Stability-indicating Assay Method Research Articles

Development and Validation of Fast and Robust Stability Indicating RP-HPLC Method for Simultaneous Estimation of Tolperisone Hydrochloride and Etoricoxib in Pharmaceutical Dosage Form

Objectives: A precise, accurate and selective stability-indicating reverse phase high performance liquid chromatographic assay method has been developed for the simultaneous quantitative determination of Tolperisone hydrochloride and Etoricoxib in tablets. Methods: The chromatographic separation of drugs was attained by using Eclipse plus C18 (150 mm × 4.6 mm, Agilent 5µm) column at room temperature. The composition of mobile phase was mixture of 0.035M triethylamine (pH 3.0 adjusted with orthophosphoric acid) and acetonitrile in ratio of 70:30 v/v and flow rate of mobile phase 1.0 ml/min with isocratic elution. The signal of eluents was observed at 290 nm by using diode array detector. Results: The retention time of Tolperisone hydrochloride and Etoricoxib were found to be 2.826 min and 7.566 min, respectively. The linearity ranges for both drugs were found to be 5-15 μg/ml and the percent recoveries were found to be 99.39% and 99.15% for Tolperisone hydrochloride and Etoricoxib respectively. Various forced degradation conditions, such as alkali hydrolysis, acid hydrolysis, thermal degradation, photolytic degradation, and oxidative degradation, were applied to the drug ingredients and drug formulation. The degradants were efficiently separated from the drugs by using optimized chromatographic conditions. The developed method was validated as per recommendation parameters of International council on harmonization guidelines Q2(R1). Conclusion: The validation parameters indicate that the drug substances were efficiently separated from its degradants and developed method can be routinely applied for the simultaneous quantitative determination of Tolperisone hydrochloride and Etoricoxib in combined tablet formulation in the quality control laboratory.

A VALIDATED STABILITY INDICATING RP-HPLC METHOD FOR ESTIMATION OF AVAPRITINIB IN BULK AND TABLET DOSAGE FORM

Objective: The present investigation aims to develop a simple, cost effective, and reliable stability-indicating RP-HPLC assay method for analysis of avapritinib in bulk and the tablet dosage form. Methods: The method was developed using Acetonitrile and Methanol in a ratio of 70:30 (v/v) as the mobile phase, flowing at a rate of 1 ml/min, in an isocratic mode. A reverse phase column (Symmetry C18 column, 250 mm x 4.6 mm, 5 µm) was used as the stationary phase. The detection of the compound was made using a UV detector set at 245 nm. The validation and force degradation studies of the method were done following the International Conference on Harmonization (ICH) guidelines. Results: The method was validated using the prescribed parameters like system suitability, LOD, LOQ, accuracy, precision, robustness, specificity etc. The relative standard deviation (% RSD) of the peak area observed in each case was found within the accepted range (< 2%). The tailing factor and the plate count were found to be less than 2 and more than 2000 respectively in each observation. The coefficient of correlation (r2) value in the linearity study was found to be 0.9997. The drug was found to be quantified accurately in presence of its degraded products. Conclusion: The developed simple and economic method is a suitable option for the qualitative and quantitative study of avapritinib in bulk and tablets even in presence of its degraded products which may arise because of oxidation, hydrolysis, thermal and photolytic decomposition.

Development and Validation of Stability-Indicating Assay Method for a Novel Oxazolidinone (PH-192) with Anticonvulsant Activity by Using UHPLC-QToF-MS.

The treatment of seizure disorders with currently available pharmacotherapeutic agents is not optimal due to the failure of some patients to respond, coupled with occurrences of side effects. There is therefore a need for research into the development of new chemical entities as potential anticonvulsant agents, which are different structurally from the existing class of drugs. We recently identified a novel triazolyl-oxazolidinone derivative, PH-192, as a potential anticonvulsant agent. PH-192 demonstrated protection comparable to phenytoin against both chemically- and electrically-induced seizures in rodents with little or no central nervous system side effects. However, PH-192 did not exhibit protection beyond 30 min; therefore, we decide to investigate a stability-indicating assay of PH-192 in plasma and other solutions. A reliable and validated analytical method was developed to investigate the stability of PH-192 for 90 min in human plasma, acidic, basic, and oxidative conditions, using a Waters Acquity ultra high-performance liquid chromatography (UHPLC) system with a quaternary Solvent Manager (H-Class). A simple extraction method indicated that PH-192 was stable in human plasma after 90 min at 37 °C, with more than 90% successfully recovered. Moreover, stress stability studies were performed, and degradants were identified using LC-QToF-MS under acidic, basic, and oxidative simulated conditions.

