Induced Degradation Products Research Articles

Simultaneous equation and area under the curve spectrophotometric methods for estimation of cefaclor in presence of its acid induced degradation product; A comparative study

Two simple spectrophotometric methods were developed and validated for determination of cefaclor in presence of its acid induced degradation product; namely simultaneous equation method using two wavelengths 265 and 235 nm Method (A) and Area under the curve method using two wavelength ranges (230–240) nm and (260–270) nm Method (B). The accuracy, precision and linearity ranges of the proposed methods were determined. The methods were validated and the specificity was assessed by analyzing synthetic mixtures containing the drug and its degradate. The two methods were applied for the determination of the cited drug in its pharmaceutical preparation and the obtained results were statistically compared with those of a reported method. The comparison showed that there is no significant difference between the proposed methods and the reported method regarding both accuracy and precision.

Reversed-Phase Liquid Chromatographic Method for Determination of Daclatasvir Dihydrochloride and Study of Its Degradation Behavior

A simple and selective reversed-phase stability-indicating liquid chromatographic method has been developed and validated for the determination of daclatasvir in drug substance and drug product. Daclatasvir was subjected to acidic, alkaline, oxidative, thermal and photo-degradation study. The LC method was based on isocratic elution of daclatasvir and its degradation products on a reversed-phase C18 Hypersil column using a mobile phase consisting of phosphate buffer (10 mM, 1 mL triethylamine L−1): acetonitrile (60:40 v/v) at a flow rate of 2 mL min−1. Quantitation was achieved with UV detection at 312 nm. Linearity, accuracy, and precision were found to be acceptable over the concentration range of 0.75–120 μg mL−1, with regression coefficient value of 0.9999, and with limit of detection and quantitation of 0.148 and 0.447 μg mL−1, respectively. Peak purity was checked for principle drug and its alkali induced degradation product, and the pathway of alkaline hydrolysis of daclatasvir was suggested by LC/MS.

Stability indicating RP-HPLC method for simultaneous determination of gatifloxacin and dexamethasone in binary combination

In this study, conditions were optimized for development of a simple RP-HPLC method for simultaneous analysis of gatifloxacin and dexamethasone in different matrices like pharmaceuticals, human serum and urine. Good separation of gatifloxacin and dexamethasone from the induced degradation products was accomplished using C8 as stationary phase; 0.02 M phosphate buffer (pH 3.0) and methanol (42:58 v/v) as mobile phase. The concentration was measured with DAD at 270 nm. Linearity was observed in the range of 0.000040-0.000280 mol/L for gatifloxacin (r2≥0.999) and 0.000013-0.000091 mol/L for dexamethasone (r2≥0.999). Both the analyte peaks were completely separated from the peaks of induced degradation products as indicated by the peak purity index (≥0.9999 for both analytes). The optimized method is recommended to be used for concurrent analysis of gatifloxacin and dexamethasone in different matrices.

Different Mathematical Processing of the Ratio Spectra for Quantification of Cefaclor in Presence of its Acid Induced Degradation Product

Three simple mathematical spectrophotometric methods based on processing the ratio spectra were developed and validated for determination of cefaclor in presence of its acid induced degradation product; namely First derivative of ratio spectra (1DD) Method (A), Ratio subtraction method (RS) Method (B) and Mean centering of ratio spectra (MCR) Method (C). The accuracy, precision and linearity ranges of the proposed methods were determined. The methods were validated and the specificity was assessed by analyzing synthetic mixtures containing the drug and its degradate. The three methods were applied for the determination of the cited drug in its pharmaceutical preparation and the obtained results were statistically compared with those of a reported method. The comparison showed that there is no significant difference between the proposed methods and the reported method regarding both accuracy and precision.

Stability Indicating Spectrophotometric Methods for Determination of Vitamin E and Vinpocetine in Their Combined Dosage Form

