Stability-indicating High-performance Liquid Chromatography Research Articles

Greener Stability-Indicating HPLC Approach for the Determination of Curcumin in In-House Developed Nanoemulsion and Curcuma longa L. Extract

Despite the fact that several analytical methodologies have been reported for the determination of curcumin (CCM) in a wide range of sample matrices, the greener liquid chromatographic approaches to determine CCM are scarce in the literature. Therefore, this research is designed to develop and validate a greener stability-indicating “high-performance liquid chromatography (HPLC)” methodology to determine CCM in an in-house developed nanoemulsion, Curcuma longa L. extract, and commercial tablets. CCM was measured on a Nucleodur (150 mm × 4.6 mm) RP C18 column with 5 µm-sized particles. Ethanol and ethyl acetate (83:17 v/v) made up the greener eluent system, which was pumped at a flow speed of 1.0 mL/min. At a wavelength of 425 nm, CCM was detected. The greener HPLC methodology was linear in the 1–100 µg/mL range, with a determination coefficient of 0.9983. The greener HPLC methodology for CCM estimation was also rapid (Rt = 3.57 min), accurate (%recoveries = 98.90–101.85), precise (%CV = 0.90–1.11), and sensitive (LOD = 0.39 µg/mL and LOQ = 1.17 µg/mL). The AGREE approach predicted the AGREE score of 0.81 for the established HPLC technique, indicating an outstanding greenness profile. The utility of the greener HPLC methodology was demonstrated by determining CCM in the in-house developed nanoemulsion, Curcuma longa extract, and commercial tablets. The % amount of CCM in the in-house developed nanoemulsion, Curcuma longa extract, and commercial tablets was found to be 101.24%, 81.15%, and 78.41%, respectively. The greener HPLC methodology was able to detect its degradation product under various stress conditions, suggesting its stability-indication characteristics. These results suggested that CCM in developed nanoemulsion, plant extract samples, and commercial tablets may be routinely determined using the greener HPLC methodology.

Inclusion Complex of Clomiphene Citrate with Hydroxypropyl-β-Cyclodextrin for Intravenous Injection: Formulation and Stability Studies.

Clomiphene citrate is the first-line treatment for women with abnormal or failed ovulation. Currently, it is available as oral tablets, and the parenteral formulation does not exist. In this study, we prepared clomiphene citrate-hydroxypropyl-β-cyclodextrin inclusion complex for its use in intravenous injection. The inclusion complex was characterized in the liquid state (phase solubility) and solid state by differential scanning calorimetry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy analyses. The sterile intravenous injection containing 0.5% clomiphene citrate was prepared and characterized for its physical properties, assay, pH, and osmolality. A stability-indicating high-performance liquid chromatography (HPLC) method for the injection was developed. The HPLC method was validated for the assay, linearity, precision and repeatability, benchtop stability, and forced degradation to elute clomiphene isomers from the degradation products. The injection was packed in sterile 10-ml glass vials with butyl rubber stoppers and stored at 40°C, room temperature, and 4°C. The samples at 0, 0.5, 1, 2, 3, and 6months were analyzed for clarity, pH, osmolality, and drug assay. The HPLC method was linear (R2 = 0.9999), precise (0.86% relative standard deviation), and stability indicating. The stability data at the accelerated (40°C) storage condition for 6months showed satisfactory results: the drug assay in the injection was between 90 and 105%, the injection remained clear, pH was between 4.0 and 4.4, and osmolality was between 270 and 350mOsm. The stability data suggests that the product is stable and meets the given analytical specifications.

Analytical Lifecycle Management (ALM) and Analytical Quality by Design (AQbD) based Analytical Method Development for Separation of Related Substances in Amodiaquine Hydrochloride along with its Degradation Products and Structural Elucidation by LC-Quadrupole-Time of Flight-Tandem Mass Spectrometry

The current study aimed to develop a robust, regulatory-flexible, stability-indicating ultra high performance liquid chromatography (UHPLC) analytical procedure compatible with mass spectrometry for the determination of impurities in amodiaquine hydrochloride using analytical lifecycle management (ALM) and analytical quality by design (AQbD) principles. The analytical target profile (ATP) and critical method attributes (CMAs) for the analytical method were identified. The pH of the mobile phase, flow rate and column oven temperature were identified as critical method parameters (CMPs) through risk assessment studies and they were screened and optimized using the design of experiments (DoE) to generate the design space (DS). Finally, all the impurities were well separated in a 15 min run time by using an Acquity UPLC BEH-C18 column with 20 mM ammonium acetate pH 8.0 as mobile phase A and acetonitrile as mobile phase B with a gradient program of time (min), % of B: 0/15, 1.0/15, 9/55, 12/55, 12.1/15 and 15/15. The flow rate was 0.3 mL min-1 and the column oven temperature were 30 ºC. Evaluated the robustness of the developed analytical method. Degradation products obtained from the forced degradation studies are well separated from process impurities and main compound. Based on the stress studies, impurity-3 was identified as a key degradation product in base degradation, while DP-1, impurity-3, DP-2, DP-3 and DP-4 were in the oxidative degradation. Total 9 impurities out of 4 process related and 5 degradation impurities were well separated in the developed method. Used the same method to LC coupled tandem mass spectrometer for separation and structure elucidation of degradation products. The method validation was carried out in accordance with ICH Q2 (R1) and USP <1225> guidelines.

