Development and validation of a stability indicating RP-UPLC method for determination of quetiapine in pharmaceutical dosage form

The present work reports a stability indicating reversed phase ultra performance liquid chromatography (RP-UPLC) method for the quantitative determination of quetiapine in pharmaceutical dosage form. The chromatographic separation is performed on an Agilent Eclipse Plus C18, RRHD 1.8 μm (50 mm x 2.1 mm) column using gradient elution. The optimized mobile phase consists of 0.1 % aqueous triethylamine (pH 7.2) as a solvent-A and 80:20 v/v mixture of acetonitrile and methanol as solvent-B. The eluted compounds are monitored at 252 nm wavelength using a UV detector. The developed method separates quetiapine from its five impurities/degradation products within a run time of 5 min. Stability indicating capability of the developed method is established by analyzing forced degradation samples in which the spectral purity of quetiapine is ascertained along with the separation of degradation products from analyte peak. The developed RP-UPLC method is validated as per International Conference on Harmonization (ICH) guidelines with respect to system suitability, specificity, precision, accuracy, linearity, robustness and filter compatibility.     

Development and validation of a HPLC method for the determination of cetirizine in pharmaceutical dosage forms

A rapid, simple and accurate HPLC method is described for the assay of cetirizine in commercial dosage forms. Methanol was found to be a suitable extraction solvent for tablets and for preparing solutions from drops and oral liquids. The samples were chromatographed on a Nova-Pak C18 column and UV detected at 227 nm. The elution was achieved isocratically with a mobile phase of 0.067 M phosphate buffer pH 3.40/acetonitrile (1:1, v/v). Ketotifen was applied as an internal standard. The method was validated for linearity, precision, accuracy and limit of detection. The recovery (mean +/- SD) for tablets was 100.88% +/- 0.8967, for drops 100.35% +/- 0.4062 and for solutions 101.20% +/- 1.1698.     

Spectrophotometric and spectrofluorimetric methods for the determination of ropinirole content in pharmaceutical dosage forms

Two simple and rapid spectrofluorimetric and spectrophotometric methods were described for the determination of ropinirole hydrochloride content in pharmaceutical dosage forms. Both methods are based on the reaction of ropinirole hydrochloride and eosin Y in aqueous medium at pH 4.0. Quenching of the fluorescence intensity of eosin Y at 540 nm upon excitation at 350 nm was used for the determination of ropinirole hydrochloride levels after ion-pair complex formation. Also, the absorbance increase of eosin Y at 546 nm after ion-pair complex formation was used for spectrophotometric measurements. Both methods showed linear relationships between the fluorescence quenching or absorbance increase and ropinirole concentration in the range of 6–150 µg/mL and 50–500 µg/mL for spectrofluorimetric and spectrophotometric methods, respectively. As no organic solvents were used in these two methods, they could be categorized as green analytical methods. Both methods were accurate (Error<1.2%) and precise (CV<1.9%), as shown by statistical analysis results. Both methods were used for determination of ropinirole hydrochloride content in pharmaceutical dosage forms without any significant interference from associated impurities.     

Development and validation of a reversed-phase HPLC method for the determination of ezetimibe in pharmaceutical dosage forms

Ezetimibe belongs to a group of selective and very effective 2-azetidione cholesterol absorption inhibitors that act on the level of cholesterol entry into enterocytes. A rapid, specific reversed-phase HPLC method has been developed for assaying ezetimibe in pharmaceutical dosage forms. The assay involved an isocratic elution of ezetimibe in a Kromasil 100 C18 column using a mobile phase composition of water (pH 6.8, 0.05%, w/v 1-heptane sulfonic acid) and acetonitrile (30:70, v/v). The flow rate was 0.5 ml/min and the analyte monitored at 232 nm. The assay method was found to be linear from 0.5 to 50 microg/ml. All the validation parameters were within the acceptance range. The developed method was successfully applied to estimate the amount of ezetimibe in tablets.     

Development and validation of spectrophotometric methods for carbapenems in pharmaceutical dosage forms

Simple and sensitive spectrophotometric methods have been developed for the determination of meropenem (MRPM) and doripenem (DRPM). These methods are based on the reduction of Fe(III) into Fe(II) by the drugs and their subsequent prussian blue color formation (λ_max 720 nm) with hexacyanoferrate (III), red color formation (λ_max 510 nm) with 1,10-phenanthroline and red color formation (λ_max 520 nm) with 2,2′-bipyridyl in the methods A, B, and C, respectively. Regression analysis of Beer’s plots showed good correlation for MRPM and DRPM in the concentration range (μg/mL) 0.5–6, 2–10; 2–10, 2–14, and 2–18, 1–8 for the methods A, B, and C, respectively.     

