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.     

Simultaneous Determination of Ofloxacin and Ornidazole in Solid Dosage Form by RP-HPLC and HPTLC Techniques

The objective of this work was to develop and validate simple, rapid and accurate chromatographic methods for simultaneous determination of ofloxacin and ornidazole in solid dosage form. The first method was based on reversed phase high performance liquid chromatography, on Intersil C(18) column (250 mm, 4.6 i.d.), using acetonitrile:methanol: 0.025M phosphate buffer, pH 3.0 (30:10:60 % v/v/v) as the mobile phase, at a flow rate of 1 ml/min at ambient temperature. Quantification was achieved with UV detection at 318 nm over a concentration range of 2-40 μg/ml for ofloxacin and 5-100 μg/ml for ornidazole. The mean retention time of ofloxacin and ornidazole was found to be 4.04 min and 5.83 min, 6.77 min (isomers), respectively. The amount of ofloxacin and ornidazole estimated as percentage of label claimed was found to be 100.23 and 99.61%, with mean percent recoveries 100.20 and 100.93%, respectively. The second method was based on TLC separation of these drugs using silica gel 60F(254) aluminium sheets and dichloromethane:methanol:25% ammonia solution (9.5:1:3 drops v/v) as mobile phase. Detection was carried out at 318 nm over the concentration range of 20-100 ng/spot for ofloxacin and 50-250 ng/spot for ornidazole. The mean R(f) value of ofloxacin and ornidazole was found to be 0.16 and 0.56, 0.78 (isomers), respectively. The amount of ofloxacin and ornidazole estimated as percentage of label claimed was found to be 100.23 and 99.61% with mean percent recoveries 100.47 and 99.32%, respectively. Both these methods were found to be simple, precise, accurate, selective and rapid and could be successfully applied for the determination of pure laboratory prepared mixtures and tablets.     

Stability-indicating Simultaneous HPTLC Method for Olanzapine and Fluoxetine in Combined Tablet Dosage Form

A rapid, selective and stability-indicating high performance thin layer chromatographic method was developed and validated for the simultaneous estimation of olanzapine and fluoxetine in combined tablet dosage form. Olanzapine and fluoxetine were chromatographed on silica gel 60 F₂₅₄ TLC plate using methanol:toluene (4:2 v/v) as the mobile phase and spectrodensitometric scanning-integration was performed at a wavelength of 233 nm using a Camag TLC Scanner III. This system was found to give compact spots for both olanzapine (R_f value of 0.63±0.01) and fluoxetine (R_f value of 0.31±0.01). The polynomial regression data for the calibration plots showed good linear relationship with r²=0.9995 in the concentration range of 100-800 ng/spot for olanzapine and 1000-8000 ng/spot for fluoxetine with r²=0.9991. The method was validated in terms of linearity, accuracy, precision, recovery and specificity. The limit of detection and the limit of quantification for the olanzapine were found to be 30 and 100 ng/spot, respectively and for fluoxetine 300 and 1000 ng/spot, respectively. Olanzapine and fluoxetine were degraded under acidic, basic and oxidation degradation conditions which showed all the peaks of degraded product were well resolved from the active pharmaceutical ingredient. Both drugs were not further degraded after thermal and photochemical degradation. The method was found to be reproducible and selective for the simultaneous estimation of olanzapine and fluoxetine. As the method could effectively separate the drugs from their degradation products, it can be employed as a stability-indicating method.     

HPTLC Method for the Simultaneous Estimation of Valsartan and Hydrochlorothiazide in Tablet Dosage Form

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the simultaneous estimation of valsartan and hydrochlorothiazide in combined dosage forms. The stationary phase used was precoated silica gel 60F₂₅₄. The mobile phase used was a mixture of chloroform: methanol: toluene: glacial acetic acid (6:2:1:0.1 v/v/v/v). The detection of spots were carried out at 260 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 300 to 800 ng/spot for valsartan and 100 to 600 ng/spot for hydrochlorothiazide. The limit of detection and the limit of quantification for the valsartan were found to be 100 and 300 ng/spot respectively and for hydrochlorothiazide 30 and 100 ng/spot respectively. The proposed method can be successfully used to determine the drug content of marketed formulation.     

Spectrophotometric Method for Simultaneous Estimation of Escitalopram Oxalate and Clonazepam in Tablet Dosage Form

A simple, accurate and precise spectrophotometric method has been developed for simultaneous estimation of escitalopram oxalate and clonazepam in combined dosage form. Simultaneous equation method is employed for simultaneous determination of escitalopram oxalate and clonazepam from combined dosage forms. In this method, the absorbance was measured at 238 nm for escitalopram oxalate and 273 nm for clonazepam. Linearity was observed in range of 5-100 μg/ml and 5-50 μg/ml for escitalopram and clonazepam respectively. Recovery studies confirmed the accuracy of proposed method and results were validated as per ICH guidelines. The method can be used for routine quality control of pharmaceutical formulation containing escitalopram and clonazepam.     

