Stability-indicating Reversed-phase Liquid Chromatographic Method Research Articles

Origanum majorana L. polyphenols: in vivo antiepileptic effect, in silico evaluation of their bioavailability, and interaction with the NMDA receptor.

Introduction: Epilepsy is a chronic brain disease characterized by repeated seizures and caused by excessive glutamate receptor activation. Many plants are traditionally used in the treatment of this disease. This study aimed to evaluate the bioavailability of a polyphenolic extract obtained from Origanum majorana L. (OMP) leaves, as well as its antiepileptic activity and its potential mechanism of action. Methods: We have developed and validated a simple, rapid, and accurate stability-indicating reversed-phase liquid chromatographic method for the simultaneous determination of caffeine and quercetin in rat plasma. The OMP antiepileptic effect was evaluated with pilocarpine-induced seizures, and a docking method was used to determine the possible interaction between caffeic acid and quercetin with the N-methyl-D-aspartate (NMDA) receptor. Results and Discussion: Both compounds tested showed low bioavailability in unchanged form. However, the tested extract showed an anticonvulsant effect due to the considerably delayed onset of seizures in the pilocarpine model at a dose of 100mg/kg. The molecular docking proved a high-affinity interaction between the caffeic acid and quercetin with the NMDA receptor. Taken together, OLP polyphenols demonstrated good antiepileptic activity, probably due to the interaction of quercetin, caffeic acid, or their metabolites with the NMDA receptor.

Using the AQbD Approach, Development and Validation of a Simple, Rapid Stability Indicating Chromatographic Method for Quantification of Related Impurities of Apixaban.

Apixaban is a new oral anticoagulant that has been approved by the United States Food and Drug Administration for the prevention of stroke and other cardiovascular complications in people with non-valvular atrial fibrillation. Then, later, it was given the green light to treat deep venous thrombosis and pulmonary embolism. The biggest challenge in the development of pharmaceutical drugs is comprehending science- and risk-based techniques for developing and maintaining analytical procedures appropriate for evaluating the quality of drug substances and drug products. The improved technique provides a methodical strategy to acquire and improve understanding of an analytical method. The current study discusses the related substances method development for an apixaban drug substance employing a regulated authority refined and approved approach of the quality-by-design concept. For the quantification of impurities, and apixaban drug substance, a simple, quick and stability-indicating reverse-phase liquid chromatographic method was developed using a full factorial design. The separation between apixaban and its nine impurities was accomplished using an Zorbax Stable Bond Phenyl, 150 × 4.6mm, 5μm column. The mobile-phase components for gradient elution at a flow rate of 1.2mL/min were chosen to be a mixture of water, acetonitrile, methanol and perchloric acid in various ratios with a total run time of 15min. Chromatograms were extracted at 278nm after a 5μL solution injection. According to regulatory requirements, the developed method has been validated for its intended purpose.

Development, Validation of RP-HPLC Method and GC MS Analysis of Desloratadine HCL and IT"s Degradation Products

Introduction: Efficacy and safety of drug therapy is directly related to the stability of active pharmaceutical ingredient (API) and drug product used. Forced degradation studies (also called stress testing) are performed for better understanding of API and drug product stability. Thus, stress testing is a prognostic research tool used to ascertain stability of drug molecules and provide support for developing a stability-indicating method. Aim: The research aim is Development, Validation of RP-HPLC Method and GC MS Analysis of Desloratadine HCL and Its Degradation Products. Objective: The objective of the current study was to develop a validated specific stability-indicating reversed-phase liquid chromatographic method for the quantitative determination of Desloratadine HCl in bulk samples in the presence of degradation products. Method: Desloratadine HCL was subjected to variable pH, oxidative, dry heat and photolytic stress condition as per ICH guideline for the stability study. Stressed samples were further studied by the validated RP-HPLC method and also studied by GC-MS to characterize degradation products (Fig 15). Result: At oxidative stress, degradation products were generated and detected by GCMS. Slight degradation was observed in acidic and alkaline stress while no degradation was observed in other stress conditions. Separation of degradation products from pure drug was achieved on C18 column 5µ (4.6 X 250 mm) using the mobile phase consists a mixture of Orthophosphoric acid (0.1%V/V), Acetonitrile and Methanol (50:35:15 V/V/V). The detection was carried out at 242 nm. The proposed validated LC method was used to quantify the stressed test solutions in order to ascertain stability-indicating potential of the method. Conclusion: The established LC approach has been shown to be suitable for determining the quality of Desloratadine HCl from its dosage form and assessing its stability when required.

