Stability-indicating High-performance Liquid Chromatography Research Articles

A Stability-indicating HPLC Method for the Simultaneous Determination of Mebeverine Hydrochloride and Chlordiazepoxide in Commercial Tablets

A stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed which can separate and accurately quantitate Mebeverine hydrochloride (MEB) and Chlordiazepoxide (CPZ) in commercial tablets. The method has shown adequate separation for MEB and CPZ from their degradation products and main impurities of CPZ whether in pure forms or in commercial tablets. A gradient mobile phase system consisting of (A) water and (B) methanol was used with Phenomenex® Luna C18 analytical column (250mm x 4.6mm i.d., 5µm ps). Quantitation was achieved with UV detection at 254 nm, based on peak area. MEB and CPZ were subjected to acidic, basic hydrolysis and oxidative degradation to apply stress conditions. The linearity of the proposed method was investigated in the range of 40-130 µg ml-1 (r = 0.9987) for MEB and 8-22 µg ml-1 (r = 0.9991) for CPZ. The limits of detection were 4.77µg ml-1 and 0.71µg ml-1 for MEB and CPZ, respectively. The limits of quantitation were 14.44 µg ml-1 and 2.14 µg ml-1 for MEB and CPZ, respectively. Degradation products of MEB, CPZ and impurities of CPZ did not interfere with the detection of MEB and CPZ. The proposed method can thus be considered as a stability indicating assay. Keywords: Mebeverine hydrochloride, chlordiazepoxide, stability-indicating, RPHPLC, validation.

Stability-Indicating LC Method for the Estimation of Bendamustine Hydrochloride and its Related Impurities

A novel, simple, sensitive and stability-indicating high-performance liquid chromatography method was developed and validated for the quantification of impurities (process related and degradants) and the assay determination of Bendamustine hydrochloride. A chromatographic separation of Bendamustine and its impurities was achieved with an Inertsil ODS-2 analytical column, 250 × 4.6 mm, 5 µm, using gradient elution with mobile phase A consisting of a mixture of water and trifluoroacetic acid (1000:1, v/v) and mobile phase B consisting of acetonitrile. The instrumental settings included a flow rate of 1.0 mL/min, column temperature of 27°C and a detector wavelength of 233 nm, using a photodiode array detector. The tailing factor for Bendamustine was 1.10. Bendamustine hydrochloride was exposed to thermal, photolytic, hydrolytic and oxidative stress conditions and the stressed samples were analyzed by the proposed method. Peak homogeneity data of Bendamustine were obtained by using a photodiode array detector in the stressed sample chromatograms, which demonstrated the specificity of the method for estimation in the presence of degradants. The developed method was validated for parameters such as precision, accuracy, linearity, limit of detection, limit of quantification, ruggedness and robustness. The stability tests were also performed on drug substances as per International Conference on Harmonization guidelines.

Physico-chemical stability of eribulin mesylate containing concentrate and ready-to-administer solutions

The aim of this study was to determine the stability of commercially available eribulin mesylate containing injection solution as well as diluted ready-to-administer solutions stored under refrigeration or at room temperature. Stability was studied by a novel developed stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay with ultraviolet detection (detection wavelength 200 nm). Triplicate test solutions of eribulin mesylate containing injection concentrate (0.5 mg/mL) and with 0.9% sodium chloride solution diluted ready-to-administer preparations (0.205 mg/mL eribulin mesylate in polypropylene (PP) syringes, 0.020 mg/mL eribulin mesylate in polypropylene/polyethylene (PE) bags) were stored protected from light either at room temperature (25) or under refrigeration (2-8). Samples were withdrawn on day 0 (initial), 1, 3, 5, 7, 14, 21 and 28 of storage and assayed. Physical stability was determined by measuring the pH value once a week and checking for visible precipitations or colour changes. The stability tests revealed that concentrations of eribulin mesylate remained unchanged over a period of 28 days irrespective of concentration, container material or storage temperature. Neither colour changes nor visible particles have been observed. The pH value varied slightly over time but remained in the stability favourable range of 5-9. Eribulin mesylate injection (0.5 mg/mL) is physico-chemically stable over a period of 28 days after first puncture of the vial. After dilution with 0.9% NaCl vehicle solution, ready-to-administer eribulin mesylate injection solutions (0.205 mg/mL in PP syringe) and infusion solutions (0.02 mg/mL in prefilled PP/PE bags) are physico-chemically stable for a period of at least four weeks either refrigerated or stored at room temperature. For microbiological reasons storage under refrigeration is recommended.

