixture of methanol, acetonitrile, and pH 2.5 aqueous acetic acid as the mobile phase in gradient elution mode. The analytical wavelengths were 256?nm for rutin, quercetin and isorhamnetin, and 368?nm for kaempferol. An ultrasound-assisted extraction protocol was performed using methanol as solvent. The detection and quantification limits were lower than 0.03?µg mL^?1 and 0.08?µg mL^?1, respectively. The inter-day and intra-day precisions were less than 4.8 and 5.1%, respectively, and the average recoveries were in the range from 96 to 107%. The method was applied for the determination of the studied flavonols in food supplements and pharmaceutical preparations. The satisfactory recovery values demonstrate the potential of the developed method for the determination of the analytes in these samples. In addition, the method is suitable for routine quality control due its ease of operation.     

Simultaneous determination of methotrexate and metoclopramide in physiological fluids using RP-HPLC with ultra-violet detection; application in evaluation of polymeric nanoparticles

Methotrexate (MTX) is an anticancer drug while metoclopramide (MCP) is an antiemetic agent. Both the drugs are commonly coprescribed to avoid the emesis caused by anticancer drug. In this study, a novel, rapid, sensitive, and cost-effective reverse-phase high-performance liquid chromatography method was developed and validated for simultaneous determination of the methotrexate and metoclopramide in biological and pharmaceutical samples using sparfloxacin as internal standard. The analytes were separated on a Kromasil 100-5C18 RP (250?×?4.6?mm, 5?µm) column, methanol, and 0.05% trifloroacetic acid (36:64?v/v) as mobile phase with a flow rate of 1?mL/min, detection wavelength of 290?nm, and column oven temperature at 40°C. Both the analytes were extracted from physiological fluids (bovine aqueous humor, vitreous humor, and human plasma) using mixture of methanol and 10% perchloric acid (50:50 v/v). The method was linear over the concentration range of 0.025–1.0?µg/mL for methotrexate and 0.030–1.0?µg/mL for metoclopramide. The % recovery from human plasma was 98.57 and 96.74% for MTX and MCP, respectively, while from aqueous humor and vitreous humor was 95.84 and 98.51% for MTX.

The developed method was applied for in vitro release of MTX from polymeric nanoparticles and can be applied for analysis of pharmaceutical and biological samples containing both the drugs.     

High-Performance Liquid Chromatography of Fat-Soluble Vitamins. I. Determination of Vitamin A-Acetate in Pharmaceutical Preparations and Blood

Abstract

A reversed phase high-performance liquid chromatography (HPLC) has been developed for the quanititive determination of retinol acetate (vitamin A-acetate) in pharmaceutical formulations and biological materials. The extraction of vitamin A-acetate from capsules and dragees and from blood is performed in a fully automated, electronically controlled extraction apparatus within 3–10 minutes. For reversed phase HPLC a column of LiChrosorb RP18 and methanol as eluent were used. Vitamin A-acetate was separated in less than 1 minute. The detection limit was 1-2 ng. The described methods were proved useful for extraction and determination of vitamin A-acetate in pharmaceutical preparations such as capsules and dragees and in blood, and can be well reproduced with a maximum coefficient of variation of <4%.     

Gradient HPLC-diode array detector stability-indicating determination of lidocaine hydrochloride and cetylpyridinium chloride in two combined oral gel dosage forms

A simple, rapid, and selective HPLC-diode array detector method was developed for the simultaneous determination of lidocaine hydrochloride (LD) and cetylpyridinium chloride (CPC) in two combined pharmaceutical formulations. Effective chromatographic separation was achieved on a Zorbax SB-C8 (4.6 x 250 mm, 5 microm particle size) column with gradient elution using a mobile phase composed of 0.05 M phosphoric acid and acetonitrile. The gradient elution started with 25% (v/v) acetonitrile, ramped up linearly to 85% in 5 min, and then was constant until the end of the run. The mobile phase was pumped at a flow rate of 1.2 mL/min. The multiple wavelength detector was set at 214 and 258 nm, and quantification of the analytes was based on measuring their peak areas. The retention times for LD and CPC were about 3.4 and 7.3 min, respectively. The reliability and analytical performance of the proposed HPLC procedure were statistically validated with respect to linearity, range, precision, accuracy, selectivity, robustness, LOD, and LOQ. Calibration curves were linear in the range of 5-200 and 10-400 microg/mL for LD and CPC, respectively, with correlation coefficients > 0.999. The proposed method was proven to be stability-indicating by the resolution of the two analytes from the related substance and potential impurity (2,6-dimethylaniline) as well as from forced-degradation products. The validated HPLC method was extended to the analysis of LD and CPC in two combined oral gel preparations for which the two analytes were successfully resolved from the pharmaceutical adjuvants and quantified with recoveries not less than 97.9%.     

Analysis of organic volatile impurities in pharmaceutical excipients by static headspace capillary gas chromatography

A systematic approach for the identification and quantification of organic volatile impurities (OVIs) in pharmaceutical excipients is described. Analytical procedures utilizing static headspace capillary gas chromatography coupled with flame-ionization and MS detection techniques were developed for the analysis of toxic ICH class 1 solvents and US Pharmacopeia OVIs at sub-ppm levels, and commonly used organic solvents in a wide range of concentrations. Chromatographic conditions and headspace parameters for the methods were optimized for separation, sensitivity, and speed. The proposed methodologies were demonstrated to be selective, accurate, and reproducible, and were successfully applied to the rapid screening of OVIs in typical excipients.