Simultaneous Spectrophotometric Determination of Drotaverine Hydrochloride and Paracetamol in Tablet

Two simple, accurate and reproducible spectrophotometric methods; Q analysis and first order derivative method have been described for the simultaneous estimation of drotaverine hydrochloride and paracetamol in combined tablet dosage form. Absorption maxima of drotaverine hydrochloride and paracetamol in distilled water were found to be 303.5 nm and 243.5 nm respectively. Beer''s law was obeyed in the concentration range 5-50 μg/ml for drotaverine and 5-60 μg/ml for paracetamol. In Q analysis method, two wavelengths were selected at isobestic point (277 nm) and λ_max of paracetamol (243.5 nm). In first order derivative method, zero crossing point for drotaverine hydrochloride and paracetamol were selected at 303.5 nm and 243.5 nm, respectively. The results of two methods were validated statistically and recovery studies were found to be satisfactory.     

Spectrophotometric and HPLC Methods for Simultaneous Estimation of Amlodipine Besilate, Losartan Potassium and Hydrochlorothiazide in Tablets

Two UV-spectrophotometric and one reverse phase high performance liquid chromatography methods have been developed for the simultaneous estimation of amlodipine besilate, losartan potassium and hydrochlorothiazide in tablet dosage form. The first UV spectrophotometric method was a determination using the simultaneous equation method at 236.5, 254 and 271 nm over the concentration range 5-25, 10-50 and 5-25 μg/ml for amlodipine besilate, losartan potassium and hydrochlorothiazide, respectively. The second UV method was a determination using the area under curve method at 231.5-241.5, 249-259 and 266-276 nm over the concentration range of 5-25, 5-25 and 10-50 μg/ml for amlodipine besilate, hydrochlorothiazide and losartan potassium, respectively. In reverse phase high performance liquid chromatography analysis is carried out using 0.025 M phosphate buffer (pH 3.7):acetonitrile (57:43 v/v) as the mobile phase and Kromasil C18 (4.6 mm i.d×250 mm) column as stationery phase with detection wavelength of 232 nm linearity was obtained in the concentration range of 2-14, 20-140 and 5-40 μg/ml for amlodipine besilate, losartan potassium and hydrochlorothiazide, respectively. Both UV-spectrophotometric and reverse phase high performance liquid chromatography methods were statistically validated and can be used for analysis of combined dose tablet formulation containing amlodipine besilate, losartan potassium and hydrochlorothiazide.     

Simultaneous spectrophotometric estimation of nitazoxanide and ofloxacin in tablets

Two simple, accurate and precise spectrophotometric methods have been developed for simultaneous determination of nitazoxanide and ofloxacin in tablets. Method I is Q-absorbance ratio method which involves Q-absorbance at isobestic point (306.25 nm) and max (347.5 nm) of nitazoxanide, while method II is two wavelength method, where 244.6 nm and 273.0 nm were selected as 1 and 2 for determination of nitazoxanide and 294.3 nm and 388.1 nm were selected as 3 and 4 for determination of ofloxacin. Both drugs obeyed the Beer's law in the concentration range 2-30 μg/ml,correlation coefficient (r(2)<1). Both methods were validated statistically and recovery studies were carried out to confirm the accuracy. Commercial tablet formulation was successfully analyzed using the developed methods.     

Stability indicating LC-method for estimation of paracetamol and lornoxicam in combined dosage form

A simple, specific and stability indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of paracetamol and lornoxicam in tablet dosage form. A Brownlee C-18, 5 μm column having 250×4.6 mm i.d. in isocratic mode, with mobile phase containing 0.05 M potassium dihydrogen phosphate:methanol (40:60, v/v) was used. The flow rate was 1.0 ml/min and effluents were monitored at 266 nm. The retention times of paracetamol and lornoxicam were 2.7 min and 5.1 min, respectively. The linearity for paracetamol and lornoxicam were in the range of 5-200 μg/ml and 0.08-20 μg/ml, respectively. Paracetamol and lornoxicam stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and dry heat degradation. The proposed method was validated and successfully applied to the estimation of paracetamol and lornoxicam in combined tablet dosage form.     

