A Validated Stability Indicating LC Method for Mitotane in Bulk Drugs and Pharmaceutical Dosage Forms

A novel, sensitive, stability indicating RP-LC method has been developed for the quantitative determination of mitotane, its impurity in both bulk drugs and pharmaceutical dosage forms. Efficient chromatographic separation was achieved using a C18 stationary phase with simple mobile phase combination delivered in an isocratic mode and quantitation was by ultraviolet detection at a wavelength of 230 nm. The mobile phase consisted of buffer and acetonitrile (25:75, v/v) delivered at a flow rate of 1.0 mL min^?1. Buffer consisted of 10 mM potassium dihydrogen orthophosphate monohydrate, pH adjusted to 2.5 by orthophosphoric acid. In the developed LC method the resolution (R _s ) between mitotane and its impurity namely Imp-1 was found to be greater than 2.5. Regression analysis shows an r value (correlation coefficient) greater than 0.999 for mitotane and its impurity. This method was capable to detect the impurity of mitotane at a level of 0.003% with respect to test a concentration of 0.2 mg mL^?1 for a 10 μL injection volume. The inter- and intra-day precision values for mitotane and its impurity was found to be within 2.0% RSD. The method has shown good and consistent recoveries for mitotane in bulk drugs (99.2–101.5%), pharmaceutical dosage forms (98.2–103.1%) and for its impurity (99.7–102.1%). The test solution was found to be stable in diluent for 48 h. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in basic stress hydrolysis. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.97%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness.     

A Stability Indicating LC Method for Deferasirox in Bulk Drugs and Pharmaceutical Dosage Forms

A novel, sensitive, stability indicating RP-LC method has been developed for the quantitative determination of deferasirox, its related impurities in both bulk drugs and pharmaceutical dosage forms. Efficient chromatographic separation was achieved on a C18 stationary phase with simple mobile phase combination delivered in an isocratic mode and quantitation was by ultraviolet detection at 245 nm. The mobile phase consisted of buffer, acetonitrile and methanol (50:45:5, v/v) delivered at a flow rate of 1.0 mL min^?1. Buffer consisted of 10 mM potassium dihydrogen orthophosphate monohydrate, pH adjusted to 3.0 by using orthophosphoric acid. In the developed LC method the resolution (R _s ) between deferasirox and its four potential impurities was found to be greater than 2.0. Regression analysis showed an r value (correlation coefficient) greater than 0.999 for deferasirox and its four impurities. This method was capable to detect all four impurities of deferasirox at a level of 0.002% with respect to test concentration of 0.5 mg mL^?1 for a 10 μL injection volume. The inter- and intra-day precision values for all four impurities and for deferasirox was found to be within 2.0% RSD. The method showed good and consistent recoveries for deferasirox in bulk drugs (98.3–101.1%), pharmaceutical dosage forms (100.2–103.1%) and for its all the four impurities (99.7–102.1%). The test solution was found to be stable in methanol for 48 h. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in acid stress hydrolysis. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.95%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness.     

Stability Indicating LC Assay Method for the Determination of Famciclovir in Bulk Drug and Pharmaceutical Dosage Forms

A simple isocratic stability indicating LC method was developed and validated for the determination of famciclovir in bulk drug and pharmaceutical dosage form. A mixture of 0.05 M potassium dihydrogen orthophosphate buffer and acetonitrile (80:20 v/v) was used as mobile phase at a flow rate of 1.0 mL min^?1. Hypersil BDS C18 (250 mm × 4.6 mm × 5 μm) column was used and the eluents were monitored at 220 nm. Forced degradation studies were performed for famciclovir active substance, reconstituted matrix and 500 mg tablets using the parameters like acid, base, peroxide, temperature, light, and relative humidity. Peak purity index was checked using PDA detection to demonstrate the specificity and stability indicating nature of the method. The developed method was validated for precision, ruggedness, linearity, LOD, LOQ, range, robustness and accuracy. The developed method can be used for regular quality control and stability study applications of famciclovir bulk drug and tablet dosage forms.     