Development and Validation of Stability-indicating High-Performance Liquid Chromatography Method for Estimation of Organic Impurities of Carvedilol from Bulk and its Dosage Form

Development and Validation of Stability-indicating High-Performance Liquid Chromatography Method for Estimation of Organic Impurities of Carvedilol from Bulk and its Dosage Form

Determination of Firocoxib and Its Related Substances in Bulk Drug Substance Batches of Firocoxib by a High-Speed Reversed-Phase HPLC Method With a Short Fused-Core Biphenyl Column.

Firocoxib is a nonsteroidal anti-inflammatory drug. It provides control of postoperative pain and inflammation associated with soft tissue and orthopedic surgery in dogs, and control of pain and inflammation associated with osteoarthritis in horses. A high-speed stability-indicating reversed-phase high-performance liquid chromatography method was developed to determine firocoxib and its related substances in bulk batches of firocoxib drug substance. Firocoxib was dissolved in neat acetonitrile (ACN) and analyzed on a short HALO (fused-core) biphenyl column (30 × 4.6mm i.d., 2.7-μm particle size) at flow rate of 2.5mL/min. Column temperature was maintained at 50°C. Mobile phase A is composed of 0.1% of H3PO4 in water and mobile phase B is composed of ACN. Analytes were detected with UV detection at 240nm and quantitated against an external reference standard. Firocoxib and its related compounds were adequately separated within 4min by a gradient elution. The method was validated for specificity, linearity, accuracy, precision and robustness according to method validation guidelines described in The International Conference on Harmonization. The validation data demonstrated that this method is sensitive, accurate, robust, specific and stability-indicating.

Development and Validation of Stability-Indicating High-Performance Liquid Chromatography Method for Estimation of Lacosamide in Bulk and Its Pharmaceutical Dosage Form.

A simple, specific, accurate and stability-indicating reversed-phase high-performance liquid chromatographic method was developed for the determination of lacosamide, using C18 column and a mobile phase composed of phosphate buffer (pH4.0):acetonitrile (40:60v/v). The retention time of lacosamide was found to be 2.7min. Linearity was established for lacosamide in the range of 10-50μg/mL. The percentage recovery of lacosamide was found to be in the range of 97.37-99.20%. The drug was subjected to acid, alkali, oxidation, dry heat and photolytic degradation. The degradation studies indicated condition was well resolved from the pure drug with significant differences in their retention time values. This method can be successfully employed for quantitative analysis of lacosamide in bulk drug and formulation.

Degradation pathways and impurity profiling of the anticancer drug apalutamide by HPLC and LC-MS/MS and separation of impurities using Design of Experiments.

Apalutamide, an androgen receptor inhibitor, is used to treat prostate cancer. A stability-indicating high-performance liquid chromatography method was developed for the estimation of assay and organic impurities of apalutamide in drug substance and in tablet dosages using Design of Experiments. The chromatographic separation was achieved within 30 min using Atlantis dC18 , 100 × 4.6mm, 3.0 μm and the binary gradient program (10 mm KH2 PO4 , pH3.5; acetonitrile). The detection wavelength, flow rate, column temperature and injection volume used were 270 nm, 1.0 ml/min, 45°C and 10 μl, respectively. The interaction of independent variables (pH, column temperature and flow rate) and their influences on HPLC parameters were studied using a central composite design, and then the peak separation and elution behaviors between apalutamide and its seven impurities were determined. The method validation was performed for linearity, detection limit, quantitation limit, accuracy, precision and robustness as per the International Conference on Harmonization. A high-quality recovery with good precision (91.7-106.0%) and correlations (r2 > 0.997) within a linear range of 0.12-2.24 μg/ml (0.05-0.3%, w/w) were achieved consistently for assay and organic impurities of apalutamide. The stability-indicating characteristics of the proposed method were assessed through forced degradation and mass balance studies. An effort was made to figure out the chemical structures of newly formed degradation products (DP1-DP5) using LC-MS/MS.

Compatibility and stability of methylprednisolone sodium succinate and granisetron hydrochloride in 0.9% sodium chloride solution.