Validated Stability-Indicating Assay UHPLC Method for Simultaneous Estimation of Doravirine, Lamivudine and Tenofovir Disoproxil Fumarate in Pure Material and Pharmaceutical Matrix

An efficient, robust, and specific stability-indicating UHPLC assay method was acquainted for simultaneous determination of antiretroviral agents doravirine (DOV), lamivudine (LVD), and tenofovir disoproxil fumarate (TDF). The determination of cited agents was performed on UPLC system using UPLC BEH C18 (150 mm × 2.1 mm) with 1.7 µm particle size column at ambient temperature using a solvent system in a proportion of (60:40 % v/v) acetonitrile: potassium dihydrogen orthophosphate buffer; pH 4.5 ± 0.2 was adjusted with 0.1 % OPA. The PDA detector was subjected to a wavelength of 235 nm. DOV, LVD, and TDF were experienced in various stress procedures of forced degradation experiments, as recommended by the ICH, to assess the established method's stability-indicating practicability. Using the optimized procedure, selected agents were successfully distinguished from the peaks of their respective degradation products. Furthermore, the calibration curves for DOV, LVD, and TDF in over wide concentration ranges of 2–12μg/mL, 5–30μg/mL, and 5–30μg/mL, respectively, with determination coefficients (r2) of 0.997, 0.9994, and 0.9994. The method validation assays had less than 2 % relative standard deviations for accuracy, precision, repeatability, and robustness.

Development and Validation of a Stability-Indicating Reversed-Phase HPLC Method for Assay and Estimation of Related Substances of Ivermectin in an Oral Paste.

Ivermectin is a potent semi-synthetic antiparasitic drug used in veterinary medicine. A reversed-phase high performance liquid chromatography (HPLC) method has been developed and validated for the identification and assay of Ivermectin, including the identification and estimation of its related impurities in an oral paste. Analytes were separated using a gradient elution at a flow rate of 1.5mL/min on a Zorbax Extend-C18 column (150mm×4.6mm i.d., 3.5-μm particle size) maintained at 30°C. The mobile phase was composed of water as mobile-phase A and acetonitrile/methanol (85/15, v/v) as mobile-phase B. Ultraviolet detection at 245nm was employed to monitor the analytes. Limit of quantitation (LOQ) and limit of detection (LOD) of the method are 0.6 and 0.2μg/mL, respectively. The validation results demonstrated excellent linearity of the method in the range of 0.1-150% of the analytical concentration (0.6mg/mL) of the method. The stability-indicating capability of the method has been demonstrated by adequately separating the degradation products from the stress degraded samples of the oral paste as per method validation requirements prescribed in the current International Council for Harmonisation guidelines.

A Stability Indicating Reverse Phase-HPLC Method Development and Validation for the Estimation of Bimatoprost 0.3% & Timolol 0.5% Pharmaceutical Ophthalmic Dosage Form

The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmic solution method development was determined on Waters HPLC instrument using a UV Detector. The separation was done by using L11, Zorbex SB phenyl (4.6 mm × 250 mm internal diameter) 5 μm analytical column, containing mobile phase of Phosphate buffer (0.02 M), methanol, and acetonitrile [50:30:20 % v/v]. The method was run at 1 ml·min-1 at 210 nm for Bimatoprost and 295 nm for Timolol for detection. The drug was eluted at 10.81 min for Bimatoprost and 3.77 min for Timolol. After developing the method, it was assured for the intended use by validation, which was done according to ICH Q2B guidelines. The analytical parameters checked were Specificity/Selectivity, linearity, Range, accuracy, ruggedness, and robustness. It was observed that the response of the detector was linear in the range of 6 - 18 μg/ml with a correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability-indicating assay method was established by using the samples generated by the forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative, and photolytic degradation, and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the quantitative analysis of Bimatoprost 0.3% + Timolol 0.5% Ophthalmic Solution drugs for pharmaceutical use. Currently, there is no official method for Bimatoprost & Timolol combination products in USP or BP. Available research work related to single Bimatoprost or Timolol products was not suitable for testing Bimatoprost and Timolol combination drugs. Additionally, there is no stability-indicating method to test Bimatoprost & Timolol combination products which insist us to do research and develop a new reverse phase-HPLC indicating method which will be faster and more accurate.

