High‐Performance Liquid Chromatographic Determination of Parecoxib in Human Plasma and Pharmaceutical Formulations

Abstract

A simple and sensitive RP‐HPLC method for the determination of parecoxib (PXB) in human plasma and pharmaceutical formulations has been developed and validated. The separation of PXB and the internal standard, ibuprofen (IBF) was achieved on a CLC C₁₈ (5 μ, 25 cm×4.6 mm i.d.) column using UV detector at 200 nm. The mobile phase consisted of acetonitrile‐water (92:8 v/v). The linear range of detection was found to be 0.9–18.4 µg/ml (r=0.9985). Intra‐ and inter‐day assay relative standard deviations were observed to be less than 0.3%. The method has been applied successfully for the determination of PXB in spiked human plasma and pharmaceutical preparations. Analytical parameters were calculated and complete statistical evaluation is incorporated.     

A Simple and Rapid Stability Indicating LC Determination of Ciprofloxacin Hydrochloride as a Bulk Drug and from Formulations

The present research work discusses the development of a stability indicating reversed phase LC method for determination of ciprofloxacin hydrochloride as a bulk drug and from formulations. The mobile phase selected was water-acetonitrile-triethylamine 75:25:0.1 (v/v/v) adjusted to pH 4.0 with o-phosphoric acid. The calibration curve of the drug was linear in the range 0.25–15 μg mL^?1. The method was accurate and precise with limits of detection and quantitation of 8.01 and 26.7 ng, respectively. Mean percent recovery was 100.71%. The method was used for analysis of ciprofloxacin hydrochloride from pharmaceutical formulations in the presence of its degradation products and commonly used excipients.     

Micellar Liquid Chromatographic Determination of Penicillins in Pharmaceuticals

A new, simple, rapid and specific micellar liquid chromatographic (MLC) method was developed and validated for the determination of amoxicillin, ampicillin, cloxacillin and dicloxacillin in pharmaceutical formulations. Separation was achieved isocratically on an Ultra C₁₈ column (150 mm × 4.6 mm) utilizing a mobile phase of 25 mM SDS–2% (v/v) 1-butanol in phosphate buffer (pH 5.0) at a flow rate of 1.0 mL min^?1 with UV detection at 200 nm. Validation experiments were performed to demonstrate linear ranges, accuracy, precision, robustness, limit of detection (LOD) and limit of quantification (LOQ). The method was applied to the determination of these penicillins in various pharmaceutical formulations. The results compared favorably with those obtained by the official methods, and were in agreement with the declared compositions. The method can be used for quality control assay of the studied penicillins.     

Stability-Indicating Chromatographic Methods for Simultaneous Determination of Mosapride and Pantoprazole in Pharmaceutical Dosage Form and Plasma Samples

Simple, sensitive, selective, precise, and stability-indicating thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) methods for the determination of mosapride and pantoprazole in pharmaceutical tablets were developed and validated as per the International Conference on Harmonization guidelines. The TLC method employs aluminum TLC plates precoated with silica gel 60F₂₅₄ as the stationary phase and ethyl acetate/methanol/toluene (4:1:2, v/v/v) as the mobile phase to give compact spots for mosapride (R _f 0.73) and pantoprazole (R _f 0.45) separated from their degradation products; the chromatogram was scanned at 276 nm. The HPLC method utilizes a C18 column and a mobile phase consisting of acetonitrile/methanol/20 mM ammonium acetate (4:2:4, v/v/v) at a flow rate of 1.0 mL min^?1 for the separation of mosapride (t _R 11.4) and pantoprazole (t _R 4.4) from their degradation products. Quantitation was achieved with UV detection at 280 nm. The same HPLC method was successfully used in performing calibrations in lower concentration ranges for both drugs in human plasma using ezetimibe as internal standard. The methods were validated in terms of accuracy, precision, linearity, limits of detection, and limits of quantification. Mosapride and pantoprazole were exposed to acid hydrolysis and then analyzed by the proposed methods. As the methods could effectively separate the drugs from their degradation products, these techniques can be employed as stability-indicating methods that have been successively applied to pharmaceutical formulations without interference from the excipients. Moreover the HPLC method was successfully used in the determination of both drugs in spiked human plasma.     