Simultaneous Spectrophotometric Estimation of Haloperidol and Trihexyphenidyl in Tablets

The combination of haloperidol and trihexyphenidyl is a dosage form to be used as antidyskinetic agent. Literature revealed that there is no single method for the simultaneous estimation of these drugs in tablet dosage form, which prompted us to develop a simple, rapid, accurate, economical and sensitive spectrophotometric method. The simultaneous estimation method is based on the principle of additivity of absorbance, for the determination of haloperidol and trihexyphenidyl in tablet formulation. The absorption maxima of the drugs were found to be at 245.0 nm and 206.0 nm respectively for haloperidol and trihexyphenidyl in methanol and 0.1N HCl (90:10). The obeyance of Beer Lambert’s law was observed in the concentration range of 2.5-12.5 µg/ml for haloperidol and 1.0-5.0 µg/ml for trihexyphenidyl. The accuracy and reproducibility of the proposed method was statistically validated by recovery studies.     

Estimation of Amlodipine Besylate, Valsartan and Hydrochlorothiazide in Bulk Mixture and Tablet by UV Spectrophotometry

A simple, precise, accurate and economic simultaneous UV spectrophotometric method has been developed for the estimation of amlodipine besylate, valsartan and hydrochlorothiazide in combination in bulk mixture and tablet. The estimation was based upon measurement of absorbance at absorbance maxima of 359 nm, 317 nm and 250 nm for amlodipine besylate, hydrochlorothiazide and valsartan in methanol, respectively in bulk mixture and tablet. The Beer Lambert''s law obeyed in the concentration range 5-25 μg/ml, 10-50 μg/ml and 5-25 μg/ml for amlodipine besylate, hydrochlorothiazide and valsartan, respectively. The estimation of bulk mixture and tablet was carried out by simultaneous equation, Q-analysis and area under curve method for estimation of amlodipine besylate and hydrochlorothiazide and standard curve method for estimation of valsartan. The results were found to be in the range of 99.6±1.52% to 102±0.51%. Method was validated with respect to specificity, linearity, range, accuracy, precision, LOD, LOQ, robustness, ruggedness and can be applied for routine analysis of tablet dosage forms.     

Estimation of paracetamol and aceclofenac in tablet formulation by ratio spectra derivative spectroscopy

A new sensitive, simple, rapid and precise method for simultaneous estimation of paracetamol and aceclofenac in combined tablet dosage form has been developed. The method is based on ratio derivative spectrophotometry. The amplitude in first derivative of the ratio spectra at 256 nm and 268 nm (minima) were selected to determine paracetamol and aceclofenac in combined formulation. The method showed good linearity, accuracy and reproducibility. Results of analysis were validated statistically and by recovery studies.     

Stability-indicating methods for the determination of mosapride citrate in the presence of its degradation products according to ICH guidelines

In the present work, different spectrophotometric methods and one spectrofluorimetric method have been developed and validated for the determination of mosapride citrate in the presence of its acid-induced degradation products. The drug was subjected to stress stability study including acid, alkali, oxidative, photolytic, and thermal stress degradation. The developed spectrophotometric methods included the use of first order derivative ((1)D), derivative of ratio spectra ((1)DD), mean centring of ratio spectra (MC) and H-point standard additions (HPSAM) spectrophotometric methods. For (1)D method, the peaks amplitudes at 282.8 and 319.6 nm were measured, while for (1)DD method those at 308 nm and 323 nm were measured. Mean centring of ratio spectra method used the values at 317 nm for calibration, while for HPSAM the absorbance at 273 and 288.6 nm were used. These methods were successfully applied for determination of mosapride in the concentration range of 5-70 μg.ml(-1). The spectrofluorimetric method was based on measuring the native fluorescence of mosapride in 0.1 M NaOH using λ(excitation) 276 nm and λ(emission) 344 nm and 684 nm with linearity ranges of 50-3000 ng.ml(-1) and 50-9000 ng.ml(-1), respectively. All the developed methods were validated according to the International Conference on Harmonization (ICH) guidelines and were applied for bulk powder and dosage form. The results obtained were statistically compared to each other using one-way ANOVA testing.     