High Performance Liquid Chromatographic–Diode Array Detector Method for Simultaneous Determination of Aspirin, Caffeine and Ephedrine in Weight Loss Formulations, Human Plasma and in vitro Drug–Drug Interaction Studies

A simple, rapid and accurate stability-indicating reversed-phase liquid chromatographic method was developed and validated for the simultaneous determination of aspirin, caffeine and ephedrine in weight loss formulations, human plasma and for the study of in vitro drug−drug interactions. Optimum chromatographic separation for aspirin, caffeine and ephedrine was achieved within 4.5 min on a Teknokroma C18 column (250 × 4.6 mm, 5 μm) with a mobile phase consisting of acetonitrile and water (55 : 45) at pH 3.18 with the flow rate of 1 mL/min with detection wavelengths of 210 and 254 nm. The method was validated in accordance with the ICH guidelines with respect to linearity, accuracy, precision, robustness, specificity, limits of detection and quantitation. Regression analysis showed good correlations (R2 > 0.998) in the concentration ranges of 100–1000, 50–500 and 20–100 μg/mL for aspirin, caffeine and ephedrine, respectively. The study of in vitro drug−drug interaction showed that the interaction of ephedrine with aspirin and caffeine was pH dependent. The proposed method is suitable for routine quality control analysis of related weight loss formulations and for stability studies.

NOVEL NOVEL STABILITY-INDICATING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC ASSAY METHOD FOR SIMULTANEOUS ESTIMATION OF HYDROCORTISONE AND TETRACYCLINE IN BULK AND PHARMACEUTICAL DOSAGE FORM

Objective: A combination of hydrocortisone and tetracycline as topical ophthalmic ointment is used for skin irritations, eye infections, inflammation, skin infections, acne, and rashes. The objective of the current work is to a simple, rapid, accurate, and precise, stability-indicating reverse-phase liquid chromatographic method was developed for the simultaneous estimation of hydrocortisone and tetracycline in bulk and pharmaceutical dosage form.
 Methods: The separation was carried out in Discovery C18 column (250 × 4.6 mm, 5 μm) using mobile phase ratio of water (pH 2.2 adjusted with orthophosphoric acid):acetonitrile (40:60 v/v) in an isocratic elution mode with a flow rate of 1.0 ml/min at detection wavelength of 244 nm. The injection volume was 10 μl and the column temperature was set at 30°C.
 Results: The retention time for hydrocortisone and tetracycline was found to be 2.214 ± 0.001 min and 3.497 ± 0.001 min, respectively. Calibration curves were linear (r2=0.999) at a concentration range of 2.5–15 mg/ml for both hydrocortisone and tetracycline. The percentage recoveries were found to be 99.13–99.67% for hydrocortisone and 99.39–99.61% for tetracycline. Relative standard deviation was found to be 0.3% for both the drugs. Limit of detection and limit of quantification values of hydrocortisone and tetracycline were found to be 0.09 μg/ml and 0.27 μg/ml and 0.17 μg/ml and 0.52 μg/ml, respectively. The drugs were subjected to various stress conditions and found no interference of degraded products peak at the retention times of analyte peaks.
 Conclusion: A rapid and accurate reverse-phase high-performance liquid chromatographic method was developed for simultaneous estimation of hydrocortisone and tetracycline, and the method was validated as per the International Council for Harmonization guidelines. Hence, the developed method can be successfully applied for the simultaneous estimation of hydrocortisone and tetracycline in bulk and ointment formulation.

A NOVEL STABILITY-INDICATING REVERSE PHASE LIQUID CHROMATOGRAPHIC METHOD FOR THE SIMULTANEOUS ESTIMATION OF METFORMIN AND TENELIGLIPTIN IN PURE AND PHARMACEUTICAL FORMULATIONS