Stability-Indicating RP-HPLC Method for the Quantitative Analysis of Perindopril Erbumine in Tablet Dosage Form

A specific, stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the estimation of perindopril erbumine (PDE) in tablet dosage form. The HPLC method showed adequate separation of PDE from its degradation products. The separation was achieved on a Phenomenex Luna C18 column (250 × 4.6 mm × 5 µm) using a mobile phase composition of 0.2% trifluoroacetic acid buffer and acetonitrile in the ratio of 60:40 (pH adjusted to 3 with ammonia) at a flow rate of 1 mL/min. The injection volume was 20 µL and the wavelength of detection was kept at 215 nm. Stress studies were performed with 1 mg/mL of each drug, starting with mild conditions and followed by stronger conditions to achieve sufficient degradation at approximately 5-20%. The linearity of the proposed method was investigated in the range of 2.5 to 50 µg/mL for PDE. The limits of detection and quantification were found to be 0.75 and 2.3 µg/mL, respectively.

Stability of extemporaneously compounded diltiazem hydrochloride infusions stored in polyolefin bags

The stability of extemporaneously compounded diltiazem hydrochloride infusions stored in polyolefin bags was studied. Sterile preparations of diltiazem hydrochloride were compounded to a concentration of 1 mg/mL in 5% dextrose solutions in accordance with United States Pharmacopeia chapter 797. The infusions were stored at -20 °C, 2-6 °C, and 22-25 °C. Three samples from each temperature were withdrawn and assessed for stability immediately after preparation (day 0) and on days 7, 15, 21, and 30 using a high-performance liquid chromatography (HPLC) assay. The physical stability of diltiazem samples was assessed by visual examination. Infusions were evaluated against black and white backgrounds for evidence of visible particulate matter, cloudiness, and color changes. The concentration of diltiazem hydrochloride in all samples was examined using a stability-indicating HPLC method at each time point. Diltiazem was considered stable if the solution retained over 90% of the initial concentration. No precipitation, cloudiness, or color change was observed at any of the temperatures studied. pH did not significantly increase or decrease among the samples, regardless of temperature, over the study period. The diltiazem hydrochloride infusions retained greater than 90% of the initial concentrations for at least 30 days. Diltiazem hydrochloride diluted to 1 mg/mL in 5% dextrose injection was stable for 30 days when stored at -20 °C, 2-6 °C, and 22-25 °C.

Stability of U-500 regular insulin in prefilled syringes

ObjectiveTo evaluate the stability of U-500 regular insulin in prefilled syringes stored under refrigeration for up to 28 days. MethodsU-500 regular insulin was drawn up in 1mL insulin syringes in a clean, nonsterile environment to emulate conditions of a patient's home. Samples were assayed using a stability-indicating reverse-phase high-performance liquid chromatography method immediately after preparation (day 0) and after 7, 14, 21, and 28 days under refrigeration. Before evaluation, all samples were diluted to a concentration of 40 units/mL in the starting mobile phase. Stability was determined by evaluating the percentage of the initial concentration remaining at each time point. ResultsAt least 93.3% of the initial U-500 insulin concentration remained throughout the 28-day study period, with no statistically significant changes in the amount remaining. The percent of initial concentration remained above 97% for the first 21 days of the study. ConclusionA prefilled syringe with U-500 regular insulin is stable for at least 28 days when stored under refrigeration. These data are similar to those reported for U-100 regular insulin, indicating that prefilling syringes with U-500 insulin is a safe and effective practice for patients who are unable to accurately draw up their own point-of-care doses.