Spectrofluorimetric method for determination of citalopram in bulk and pharmaceutical dosage forms

A simple accurate, sensitive reproducible spectrofluorimetric method was developed for the analysis of citalopram in pure and pharmaceutical dosage form. Citalopram showed strong native fluorescence in 0.05 M sulphuric acid having excitation at 239 nm and emission at 300 nm. All parameters like the effect of different solvents, pH, dilutions, reaction time, temperature and effect of excipients were thoroughly investigated. The calibration graph was linear in the range from 0.100 to 0.900 μg/ml. The proposed method was statistically validated and successfully applied for analysis of tablet dosage forms. The percentage recovery was found to be between 99.08% to 99.28%.     

Development and validation of a stability-indicating analytical method for the quantitation of oxytocin in pharmaceutical dosage forms

A single stability-indicating assay for oxytocin (OT) in pharmaceutical dosage forms using gradient elution over 21 min has been reported in the literature. Furthermore, published and compendial methods for the analysis of OT containing dosage forms also involve using HPLC with gradient elution and complicated mobile phases that include hydrophobic ion pairing agents. A simple isocratic and stability-indicating assay was developed and validated. The conditions are as follows, column: Phenomenex C18 Hypersil, 5 microm packing, 4.6 mm x 150 mm with acetonitrile-phosphate buffer (pH 5; 0.08 M) (20:80) as the mobile phase with UV detection at 220 nm The method was found to be specific for OT in the presence of degradation products and chlorbutol (preservative) with an overall analytical run time of 16 min. Accuracy was determined to be 0.77-1.18% bias for all samples tested. Intra-assay precision (repeatability) was found to be 0.22-1.04%R.S.D. while the inter-day precision (intermediate precision) was found to be 1.27-1.68%R.S.D. for the samples studied. The calibration curve was found to be linear with the equation y = 1.81x + 0.02 and a linear regression coefficient of 0.9991 over the range 0.4-12.0 IU/ml. The LOD and the LOQ were determined to be 0.1 and 0.4 IU/ml, respectively. Syntocinon, a commercially available dosage form of OT was assayed resulting in 100.5-106.6% recovery of the label claim and an average of 10.04 IU/ml.     

Development and validation of HPLC method for analysis of some antiretroviral agents in their pharmaceutical dosage forms

Anew analytical method using reversed-phase high performance liquid chromatography (HPLC) has been developed for analysis of four antiretroviral molecules Lamivudine, Abacavir, Zidovudine, and Efavirenz. The proposed method was validated in accordance with the ICH Q2 (R1) validation guidelines by determining its selectivity, linearity, accuracy, and precision. Based on the results, the method is an effective choice to analyze these drugs in their single and combined pharmaceutical dosage forms.     

Development and validation of a rapid RP-HPLC method for the determination of cetirizine or fexofenadine with pseudoephedrine in binary pharmaceutical dosage forms

Chagas disease is a serious health problem in Latin America. Hidroxymethylnitrofurazone (NFOH) is a nitrofurazone prodrug more active than nitrofurazone against Trypanosoma cruzi. However, NFOH presents low aqueous solubility, high photodecomposition and high toxicity. The present work is focused on the characterization of an inclusion complex of NFOH in 2-hydroxypropyl-β-cyclodextrin (HP-β-CD). The complexation with HP-β-CD was investigated using reversed-phase liquid chromatography, solubility isotherms and nuclear magnetic resonance. The retention behavior was analyzed on a reversed-phase C₁₈ column, using acetonitrile–water (20/80, v/v) as the mobile phase, in which HP-β-CD was incorporated as a mobile phase additive. The decrease in the retention times with increasing concentrations of HP-β-CD enables the determination of the apparent stability constant of the complex (K = 6.2 ± 0.3 M⁻¹) by HPLC. The solubility isotherm was studied and the value for the apparent stability constant (K = 7.9 ± 0.2 M⁻¹) was calculated. The application of continuous variation method indicated the presence of a complex with 1:1 NFOH:HP-β-CD stoichiometry. The photostability study showed that the formation of an inclusion complex had a destabilizing effect on the photodecomposition of NFOH when compared to that of the “free” molecule in solution. The mobility investigation (by NMR longitudinal relaxation time) gives information about the complexation of NFOH with HP-β-CD. In preliminary toxicity studies, cell viability tests revealed that inclusion complexes were able to decrease the toxic effect (p < 0.01) caused by NFOH.     