Development and validation of a TLC-densitometry method for quantitative analysis of nefopam hydrochloride beside its degradation products

A quantitative densitometric thin-layer chromatographic method for determination of nefopam hydrochloride in pharmaceutical preparations has been established and validated. Nefopam from the formulations was separated and identified on silica gel 60 F₂₅₄ TLC plates with chloroform-methanol-glacial acetic acid (9: 2: 0.1, v/v/v) as mobile phase. Densitometric quantification was performed at absorbance maximum 266 nm. The method was validated for linearity, sensitivity, precision and recovery in accordance with ICH guidelines. The presented method is selective and specific with potential application in pharmaceutical analysis. Nefopam hydrochloride was subjected to acidic and alkaline hydrolysis at different temperatures. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating one.     

Development and Validation of a Stability Indicating LC Method for the Determination of Faropenem in Pharmaceutical Formulations

A simple, selective and sensitive stability indicating LC method has been developed and validated for the determination of faropenem in bulk drug and pharmaceutical formulations in the presence of degradation products. The separation was achieved by using an isocratic mobile phase mixture of acetate buffer of pH 3.5 and methanol (65:35, v/v) and 250 mm × 4.6 mm I.D., 5 μm particle size SGE make Wakosil C-18 AR column at flow rate of 1.0 mL min^?1 with detection at 305 nm. The retention time of faropenem is 6.63 min and was linear in the range of 5–75 μg mL^?1 (r = 0.9999). The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation and was found to be unstable in all the stress conditions. The proposed method was successfully employed for quantification of faropenem in bulk drug and its pharmaceutical formulations.     

Simultaneous quantification of cefpirome and cetirizine or levocetirizine in pharmaceutical formulations and human plasma by RP-HPLC

A rapid and sensitive high-performance liquid chromatographic (HPLC) assay for the simultaneous determination and quantification of cefpirome and cetirizine or cefpirome and levocetirizine in pharmaceutical formulations and human plasma without changing the chromatographic conditions is described. Chromatographic separations were performed on a prepacked Nucleosil 120, C₁₈ (5 μm, 12.5 ± 0.46 mm) column using CH₃CN: H₂O (75: 25, v/v) as a mobile phase at a flow rate of 1 mL/min while UV detection was performed at 232 nm for monitoring the effluent. A number of other brands of C₁₈ columns were also employed which had a significant effect on the separation. The method has been validated over the concentration range of 0.5–50 μg/mL (r ₂ > 0.999). The limit of detection (LOD) and quantification (LOQ) for cefpirome and levocetirzine in pharmaceutical formulations and serum were in the range 0.24–1.31 μg/mL. Analytical recovery from human plasma was >98%, and the within and between-day relative standard deviation was <3.1%. The small sample volume and simplicity of preparation make this method suitable for use in pharmaceutical industries, drug research centers, clinical laboratories, and forensic medical centers. The text was submitted by the authors in English.     

Separation and quantitation of oxprenolol in urine and pharmaceutical formulations by HPLC using a Chiralpak IC and UV detection

Abstract  

A stereoselective HPLC method has been developed for the simultaneous determination of oxprenolol enantiomers in urine and pharmaceutical products. Enantiomeric resolution of oxprenolol was achieved on cellulose tris(3,5-dichlorophenylcarbamate) immobilized onto a 5 μm spherical porous silica chiral stationary phase (CSP) known as Chiralpak IC with UV detection at 273 nm. The mobile phase consisted of n-hexane:isopropanol:triethylamine 70:30:0.1 (v/v/v) at a flow rate of 1.0 cm³/min. The method was validated for its linearity, accuracy, precision, and robustness. The calibration curves were linear over the range of 0.5–75 μg/cm³, with a detection limit of 0.1 μg/cm³ for each enantiomer. An average recovery of 99.0% and a mean relative standard deviation of 2.6% at 40.0 μg/cm³ for S-(−)- and R-(+)-enantiomers were obtained. The overall recoveries of oxprenolol enantiomers from pharmaceutical formulations were in the range 97.5–99.0%, with RSDs ranging from 0.6 to 0.8%. The mean extraction efficiency of oxprenolol from urine was in the range of 86.0–93.0% at 0.5–5 μg/cm³ for each enantiomer. The assay method proved to be suitable as a chiral quality control for oxprenolol formulations using HPLC and for therapeutic drug monitoring.     