Stability of Propranolol in Extemporaneously Compounded Suspensions

Propranolol is a drug of choice for many diseases occurring in neonates and infants, an age group for which oral suspensions are required almost exclusively. Many adult and elderly patients for whom propranolol is prescribed are also unable to swallow solid dosage forms. In Canada, propranolol is not commercially available in a liquid dosage form, and existing recipes for extemporaneously compounded suspensions of propranolol (1 mg/mL) are limited by concerns regarding diabetes mellitus in certain subpopulations, the need for a more concentrated suspension for patients taking larger doses, and the tediousness of compounding. To evaluate the stability of propranolol suspensions in a sugar-free, commercially available vehicle after storage at room temperature and under refrigeration for up to 120 days. Suspensions of propranolol (2 and 5 mg/mL) were prepared in the sugar-free vehicle (Ora-Blend SF), placed in 100-mL amber plastic prescription bottles, and stored at 25°C and 4°C. Samples were collected from each bottle once weekly for 120 days, stored frozen, and analyzed by a validated, stability-indicating high-performance liquid chromatography - ultraviolet detection method. A suspension was considered stable if it maintained at least 90% of its initial concentration of propranolol. Physical compatibility was evaluated in terms of colour, taste, precipitation, and pH. Propranolol suspensions 2 mg/mL and 5 mg/mL stored at 25°C maintained at least 94.7% of their initial concentration for 120 days, and suspensions stored at 4°C maintained at least 93.9% of their initial concentration for 120 days. There were no notable changes in pH, and all samples remained physically unchanged except for a slight change in colour, around day 70, of suspensions stored at room temperature. Propranolol suspensions (2 mg/mL and 5 mg/mL) prepared in Ora-Blend SF and stored in plastic prescription bottles at either 25°C or 4°C are expected to remain stable for 120 days.

Effect of Counterion on the Solid State Photodegradation Behavior of Prazosin Salts

The effect of counterion was evaluated on the photodegradation behavior of six prazosin salts, viz., prazosin hydrochloride anhydrous, prazosin hydrochloride polyhydrate, prazosin tosylate anhydrous, prazosin tosylate monohydrate, prazosin oxalate dihydrate, and prazosin camsylate anhydrous. The salts were subjected to UV-Visible irradiation in a photostability test chamber for 10 days. The samples were analyzed for chemical changes by a specific stability-indicating high-performance liquid chromatography method. pH of the microenvironment was determined in 10%w/v aqueous slurry of the salts. The observed order of photostability was: prazosin hydrochloride anhydrous>prazosin camsylate anhydrous~prazosin-free base>prazosin hydrochloride polyhydrate>prazosin tosylate anhydrous>prazosin oxalate dihydrate~prazosin tosylate monohydrate. Multivariate analysis of the photodegradation behavior suggested predominant contribution of the state of hydration and also intrinsic photosensitivity of the counterion. Overall, hydrated salts showed higher photodegradation compared to their anhydrous counterparts. Within the anhydrous salts, aromatic and carbonyl counterion-containing salts showed higher susceptibility to light. The pH of microenvironment furthermore contributed to photodegradation of prazosin salts, especially for drug counterions with inherent higher pH. The study reveals importance of selection of a suitable drug salt form for photosensitive drugs during preformulation stage of drug development.