Development and Validation of a RP-HPLC Method for Estimation of Prulifloxacin in Tablet Dosage Form

A simple, precise, rapid, accurate and economic reverse phase high performance liquid chromatographic method has been developed for the estimation of prulifloxacin in tablet dosage form. The separation was achieved by using octadecylsilane column (C(18)) and KH(2)PO(4) buffer: acetonitrile adjusted to pH 7.3 with triethyl amine in proportion of 10:90 v/v as mobile phase, at a flow rate of 1.0 ml/min. The detection was carried out at 278 nm. The retention time of prulifloxacin was found to be 2.4 min. The limit of detection and limit of quantitation were found to be 0.14 μg/ml and 0.42 μg/ml respectively. The accuracy and reliability of the proposed method was ascertained by evaluating various validation parameters like linearity, precision, accuracy and specificity according to ICH guidelines. The proposed method provides an accurate and precise quality control tool for routine analysis of prulifloxacin in tablet dosage form.     

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 an ultra performance liquid chromatography method for venlafaxine hydrochloride in bulk and capsule dosage form

A simple, specific, accurate, and precise ultra performance liquid chromatographic method was developed and validated for the estimation of venlafaxine hydrochloride in tablet dosage forms. A acquity TM BEH column having C18, 100×2.1 mm i.d. in isocratic mode, with mobile phase containing dipotassium hydrogen phosphate: Acetonitrile (30:70 v/v; pH 7.00 with dilute o-phosphoric acid) was used. The flow rate was 0.75 ml/min and effluents were monitored at 227 nm. The retention time of venlafaxine hydrochloride was 0.548 min. The method was validated for specificity, linearity, accuracy, precision, limit of quantification, limit of detection, robustness and solution stability. Limit of detection and limit of quantification for estimation of venlafaxine hydrochloride were found to be 6.11 μg/ml and 20.33 μg/ml, respectively. Recoveries of venlafaxine hydrochloride in tablet formulations were found to be in the range of 99.3-99.5%. Proposed method was successfully applied for the quantitative determination of venlafaxine hydrochloride in tablet dosage forms.     

Concurrent Estimation of Clopidogrel Bisulfate and Aspirin in Tablets by Validated RP-HPLC Method

A simple, rapid, precise RP-HPLC method was developed for simultaneous estimation of aspirin and clopidogrel bisulphate in tablet dosage form used in the treatment of cardiovascular diseases. To achieve the maximum resolution, acetonitrile:50 mM potassium dihydrogen phosphate buffer:methanol, solution pH adjusted to 3, in the ratio 50:30:20; v/v was selected as mobile phase. This mixture was found to be appropriate allowing good separation of both the components at a flow rate of 1.5 ml/min and detection wavelength 240 nm. In these conditions clopidogrel bisulfate and aspirin were eluated at the 7.47 and 2.2 min. The linearity was found in the concentration range 1.5-7.5 and 3.5-15.0 μg/ml, respectively. All the analytical validation parameters were determined and found with in the limit as per ICH guideline, which indicates the validity of method.     

Development and Validation of Stability-indicating HPLC Method for Simultaneous Estimation of Cefixime and Linezolid

A stability-indicating reverse phase high performance liquid chromatography method was developed and validated for cefixime and linezolid. The wavelength selected for quantitation was 276 nm. The method has been validated for linearity, accuracy, precision, robustness, limit of detection and limit of quantitation. Linearity was observed in the concentration range of 2-12 μg/ml for cefixime and 6-36 μg/ml for linezolid. For RP-HPLC, the separation was achieved by Phenomenex Luna C₁₈ (250×4.6 mm) 5 μm column using phosphate buffer (pH 7):methanol (60:40 v/v) as mobile phase with flow rate 1 ml/min. The retention time of cefixime and linezolid were found to be 3.127 min and 11.986 min, respectively. During force degradation, drug product was exposed to hydrolysis (acid and base hydrolysis), H₂O₂, thermal degradation and photo degradation. The % degradation was found to be 10 to 20% for both cefixime and linezolid in the given condition. The method specifically estimates both the drugs in presence of all the degradants generated during forced degradation study. The developed methods were simple, specific and economic, which can be used for simultaneous estimation of cefixime and linezolid in tablet dosage form.     