Enantiospecific resolution of rabeprazole by liquid chromatography on amylose-derived chiral stationary phase using photo diode array and polarimetric detectors in series

A simple and rapid liquid chromatographic method for enantioselective separation and determination of R-(+) and S-(−) enantiomers of rabeprazole in drugs and pharmaceuticals using photo diode array (PDA) and polarimetric detectors connected in series was developed. Chiralpak AD-H (250 mm × 4.6 mm) 5 μm column packed with amylose tris(3,5-dimethylphenyl carbamate) as a stationary phase and the mobile phase containing n-hexane:ethanol:2-propanol(75:15:10, v/v/v) in an isocratic mode has yielded baseline separation with resolution greater than 3.0 at 40 °C. Effects of ethanol, 2-propanol and temperature on separation were studied for optimum resolution. Lansoprazole sulphone was used as an internal standard (IS) for quantitative determination of individual enantiomers in bulk drugs as well as pharmaceutical formulations. The method was validated in terms of accuracy, precision and linearity according to ICH guidelines. The linearity of the method was studied in the range of 0.5-50 μg/ml and the r² was >0.9997. The inter- and intra-day precision of assay were determined (R.S.D. < 1%) and the recoveries were in the range of 99.63-100.22% with <1% R.S.D. The limits of detection (LOD) and quantification (LOQ) were 0.02 μg/ml and 0.07 μg/ml for both the enantiomers, respectively.     

RP‐HPLC Method for the Determination of Tenofovir in Pharmaceutical Formulations and Spiked Human Plasma

Abstract

A simple reverse‐phase high‐performance liquid chromatographic method for the determination of tenofovir disoproxil fumarate (TDF) in pharmaceutical formulations and human plasma samples has been developed and validated. Piroxicam (PRX) was used as an internal standard. The assay of the drug was performed on a CLC C₁₈ (5 μ, 25 cm×4.6 mm i.d.) with UV detection at 259 nm. The mobile phase consisted of acetonitrile–water mixture in the ratio of 75∶25, and a flow rate of 1 ml/min was maintained. The standard curve was linear over the range of 0.2–10 µg/ml (r ²=0.9966). Analytic parameters have been evaluated. Within‐day and between‐day precision as expressed by relative standard deviation was found to be less than 2%. The method has been applied successfully for the determination of TDF in spiked human plasma samples and pharmaceutical 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 New HPLC Method for the Simultaneous Determination of Acetaminophen,Phenylephrine, Dextromethorphan and Chlorpheniramine in Pharmaceutical Formulations

Abstract

Acetaminophen, phenylephrine, dextromethorphan, and chlorpheniramine are frequently associated in pharmaceutical formulations against the common cold. A new high performance liquid chromatography (HPLC) method has been developed for the simultaneous determination of these active pharmaceutical ingredients in pharmaceutical formulations. The separation and quantitation were achieved on a 25 cm underivatized silica column using a mobile phase of methanol: water (containing 6.0 g of ammonium acetate and 10 ml of triethylamine per liter, pH adjusted to 5.0 with orthophosphoric acid), 95:5%(v/v). Detection was carried out using a variable wavelength UV-vis detector at 254 nm for acetaminophen, at 220 nm for phenylephrine, and at 227 nm for dextromethorphan and chlorpheniramine. The method showed linearity for the acetaminophen, phenylephrine, dextromethorphan, and chlorpheniramine in the 162.5–650, 2.5–10, 7.5–30, and 1–4 µg/ml ranges, respectively. The intraday and interday RSDs ranged from 0.92 to 1.52%, 1.00 to 1.76%, 1.21 to 1.74% and 1.26 to 1.80% for the acetaminophen, phenylephrine, dextromethorphan, and chlorpheniramine, respectively. Compounds were eluted in a run time of less than 12 min.     

Development and validation of RP-HPLC method for simultaneous determination of glipizide, rosiglitazone, pioglitazone, glibenclamide and glimepiride in pharmaceutical dosage forms and human plasma

A simple, high performance liquid chromatographic method has been developed for the simultaneous determination of glipizide, rosiglitazone, pioglitazone, glibenclamide and glimepiride in pharmaceutical dosage forms and human plasma. The elution was performed using a mobile phase mixture of 0.05% Triethylamine (pH-3.5, adjusted with ortho phosphoric acid), acetonitrile and methanol in the ratio of 55:15:30 at a flow rate of 1 ml min^?1 on a phenomenex C₁₈ column (150 × 4.6 mm, i.d., 5 ??m) at ambient temperature. The drugs were monitored at a wavelength of 248 nm and were separated within 20 min. Mixtures of formulations were prepared in suitable dilutions and plasma samples were prepared by extraction with acetonitrile. The method was successful in detecting the drugs at a concentration of less than 0.1 ??g ml^?1 for each drug and %RSD for intra- and inter-day studies was found to be less than 4.34 for all the selected concentrations. Moreover, the method was validated as per ICH guidelines and the results were found to be within the acceptable range. Hence, the proposed method can be used for the routine quality control of the drugs and can also be applied to pharmacokinetic studies.     