CHEMICAL FINGERPRINTING OF PIPERINE AND TANNIC ACID IN AN AYURVEDIC FORMULATION OF DASANAKANTHI CHURNAM USING RP-HPLC

Dental diseases are one of the significant public health problems globally. Herbal medicines for managing oral diseases are considered an effective alternative to synthetic compounds due to their lower side effect. Acacia catechu, Piper nigrum, Piper longum, and Piper cubeba are vital components of Dasanakanthi Churnam used to control and prevent oral inflammations in dentistry. Tannic acid and Piperine are major markers for the chemical fingerprinting of Dasanakanthi Churnam. They serve as quality indicating parameters for Dasanakanthi Churnam because of their pharmacological action. Development and validation of a stability-indicating assay method using RP-HPLC become an integral part of simultaneous estimation of Tannic acid and Piperine in Dasanakanthi Churnam. Stability indicating the method is established by exposing markers to various stress conditions such as alkaline hydrolysis, photolytic, oxidative and thermal conditions. Stress testing of the markers can help identify the likely degradation products and validate the stability indicating the power of the analytical procedures used. Tannic acid and Piperine were effectively separated at 5.2 and 22.5 minutes respectively using a PDA detector without interference from any degradant and impurities. This research gives a scope to further carry out the stability studies such as accelerated, intermediate, and long-term studies for Dasanakanthi Churnam.

QbD-Based Development and Validation of Novel Stability-Indicating Method for the Assay and Dissolution of Garenoxacin in Garenoxacin Tablets.

Garenoxacin mesylate is a novel des-fluoro(6) quinolone, approved and marketed for human use in Japan under the name Geninax. In this current work, a simple and stability-indicating method for the assay and dissolution of garenoxacin in garenoxacin tablets 200 mg was performed. New method developed for the particle size measurement of Garenoxacin mesylate Active Pharmaceutical Ingredient using Malvern 2000. A quality by design (QbD)-based stability-indicating assay method was developed using 0.1% (v/v) formic acid in water and methanol (70:30). Using a photodiode array detector the peak purity of the garenoxacin peak for all degradation samples was studied. The biopharmaceutical classification system (BCS) solubility of garenoxacin mesylate active pharmaceutical ingredient (API) was studied by a modified shake flask method. A dissolution test method was developed using 0.1 N hydrochloric acid as the medium, United State Pharmacopoeia apparatus-II (paddle), revolution per minute (rpm) 50, temperature 37 ± 0.5°C and time 30 min. Liquid paraffin was used as the dispersant in the particle size measurement of garenoxacin mesylate API using the Malvern Mastersizer-wet method. The QbD-based RP-HPLC method was stability-indicating, simple, precise, and accurate. The assay method was linear over 12.5 to 75 µg/mL at the detection wavelength of 280 nm. A UV-based method was developed and validated for the dissolution of garenoxacin 200 mg tablets and the method was found to be linear over 2.9 to 34.2 µg/mL at 280 nm. Based on data, the dissolution tolerance for garenoxacin 200 mg tablets was proposed as Q not less than 80% at time 30 min (% drug released with respect to label claim (Q). The effect of garenoxacin mesylate API particle size in the tablet dosage form was studied using particles of 92 µm and 220 µm [90% of the total particles are smaller than this size (D90)] and it was found that there was no impact on the in vitro dissolution profile. The reported stability-indicating assay and dissolution test methods can be used in regular QC testing of garenoxacin 200 mg tablets. The Malvern particle size wet dispersion measurement method developed and validated for garenoxacin mesylate API is simple and robust. A QbD based RP-HPLC method (using Design Expert Software version 11) was developed and studied peak purity of Garenoxacin peak using Photo Diode Array detector (for all degradation samples, control sample and standard solution) and the same method is validated following USP and ICH guidelines.LC-MS compatible volatile buffer solution is used in the preparation of the mobile phase for the novel stability-indicating RP-HPLC assay method.