Simultaneous Spectrophotometric Estimation of Paracetamol and Metoclopramide Hydrochloride in Solid Dosage Form

Two simple, accurate, rapid and economical spectrophotometric methods have been developed for the simultaneous determination of paracetamol and metoclopramide hydrochloride from tablet dosage form. The first method developed employs formation and solving simultaneous equations using 248.6 nm and 275.6 nm as two wavelengths for formation of equations. Second method is absorbance ratio in which wavelengths selected were 265.6 nm as isoabsorptive point and 275.6 nm as λmax of paracetamol. Both the drugs and their mixtures obey Beer-Lamberts law at selected wavelengths at given concentration range. The methods have been validated statistically and by recovery studies. The results of analysis have been validated statistically and by recovery studies.     

Stability Indicating RP-HPLC Estimation of Atorvastatin Calcium and Amlodipine Besylate in Pharmaceutical Formulations

A simple, specific, accurate and stability indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of atorvastatin calcium and amlodipine besylate in tablet dosage forms. A phenomenex Gemini C-18, 5 μm column having 250×4.6 mm i.d. in isocratic mode, with mobile phase containing 0.02 M potassium dihydrogen phosphate:acetonitrile:methanol (30:10:60, v/v/v) adjusted to pH 4 using ortho phosphoric acid was used. The flow rate was 1.0 ml/min and effluents were monitored at 240 nm. The retention times of atorvastatin calcium and amlodipine besylate were 11.6 min and 4.5 min, respectively. The calibration curves were linear in the concentration range of 0.08-20 μg/ml for atorvastatin calcium and 0.1-20 μg/ml for amlodipine besylate. Atorvastatin calcium and amlodipine besylate stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and dry heat degradation. The degraded product peaks were well resolved from the pure drug peak with significant difference in their retention time values. The proposed method was validated and successfully applied to the estimation of atorvastatin calcium and amlodipine besylate in combined tablet dosage forms.     

Simultaneous spectrophotometric determination of Cefpodoxime proxetil and Potassium clavulanate

Two accurate, precise, sensitive and economical procedures for simultaneous estimation of Cefpodoxime proxetil and Potassium clavulanate in tablet dosage form have been developed. The methods employed were absorbance correction method (I) and first order derivative spectroscopic method (II). The first method employs wavelength 288 nm for direct estimation of Cefpodoxime proxetil where Potassium clavulanate shows nil absorbance. Estimation of Potassium clavulanate is carried out after correction for absorbance of Cefpodoxime proxetil at 218 nm. The second method is based on first order derivative spectroscopy. Wavelengths 235.6 nm and 308.2 nm were selected for the estimation of the Potassium clavulanate and Cefpodoxime proxetil, respectively. Both the drugs obey Beer's law in the concentration range 5-50 microg/ml. The results of analysis have been validated statistically and by recovery studies. The percentage assay was found to be 99.54 +/- 0.285 for Cefpodoxime proxetil and 98.53 +/- 0.760 for Potassium clavulanate (Mean +/- SD) by method I and 99.93 +/- 0.270 for Cefpodoxime proxetil and 99.40 +/- 0.723 for Potassium clavulanate (Mean +/- S.D) by method II respectively.     