A combination of methylprednisolone sodium succinate (MSS) and granisetron hydrochloride (GH) is generally devoted to treating the chemotherapy-induced nausea and vomiting. To date, none of these novel mixtures have been commercially available. The present study was aimed at investigating physical and chemical compatibility and stability of a combination of MSS with GH in 0.9% sodium chloride injection for 72 hours at 4°C and 25°C. A mixture of MSS (0.4-0.8 mg/mL) with GH (0.03 mg/mL) was prepared and stored in both polyvinyl chloride bags and glass bottles using 0.9% sodium chloride injection as a diluent. The study was performed using a validated and stability-indicating high-performance liquid chromatography method. The physical compatibility was assessed by a spectrometer. Furthermore, the pH measurement of each sample was measured electronically. All test solutions stored at 4°C or 25°C had a no >2% loss of the initial concentration throughout the 72-hour study period. All solutions remained clear and colorless throughout the study and were without precipitation or turbidity in any of the batches. The drug mixtures of MSS (0.4-0.8 mg/mL) and GH (0.03 mg/mL) in 0.9% sodium chloride injections were physically and chemically stable for at least 72 hours when stored at 4°C or 25°C in polyvinyl chloride bags or glass bottles.

Stability evaluation of compounded hydroxyurea 100 mg/mL oral liquids using a novel analytical method involving chemical derivatization.

This study assessed the stability of six extemporaneously compounded hydroxyurea oral liquids stored at room temperature. Hydroxyurea oral liquids (100 mg/mL) were prepared using three different mixing methods (mortar, mixer or QuartetRx) from either bulk powder, capsule content, or whole capsules. Two brands of capsules were tested in this study. All formulations were stored at room temperature (25°C / 60% RH) in amber plastic bottles for 90 days and amber plastic syringes for 14 days. Physical stability was assessed visually, while chemical stability was evaluated using a stability-indicating high-performance liquid chromatography method. Chemical derivatization with xanthydrol allowed the retention of hydroxyurea on a reverse-phase column. At least 93.9% and 97.0% of the initial concentration of hydroxyurea remained after 90 days in bottles and 14 days in syringes, respectively. There were no visual changes in formulations over the study period. Changes in pH up to 1.6 units were observed after 90 days of storage and were explained most likely by an ammonium generating degradation pathway. Ammonium was quantified and remained within safe levels in each HU 100 mg/mL oral preparations. Hydroxyurea oral liquids were all stable for 90 days in amber plastic bottles and 14 days in amber plastic syringes.

Stability of benzylpenicillin for continuous intravenous infusions: An isotonic formulation for therapeutic use and a low-dose formulation for clinical trial

IntroductionThe objectives of this study were to develop a stability-indicating high performance liquid chromatography (HPLC) assay for benzylpenicillin (BPC) in pharmaceutical fluids, and to investigate the stability of (i) isotonic citrate-buffered BPC solutions at the clinically relevant concentration of 30 mg/mL, and (ii) low concentration citrate-buffered BPC intravenous infusions (5–30 μg/mL). MethodsThe stability of isotonic BPC solutions containing 3.4 or 7.2 mg/mL sodium citrate was compared against contemporary hypertonic solutions. The HPLC assay was shown to be stability-indicating following acidic, alkali, oxidative and elevated temperature stress testing. ResultsAfter 7 d storage at 4 °C and 24 h at 35 °C, the concentrations of isotonic BPC 30 mg/mL solutions containing 3.4 and 7.2 mg/mL sodium citrate were 96% and 95% respectively, compared to day 0. After 3 d at 4 °C and 24 h at room temperature (22 °C), the concentrations of isotonic BPC solutions with 3.4 and 7.2 mg/mL sodium citrate were 99% and 96% respectively, compared to day 0. These data were comparable to the hypertonic solutions and meet pharmacopeial stability requirements. Low concentration BPC infusions showed 0.5% and 2.5% degradation after 24 h storage at 22 °C and 35 °C, respectively. ConclusionsThe isotonic BPC 30 mg/mL formulation is simple to prepare and may offer clinical benefits in settings where hypertonic solutions are problematic. This study provides assurance that high- and low-dose isotonic BPC infusions are stable at room temperature and our findings may be applicable to in vitro studies of BPC.

Physicochemical and Microbiological Stability of Two Oral Solutions of Methadone Hydrochloride 10 mg/mL.