RP-HPLC Method for Simultaneous Estimation of Nitazoxanide and Ofloxacin in Tablets

A reverse phase high performance liquid chromatography method was developed for simultaneous estimation of nitazoxanide and ofloxacin in tablet formulation. The separation and quantification was achieved by Hiq Sil C₁₈V Size 4.6 mm Ø ^*250 mm column in isocratic mode, with mobile phase consisting of acetonitrile-methanol-0.4 M citric acid, (60:30:10, v/v/v). Citric acid used to stabilize nitazoxanide and ofloxacin in mobile phase. The mobile phase was pumped at a rate of 0.6 ml/min and the detection was carried out at 304 nm. The retention time of ofloxacin and nitazoxanide was found to be 3.122 and 5.902 min, respectively. The method was validated for linearity, accuracy, and precision. Linearity for ofloxacin and nitazoxanide were in the range 2-36 μg/ml and 5-90 μg/ml, respectively. The developed method was found to be accurate, precise and selective for simultaneous estimation of ofloxacin and nitazoxanide in tablets.     

氧氟沙星氯化钠注射液有关物质测定方法的改进

目的改进氧氟沙星氯化钠注射液有关物质的测定方法。方法采用反相高效液相色谱（RP-HPLC）法，色谱柱为Agilent Zorbax Eclipse XDB—C18柱（250mm×4．6mm，5μm），流动相为草酸铵高氯酸钠溶液（取草酸铵2．0g和高氯酸钠3．5g，加水650mL使溶解，用磷酸调节pH值至2．2）-乙腈（85：15），流速为1．0mL／min，检测波长为294nm，柱温为35℃，进样量为10μL。结果在选定的色谱条件下，主峰和紧邻杂质峰能得到较好分离，精密度和理论塔板数很好。结论RP—HPLC法结果准确，分离效果好，可用于氧氟沙星氯化钠注射液有关物质的测定。     

RP-HPLC法测定复方氧氟沙星滴眼液中氧氟沙星的含量

目的 :应用反相高效液相色谱法测定复方氧氟沙星滴眼液中氧氟沙星的含量。方法 :用外标法 ,以Shim -packODS为固定相 ,枸橼酸 (0 05mol/L) -乙腈 -醋酸铵 (0 5mol/L) -0 3 %磷酸 (78∶22∶1∶3)为流动相 ,检测波长为293nm ,流速为1 0ml/min。结果 :氧氟沙星线性范围为8 12μg～40 6μg(r=0 9996 ,n=5) ,平均回收率为99 29 % ,RSD=0 57 % (n=6)。结论 :本法简便、快速、准确     

Simultaneous HPTLC Determination of Rabeprazole and Itopride Hydrochloride From Their Combined Dosage Form

A simple, precise, sensitive, rapid and reproducible HPTLC method for the simultaneous estimation of the rabeprazole and itopride hydrochloride in tablets was developed and validated. This method involves separation of the components by TLC on precoated silica gel G60F254 plate with solvent system of n-butanol, toluene and ammonia (8.5:0.5:1 v/v/v) and detection was carried out densitometrically using a UV detector at 288 nm in absorbance mode. This system was found to give compact spots for rabeprazole (Rf value of 0.23 0.02) and for itopride hydrochloride (Rf value of 0.75±0.02). Linearity was found to be in the range of 40-200 ng/spot and 300-1500 ng/spot for rabeprazole and itopride hydrochloride. The limit of detection and limit of quantification for rabeprazole were 10 and 20 ng/spot and for itopride hydrochloride were 50 and 100 ng/spot, respectively. The method was found to be beneficial for the routine analysis of combined dosage form.     

RP-HPLC法测定氧氟沙星栓中氧氟沙星的含量

目的建立反相高效液相色谱法测定氧氟沙星栓中氧氟沙星的含量。方法采用C18色谱柱(250mm×4.6mm,5μm),流动相为乙腈-0.05mol.L-1枸橼酸溶液(三乙胺调节pH4.0)(15∶85);检测波长为293nm。结果氧氟沙星质量浓度在20.02～400.3μg.mL-1范围内呈良好线性关系(r=0.999 7),平均加样回收率为99.3%(n=9),RSD为0.6%。结论该方法简便快速,结果准确,可作为该制剂含量测定的方法。     

Validated Stability-Indicating RP-HPLC Method for the Simultaneous Determination of Azelnidipine and Olmesartan in Their Combined Dosage Form

A simple, rapid, and highly selective RP-HPLC method was developed for the simultaneous determination of Azelnidipine (AZL) and Olmesartan (OLM) drug substances in the fixed dosage strength of 16 mg and 20 mg, respectively. Effective chromatographic separation was achieved using a Hypersil GOLD C18 column (150 mm × 4.6 mm internal diameter, 5 µm particle size) with a mobile phase composed of methanol, acetonitrile, and water in the ratio of 40:40:20 (by volume). The mobile phase was pumped using a gradient HPLC system at a flow rate of 0.5 mL/min, and quantification of the analytes was based on measuring their peak areas at 260 nm. The retention times for Azelnidipine and Olmesartan were about 8.56 and 3.04 min, respectively. The reliability and analytical performance of the proposed HPLC procedure were statistically validated with respect to system suitability, linearity, ranges, precision, accuracy, specificity, robustness, detection, and quantification limits. Calibration curves were linear in the ranges of 2–48 μg/mL for Azelnidipine and 2.5–60 μg/mL for Olmesartan with correlation coefficients >0.990. The proposed method proved to be selective and stability-indicating by the resolution of the two analytes from the forced degradation (hydrolysis, oxidation, and photolysis) products. The validated HPLC method was successfully applied to the analysis of AZL and OLM in their combined dosage form.     