Stability indicating methods for the determination of aceclofenac

Five new selective, precise and accurate methods for the determination of aceclofenac in the presence of its degradation product; diclofenac are described. Method A utilizes third derivative spectrophotometry at 242 nm. Method B is RSD(1) spectrophotometric method based on the simultaneous use of the first derivative of ratio spectra and measurement at 245 nm. Method C is a pH-induced difference (deltaA) spectrophotometry using UV measurement at 273 nm. Method D is a spectrodensitometric one, which depends on the quantitative densitometric evaluation of thin layer chromatogram of aceclofenac at 275 nm. Method E is RP-HPLC that depends on using methanol: water (60:40 v/v) as mobile phase at a flow rate of 1 ml/min and UV detection at 275 nm. Regression analysis of a beer's plot showed good correlation in the concentration ranges 5-40, 10-40, 15-50, 50-200, 1-50 microg/ml for methods A, B, C, D and E, respectively. These methods are suitable as stability indicating methods for the determination of aceclofenac in presence of its main degradation product, diclofenac. The proposed methods were applied for the analysis of the drug in its pharmaceutical formulation and the results obtained were compared with those obtained with the official B.P. method.     

Simultaneous Estimation of Metformin Hydrochloride and Pioglitazone Hydrochloride by RPHPLC Method from Combined Tablet Dosage Form

A high performance reverse phase liquid chromatographic procedure is developed for simultaneous estimation of metformin hydrochloride and pioglitazone hydrochloride in combined tablet dosage form. The mobile phase used was a combination of acetonitrile:water:acetic acid (60:40:0.3) and the pH was adjusted to 5.5 by adding triethylamine. The detection of the combined dosage form was carried out at 230 nm and a flow rate employed was 1 ml/min. Linearity was obtained in the concentration range of 0.015 to 0.120 μg/ml of pioglitazone hydrochloride and 0.5 to 4.0 μg/ml of metformin hydrochloride with a correlation coefficient of 0.9992 and 0.9975. The results of the analysis were validated statistically and recovery studies confirmed the accuracy and precision of the proposed method.     

RP-HPLC Method for Simultaneous Estimation of Frusemide and Amiloride Hydrochloride in Tablet Formulation

A new reverse phase high performance liquid chromatography method for the simultaneous estimation of frusemide and amiloride hydrochloride in tablet formulation is developed. The determination was carried out on a HIQ SIL, C18 (250×4.6 mm, 5 μm) column using a mobile phase of 50 mM phosphate buffer solution:acetonitrile (50:50 v/v, pH 3.0). The flow rate was 1.0 ml/min with detection at 283 nm. The retention time for frusemide was 3.038 min and for amiloride hydrochloride 10.002 min. Frusemide and amiloride hydrochloride showed a linear response in the concentration range of 20-200 μg/ml and 10-100 μg/ml, respectively. The results of analysis have been validated statistically and by recovery studies. The mean recoveries found for frusemide was 99.98% and for amiloride hydrochloride was 100.09%. Developed method was found to be simple, accurate, precise and selective for simultaneous estimation of frusemide and amiloride hydrochloride in tablets.     

Determination of cisapride in pharmaceutical preparations using derivative spectrophotometry

Derivative spectrophotometric and high performance liquid chromatographic methods (HPLC) were described for the determination of cisapride in pharmaceutical preparations. Spectrophotometrically, cisapride was determined by measuring the 1D-values at 264, 300 nm and 2D-values at 276, 290 and 276-290 nm. Beer's Law was obeyed in the range 2-12 microg ml(-1). The HPLC method depends upon using micropack-Si-10 column at ambient temperature with a mobile phase consisting of methanol-concentrated ammonia (99.25:0.75) at a flow rate of 1 ml min(-1). Quantitation was achieved by UV detection at 272 nm using quinine as internal standard. Calibration curve was linear over the concentration range 2-10 microg ml(-1). Both derivative spectrophotometry and HPLC methods showed good linearity, precision and reproducibility. No interference was found from tablet or suspension matrices at the selected derivative wavelengths and chromatographic conditions. The proposed methods were successfully applied to the assay of commercial tablets and suspension. The procedures were rapid, simple and suitable for quality control applications.