Development and Validation of a Stability-Indicating Reversed-Phase Ultra High Pressure Liquid Chromatography Method for Assay of Delmopinol Hydrochloride and Estimation of Its Related Substances in Commercial Bulk Batches.

Delmopinol hydrochloride is widely used as an active ingredient (AI) in many human oral hygiene products. To the best of our knowledge (via literature search), there is no stability-indicating liquid chromatography method available in the public domain for assay and estimation of related substances of Delmopinol hydrochloride. A fast stability-indicating Reversed-Phase Ultra High-Performance Liquid Chromatography (RP-UHPLC) method has been developed and validated for identification, assay and estimation of related substances in commercial bulk batches of this AI. The major peak of the AI and its related compounds are adequately separated in 6min by a gradient elution on a hybrid silica-based C18 column (Waters Acquity UPLC® BEH C18, 50mm × 2.1mm I.D., 1.7μm particle size) maintained at 50°C. Mobile phase-A is composed of aqueous 10mM NH4OH and mobile phase-B is ACN. The AI and its related compounds are detected with UV detection at 220nm and quantitated by an external Delmopinol hydrochloride reference standard. The quantitation limit of the method is 0.1% of the target analytical concentration. This UHPLC method is fast and green and has been demonstrated to be specific, accurate, linear, precise, sensitive and robust as per ICH guidelines.

HPLC-DAD approach for determination of pyridoxine HCl and doxylamine succinate in pure and pharmaceutical dosage forms: A green stability-indicating assay method

The environmental impact of analytical procedures is a major concern nowadays. As a result, scientists are now working to reduce the adverseenvironmental impact of chemicals and solvents. Stability testing is an important stage in the pharmaceutical industry because it determines how a drug product's quality changes over time as a result of environmental and laboratory conditions. This study demonstrates the use of green reversed phase (RP-HPLC) to determine pyridoxine HCl (PYR) and doxylamine succinate (DOX) in the presence of DOX oxidative degradation product (DOX DEG). DOX DEG was identified by using (LC-MS). The chromatographic separation was achieved using a mobile phase consisting of ethanol and 0.01 M phosphate buffer pH = 5.0 (10: 90, v/v) with isocratic elution, pumped at 1.0 mL/min on an Xterra C18 column (100 mm × 4.6 mm × 5 m). DAD was used for detection at 254.0 nm and the retention times for PYR, DOX and DOX DEG were 1.41 min, 5.89 min, and 7.36 min, respectively. This procedure was validover linearity ranges of 10.00–120.00 μg/mL and 5.00–100.00 μg/mL, with mean percentage recoveries100.09 ± 0.949 and 100.29 ± 0.519 for PYR and DOX, respectively. The presented chromatographic method was fully validated in accordance with ICH requirements and was statistically compared with those of the reported method and there was no significant difference between them. The proposed approach was shown to be more eco -friendly in terms of the use of hazardous chemicals and solvents, energy consumption, and waste generation than the reported one.

A NOVEL VALIDATED HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC STABILITY-INDICATING ASSAY METHOD IN REVERSE PHASE FOR ESTIMATION OF HYDROXYPROGESTERONE CAPROATE IN AN INJECTABLE FORMULATION.