Stability indicating spectrophotometric methods have been developed and validated for determination of Vitamin E (VIT E) and Vinpocetine (VINP) in presence of alkaline induced degradation product of Vinpocetine (DEG) without prior separation. In method (A), two wavelengths were selected for each drug in such a way that the difference in absorbance was zero for the other drugs. Absorbance difference between 217.4 and 234.4 nm were used to determine VIT E while difference between 250.4 and 314.0 nm were selected for VINP determination and the difference between 258.6 and 312.0 nm were selected to determine DEG. In method (B), area under the curve method (AUC) was used for measuring VINP concentration by direct measuring AUC in the range of 330-350 nm, at which no interference from other components. While for determination of VIT E and DEG, the ternary mixture was divided by standard spectrum of 6 μg/mL VINP, in the obtained ratio spectra VIT E and DEG has been directly determined at 210.0 and 230.0 nm, respectively. In method (C), VIT E and DEG were determined by second derivative of ratio spectra (2DD) method by measuring their peak amplitudes at 215.2 and 237.2 nm, respectively, using 6 μg/mL standard spectrum of VINP as a divisor, while the absorbance at isoabsorptive point (λiso=264.4 nm) was used to determine the total concentration of VINP and DEG (where no contribution from VIT E) in the mixture and then by subtraction, VINP concentration could be obtained. The developed methods were validated according to ICH guidelines revealing good accuracy and precision. The results obtained by the proposed methods were statistically compared with those obtained by the reported HPLC methods and no significant difference was obtained. These methods are the first developed SIAM ones for analysis of the studied components.

Stability-indicating methods for the analysis of ciprofloxacin in the presence of its acid induced degradation product: A comparative study

Four rapid, simple, accurate and precise spectrophotometric methods were used for the determination of ciprofloxacin in the presence of its acidic degradation product. The methods under study are ratio derivative, ratio difference, mean centering and dual wavelength. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of ciprofloxacin in quality-control laboratories.

Stability indicating methods for the analysis of cefprozil in the presence of its alkaline induced degradation product

Three simple, specific, accurate and precise spectrophotometric methods were developed for the determination of cefprozil (CZ) in the presence of its alkaline induced degradation product (DCZ). The first method was the bivariate method, while the two other multivariate methods were partial least squares (PLS) and spectral residual augmented classical least squares (SRACLS). The multivariate methods were applied with and without variable selection procedure (genetic algorithm GA). These methods were tested by analyzing laboratory prepared mixtures of the above drug with its alkaline induced degradation product and they were applied to its commercial pharmaceutical products.

Determination of stress-induced degradation products of cetirizine dihydrochloride by a stability-indicating RP-HPLC method.

BackgroundA new, simple and accurate stability-indicating reverse phase high performance liquid chromatography method was developed and validated during the early stage of drug development of an oral lyophilizate dosage form of cetirizine dihydrochloride.MethodsFor RP-HPLC analysis it was used an Eclipse XDB C8 column 150 mm × 4.6 mm, 5 μm (Agilent columns, Barcelona, Spain) as the stationary phase with a mobile phase consisted of a mixture of 0.2 M K2HPO4 pH 7.00 and acetonitrile (65:35, v/v) at a flow rate of 1 mL min −1. Detection was performed at 230 nm using diode array detector. The method was validated in accordance with ICH guidelines with respect to linearity, accuracy, precision, specificity, limit of detection and quantification.ResultsThe method results in excellent separation between the drug substance and its stress-induced degradation products. The peak purity factor is >950 for the drug substance after all types of stress, which confirms the complete separation of the drug substance peak from its stress induced degradation products.Regression analysis showed r2 > 0.999 for cetirizine dihydrochloride in the concentration range of 650 μg mL −1 to 350 μg mL−1 for drug substance assay and a r2 > 0.999 in the concentration range of 0.25 μg mL−1 to 5 μg mL−1 for degradation products. The method presents a limit of detection of 0.056 μg mL −1 and a limit of quantification of 0.25 μg mL−1. The obtained results for precision and accuracy for drug substance and degradation products are within the specifications established for the validation of the method.ConclusionsThe proposed stability-indicating method developed in the early phase of drug development proved to be a simple, sensitive, accurate, precise, reproducible and therefore useful for the following stages of the cetirizine dihydrochloride oral lyophilizate dosage form development.

Simultaneous estimation of rosuvastatin and amlodipine in pharmaceutical formulations using stability indicating HPLC method

A viable cost-effective and isocratic approach employing C-18 column (250 mm × 4.6 mm, 5 µm) based HPLC has been utilized to separate and estimate the drugs, rosuvastatin, amlodipine and their stress induced degradation products, simultaneously in pharmaceutical formulations. Focused on ICH guideline parameters, the efficient separation of both drugs and their degradation products was achieved by optimizing a 30:70 (v/v) solvent mixture of acetonitrile and 0.1 M ammonium acetate buffer (pH 5) as mobile phase. The flow rate of the mobile phase was 1.5 mL/min and all the detections were carried out at 240 nm using UV detector. The method was linear in the concentration range of 1-200 µg/mL for rosuvastatin with 0.996 coefficient of determination value. For amlodipine, linearity was in the range of 0.5-100 µg/ml with 0.994 coefficient of determination value. Both the drugs along with their degradation products were separated in less than twenty minutes. The results of within-day and between-day precision were varied from 0.72 to 1.81% for rosuvastatin and 0.83 to 1.88% for amlodipine. The results show that this ICH validated method can be employed successfully for the routine as well as stability quantification of both the active ingredients simultaneously in pharmaceutical formulations.