Development and validation of a rapid RP-HPLC method for the determination of cetirizine or fexofenadine with pseudoephedrine in binary pharmaceutical dosage forms

The objective of the current study was to develop a simple, accurate, precise and rapid reversed-phase HPLC method and subsequent validation using ICH suggested approach for the determination of antihistaminic-decongestant pharmaceutical dosage forms containing binary mixtures of pseudoephedrine hydrochloride (PSE) with fexofenadine hydrochloride (FEX) or cetirizine dihydrochloride (CET). The chromatographic separation of PSE, FEX and CET was achieved on a Zorbax C8 (150 mm × 4.6 mm; 5 μm particle size) column using UV detection at 218 and 222 nm. The optimized mobile phase was consisted of TEA solution (0.5%, pH 4.5)–methanol–acetonitrile (50:20:30, v/v/v). The retention times were 1.099, 2.714 and 3.808 min for PSE, FEX and CET, respectively. The proposed method provided linear responses within the concentration ranges 30–240 and 1.25–10 μg ml⁻¹ with LOD values of 1.75 and 0.10 μg ml⁻¹ for PSE and CET, respectively. Linearity range for PSE–FEX binary mixtures were 10–80 and 5–40 μg ml⁻¹ with LOD values of 0.75 and 0.27 μg ml⁻¹ for PSE and FEX, respectively. Correlation coefficients (r) of the regression equations were greater than 0.999 in all cases. The precision of the method was demonstrated using intra- and inter-day assay R.S.D. values which were less than 1% in all instances. No interference from any components of pharmaceutical dosage forms or degradation products was observed. According to the validation results, the proposed method was found to be specific, accurate, precise and could be applied to the quantitative analysis of these drugs in capsules containing PSE–CET or extended-release tablets containing PSE–FEX binary mixtures.     

Derivative spectrophotometric method for simultaneous determination of clindamycin phosphate and tretinoin in pharmaceutical dosage forms

A derivative spectrophotometric method was proposed for the simultaneous determination of clindamycin and tretinoin in pharmaceutical dosage forms. The measurement was achieved using the first and second derivative signals of clindamycin at (¹D) 251 nm and (²D) 239 nm and tretinoin at (¹D) 364 nm and (²D) 387 nm.The proposed method showed excellent linearity at both first and second derivative order in the range of 60–1200 and 1.25–25 μg/ml for clindamycin phosphate and tretinoin respectively. The within-day and between-day precision and accuracy was in acceptable range (CV<3.81%, error<3.20%). Good agreement between the found and added concentrations indicates successful application of the proposed method for simultaneous determination of clindamycin and tretinoin in synthetic mixtures and pharmaceutical dosage form.     

Development of electrochemical methods for determination of tramadol--analytical application to pharmaceutical dosage forms

A square-wave voltammetric (SWV) method and a flow injection analysis system with amperometric detection were developed for the determination of tramadol hydrochloride. The SWV method enables the determination of tramadol over the concentration range of 15-75 microM with a detection limit of 2.2 microM. Tramadol could be determined in concentrations between 9 and 50 microM at a sampling rate of 90 h(-1), with a detection limit of 1.7 microM using the flow injection system. The electrochemical methods developed were successfully applied to the determination of tramadol in pharmaceutical dosage forms, without any pre-treatment of the samples. Recovery trials were performed to assess the accuracy of the results; the values were between 97 and 102% for both methods.     

Application of stability-indicating HPTLC method for quantitative determination of metadoxine in pharmaceutical dosage form

A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatographic method for analysis of metadoxine both as a bulk drug and in formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of acetone-chloroform-methanol-ammonia (7.0:4.0:3.0:1.2, v/v/v/v). Densitometric analysis of metadoxine was carried out in the absorbance mode at 315 nm. This system was found to give compact spots for metadoxine (Rf value of 0.45+/-0.02, for six replicates). Metadoxine was subjected to acid, alkali and neutral hydrolysis, oxidation, dry and wet heat treatment and photo and UV degradation. The drug undergoes degradation under all stress conditions. Also, the degraded products were well resolved from the pure drug with significantly different Rf values. The method was validated for linearity, precision, robustness, LOD, LOQ, specificity and accuracy. Linearity was found to be in the range of 100-1500 ng/spot with significantly high value of correlation coefficient r2=0.9997+/-1.02. The linear regression analysis data for the calibration plots showed good linear relationship with r2=0.9999+/-0.58 in the working concentration range of 200-700 ng/spot. The mean value of slope and intercept were 0.11+/-0.04 and 18.73+/-1.89, respectively. The limits of detection and quantitation were 50 and 100 ng/spot, respectively. Statistical analysis proves that the method is repeatable and specific for the estimation of the said drug. As the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating one. Moreover, the proposed HPTLC method was utilized to investigate the kinetics of acid and base degradation process. Arrhenius plot was constructed and activation energy was calculated respectively for acid and base degradation process.     