A high-performance liquid chromatographic stability-indicating assay method in reverse-phase has been developed and validated for the quantitative measurement of Hydroxyprogesterone corporate in injectable formulation prepared in castor oil base containing excipient benzyl benzoate as preservative. The reverse-phase method was developed by using Sunfire C18 column having dimensions (150 x 4.6 mm x 5μm) with a mobile phase[A] comprised of water, acetonitrile, and Methanol mixed in 40:30:30 v/v ratio and mobile phase [B] comprised of water, acetonitrile, and Methanol mixed in 20:40:40 v/v ratio pumped gradient program at a flow rate of 1.0 ml/min where the thermostat of the column oven controlled at 30°C and sample compartment at 5°C. The injection volume is set at 20μL. Hydroxyprogesterone corporate has a retention time of 10 minutes with UV detection at 240 nm. The detector was showing linear response in a range of 0.25 μg/ml to 150 μg/ml for Hydroxyprogesterone corporate. The guidelines of the International Conference on Harmonization on guidance for industry (2005) validation of analytical procedures, text, and methodology Q2(R1) were followed for the validation of this novel method. For quantification of Hydroxyprogesterone corporate the developed method was found to be genuinely exact precise, accurate, linear, robust, rugged, stable. and cost-effective.

Validated Stability-Indicating Assay UHPLC Method for Simultaneous Analysis of Saxagliptin and Metformin in Fixed-Dose Combinations

A Saxagliptin (SAX) and Metformin (MET) fixed-dose combination (FDC) can improve the chances of achieving optimal glycaemic control in type 2 diabetes mellitus subjects. Accordingly, the scientific novelty of design work was to develop a specific and precise stability-indicating UHPLC assay method for simultaneous quantification of cited drugs in extended-release FDC's. The reversed-phase UHPLC resolution was analyzed with the assistance of UPLC BEH C18 (150 mm × 2.1 mm) with 1.7 µm particle size column at ambient temperature using a solvent system in a proportion of (85:15 % v/v) potassium dihydrogen orthophosphate buffer and acetonitrile, with 0.4 mL/min rate of flow of a solvent system. The analytes were supervised at 220 nm by employing photodiode array recognition. The retention times of analytes SAX and MET were 2.687 ± 0.022 min and 1.856 ± 0.03 min, respectively. The SAX and MET have confirmed the linearity ranges of 10 – 60 μg/mL and 100 – 600 μg/mL, with 0.9989 and 0.9979 determination coefficients. The UHPLC method was effectually validated concerning the accuracy, precision, sensitivity, robustness, ruggedness, selectivity, and specificity. Moreover, the anticipated UHPLC method's capability to analyzed the SAX and MET with no obstruction from degradation products.

STABILITY-INDICATING HPTLC METHOD FOR DETERMINATION OF DACLATASVIR IN PHARMACEUTICAL DOSAGE FORM

A simple, specific, precise, and accurate stability-indicating assay method using high performance thinlayer chromatography (HPTLC) is described for estimation of daclatasvir dihydrochloride (DCV) in bulk drug and in the tablet dosage form. The separations were achieved on prepared TLC plates precoated with silica gel 60 F254. The mobile phase developed and optimized for bringing out the separation involves toluene: methanol in the ratio of (6:4 V/V). The densitometric scanning wavelength selected was 312.0 nm. The compact bands of DCV were obtained at RF value of 0.702±0.032. The method developed was able to separate peaks of all the degradation products formed in ICH prescribed stress conditions with sufficient difference in their RF values. The developed method was validated for linearity and range, specificity, precision, accuracy, and robustness, and the results were found to be within acceptance criteria. The reliability of the method was evaluated when it was applied for the estimation of DCV in pharmaceutical tablet formulation and assay results gave good recovery.

Development of a stability-indicating assay method by HPLC-DAD and MS characterization of forced degradation products of ravuconazole.

Ravuconazole (RAV) is a triazole antifungal with broad spectrum and a novel alternative in the treatment of systemic fungal infections. A stability-indicating method by high-performance liquid chromatography-diode array detection was developed and fully validated to assay ravuconazole in the presence of its degradation products. Separation was achieved with a Sunfire C18 column (250 mm × 4.6 mm id, 5 μm), mobile phase composed of acetonitrile and water (80:20), at 1 mL/min. The volume of injection was 5 μL and DAD detection was performed at 287 nm. RAV was well resolved from its degradation products and the method proved to be linear, selective, accurate, precise and robust. A forced degradation study was conducted on the pure drug under oxidative conditions in presence of H2O2 and metallic ions and under acid, alkaline and neutral hydrolysis. RAV was degraded mainly under alkaline hydrolysis, forming two main degradation products. The chemical structures were proposed according to the data obtained by liquid chromatography coupled to mass spectrometry (LC-MS) analysis. This study provided a new and selective stability-indicating method to evaluate the intrinsic stability of ravuconazole in active pharmaceutical ingredients. The developed method was found to be suitable for quality control routine analysis and to stability studies of ravuconazole.