Objective: The present method was proposed to develop a simple, sensitive, rapid, accurate and stability-indicating reverse phase liquid chromatographic method for the simultaneous estimation of metformin and teneligliptin in pure and pharmaceutical formulations. Methods: The chromatographic separation was done on Discovery [250 mm X 4.6 mm: 5 μm is particle size] using a mobile phase composed of 0.1% orthophosphoric acid buffer: acetonitrile [65:35, v/v], the flow rate is 1 ml/min and the detection was carried out at 260 nm.Results: The retention time of metformin and teneligliptin were found to be 2.517 min and 3.687 min, respectively. Stability indicating studies were conducting under the guidelines of an international conference on harmonization [ICH] Q1A R2 and the developed method was validated as per guidelines of ICH Q2 RI. The linearity was found in the range of concentration of 125-750 μg/ml and 5-30 μg/ml for metformin and teneligliptin. The detection of limit and quantification of limit was found to be 0.02 μg/ml and 0.07 μg/ml for metformin and 0.19 μg/ml and 0.56 μg/ml for teneligliptin, respectively.Conclusion: A novel stability-indicating reverse-phase liquid chromatographic method for the simultaneous estimation of metformin and teneligliptin. The proposed method was adopted for the routine estimation of metformin and teneligliptin in bulk and pharmaceutical dosage forms.

Stability-indicating RP-LC method for quantification of fusidic acid in cream

Fusidic acid is an antibiotic steroid indicated for the treatment of infections caused by the genus Staphylococcus, including methicillin resistant Staphylococcus aureus strains, and other Gram-positive bacteria. In the present study, a stability-indicating reversed-phase liquid chromatography (RP-LC) method was developed and validated for the determination of fusidic acid in dermatological cream as an alternative to existing methods. Analyses were performed using a C18 column and guard column at room temperature, eluting with an isocratic mobile phase of acetonitrile and water (72:28, v/v), adjusted to pH 3.5 with acetic acid, pumped at a flow rate of 1.0 mL min-1, detection at 210 nm and 20 µL of injection volume. The forced degradation study was conducted under acidic, alkaline, neutral, photolytic, and oxidative stress conditions. The method was validated according to ICH and FDA guidelines; it was linear, precise, accurate, selective, and robust over concentrations of 5-95 µg mL-1, with detection and quantification limits of 0.43 and 1.31 μg mL-1, respectively. Therefore, we conclude that this method is suitable for quantifying fusidic acid in pharmaceutical dermatological creams and determining its stability, representing a more economical and practical alternative for routine analysis in quality control.

Development and Validation of A Stability-Indicating RP-HPLC Method for the Determination of Sitagliptin Phosphate and Simvastatin in the Presence of their Degradation Products in Bulk and Binary Mixture

A simple, selective, and precise stability-indicating reversed-phase liquid chromatographic method has been developed and validated for the determination of sitagliptin phosphate monohydrate (STG); and simvastatin (SIM) in the presence of acid and alkali degradation products of STG, and the hydrolytic degradation product of SIM. The method was based on gradient elution on a reversed phase C18 column (150 mm × 4.6 mm, 5 μm)— Cosmosil using a mobile phase consisting of acetonitrile and 10mM potassium dihydrogen orthophosphate (pH 3.0; 0.01M) (85: 15% v/v) and flow rate 1.0ml/min. Quantitation was achieved using UV detection at 225 nm for SIT and SIM and their degradation product was achieved. Linearity, accuracy, and precision were found tobe acceptable over the concentration ranges of 20–100 μg mL−1 and 0.4–20 μg mL−1 for STG and SIM, respectively. Limits of detection and quantitation for SIT were found to be 5.65 ng and 17.12 ng, respectively, while for SIM were found to be 2.72 ng and 8.25 ng, respectively. The proposed method was validated as per ICH guideline.

Forced degradation study and validated stability-indicating RP-LC method for determination of nilotinib in bulk and capsules

A simple, selective, and precise stability-indicating reversed-phase liquid chromatographic method was developed and validated for the determination of nilotinib. Nilotinib was subjected to acid and alkali hydrolysis, oxidation, thermal, and photo-degradation. The degradation products were well separated from the pure drug. The method was based on isocratic elution of nilotinib and its degradation products on reversed phase C18 column (100 mm × 4.6 mm, 3.5 μm) — Zorbax Eclipse Plus using a mobile phase consisting of 10 mM KH2PO4:acetonitrile (54.5:45.5%, v/v) at a flow rate of 1 mL min−1. Quantitation was achieved with UV detection at 265 nm. Linearity, accuracy and precision were found to be acceptable over the concentration range of 0.1–80 μg mL−1. The drug was found to be susceptible to acid and base hydrolysis but resistant to oxidation, dry heat degradation, and photodegradation. The proposed method was successfully applied to the determination of nilotinib in bulk and in its pharmaceutical preparation.

Validated stability-indicating liquid chromatographic method for the determination of ribavirin in the presence of its degradation products: application to degradation kinetics.