Selective determination of diclazuril in the presence of its degradation products.

A simple stability-indicating high-performance liquid chromatographic method was developed and validated for the determination of diclazuril (DIC) in the presence of its induced degradation products. The drug was subjected to stress stability study including acidic, alkaline, photolytic, thermal and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. The developed method utilized a C18 column (250 × 4.6 mm, i.d., 5 μm) in an isocratic separation mode with mobile phase consisting of acetonitrile and 0.2% phosphoric acid at a flow rate of 1.2 mL/min with UV-detection at 275 nm. The proposed method was validated according to the International Conference on Harmonization guidelines. The method was applied in short term and accelerated stability studies for determination of the DIC in bulk powder and in its pharmaceutical formulation.

Determination of stress-induced degradation products of cetirizine dihydrochloride by a stability-indicating RP-HPLC method

A new, simple and accurate stability-indicating reverse phase high performance liquid chromatography method was developed and validated during the early stage of drug development of an oral lyophilizate dosage form of cetirizine dihydrochloride. For RP-HPLC analysis it was used an Eclipse XDB C8 column 150 mm × 4.6 mm, 5 μm (Agilent columns, Barcelona, Spain) as the stationary phase with a mobile phase consisted of a mixture of 0.2 M K2HPO4 pH 7.00 and acetonitrile (65:35, v/v) at a flow rate of 1 mL min −1. Detection was performed at 230 nm using diode array detector. The method was validated in accordance with ICH guidelines with respect to linearity, accuracy, precision, specificity, limit of detection and quantification. The method results in excellent separation between the drug substance and its stress-induced degradation products. The peak purity factor is >950 for the drug substance after all types of stress, which confirms the complete separation of the drug substance peak from its stress induced degradation products. Regression analysis showed r2 > 0.999 for cetirizine dihydrochloride in the concentration range of 650 μg mL −1 to 350 μg mL−1 for drug substance assay and a r2 > 0.999 in the concentration range of 0.25 μg mL−1 to 5 μg mL−1 for degradation products. The method presents a limit of detection of 0.056 μg mL −1 and a limit of quantification of 0.25 μg mL−1. The obtained results for precision and accuracy for drug substance and degradation products are within the specifications established for the validation of the method. The proposed stability-indicating method developed in the early phase of drug development proved to be a simple, sensitive, accurate, precise, reproducible and therefore useful for the following stages of the cetirizine dihydrochloride oral lyophilizate dosage form development.

DETERMINATION OF CINACALCET HYDROCHLORIDE BY CAPILLARY ELECTROPHORESIS WITH PHOTODIODE ARRAY DETECTION

This article reports a validated stability-indicating capillary electrophoresis method using a photodiode array detector at 220 nm for the determination of cinacalcet hydrochloride. The best electrophoretic separation between the analyte and internal standard (lamotrigine) was achieved within 5 min in a deactivated fused silica capillary (55 cm effective length × 75 µm internal diameter) maintained at 24°C using a background electrolyte solution consisted of phosphate buffer (50 mM, pH 6.4):methanol (95:5, v/v) at a separation voltage of 30 kV. The linear range of the method was 0.5–30 µg/mL (r = 0.9999) with limits of detection and quantitation of 0.1 and 0.5 µg/mL, respectively. The assay precision and accuracy were favorable as the relative standard deviations did not exceed 1.09%, and the recovery values were 98.99–100.33 ± 0.19–1.09%. The induced degradation products, when any, did not interfere with the detection of analyte. The proposed method was successfully applied for the determination of cinacalcet hydrochloride in bulk and pharmaceutical formulations; the percentage recovery values were 98.16–102.00 ± 0.24–1.08%. The results demonstrated the value of the method.