Stability-Indicating Chromatographic Methods for Simultaneous Determination of Mosapride and Pantoprazole in Pharmaceutical Dosage Form and Plasma Samples

Simple, sensitive, selective, precise, and stability-indicating thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) methods for the determination of mosapride and pantoprazole in pharmaceutical tablets were developed and validated as per the International Conference on Harmonization guidelines. The TLC method employs aluminum TLC plates precoated with silica gel 60F₂₅₄ as the stationary phase and ethyl acetate/methanol/toluene (4:1:2, v/v/v) as the mobile phase to give compact spots for mosapride (R _f 0.73) and pantoprazole (R _f 0.45) separated from their degradation products; the chromatogram was scanned at 276 nm. The HPLC method utilizes a C18 column and a mobile phase consisting of acetonitrile/methanol/20 mM ammonium acetate (4:2:4, v/v/v) at a flow rate of 1.0 mL min⁻¹ for the separation of mosapride (t _R 11.4) and pantoprazole (t _R 4.4) from their degradation products. Quantitation was achieved with UV detection at 280 nm. The same HPLC method was successfully used in performing calibrations in lower concentration ranges for both drugs in human plasma using ezetimibe as internal standard. The methods were validated in terms of accuracy, precision, linearity, limits of detection, and limits of quantification. Mosapride and pantoprazole were exposed to acid hydrolysis and then analyzed by the proposed methods. As the methods could effectively separate the drugs from their degradation products, these techniques can be employed as stability-indicating methods that have been successively applied to pharmaceutical formulations without interference from the excipients. Moreover the HPLC method was successfully used in the determination of both drugs in spiked human plasma.

     

TLC Determination of Amitriptyline HCl,Trifluoperazine HCl,Risperidone and Alprazolam in Pharmaceutical Products

A simple, sensitive, and precise thin layer chromatographic (TLC) method for simultaneous analysis of psychopharmacological drugs like amitriptyline HCl, trifluoperazine HCl, risperidone and alprazolam in their single dosage forms has been developed, validated, and used for determination of the compounds in commercial pharmaceutical products. The TLC separation was carried out on Merck TLC aluminium sheets of silica gel 60 F254 using carbon tetrachloride:acetone:triethylamine (8:2:0.3, v/v/v), as mobile phase. Densitometric measurements of their spots were achieved at 250 nm over the concentration range for amitriptyline HCl (50–1,200 ng spot⁻¹), trifluoperazine HCl (50–1,200 ng spot⁻¹), risperidone (100–2,400 ng spot⁻¹) and alprazolam (25–600 ng spot⁻¹). Limit of detection (LOD) for amitriptyline HCl (20 ng spot⁻¹), trifluoperazine HCl (20 ng spot⁻¹), risperidone (40 ng spot⁻¹) and alprazolam (5 ng spot⁻¹) was obtained. The study showed that TLC was sensitive and selective for determination of amitriptyline HCl, trifluoperazine HCl, risperidone and alprazolam using a single mobile phase. This proposed method is able for simultaneous determination of psychopharmacological drugs and also applicable for analysis of pharmaceutical formulations.

     

Voltammetric determination of azithromycin at the carbon paste electrode

Azithromycin (AZ) is the first member of a class of macrolide azalides antibiotics called azolides. A simple and selective square-wave voltammetric (SWV) method has been developed for the determination of azithromycin in pure form, in pharmaceutical preparation and in biological samples. Determination of azithromycin was accomplished with hand-make carbon paste electrode (CPE) in oxidative screen mode. The counter and reference electrodes were a Pt wire and a Ag/AgCl, respectively. Various parameters that can influence the peak signal (effect of buffer, ionic strength, accumulation time, pH and the composition of the paste) have been scrutinized. The best results were obtained in acetonitrile—aqueous 1 M sodium acetate-acetic acid buffer (pH 4.6) containing 0.1 M KCl (1:9; v/v) using a 15% paraffin oil CPE. The limits of detection and quantification of the pure drug are 0.463 and 1.544 ppb (with the correlation coefficient, r=0.9785and the standard deviation, S.D.=0.1 (n=5), for the accumulation time of 60 s), respectively. The method was successfully applied to the determination of the drug in urine and two forms of pharmaceutical formulations. Recoveries were 99.2—100.5% with S.D.=0.1—and 0.8% (n=5).     