Ribavirin was found to be liable to acidic, alkaline, oxidative and photolytic degradation. Hence, a simple, sensitive and stability-indicating reversed-phase liquid chromatographic method was developed and validated for the determination of ribavirin in the presence of its degradation products. The analysis was carried out on an ODS C18 (250 × 4.6 mm i.d.) stainless steel column using a mobile phase consisting of 0.02 M potassium dihydrogen phosphate. The analysis was performed at ambient temperature with a flow rate of 1 mL/min and UV detection at 207 nm. Pyridoxine hydrochloride was used as an internal standard. The method showed good linearity over the concentration range of 2.0-40 µg/mL with limit of detection of 0.34 µg/mL and limit of quantification of 1.03 µg/mL. The suggested method was successfully applied for the analysis of ribavirin in its commercial capsules. Statistical evaluation and comparison of the data obtained by the proposed and comparison method revealed good accuracy and precision of the proposed method. The drug was exposed to forced alkaline, acidic, oxidative and photolytic degradation according to the ICH guidelines. Moreover, the method was utilized to investigate the kinetics of alkaline and acidic degradation of the drug. The apparent first-order rate constants, half-life times and activation energies of the degradation process were calculated.

DEVELOPMENT AND VALIDATION OF A STABILITY-INDICATING RP-LC METHOD FOR THE DETERMINATION OF SITAGLIPTIN AND SIMVASTATIN IN THE PRESENCE OF THEIR DEGRADATION PRODUCTS IN BULK DRUG MIXTURE AND COMBINED PHARMACEUTICAL PREPARATIONS

□ A simple, selective, and precise stability-indicating reversed-phase liquid chromatographic method has been developed and validated for the determination of the first Food and Drug Administration (FDA) approved fixed-dose combination for both diabetes type II and high cholesterol; sitagliptin phosphate monohydrate (SIT); and simvastatin (SIM) in the presence of acid and alkali degradation products of SIT, and the hydrolytic degradation product of SIM. The method was based on gradient elution on a reversed phase C8 column (250mm×4.6mm, 5 µm)—Zorbax SB using a mobile phase consisting of 0.01M potassium dihydrogen orthophosphate (pH=2.6) and acetonitrile. Quantitation was achieved using UV detection at 210nm for SIT and its degradation products, while quantitation of SIM and its degradation product was achieved using UV detection at 240nm. Linearity, accuracy, and precision were found to be acceptable over the concentration ranges of 0.5–200µ g mL −1 and 0.5–100 µ g mL −1 for SIT and SIM, respectively. Limits of detection and quantitation for SIT were found to be 5.65ng and 17.12ng, respectively, while for SIM were found to be 2.72ng and 8.25ng, respectively. The proposed method was successfully applied to the determination of the cited drugs in bulk and in their combined pharmaceutical preparations.

A Validated Specific Stability-Indicating RP-HPLC Assay Method for Ambrisentan and Its Related Substances

A validated specific stability-indicating reverse-phase liquid chromatographic method was developed for the quantitative determination of Ambrisentan as well as its related substances in bulk samples, pharmaceutical dosage forms in the presence of degradation products and its related impurities. Forced degradation studies were performed on bulk samples of Ambrisentan as per the ICH-prescribed stress conditions using acid, base, oxidative, thermal stress and photolytic degradation to show the stability-indicating power of the LC method. Significant degradation in acidic, basic stress conditions was observed and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from the forced degradation studies and the impurity-spiked solution. Good resolution between the peaks corresponds to Ambrisentan-related impurities and degradation products from the analyte were achieved on a SunFire C18 column using a mobile phase consisting of a mixture of potassium dihydrogen orthophosphate at a pH adjusted to 2.5 with ortho-phosphoric acid in water and a mixture of acetonitrile:methanol using a simple linear gradient. The detection was carried out at 225 nm. The limit of detection and the limit of quantification for the Ambrisentan and its related impurities were established. The stressed test solutions were assayed against the qualified working standard of Ambrisentan and the mass balance in each case was between 98.9 and 100.3%, indicating that the developed LC method was stability indicating. Validation of the developed LC method was carried out as per the ICH requirements. The developed method was found to be suitable to check the quality of bulk samples of Ambrisentan at the time of batch release and also during its storage (long-term and accelerated stability).