Stability of the Combination of Ceftazidime and Cephazolin in Icodextrin or PH Neutral Peritoneal Dialysis Solution

The objective of this study was to investigate the stability of ceftazidime and cephazolin in a 7.5% icodextrin or pH neutral peritoneal dialysis (PD) solution. Ceftazidime and cephazolin were injected into either a 7.5% icodextrin or pH neutral PD bag to obtain the concentration of 125 mg/L of each antibiotic. A total of nine 7.5% icodextrin or pH neutral PD bags containing ceftazidime and cephazolin were prepared and stored at 1 of 3 different temperatures: 4°C in a domestic refrigerator; 25°C at room temperature; or 37°C (body temperature) in an incubator. An aliquot was withdrawn immediately before (0 hour) or after 12, 24, 48, 96, 120, 144, 168 and 336 hours of storage. Each sample was analyzed in duplicate for the concentration of ceftazidime and cephazolin using a stability-indicating high-performance liquid chromatography technique. Ceftazidime and cephazolin were considered stable if they retained more than 90% of their initial concentration. Samples were also assessed for pH, colour changes and evidence of precipitation immediately after preparation and on each day of analysis. Ceftazidime and cephazolin in both types of PD solution retained more than 90% of their initial concentration for 168 and 336 hours respectively when stored at 4°C. Both of the antibiotics lost more than 10% of the initial concentration after 24 hours of storage at 25 or 37°C. There was no evidence of precipitation at any time under the tested storage conditions. Change in the pH and color was observed at 25 and 37°C, but not at 4°C. Premixed ceftazidime and cephazolin in a 7.5% icodextrin or pH neutral PD solution is stable for at least 168 hours when refrigerated. This allows the preparation of PD bags in advance, avoiding the necessity for daily preparation. Both the antibiotics are stable for at least 24 hours at 25 and 37°C, permitting storage at room temperature and pre-warming of PD bags to body temperature prior to its administration.

Stability of alemtuzumab solutions at room temperature

The 24-hour stability of alemtuzumab solutions prepared at concentrations not included in the product label and stored in glass or polyolefin containers at room temperature was evaluated. Triplicate solutions of alemtuzumab (6.67, 40, and 120 μg/mL) in 0.9% sodium chloride were prepared in either glass bottles or polyolefin containers and stored at room temperature under normal fluorescent lighting conditions. The solutions were analyzed by a validated stability-indicating high-performance liquid chromatography (HPLC) assay at time zero and 8, 14, and 24 hours after preparation; solution pH values were measured and the containers visually inspected at all time points. Stability was defined as the retention of ≥90% of the initial alemtuzumab concentration. HPLC analysis indicated that the percentage of the initial alemtuzumab concentration retained was >90% for all solutions evaluated, with no significant changes over the study period. The most dilute alemtuzumab solution (6.67 μg/mL) showed some degradation (91% of the initial concentration retained at hour 24), whereas the retained concentration was >99% for all other preparations throughout the study period. Solution pH values varied by drug concentration but did not change significantly over 24 hours. No evidence of particle formation was detected in any solution by visual inspection at any time during the study. Solutions of alemtuzumab 6.67 μg/mL stored in glass bottles and solutions of 40 and 120 μg/mL stored in polyolefin containers were stable for at least 24 hours at room temperature.

Development and Validation of a Simple, Rapid and Stability-Indicating High Performance Liquid Chromatography Method for Quantification of Norfloxacin in a Pharmaceutical Product

A stability-indication high performance liquid chromatographic method has been developed for the determination of norfloxacin in tablet dosage forms. Optimum separation was achieved in less than 7 minutes using Eclipse Plus Zorbax C18 Agilent, 150 mm×4.6 mm i.d., 5 μm particle size column. The analyte was resolved by using a mobile phase 5% acetic acid aqueous solution and methanol (80:20, v/v) at a flow rate 1.0 ml/min on an isocratic high performance liquid chromatographic system at a wavelength of 277 nm. Linearity, system suitability, precision, sensitivity, selectivity, specific, and robustness were established by International Conference Harmonization guidelines. For stress studies the drug was subjected to photolysis, oxidation, acid, alkaline and neutral conditions. The analytical conditions and the solvent developed provided good resolution within a short analysis time and economic advantages. The proposed method not required sophisticated and expensive instrumentation.