A Validated LC Method for Determination of the Enantiomeric Purity of Montelukast Sodium in Bulk Drug Samples and Pharmaceutical Dosage Forms

A new and accurate chiral liquid chromatographic method has been developed for determination of the enantiomeric purity of montelukast sodium (R enantiomer) in bulk drugs and dosage forms. Normal phase chromatographic separation was performed on an immobilized amylose-based chiral stationary phase with n-hexane–ethanol–1,4-dioxane–trifluoroacetic acid–diethylamine 65:25:10:0.3:0.05 (v/v) as mobile phase at a flow rate of 1.0 mL min^?1. The elution time was approximately 15 min. The resolution (R _S) between the enantiomers was >3. The mobile phase additives trifluoroacetic acid and diethylamine played a key role in achieving chromatographic resolution between the enantiomers and also in enhancing chromatographic efficiency. Limits of detection and quantification for the S enantiomer were 0.07 and 0.2 μg, respectively, for a test concentration of montelukast sodium of 1,000 μg mL^?1 and 10 μL injection volume. The linearity of the method for the S enantiomer was excellent (R ² > 0.999) over the range from the LOQ to 0.3%. Recovery of the S enantiomer from bulk drug samples and dosage forms ranged from 97.0 to 103.0%, indicative of the high accuracy of the method. Robustness studies were also conducted. The sample solution stability of montelukast sodium was determined and the compound was found to be stable for a study period of 48 h.     

A Stability-Indicating LC Method for Analysis of Balsalazide Disodium in the Bulk Drug and in Pharmaceutical Dosage Forms

A novel, sensitive, stability-indicating gradient RP-LC method has been developed for quantitative analysis of balsalazide disodium and its related impurities both in the bulk drug and in pharmaceutical dosage forms. Efficient chromatographic separation was achieved on a C₁₈ stationary phase with a simple mobile-phase gradient prepared from methanol and phosphate buffer (10 mm potassium dihydrogen orthophosphate monohydrate, adjusted to pH 2.5 by addition of orthophosphoric acid). The mobile-phase flow rate was 1.0 mL min^?1. Quantification was achieved by use of ultraviolet detection at 240 nm. Under these conditions resolution of balsalazide disodium from its three potential impurities was greater than 2.0. Regression analysis resulted in a correlation coefficient greater than 0.99 for balsalazide disodium and all three impurities. This method was capable of detecting the three impurities at 0.003% of the test concentration of 0.3 mg mL^?1, using an injection volume of 10 μL. Inter-day and intra-day precision for all three impurities and for balsalazide disodium was within 2.0% RSD. Recovery of balsalazide disodium from the bulk drug (99.2–101.5%) and from pharmaceutical dosage forms (99.8–101.3%), and recovery of the three impurities (99.1–102.1%) was consistently good. The test solution was found to be stable in 70:30 (v/v) methanol–water for 48 h. When the drug was subjected to hydrolytic, oxidative, photolytic, and thermal stress, acidic and alkaline hydrolysis and oxidizing conditions led to substantial degradation. The RP-LC method was validated for linearity, accuracy, precision, and robustness.     

Stability Indicating HPTLC and LC Determination of Dasatinib in Pharmaceutical Dosage Form

Two sensitive and reproducible methods are described for the quantitative determination of dasatinib in the presence of its degradation products. The first method was based on high performance thin layer chromatography (HPTLC) followed by densitometric measurements of their spots at 280 nm. The separation was on HPTLC aluminium sheets of silica gel 60 F₂₅₄ using toluene:chloroform (7.0:3.0, v/v). This system was found to give compact spots for dasatinib after development (R _F value of 0.23 ± 0.02). The second method was based on high performance liquid chromatography (HPLC) of the drug from its degradation products on reversed phase, PerfectSil column [C₁₈ (5 μm, 25 cm × 4.6 mm, i.d.)] at ambient temperature using mobile phase consisting of methanol:20 mM ammonium acetate with acetic acid (45:55, v/v) pH 3.0 and retention time (t _R = 8.23 ± 0.02 min). Both separation methods were validated as per the ICH guidelines. No chromatographic interference from the tablet excipients was found. Dasatinib was subjected to acid–alkali hydrolysis, oxidation, dry heat, wet heat and photo-degradation. The drug was susceptible to acid–alkali hydrolysis and oxidation. The drug was found to be stable in neutral, wet heat, dry heat and photo-degradation conditions. As the proposed analytical methods could effectively separate the drug from its degradation products, they can be employed as stability indicating.     