Validation of a Stability-Indicating RP-LC Method for the Determination of Tigecycline in Lyophilized Powder

A reversed-phase liquid chromatography (RP-LC) method was validated for the determination of tigecycline in lyophilized powder. The LC method was conducted on a Luna C18 column (250 × 4.6 mm i.d.), maintained at room temperature. The mobile phase consisted of buffer containing sodium phosphate monobasic (0.015M) and oxalic acid (0.015M) (pH 7.0)-acetonitrile (75:25, v/v), run at a flow rate of 1.0 mL/min and using ultraviolet detection at 280 nm. The chromatographic separation was obtained with a retention time of 8.6 min, and was linear in the range of 40-100 µg/mL (r(2) = 0.9997). The specificity and stability-indicating capability of the method was proven through forced degradation studies, which also showed no interference of the excipients. The accuracy was 99.01% with a bias lower than 1.81%. The limits of detection and quantitation were 1.67 and 5.05 µg/mL, respectively. Moreover, method validation demonstrated satisfactory results for precision and robustness. The proposed method was applied for the analysis of the lyophilized powder formulation, contributing to improve the quality control and to assure the therapeutic efficacy.

Development of a Stability-Indicating RP-LC Method for the Separation of a Critical Pair of Impurities and their Degradants in Zafirlukast

A high-throughput reverse-phase liquid chromatographic (RP-LC) method is developed for the quantification of zafirlukast and its related impurities in drug substance. The separation of known impurities is accomplished using a short (50 mm) LC column with sub-2-µm particle size in a relatively short run-time. A linear gradient elution involves ammonium formate and acetonitrile as mobile phase. The critical impurity pair is the meta and para isomers of zafirlukast, which are known to be potential impurities of zafirlukast, whose resolution is sensitive to pH. The stability-indicating capability of the developed method is demonstrated using forced degradation samples from stress conditions such as hydrolysis, oxidation, thermal and photolytic degradation. The developed RP-LC method is validated in accordance with International Conference on Harmonization requirements. The results from the validation study indicate that this RP-LC method can be used for the determination of synthetic and degradation impurities in regular quality control analysis for the drug substance.

Stability-Indicating RP-LC Method for the Determination of Vildagliptin and Mass Spectrometry Detection for a Main Degradation Product

A simple, precise and stability-indicating reversed-phase liquid chromatography method was developed and validated for the determination of vildagliptin (VLG) in pharmaceutical dosage form. The chromatographic separation was obtained within 6 min and was linear in the range of 20-80 µg/mL (r(2) = 0.9999). Limit of detection and limit of quantitation were 0.63 and 2.82 µg/mL, respectively. The method was validated in accordance with International Conference on Harmonization acceptance criteria for specificity, linearity, precision, accuracy, robustness and system suitability. Stress studies were carried out and no interference of the degradation products was observed. The excipients did not interfere in the determination of VLG. Furthermore, the main degradation product obtained from the stress studies (thermal, oxidative and alkaline hydrolysis) was evaluated for mass spectrometry and its molecular structure was predicted. The proposed method was successfully applied for the quantitative analysis of VLG in tablet dosage form, which will help to improve quality control and contribute to stability studies of pharmaceutical tablets containing this drug.

Validation of a Stability-indicating RP-LC Method for the Assessment of Recombinant Human Interleukin-11 and Its Correlation with Bioassay

A stability-indicating reversed-phase liquid chromatography (RP-LC) method was validated for the assessment of recombinant human interleukin-11 (rhIL-11), based on the ICH guidelines. The method was carried out on a Jupiter C(4) column (250 mm × 4.6 mm i.d.), maintained at 25°C. The mobile phase A consisted of 0.1% trifluoroacetic acid (TFA) and the mobile phase B was acetonitrile with 0.1% TFA, run at a flow rate of 1 mL/min, and using a photodiode array (PDA) detection at 214 nm. Separation was obtained with a retention time of 27.6 min, and was linear over the concentration range of 1-200 µg/mL (r(2) = 0.9995). Specificity was established in degradation studies, which also showed that there was no interference of the excipients. The accuracy was 100.22% with bias lower than 1.25%. Moreover, the in vitro cytotoxicity test of the degraded products showed non-significant differences (p > 0.05). The method was applied to the assessment of rhIL-11 and related proteins in biopharmaceutical dosage forms, and the results were correlated to those of a bioassay.