Development and Validation of RP-HPLC Method for Simultaneous Estimation of Atorvastatin Calcium and Fenofibrate in Tablet Dosage Forms

A reverse phase high performance liquid chromatographic method was developed for the simultaneous estimation of atorvastatin calcium and fenofibrate in tablet formulation. The separation was achieved by Luna C18 column and methanol:acetate buffer pH 3.7 (82:18 v/v) as mobile phase, at a flow rate of 1.5 ml/min. Detection was carried out at 248 nm. Retention time of atorvastatin calcium and fenofibrate was found to be 3.02+0.1 and 9.05+0.2 min, respectively. The method has been validated for linearity, accuracy and precision. Linearity for atorvastatin calcium and Fenofibrate were in the range of 1-5 μg/ml and 16-80 μg/ml, respectively. The mean recoveries obtained for Atorvastatin calcium and fenofibrate were 101.76% and 100.06%, respectively. Developed method was found to be accurate, precise, selective and rapid for simultaneous estimation of atorvastatin calcium and fenofibrate in tablets.     

Hydrolytic Degradation Profile and RP-HPLC Estimation of Cilostazol in Tablet Dosage Form

A simple, selective, precise and stability-indicating high-performance liquid-chromatographic method of analysis of cilostazol in pharmaceutical dosage form was developed and validated. The solvent system consisted of 10 mM phosphate buffer (pH 6.0):acetonitrile:methanol (20:40:40). Retention time of cilostazol in C18 column was 5.7 ± 0.1 min at the flow rate 1.3 ml/min. Cilostazol was detected at 248 nm at room temperature. The linear regression analysis data for the calibration plots showed good linear relationship with correlation coefficient value, r ² =0.9998 in the concentration range 100–3200 ng/ml with slope 43.45 intercept 156.75. The method was validated for linearity, range, accuracy, precision and specificity. Cilostazol was determined in tablet dosage form in range of 99.58-100.67% with 0.4600 standard deviation. Stress studies were conducted in acid and alkali hydrolysis with gradual increasing concentration. Cilostazol was found to be stable in various concentrations of acidic and alkaline.     

零交导数分光光度法测定氧氟沙星葡萄糖注射液中氧氟沙星的含量

用零交导数分光光度法测定氧氟沙星葡萄糖注射液中氧氟沙星的含量。以278.4nm(峰）处的半振幅为定量依据，可排除注射液中葡萄糖分2解产物对测定的干扰。该方法平均回收率为100．16％，RSD＝0．47％。方法简便，快速，准确。     

HPLC法测定硝唑尼特中的3种有关物质

目的:建立HPLC法测定药物硝唑尼特中三种有关物质的方法.方法:色谱柱:Alltima C8(250 mm×4.6 mm,5 μm);流动相为乙腈-水(磷酸调节pH至2.5)梯度洗脱;流速:1.0 ml·min-1;柱温:25 ℃;检测波长210 nm.结果:硝唑尼特三种有关物质定量限分别为0.087 6,0.050 4,0.013 5 μg·ml-1,硝唑尼特峰的理论塔板数大于7 000,且与杂质峰的分离度大于1.5.结论:本方法专属性强、灵敏度高、准确性高,适宜分析硝唑尼特中的有关物质.     

RP-HPLC Method for the Estimation of Dutasteride in Tablet Dosage Form

A simple, sensitive and precise RP-HPLC method was developed for the determination of dutasteride in tablet dosage form. The RP-HPLC separation was achieved on phenomenex C₁₈ column (250 mm, id 4.6 mm, 5 μm) using mobile phase methanol:water (90:10 v/v) at a flow rate of 1 ml/min at an ambient temperature. Quantification was achieved with photodiode array detection at 235 nm over the concentration range 1-12 μg/ml. The method was validated statistically and was applied successfully for the determination of dutasteride in tablets.     

RP-HPLC Method for the Determination of Losartan Potassium and Ramipril in Combined Dosage Form

A simple, specific and accurate reverse phase liquid chromatographic method was developed for the simultaneous determination of losartan potassium and ramipril in table dosage forms. A hypersil ODS C18, 4.6×250 mm, 5 μm column in isocratic mode, with mobile phase acetonitrile:methanol:10 mM tetra butyl ammonium hydrogen sulphate in water in the ratio of 30:30:40% v/v/v was used. The flow rate was 1.0 ml/min and effluent was monitored at 210 nm. The retention times of losartan potassium and ramipril were 4.7 and 3.3 min, respectively. The linearity range for losartan potassium and ramipril were in the range of 0.04-100 μg/ml and 0.2-300 μg/ml, respectively. The proposed method was also validated and successfully applied to the estimation of losartan potassium and ramipril in combined tablet formulations.     

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.