A simple stability indicating RP-HPLC-DAD method for concurrent analysis of Tenofovir Disoproxil Fumarate, Doravirine and Lamivudine in pure blend and their combined film coated tablets

The main aim of the study was to develop an economical, insightful, accurate and simple RP-HPLC-DAD method with high precision and good sensitivity for concurrent determination of Tenofovir disoproxil fumarate, Doravirine and Lamivudine in blended bulk form and their combined tablet form. A method with Ascentis C18 (150×4.6mm, 5μm) column, mobile phase ratio of 0.1% ortho phosphoric acid and Acetonitrile in 70:30 (v/v), 1mL/min flow rate and detection wavelength of 260nm was highly proficient in effective separation of all three drugs. The developed method was validated in accordance with ICH specifications. The retention times of Doravirine, Lamivudine and Tenofovir disoproxil fumarate observed were 2.4, 2.9, and 3.6min, respectively. The linear responses were observed for Doravirine, Lamivudine and Tenofovir disoproxil fumarate in the range of 12.5-75μg/mL, 75-225μg/mL and 75-225μg/mL, respectively. The limit of detection and quantification values were calculated to be 0.36μg/mL and 0.11μg/mL for Lamivudine, 0.55μg/mL and 1.66μg/mL for Tenofovir disoproxil fumarate and 0.03μg/mL and 0.09μg/mL for Doravirine. The % RSD values of the intra-day and inter-day precision were calculated in the range of 0.134-1.749. The mean percentage recovery of all three analytes was in the range of 98.85-100.18%. The statistical results of the validation parameters ensured that the method was accurate, specific, and precise with good sensitivity. Investigation of analytes under different stressed conditions ensures the stability of analytes reflecting the stability indication of the method. The developed method has high proficiency in separation of Tenofovir disoproxil fumarate, Doravirine and Lamivudine. The degradation products generated due to stress conditions also separated with good resolution. The current method is a stability-indicating assay method consisting of appropriate specificity, accuracy, precision and sensitivity. The developed method has a good potential to be adopted by the pharmaceutical industrial sector.

Development and Validation of a Stability-Indicating Reversed-Phase High-Performance Liquid Chromatography Method for Assay of Doramectin and Estimation of its Related Substances in Commercial Batches of Doramectin Drug Substance.

Doramectin is a broad-spectrum antiparasitic drug used in veterinary medicine. It belongs to the family of avermectins, which possess a macrocyclic lactone structure, and is widely used for the treatment of parasites. This study aimed to develop a stability-indicating reversed-phase (RP) HPLC method for the assay and identification of doramectin including identification and estimation of its related substances in commercial batches of doramectin drug substance. Methanol was used to dissolve and prepare doramectin samples. Doramectin and its related substances were separated on a HALO C8 (100 mm × 4.6 mm i.d., 2.7 µm particle size) column maintained at 40 °C using an isocratic HPLC method with a mobile phase composed of acetonitrile-water (70 + 30, v/v). Analytes were detected with UV detection at 245 nm and quantitated against a single point external reference standard of doramectin. The LOQ of the method is 0.1% of the target concentration as described in the method. The HPLC method can separate all analytes of interest by an isocratic elution within 10 min. The method was validated according to the guidelines described in the International Conference on Harmonization Q2(R1). The HPLC method for assay of doramectin and estimation of its related substances was successfully developed, validated, and demonstrated to be accurate, robust, specific, and stability-indicating. This is the first known paper to report an HPLC method for assay of doramectin and estimation of its related substances in commercial batches of doramectin drug substance.