A Validated Stability Indicating RPLC Method for Tazarotene

A simple, isocratic, rapid and accurate reversed phase high performance liquid chromatography method was developed for the quantitative determination of tazarotene. The developed method is also applicable for the related substance determination in bulk drugs. The chromatographic separation was achieved on a Hypersil C18 (250 mm × 4.6 mm 5 μm) column using water pH 2.5 with orthophosphoric acid:acetonitrile (15:85, v/v) as a mobile phase. The chromatographic resolutions between tazarotene and its potential impurity A and B were found greater than three. The limit of detection and limit of quantification of impurities were found to be 25 and 75 ng mL⁻¹. The percentage recovery of impurities in bulk drug sample was ranged from 96.8 to 103.5.The percentage recovery of tazarotene in bulk drug sample was ranged from 98.4 to 100.9. The developed RPLC method was validated with respect to linearity, accuracy, precision and robustness.     

Validated Voltammetric Method for the Simultaneous Determination of Anti‐diabetic Drugs,Linagliptin and Empagliflozin in Bulk,Pharmaceutical Dosage Forms and Biological Fluids

A cobalt oxide nanoparticles (Co₃O₄NPs) and multi walled carbon nanotubes (MWCNTs) modified carbon paste electrodes were used to study the electrochemical behavior of linagliptin and empagliflozin in Britton Robinson buffer solution of pH 8.0 using cyclic and square wave voltammetry. The above mentioned modified electrodes showed highly sensitive sensing and gave an excellent anodic response for both drugs. The peak current varied linearly over the concentration ranges: 3.98×10^?5–1.53×10^?3 mol L^?1 (18.82–723.00 μg/mL) and 7.94×10^?6–1.07×10^?4 mol L^?1 (3.65–48.25 μg/mL) with determination coefficients of 0.9999 and 0.9998 for linagliptin and empagliflozin, respectively. The recoveries and relative standard deviations were found in the following ranges: 98.80 %–102.00 % and 0.23 %–1.90 % for linagliptin and 98.30 %–101.80 % and 0.11 %–1.86 % for empagliflozin. The detection and quantification limits were 1.13×10^?5 and 3.76×10^?5 mol L^?1 (5.34and17.77 μg/mL) for linagliptin, 1.71×10^?6and 5.68×10^?6 mol L^?1 (0.77 and 2.56 μg/mL) for empagliflozin. The proposed sensors have been successfully applied for the determination of the drugs in bulk, pharmaceutical formulations and biological fluids.     

A Stability Indicating LC Method for Amtolmetin Guacyl

A simple, sensitive gradient RP-LC assay method has been developed for the quantitative determination of amtolmetin guacyl in bulk drug, used as anti-inflammatory drug. The developed method is also applicable for related substances determination. Efficient chromatographic separation was achieved on a C18 stationary phase with simple mobile phase combination delivered in a gradient mode and quantification was carried out using ultraviolet detection at 313 nm at a flow rate of 1.0 mL min^?1. In the developed LC method the resolution between Amtolmetin Guacyl and its three potential impurities was found to be greater than 2.0. Regression analysis shows an r value (correlation coefficient) greater than 0.99 for amtolmetin guacyl and its three impurities. This method was capable to detect all three impurities of amtolmetin guacyl at a level of 0.002% with respect to test concentration of 0.5 mg mL^?1 for a 10 μL injection volume. The inter- and intra-day precision values for all three impurities and for amtolmetin guacyl was found to be within 2.0% RSD at its specification level. The method has shown good and consistent recoveries for amtolmetin guacyl (99.2–101.5%) and its three impurities (94.5–104.8%). The test solution was found to be stable in diluent for 48 h. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. Considerable degradation was found to occur in oxidative stress conditions. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.6%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness.     