Stability Indicating Spectrophotometric and Chemometric Methods for Determination of Buflomedil in Presence of its Acid Induced Degradation Products

Simple, accurate, sensitive, selective and validated UV spectrophotometric univariate and multivariate methods were developed for determination of Buflomedil (BFM) in presence of BFM degradation products (BFM Deg). The univariate methods includes mean centering of ratio spectra (MCR), ratio difference spectrophotometric method (RDSM) and H-point standard addition method (HPSAM); the first one used the amplitude at 235.7 nm, the second utilized the difference in amplitudes at 250 nm and 282 nm; while, the third method utilized the absorbance values at 247 and 282.4 nm. Linearity was obtained for the proposed methods in the ranges of 10–100 µgmL-1. The percentage recoveries were 100.06±0.963, 100.17±0.962 and 100.90±0.667 for the three methods in a respective order. Multivariate methods involves the application of three chemometric techniques, and classical least square (CLS) principal component regression (PCR) and partial least-squares regression (PLS), which were used for the simultaneous determination of the BFM and its degradation products. The results obtained from the proposed methods, together with the reported one, were statistically compared using one-way analysis of variance (ANOVA). These methods are suitable as stability indicating methods for the determination of BFM in presence of its degradation products either in bulk powder or in pharmaceutical formulations.

SIMULTANEOUS DETERMINATION OF PIROXICAM AND PARACETAMOL IN PHARMACEUTICAL FORMULATIONS USING STABILITY INDICATING HPLC METHOD

A fast, simple, specific, and accurate stability indicating liquid chromatographic method is described for simultaneous determination of piroxicam and paracetamol in bulk drugs and pharmaceutical formulations. Optimum chromatographic separations among the piroxicam, paracetamol, and stress-induced degradation products were achieved within 6 min by using a Hypersil BDS C8 column as stationary phase with acetonitrile and 0.02 M phosphate buffer pH 3.0 (60:40, v/v) as the mobile phase at a flow rate of 1.0 mL min−1 with detection using a diode array detector at 254 nm. ICH guidelines were used to validate the developed method. Linearity was from 1.6–6.4 µg mL−1 for piroxicam and 26–104 µg mL−1 for paracetamol. All the analytes including the degradation products were separated with acceptable peak tailing and resolution. The peak purity index for both the analytes after all types of stress is >0.999, indicating complete separation of both analytes peaks from the stress induced degradation products. The developed method can be successfully used for simultaneous determination of piroxicam and paracetamol in pharmaceutical formulations and stability studies.

Spectrophotometric Bivariate Method for Determination of Candesartan Cilexetil in Presence of its Alkaline Induced Degradation Product

Spectrophotometric Bivariate Method for Determination of Candesartan Cilexetil in Presence of its Alkaline Induced Degradation Product

Forced Degradation Studies of Corticosteroids With an Alumina–Steroid–Ethanol Model for Predicting Chemical Stability and Degradation Products of Pressurized Metered-Dose Inhaler Formulations

An alumina (Al(2)O(3))-steroid-ethanol model is used for forced degradation testing of corticosteroids to predict chemical stability and degradation products in pressurized metered-dose inhaler (pMDI) solution formulations. The model involves an ethanolic solution of a test steroid with Al(2)O(3), stressed at elevated temperatures to mimic the chemical interaction of drug, excipient, and packaging (an aluminum aerosol canister). The reactivity order of eight synthetic corticosteroids toward Al(2)O(3)-induced reactions is ranked with the stress model. The corticosteroids containing a C21-OH group possess the highest reactivity, suggesting that aluminum canisters with an inert interior coating are needed to stabilize their solution pMDIs. The Al(2)O(3)-induced degradation products and degradation pathways of a steroid containing C21-OH and triamcinolone acetonide are presented, and the role of Al(2)O(3) in the degradation pathways is briefly discussed. A potential degradation profile of beclomethasone dipropionate (BDP) established with an Al(2)O(3)-BDP-ethanol stress model is the same as the actual degradation profile of the BDP pMDI product, indicating that the model indeed predicts the degradation products.

Stability indicating HPLC method for the simultaneous determination of ofloxacin and ketorolac tromethamine in pharmaceutical formulations

A simple, specific and accurate stability indicating liquid chromatographic method is established for simultaneous determination of ofloxacin and ketorolac tromethamine in bulk drugs and pharmaceutical formulations. Optimum chromatographic separations among ofloxacin, ketorolac and stress-induced degradation products have been achieved within 15 min by using a BDS Hypersil C8 column (250 × 4.6 mm, 5 μm) as the stationary phase with methanol and phosphate buffer pH 3.0 (55 : 45 v/v) as the mobile phase at a flow rate of 0.8 mL min−1. Detection is performed at 270 nm using a diode array detector. The method is validated in accordance with ICH guidelines. The response is a linear function of concentration over the range of 12–84 μg mL−1 for ofloxacin and 20–140 μg mL−1 for ketorolac tromethamine. The method results in excellent separation of analytes and their stress induced degradation products with acceptable tailing and resolution. The peak purity index for both the analytes after all types of stress is >0.999 indicating complete separation of both analyte peaks from the stress induced degradation products. The method can therefore be regarded as stability-indicating. The developed method can be applied successfully for simultaneous determination of ofloxacin and ketorolac in pharmaceutical formulations and their stability studies.