Quantitative determination of imatinib stability under various stress conditions

Objective:A simple, rapid, reverse phase and stability-indicating high-performance liquid chromatography (HPLC) method for the estimation of imatinib in solution and in plasma under forced degradation conditions was developed.Materials and Methods:The method employed isocratic elution using a Waters Atlantis C18 (5 μ, 4.6 mm × 150 mm) HPLC column. The mobile phase consisted of acetonitrile and 10 mM KH2PO4 buffer in the ratio of 35:65 (v/v, pH = 4.6), which was delivered using isocratic flow at a rate of 1 mL/min. The injection volume of 50 μL and imatinib was monitored using UV detection 270 nm after a clean-up step with diethyl ether and with a total run time of 6 min.Results:The method was validated in solution as well as in plasma, and the response was found to be linear in the concentration range of 0.5-20 μg/mL. The coefficient of correlation was found to be >0.99. Forced degradation studies revealed that imatinib undergoes degradation under different stress conditions.Discussion:The developed HPLC method could effectively resolve degradation product peaks from imatinib except at neutral pH. Further, no interference was found at the retention time of imatinib from any plasma components, indicating selectivity of the developed method. The limits of detection and quantitation of the method were 0.025 and 0.5 μg/mL, respectively.

Stability of Nafcillin Sodium Solutions in the Accufuser<sup>®</sup> Elastomeric Infusion Device

The aim of this study was to investigate the stabilities of two kinds of solutions of nafcillin sodium (2.5 mg/mL) in 0.9% sodium chloride solution (NS, normal saline) and in injectable 5% dextrose water (D5W) in the intravenous elastomeric infusion device (Accufuser?) based on recommended solutions and storage periods. The injectable nafcillin solutions (NS- and D5W-nafcillin) in the Accufuser? device were stored and evaluated at controlled temperatures (room temperature, RT, 5℃ ± 2℃ and cold temperature, CT, 4℃ ± 2℃) during 6 weeks. Effects of the periods of storage (from 0 to 6 weeks) and the temperatures of storage (RT and CT) on the physicochemical appearances and concentrations of active compounds were determined. The visual clarity, pH, and concentrations of nafcillin sodium were determined by stability-indicating high-performance liquid chromatography (HPLC)-ultraviolet (UV) detection. The results showed that in NS and D5W solutions, the amount of nafcillin slightly changed and remained 92.66% and 97.30% of their initial amounts at CT during 6 weeks, respectively. On the other hand, in NS and D5W solutions at RT, the amount significantly decreased with time and reached 27.66% and 31.97% of their initial amounts during 4 weeks, respectively. Slight decrement of pH was observed in CT storage while significant change was observed in the RT storage. Moreover, in CT, no significant changes in physical appearances and colors of the solutions were observed during the study. However, the solutions changed into yellowish color and some particles were detected in both kinds of nafcillin solutions (NS and D5W) after 1.5 weeks in RT conditions. To sum up, under CT two kinds of nafcillin sodium solutions (NS and D5W) were stable with time in Accufuser? without any significant physical changes and retained almost all of the initial concentrations up to 6 weeks. However, the solutions were not stable in RT storage. We suggest that nafcillin sodium solutions in an Accufuser? should be preferentially diluted in NS and D5W while storing in CT condition.