A Stability Indicating LC Method for Vardenafil HCl

A simple, sensitive gradient RP-LC assay method has been developed for the quantitative determination of vardenafil HCl in bulk drug and in pharmaceutical dosage forms, used to treat erectile dysfunction. The developed method is also applicable for the related substances determination. Efficient chromatographic separation was achieved on a C18 stationary phase with simple mobile phase combination delivered in a gradient mode and quantification was carried out using ultraviolet detection at a flow rate of 1.0 mL min^?1. In the developed LC method the resolution between vardenafil and its four potential impurities was found to be greater than 3.0. Regression analysis shows an r ² value (correlation coefficient) greater than 0.99 for vardenafil and its four impurities. This method was capable of detecting all four impurities of vardenafil at a level of 0.009% with respect to test concentration of 1.0 mg mL^?1 for a 10 μL injection volume. The method has shown good and consistent recoveries for vardenafil (98.4–100.6%) and its four impurities (93.5–106.2%). The test solution was found to be stable in the diluent for 48 h. Mass balance was found close to 99.4%.     

Stress Degradation Studies on Aripiprazole and Development of a Validated Stability Indicating LC Method

The present paper describes the development of a stability indicating reversed phase column liquid chromatographic method for aripiprazole in the presence of its impurities and degradation products generated from forced decomposition studies. The drug substance was subjected to stress conditions of aqueous hydrolysis, oxidative, photolytic and thermal stress degradation. The degradation of aripiprazole was observed under acid hydrolysis and peroxide. The drug was found to be stable to other stress conditions attempted. Successful separation of the drug from the synthetic impurities and degradation products formed under stress conditions was achieved on an Inertsil phenyl column using a mixture of 0.2% trifluoroacetic acid and acetonitrile (55:45, v/v). The developed LC method was validated with respect to linearity, accuracy, precision, specificity and robustness. The assay method was found linear in the range of 25–200 μg mL^?1 with a correlation coefficient of 0.9999 and the linearity of the impurities were established from LOQ to 0.3%. Recoveries of the assay and impurities were found between 97.2 and 104.6%. The developed LC method for the related substances and assay determination of aripiprazole can be used to evaluate the quality of regular production samples. It can also be used to test the stability samples of aripiprazole. To the best of our knowledge, the validated stability indicating LC method which separates all the impurities disclosed in this investigation was not published elsewhere.     

Stability-Indicating HPTLC Method of Carteolol in Bulk Drug and in Pharmaceutical Dosage Forms

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive, selective, precise and stability-indicating high-performance thin-layer chromatography (HPTLC) method was developed...     

Stability-Indicating LC Method for the Determination of Olmesartan in Bulk Drug and in Pharmaceutical Dosage Form

A novel stability-indicating LC assay method was developed and validated for quantitative determination of olmesartan in bulk drugs and in pharmaceutical dosage form in the presence of degradation products generated from forced degradation studies. An isocratic, reversed phase LC method was developed to separate the drug from the degradation products, using an Ace5-C18 (250 mm × 4.6 mm, 5 μm) column, and 50 mM ammonium acetate (pH-5.5 by acetic acid) and acetonitrile (70:30 v/v) as a mobile phase. The detection was carried out at the wavelength of 235 nm. The olmesartan was subjected to stress conditions of hydrolysis (acid, base), oxidation, photolysis and thermal degradation. Degradation was observed for olmesartan in acid, base and in 30% H₂O₂ conditions. The drug was found to be stable in the other stress conditions attempted. The degradation products were well resolved from the main peak. The percentage recovery of olmesartan ranged from (99.89 to 100.95%) in pharmaceutical dosage form. The developed method was validated with respect to linearity, accuracy (recovery), precision, specificity and robustness. The forced degradation studies prove the stability-indicating power of the method.