ACID- ALKALI DEGRADATION STUDY ON OLMESARTAN MEDOXOMIL AND DEVELOPMENT OF VALIDATED STABILITY-INDICATING CHROMATOGRAPHIC METHODS

A reversed phase liquid chromatography (RP-HPLC) and thin layer chromatography (HPTLC) densitometry methods as a stability indicating assays of olmesartan medoxomil in presence of its acid or alkaline induced degradation products were developed. Olmesartan medoxomil and its degradation products were analyzed by HPLC equipped with UV-Variable wave length detector at 257 nm where quantitation was achieved by isocratic elution on Agilent, Exclipse XDB- C 18 column with mobile phase composed of acetonitrile: methanol: water: glacial acetic acid (40:35:25:0.1 v/v/v/v) at flow rate 1ml min.-1. HPTLC was performed on aluminum packed Nano silica gel 60 F 254 TLC plates as stationary phase with significant difference in Rƒ values between olmesartan medoxomil and its degradates using chloroform: methanol: formic acid (8:1.5:0.5 v/v/v) as mobile phase. Densitometric evaluation of intact drug was carried out at 260 nm. The calibration curve of olmesartan medoxomil in bulk form was linear from 0.5- 10 µg ml-1 and 0.05- 1 mg ml-1 with mean percentage accuracy 99.97 ± 1.085 % and 100.35 ± 1.060 % for HPLC and HPTLC methods, respectively. The two proposed methods were successfully applied for the determination of olmesartan medoxomil in drug substance and in drug product. Methods validation was tested for linearity; accuracy; precision; selectivity and robustness, according to USP guidelines.

Development and Validation of HPLC, TLC and Derivative Spectrophotometric Methods for the Analysis of Ezetimibe in the Presence of Alkaline Induced Degradation Products

AbstractReversed phase‐high performance liquid chromatography (RP‐HPLC), thin layer chromatography (TLC) densitometry and first derivative spectrophotometry (1D) techniques are developed and validated as a stability‐indicating assay of ezetimibe in the presence of alkaline induced degradation products. RP‐HPLC method involves an isocratic elution on a Phenomenex Luna 5μ C18 column using acetonitrile: water: glacial acetic acid (50:50:0.1 v/v/v) as a mobile phase at a flow rate of 1.5 mL/min. and a UV detector at 235 nm. TLC densitometric method is based on the difference in Rf‐values between the intact drug and its degradation products on aluminum‐packed silica gel 60 F254 TLC plates as stationary phase with isopropanol: ammonia 33% (9:1 v/v) as a developing mobile phase. On the fluorescent plates, the spots were located by fluorescence quenching and the densitometric analysis was carried out at 250 nm. Derivative spectrophotometry, the zero‐crossing method, ezetimibe was determined using first derivative at 261 nm in the presence of its degradation products. Calibration graphs of the three suggested methods are linear in the concentration ranges 1–10 mcg/mL, 0.1–1 mg/mL and 1–16 mcg/mL with a mean percentage accuracy of 99.05 ± 0.54%, 99.46 ± 0.63% and 99.24 ± 0.82% of bulk powder, respectively. The three proposed methods were successfully applied for the determination of ezetimibe in raw material and pharmaceutical dosage form; the results were statistically analyzed and compared with those obtained by the reported method. Validation parameters were determined for linearity, accuracy and precision; selectivity and robustness and were assessed by applying the standard addition technique.

A Fast, Validated HPLC Method Applied to the Dissolution Test of Gastro‐Resistant Capsules of Pantoprazole Pellets

A fast and simple liquid chromatographic method has been developed for determination of pantoprazole in delayed release gastro‐resistant capsules employing a reverse‐phase column, mobile phase consisting of acetonitrile‐water (75:25), flow rate 1.0 mL min−1 and 290 nm detection. Selectivity, accuracy, linearity, intra‐ and inter‐day precision were evaluated. The method is not affected by the pellets excipients or induced acid degradation products. Linearity ranged from 2.0–18.0 µg mL−1. The relative standard deviation (RSD) for intra‐day and inter‐day precision varied from 0.92–2.00%. Capsules analysis resulted in 93.48–105.15% of the labeled pantoprazole amount. Recoveries after spiking pellets with pantoprazole ranged from 96.27–102.87%.