Development and Validation of a Novel Stability-Indicating RP-HPLC Method for Simultaneous Determination of Halometasone, Fusidic Acid, Methylparaben, and Propylparaben in Topical Pharmaceutical Formulation

A stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the simultaneous determination of halometasone, fusidic acid, methylparaben, and propylparaben in topical pharmaceutical formulation. The desired chromatographic separation was achieved on an Agilent Zorbax CN (Cyano), 5 μm (250 × 4.6 mm) column using gradient elution at 240 nm detector wavelength. The optimized mobile phase consisted of a mixture of 0.01 M phosphate buffer and 0.1% orthophosphoric acid, pH-adjusted to 2.5 with an ammonia solution as solvent-A and acetonitrile as solvent-B. The developed method separated halometasone, fusidic acid, methylparaben, and propylparaben in the presence of known impurities/degradation products. The stability-indicating capability was established by forced degradation experiments and separation of known and unknown degradation products. The developed RP-HPLC method was validated according to the International Conference on Harmonization (ICH) guidelines. This validated method was applied for the simultaneous estimation of HM, FA, MP, and PP in commercially available cream samples. Further, the method can be extended for the estimation of HM, FA, MP, and PP in various commercially available dosage forms.

Development and application of stability-indicating HPLC method for the determination of nevirapine and its impurity in combination drug product

Summary A stability-indicating reversed-phase high-performance liquid chromatography method has been developed and validated for the estimation of nevirapine and its impurity, namely the related compound A and the related compound B in combination drug product. The separation was carried out on SUPELCOSIL ABZ (150 mm × 4.6 mm, 5 µm) column. Tablet was admitted to the stress conditions of acid, base, peroxide, thermal, humidity, and photolytic degradation. The degradation products were well resolved from nevirapine, and its impurities peaks and the peak homogeneity of compound were obtained using photo diode array detector, hence proving the stability-indicating nature of the method. Moreover, to prove the selectivity of the method, individual lamivudine, zidovudine, and their main impurities were injected. The developed method was linear for nevirapine from 120 to 360 µg mL−1, and the linear regression obtained was >0.999. Recovery data were in the range 98.2–101.5%. The limit of quantification for related compound A and related compound B was found to be 0.02%. The proposed method was validated according to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines and proved suitable for stability testing and quality control of these drugs in pharmaceutical preparations.

Development and Validation of a Stability-Indicating RP-HPLC Assay Method and Stress Degradation Studies on Dapiprazole

Dapiprazole (DPZ) was subjected to different stress conditions prescribed by the International Conference on Harmonization. A stability-indicating high-performance liquid chromatography method was developed for the analysis of the drug in the presence of its degradation products. The degradation was found to occur in hydrolytic, and to some extent, photolytic conditions, however, the drug was stable to oxidative and thermal stress. The drug was particularly labile under neutral and alkaline hydrolytic conditions. The assay was involved an isocratic elution of DPZ in a Kromasil 100C18 column using a mobile phase composition of water (pH 6.5, 0.05%, w/v, 1-heptane sulfonic acid) and acetonitrile (40:60, v/v). The flow rate was 0.8 mL/min and the detection was conducted at 246 nm. The assay method was found to be linear from 5 to 30 µg/mL. The method was validated for linearity, range, precision, accuracy, specificity, selectivity, limit of detection and limit of quantitation.

Stability-Indicating HPLC Method for the Determination of Darunavir Ethanolate

A novel stability-indicating reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the quantitative determination of darunavir ethanolate, an HIV-1 protease inhibitor. The chromatographic separation was achieved using an X-Bridge C18 (150 × 4.6 mm × 3.5 µm) HPLC column in isocratic mode employing 0.01M ammonium formate (pH.3.0) buffer and acetonitrile in the ratio of 55:45 (v/v) with a flow rate of 1.0 mL/min. The detector wavelength was monitored at 265 nm and the column temperature was maintained at 30°C. Darunavir ethanolate was exposed to thermal, photolytic, acid, base and oxidative stress conditions. Considerable degradation of the drug substance was found to occur under acid, base and oxidative stress conditions. The peak homogeneity data of darunavir ethanolate obtained by photodiode array detection demonstrated the specificity of the method in the presence of degradants. The degradation products were well resolved from primary peak of darunavir, indicating that the method is specific and stability-indicating. The HPLC method was validated as per International Conference on Harmonization guidelines with respect to specificity, precision, linearity, accuracy and robustness. Regression analysis showed a correlation coefficient value greater than 0.999. The accuracy of the method was established based on the recovery obtained for darunavir ethanolate.