Development and Validation of a Stability-Indicating HPLC Method for Assay of Milbemycin Oxime and Estimation of Its Related Compounds

A stability-indicating reversed-phase HPLC method for assay of milbemycin oxime (MO) and estimation of its related compounds has been developed and validated as per VICH and ICH method validation guidelines. The stability-indicating capability of this method has been demonstrated by adequate separation of all process-related impurities including all potential degradation products of milbemycin oxime (MO) that were generated using stress degradation conditions that are prescribed in ICH guideline. The stability-indicating capabilities of this method were further challenged by analyzing aged stability samples of MO active pharmaceutical ingredient (API). Chromatographic separation of MO and its related compounds was achieved using an isocratic elution at a flow rate of 0.5 mL/min on a Supelco Ascentis Express C18 column (100 mm × 3.0 mm, 2.7 µm particle size, 90 A pore size) maintained at 50 °C. The isocratic mobile phase was composed of 30% v/v of 0.05% phosphoric acid in aqueous solution and 70% v/v of a mixture of methanol and acetonitrile (6:4, v/v). UV detection at 244 nm was employed to monitor the analytes.

Development of HPLC-CAD stability indicating assay method for polyethylene glycol-conjugated phospholipid (DMPE-PEG 2000) and identification of its degradation products

The study introduces first report on a liquid chromatographic method for the quantification of 1,2-Dimyristoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] ammonium salt (DMPE-PEG 2000), which is an important constituent of lipid-based nanoparticles. It involves an HPLC-CAD stability-indicating assay method development for DMPE-PEG 2000 and structure elucidation of its degradation products. Hypersil Gold™ PFP column (150 mm × 4.6 mm, 3.0 μm) was used to achieve the separation among DMPE-PEG 2000 and its degradation products using 0.0025% formic acid in water: methanol (80:20 v/v) as mobile phase A and methanol: acetonitrile (60:40 v/v) as mobile phase B in a gradient elution mode. The method was validated for precision, linearity, sensitivity, solution stability and robustness. Relative standard deviations for the intra-day precision, inter-day precision and sensitivity were 1.6%, 0.6% and 3.8%, respectively. The method was linear in the range from 210 μg/mL to 390 μg/mL with R2 value of 0.996. Further, the solution stability of DMPE-PEG 2000 was evaluated under different stressed and storage conditions to understand the impact of any excursion to its regular storage temperature of −20 °C. The observed degradation products were identified through liquid chromatography high resolution mass spectrometry and a tentative pathway was proposed for the generation of these degradants.

HPLC-DAD Approach for Determination of Pyridoxine HCl and Doxylamine Succinate in Pure and Pharmaceutical Dosage Forms: A Green Stability-Indicating Assay Method

HPLC-DAD Approach for Determination of Pyridoxine HCl and Doxylamine Succinate in Pure and Pharmaceutical Dosage Forms: A Green Stability-Indicating Assay Method

The solution and solid-state degradation study followed by identification of tedizolid related compounds in medicinal product by high performance liquid chromatography with diode array and tandem mass spectrometry detection

The aim of the study was to investigate the intrinsic stability and to identify potential degradation products of tedizolid disodium phosphate (TED-OPO3Na2), which belongs to the antimicrobial agents of the oxazolidinone class. Tedizolid, as disodium phosphate (prodrug), is registered under the trade name SIVEXTRO®, at a dose of 200 mg, in the form of powder for injection or infusion. The stability-indicating assay method was optimised using HPLC with diode array detection and with electrospray ionisation time-of-flight mass spectrometry.In solution-state studies, the forced decomposition of TED-OPO3Na2 carried out under acidic, basic, oxidative, photocatalytic, and thermal conditions revealed the lability of TED-OPO3Na2 to acidic, basic, and photocatalytic (UV) conditions, while it was relatively stable in oxidative conditions and during thermolysis processes. The kinetics of degradation and shelf-life values in solution-state studies were determined, and activation energies were calculated for alkaline and thermolytic degradation. In contrast, in the solid state degradation study, TED-OPO3Na2 was stable under thermal conditions at high humidity and in visible light, while moderate degradation was observed under thermal conditions of low humidity and ultraviolet light.The developed method enabled the identification of 12 new degradation products and 3 new by-products.