     

Stress Degradation Studies on Tadalafil and Development of a Validated Stability-Indicating LC Assay for Bulk Drug and Pharmaceutical Dosage Form

A stability-indicating HPLC assay method was developed for the quantitative determination of tadalafil in bulk samples and in pharmaceutical dosage forms in the presence of the degradation products. It involved a 250 mm × 4.6 mm, 5 μm C-18 column. The gradient LC method employs solution A and B as mobile phase. Solution A contains a mixture of buffer (phosphate buffer and tetra-n-butyl ammonium hydrogen sulfate) pH 2.5: acetonitrile (80:20, v/v) and solution B contains a mixture of water: acetonitrile (20:80, v/v). The flow rate was 1.0 mL min⁻¹ and the detection wavelength was 220 nm. The retention time of tadalafil is about 17 min. Tadalafil was subjected to different ICH prescribed stress conditions. Degradation was found to occur in hydrolytic and to some extent in oxidative stress conditions, while the drug was stable to photolytic and thermal stress. The drug was particularly labile under alkaline hydrolytic conditions. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. The assay of stress samples was calculated against a qualified reference standard and the mass balance was close to 99.5%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and ruggedness.     

LC-DAD Determination of Fleroxacin in Bulk and Pharmaceutical Dosage Forms

Fleroxacin is a third generation fluoroquinolone with broad spectrum antibacterial activity. In this work an LC-DAD method for the analysis of fleroxacin was developed and validated using UV detection at 286 nm. The method was validated for linearity, precision, robustness, LOD, LOQ, specificity and accuracy at concentrations of 0.2–20.0 μg mL⁻¹ and r ² = 1. The LOD and LOQ were 0.059 and 0.197 μg, respectively, the recoveries were 99.92–102.0% and the CV was less than 2.0%. The LC-DAD validated method provided analytical sensitivity, specificity and reproducibility suitable for quality control analysis.

     

LC-DAD Determination of Fleroxacin in Bulk and Pharmaceutical Dosage Forms

Fleroxacin is a third generation fluoroquinolone with broad spectrum antibacterial activity. In this work an LC-DAD method for the analysis of fleroxacin was developed and validated using UV detection at 286 nm. The method was validated for linearity, precision, robustness, LOD, LOQ, specificity and accuracy at concentrations of 0.2–20.0 μg mL⁻¹ and r ² = 1. The LOD and LOQ were 0.059 and 0.197 μg, respectively, the recoveries were 99.92–102.0% and the CV was less than 2.0%. The LC-DAD validated method provided analytical sensitivity, specificity and reproducibility suitable for quality control analysis.     

Spectrophotometric Determination of Ondansetron Hydrochloride in Pharmaceutical Bulk and Dosage Forms

A rapid, simple and accurate spectrophotometric method is developed for the determination of ondansetron hydrochloride in pure and tablet formulations. The method depends on the charge‐transfer complexation between ondansetron base as n‐electron donor with chloranil as π‐acceptor to give a colored complex, which absorbs maximally at 470 nm. Beer's law is obeyed in the concentration ranges 70–980 μg mL^?1 with molar absorptivity of 4.47 × 10² L mole^?1 cm^?1. The proposed method is precise, accurate and specific for the quantitative determination of drug in bulk and tablet formulations.     

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.     

Stability-Indicating LC Determination of Nitazoxanide in Bulk Drug and in Pharmaceutical Dosage Form

A novel stability-indicating high-performance liquid chromatographic assay method was developed and validated for quantitative determination of nitazoxanide in bulk drugs and in pharmaceutical dosage form in the presence of degradation products generated from forced decomposition studies. An isocratic, reversed phase LC method was developed to separate the drug from the degradation products, using an Ace5- C18 (250 mm × 4.6 mm, 5 μm) column, and 50 mM ammonium acetate (pH 5.5 by acetic acid) and acetonitrile (55:45 v/v) as a mobile phase. The detection was carried out at a wavelength of 240 nm. The nitazoxanide was subjected to stress conditions of hydrolysis (acid, base), oxidation, photolysis and thermal degradation. Degradation was observed for nitazoxanide in base, acid and in 30% H₂O₂ conditions. The drug was found to be stable in the other stress conditions attempted. The degradation products were well resolved from the main peak. The percentage recovery of nitazoxanide was from (100.55 to 101.25%) in the pharmaceutical dosage form. The developed method was validated with respect to linearity, accuracy (recovery), precision, system suitability, specificity and robustness. The forced degradation studies prove the stability indicating power of the method.