Study of forced degradation behaviour of florfenicol by LC and LC-MS and development of a validated stability-indicating assay method

A stability-indicating high performance liquid chromatography (HPLC) method was developed for the analysis of florfenicol in presence of its two available identified degradation products (thiamphenicol and chlorfenicol). The drug was subjected to different International Conference On Harmonisation (ICH) prescribed stress conditions (hydrolysis, oxidation and photolysis). The products formed under different stress conditions were investigated by liquid chromatography (LC) and liquid chromatography-mass spectrometry (LC-MS). The LC method involved a Knauwer Eurospher C18 thermostated column at 25°C; and ammonium acetate buffer 6.49mM (pH adjusted to 4.5)-methanol (70:30 v/v) as mobile phase. The flow rate and detection wavelength were 1ml/min and 225nm respectively. The drug showed instability under acidic, alkaline and photolytic stress conditions mainly in solution state form; however, it remains stable in solid state form and under oxidative stress conditions. The developed method was validated for linearity, precision, accuracy and specificity. The degradation products were characterized by LC-MS. Through the mass/ionization (m/z) values and fragmentation patterns, two principal degradation products listed in bibliography have been shown: the florfenicol amine and thiamphenicol. Based on the results, a more complete degradation pathway of the drug could be proposed.

Development and Validation of a Stability-Indicating RP-HPLC Method for the Simultaneous Estimation of Process Related Impurities and Degradation Products of Rasagiline Mesylate in Pharmaceutical Formulation

A sensitive, stability-indicating gradient reverse phase high-performance liquid chromatography-ultraviolet method has been developed for the quantitative determination of process-related impurities and forced degradation products of rasagiline mesylate in pharmaceutical formulation. Efficient chromatographic separation was achieved on an ACE C8, 150 × 4.6 mm, 3 µm column with mobile phase containing a gradient mixture of solvents A and B. The flow rate of the mobile phase was 0.8 mL/min with column temperature of 30°C and detection wavelength at 210 nm. Rasagiline was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Rasagiline was found to degrade significantly in acid and thermal stress conditions. The degradation products were well resolved from rasagiline and its impurities. The peak purity test results confirmed that the rasagiline peak was homogenous and pure in all stress samples and the mass balance was found to be more than 97%, thus proving the stability-indicating power of the method. The developed method was validated according to the guidelines of the International Conference on Harmonization with respect to specificity, linearity, limits of detection and quantification, accuracy, precision and robustness.

A Stability-Indicating HPLC Method for the Determination of Bazedoxifene Acetate and its Related Substances in Active Pharmaceutical Ingredient

A simple, cost effective, stability-indicating reversed-phase high-performance liquid chromatography method was developed for the quantitative determination of bazedoxifene acetate (BAZ) drug substance in the presence of its impurities and degradation products. The method was developed using an X-terra RP-18, 150 × 4.6 mm, 3.5 μm column with a mobile phase containing solvent A, a mixture of 10 mM K(2)HPO(4) (pH 8.3) and acetonitrile in the ratio of 70:30 (v/v); and solvent B, a mixture of water and acetonitrile in the ratio 10:90 (v/v). The eluted compounds were monitored at 220 nm, and within a short run time of 18 min, BAZ and its impurities were satisfactorily separated with resolution more than 2.0. BAZ was subjected to stress degradation and found to be sensitive towards acidic, basic, oxidative, thermal and hydrolytic stress conditions and stable in photo degradation conditions. The degradation products were well resolved from BAZ peak and its impurities; the mass balance in each case was more than 99.5%, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization guidelines with respect to specificity, linearity (correlation coefficient > 0.9994), limit of detection, limit of quantification, accuracy (recovery range 96.3 to 102.1%), precision (relative standard deviation < 2.8%) and robustness.