Stability-indicating reversed-phase liquid chromatographic method for simultaneous determination of losartan potassium and ramipril in tablets

A stability-indicating reversed-phase liquid chromatographic method has been developed and validated for simultaneous determination of losartan potassium and ramipril. Separations were achieved using a C18 column with mobile phase consisting of acetonitrile and (0.2% v/v, pH 2.5) aqueous trifluoroacetic acid (45:55, v/v) in isocratic mode at 1 ml/min flow rate. Column effluent was monitored at 210 nm using a UV detector. The method was validated for selectivity, linearity, accuracy, precision, sensitivity and robustness. Novel microwave-assisted forced degradation technique was employed for evaluation of selectivity. The method demonstrated excellent linearity for losartan potassium and ramipril with regression coefficients of 0.9999 and 0.9998, respectively. The linearity range was found to be 62.5-5000 ng/ml and 125-10,000 ng/ml with the mean percentage recoveries of 100.36% (±2.27) and 100.16% (±3.33) for losartan potassium and ramipril, respectively. In a robustness study, a full factorial design revealed that the analytical response remains unaffected by small variations in the critical chromatographic factors. The method was found to be sensitive with quantification limits of 44.30 and 79.93 ng/ml for losartan potassium and ramipril. The method was successfully employed for the determination of losartan potassium and ramipril in commercially available and in-house prepared tablets.

Stability-indicating HPLC Method for the Determination of Atenolol in Pharmaceutical Preparations

A stability-indicating reversed-phase liquid chromatographic method for the determination of atenolol was developed. Different chromatographic conditions were carefully studied to optimize the parameters for the evaluation of the studied drug. The chromatographic assay involved the use of a C8 Column (250 mm×4.6 mm i.d., 5 μm) with a simple mobile phase composed of acetonitrile:methanol:0.02 M phosphate buffer, pH 5 (20:20:60) at a flow rate of 1 ml/min and UV detection at 226 nm. Pindolol was used as an internal standard. The method showed good linearity over the range of 0.05-10 μg/mL with a detection limit of 0.01 μg/mL and a quantitation limit of 0.03 μg/mL. The proposed method was successfully applied for the analysis of atenolol in three commercial tablets with average percent recoveries of 100.14 ± 1.04, 100.20 ± 0.92, 100.00 ± 0.91 and 100.75 ± 0.67, respectively. Several co-formulated and co-administered drugs did not interfere with the proposed method. The results were statistically compared with those obtained by the official method and were found to be in good agreement. The stability-indicating capability of the method was also tested after accelerated degradation of atenolol in acidic and basic media and after freezing and heating treatments.

Stress Degradation Studies on Varenicline Tartrate and Development of a Validated Stability-Indicating HPLC Method

A simple, rapid and stability-indicating reversed-phase liquid chromatographic method was developed for the assay of varenicline tartrate (VRT) in the presence of its degradation products generated from forced decomposition studies. The HPLC separation was achieved on a C18 Inertsil column (250 mm × 4.6 mm i.d. particle size is 5 μm) employing a mobile phase consisting of ammonium acetate buffer containing trifluoroacetic acid (0.02M; pH 4) and acetonitrile in gradient program mode with a flow rate of 1.0 mL min−1. The UV detector was operated at 237 nm while column temperature was maintained at 40 °C. The developed method was validated as per ICH guidelines with respect to specificity, linearity, precision, accuracy, robustness and limit of quantification. The method was found to be simple, specific, precise and accurate. Selectivity of the proposed method was validated by subjecting the stock solution of VRT to acidic, basic, photolysis, oxidative and thermal degradation. The calibration curve was found to be linear in the concentration range of 0.1–192 μg mL−1 (R2 = 0.9994). The peaks of degradation products did not interfere with that of pure VRT. The utility of the developed method was examined by analyzing the tablets containing VRT. The results of analysis were subjected to statistical analysis.

Forced degradation study to develop and validate stability-indicating RP-LC method for the determination of ciclesonide in bulk drug and metered dose inhalers

A simple, selective and precise stability-indicating reversed-phase liquid chromatographic method was developed and validated for the determination of ciclesonide. Ciclesonide was subjected to acid and alkali hydrolysis, oxidation, thermal and photo-degradation. The degradation products were well separated from the pure drug. The method was based on isocratic elution of ciclesonide and its degradation products on reversed phase C18 column (250mm×4.6mm, 10μm) – Phenomenex using a mobile phase consisting of ethanol–water (70:30, v/v) at a flow rate of 1mLmin−1. Quantitation was achieved with UV detection at 242nm. Linearity, accuracy and precision were found to be acceptable over the concentration range of 5–200μgmL−1. Desisobutyryl-ciclesonide was prepared by selective alkaline hydrolysis of the ester and proved to be the main degradation product. The proposed method was successfully applied to the determination of ciclesonide in bulk and in its pharmaceutical preparation.