Stability-indicating UPLC method for determination of Valsartan and their degradation products in active pharmaceutical ingredient and pharmaceutical dosage forms

A simple, precise, accurate stability-indicating gradient reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for the quantitative determination of purity of Valsartan drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. The method was developed using Waters Aquity BEH C18 (100 mm × 2.1 mm, 1.7 μm) column with mobile phase containing a gradient mixture of solvents A and B. The eluted compounds were monitored at 225 nm, the run time was within 9.5 min, which Valsartan and its seven impurities were well separated. Valsartan was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Valsartan was found to degrade significantly in acid and oxidative stress conditions and stable in base, hydrolytic and photolytic degradation conditions. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per international conference on harmonization (ICH) guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of Valsartan in pharmaceutical dosage forms.     

Development and validation of HPLC method for the determination of pregabalin in capsules

A simple, precise, specific, and accurate reverse phase HPLC method has been developed for the determination of pregabalin in capsule dosage form. The chromatography was set on Hypersil BDS, C8, 150×4.6 mm, 5 μm column using photodiode array detector. The mobile phase consisting of phosphate buffer pH 6.9 and acetonitrile in the ratio of 95:05 with flow rate of 1 ml/min. The method was validated according to ICH guidelines with respect to specificity, linearity, accuracy, precision and robustness. Lower limit of quantification is 0.6 mg/l. The pregabalin sample solution was found to be stable at room temperature for about 26 h.     

Polarographic determination of EDTA in certain pharmaceutical dosage forms

A highly sensitive polarographic method was developed for the determination of EDTA added as a preservative in certain pharmaceutical preparations. The method involved chelation with Eu(III) followed by polarographic measurement of the chelate formed. A well-defined cathodic wave was developed in Britton–Robinson buffers over the pH range 2–12. The wave was characterized as being quasi-reversible and diffusion controlled. The current–concentration relationship was found to be rectilinear over the ranges 8–160 and 2–120 μg ml⁻¹, using DCt and DPP modes, respectively, with limit of detection of 0.1 μg ml⁻¹ using the DDP technique. The mechanism of the electrode reaction was verified. The proposed method was applied for the determination of EDTA in certain pharmaceutical dosage forms, and the results obtained were in agreement with those obtained by a reference method.     

Development and validation of a liquid chromatographic method for the determination of branched-chain amino acids in new dosage forms

A reversed-phase liquid chromatographic method (RP-LC) is proposed and validated for the analysis of branched-chain amino acids (l-leucine, l-isoleucine and l-valine) in new pharmaceutical formulations. The pre-column derivatization reaction of these amino acids with 2,4-dinitrofluorobenzene (DNFB) has been investigated considering the matrix effect. The compound reacts at 60 degrees C for 10 min at pH 9 with the amino function, in presence of cetyltrimethylammonium bromide (CTAB), to give adducts that have been separated on a RP amide C16 column and detected at lambda=360 nm. Linear responses were observed for each derivative. The intra-day precision (R.S.D.) was 相似文献   

Analysis of some antifungal drugs by spectrophotometric and spectrofluorimetric methods in different pharmaceutical dosage forms

Simple spectrophotometric and spectrofluorimetric methods are suggested for the determination of antifungal drugs; clotrimazole, econazole nitrate, ketoconazole, miconazole and tolnaftate. Spectrophotometric one depends on the interaction between imidazole antifungal drugs as n-electron donor with the pi acceptor 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in methanol or with p-chloranilic acid (p-CA) in acetonitrile. The produced chromogens obey Beer's law at lambda(max) 460, and 520 nm in the concentration range 22.5-200 and 7.9-280 microg ml(-1) for DDQ, and p-CA, respectively. Spectrofluorimetric method is based on the measurement of the native fluorescence of ketoconazole at 375 nm with excitation at 288 nm and or the induced fluorescence after alkaline hydrolysis of tolnaftate with 5 M NaOH solution at 420 nm with excitation at 344 nm. Fluorescence intensity versus concentration is linear for ketoconazole at 49.7-800 ng ml(-1) while for tolnaftate, it is in the range of 20.4-400 ng ml(-1). The proposed methods were applied successfully for the determination of all the studied drugs in their pharmaceutical formulations.