Simultaneous separation and determination of process-related substances and degradation products of venlafaxine by reversed-phase HPLC

A simple and rapid gradient RP HPLC method for simultaneous separation and determination of venlafaxine and its related substances in bulk drugs and pharmaceutical formulations has been developed. As many as four process impurities and one degradation product of venlafaxine have been separated on a Kromasil KR100-5C18 (4.6 mm x 250 mm; particle size 5 microm) column with gradient elution using 0.3% diethylamine buffer (pH 3.0) and ACN/methanol (90:10 v/v) as a mobile phase. The column was maintained at 40 degrees C and the eluents were monitored with photo diode array detection at 225 nm. The chromatographic behaviour of all the compounds was examined under variable compositions of different solvents, temperatures, buffer concentrations and pH. The method was validated in terms of accuracy, precision and linearity as per ICH guidelines. The inter- and intraday assay precision was < 4.02% (%RSD) and the recoveries were in the range of 96.19-101.14% with %RSD < 1.15%. The correlation coefficients (r2) for calibration curves of venlafaxine as well as impurities were in the range of 0.9942-0.9999. The proposed RP-LC method was successfully applied to the analysis of commercial formulations and the recoveries of venlafaxine were in the range of 99.32-100.67 with %RSD <0.58%. The method could be of use not only for rapid and routine evaluation of the quality of venlafaxine in bulk drug manufacturing units but also for the detection of its impurities in pharmaceutical formulations. Forced degradation of venlafaxine was carried out under thermal, photo, acidic, basic and peroxide conditions and the acid degradation products were characterized by ESI-MS/MS, 1H NMR and FT-IR spectral data.     

Simultaneous Determination of Diclofenac Sodium and Rabeprazole Sodium in Bulk and Pharmaceutical Dosage Form by LC

A simple, selective, rapid, precise and accurate reverse phase high pressure liquid chromatographic method has been developed for the simultaneous estimation of diclofenac sodium and rabeprazole sodium from pharmaceutical formulations. The method was developed using a HiQ SiL C18 (250 mm × 4.6 mm i.d.) column with a mobile phase consisting of methanol:water, (80:20 v/v), at a flow rate of 1.25 mL min^?1. Detection was carried out at 284 nm. Indapamide was used as an internal standard. The developed method was validated for linearity, accuracy, precision, limit of detection and limit of quantitation. The proposed method can be used for the estimation of these drugs in combined dosage forms.     

High-Performance Liquid Chromatographic Method for the Determination of Nimesulide in Pharmaceutical Preparations

A simple, rapid, and precise high-performance liquid chromatographic method for the determination of nimesulide in pharmaceutical preparations was proposed using Ibuprofen as an internal standard. The separation was performed on a CLC C₁₈ (5 m, 25 cm × 4.6 mm i.d.) column with a mobile phase consisting of an acetonitrile–0.05 M KH₂PO₄ buffer mixture of pH 7.00 (55 : 45, v/v). The detection was carried out at 230 nm and the linearity range was found to be 0.5–100 g/mL. The method has been applied successfully to the determination of nimesulide in pharmaceutical formulations. The recovery values were found to be in the range of 99.23–100.13% with RSD values of less than 0.97%.     

Second-Derivative Spectrophotometric Determination of Some Benzenoid Drugs

Abstract

A rapid second-derivative spectrophotometric assay procedure has been described for the determination of some benzenoid drugs in pharmaceutical dosage forms. Spectral interference from formulation excipients in simple uv spectrophotometric methods has been eliminated by the application of the proposed method. The different assay parameters, linearity and precision of the method have been assessed. The assay results obtained for eight batches of the pharmaceutical formulations of these drugs are in accord with the declared amounts. The high specificity, ease and simplicity offered by second-derivative spectrophotometry permit unit dose assay of these formulations.