In this article, we studied physicochemical and microbiological stability and determined the beyond-use date of two oral solutions of methadone in three storage conditions. For this, two oral solutions of methadone (10 mg/mL) were prepared, with and without parabens, as preservatives. They were packed in amber glass vials kept unopened until the day of the test, and in a multi-dose umber glass bottle opened daily. They were stored at 5 ± 3 °C, 25 ± 2 °C and 40 ± 2 °C. pH, clarity, and organoleptic characteristics were obtained. A stability-indicating high-performance liquid chromatography method was used to determine methadone. Microbiological quality was studied and antimicrobial effectiveness testing was also determined following European Pharmacopoeia guidelines. Samples were analyzed at days 0, 7, 14, 21, 28, 42, 56, 70, and 91 in triplicate. After 91 days of storage, pH remained stable at about 6.5–7 in the two solutions, ensuring no risk of methadone precipitation. The organoleptic characteristics remained stable (colorless, odorless, and bitter taste). The absence of particles was confirmed. No differences were found with the use of preservatives. Methadone concentration remained within 95–105% in all samples. No microbial growth was observed. Hence, the two oral methadone solutions were physically and microbiologically stable at 5 ± 3 °C, 25 ± 2 °C, and 40 ± 2 °C for 91 days in closed and opened amber glass bottles.

Study of erdafitinib stress degradation behavior using HPLC-UV analysis and multistage fragmentation ion trap mass spectrometry

Erdafitinib is a fibroblast growth factor receptor inhibitor, which has been recently approved for the treatment of urothelial carcinoma. The stress degradation behavior of erdafitinib was examined using a validated stability-indicating high-performance liquid chromatography method. The study was extended to investigate the fragmentation pathways of erdafitinib using ion trap mass spectrometry. Six degradation products and an impurity were characterized depending on their multistage fragmentation pattern. The degradation products formed under different stress conditions showed molecular masses of 443, 477, 433, 479, 463, and 459. The molecular mass of the detected impurity was 525. The drug and its related substances were efficiently separated on an Eclipse Plus C18 column (4.6 × 100 mm, 3.5 µm). An isocratic mobile phase consisting of acetonitrile and 0.01 M ammonium formate in water containing 0.1% formic acid (26:74, v/v) was used at a flow rate of 0.5 mL/min. Erdafitinib was exposed to oxidative, photolytic, acidic, basic, and thermal hydrolysis as recommended by ICH guidelines. The drug was found to be more sensitive to oxidative hydrolysis and slightly sensitive to acidic and photolytic hydrolysis. The method was fully validated according to ICH guidelines. The limit of detection and quantitation were 0.2 and 0.5 µg/mL, respectively. The relative standard deviations of intraday and interday precisions were not more than 1.99%. The developed method was successfully applied for the determination of erdafitinib in bulk and laboratory-prepared tablets.

Development and Validation of Stability Indicating RP-HPLC Method for Simultaneous Determination of Doxycycline and Rifampicin in Polymeric Nanoparticles

Background: The combination of doxycycline (DOXY) and rifampicin (RIF) is recom-mended as a treatment therapy for brucellosis by the World Health Organization. Objective: The aim of the current study was to develop and validate the stability-indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method for the analysis of a combina-tion of doxycycline & rifampicin. Methods: The RP-HPLC method was developed and validated to estimate the doxycycline and ri-fampicin combination as per ICH guidelines. The drug combination solution was exposed to differ-ent stress conditions: acidic, basic, photo-oxidation, and oxidation. Results: The method was found linear in the range of 2 -10μg/mL for both the drugs with a reten-tion time of 3.5 min for doxycycline and 6.5 min for rifampicin at lambda maximum of 350 nm. The RP-HPLC method was precise and accurate with %RSD < 2%. The intra-day and inter-day precisions were calculated and found within the acceptable range of 5%. Both drugs demonstrated good stability in the mobile phase after 6 hours. The LOD and LOQ of doxycycline and rifampicin were 100 ng/mL & 200ng/mL and 150ng/mL & 500ng/mL, respectively. The forced degradation of the combination of drug solutions was performed. The degraded drug peaks were well-resolved from the peaks of drugs. The percentage encapsulation efficiency of doxycycline and rifampicin in the nanoparticle system was assessed by utilizing the validated RP-HPLC method and found >60% (DOXY) and >70% (RIF). Conclusion: The developed RP-HPLC method of DOXY-RIF combination was rapid, accurate, precise, and stability-indicating. The method can be appropriately applied todetecte drugs in the na-noparticulate system.

Stability of extemporaneously compounded 5-fluorouracil utilizing high performance liquid chromatography.

The goal of the current study is to determine stability of compounded 5-fluorouracil (5-FU) in Intravia™ bags and CADD™ cassettes stored up to 15 days under refrigeration (2-8°C) and room temperature (25°C with 60% relative humidity), with four different concentrations (20 mg/mL, 30 mg/mL, 40 mg/mL, and 50 mg/mL) and two diluents (0.9% sodium chloride and 5% dextrose). A stability-indicating high-performance liquid chromatography (HPLC) method was developed to analyze the 5-FU concentrations. The stability of compounded 5-FU infusions was investigated using this method. Two samples from each storage condition were assessed for stability on days 0, 4, 7, 10, and 15 as per United States Pharmacopeia (USP) guidelines. The assay of 5-FU was done utilizing a calibrated stability-indicating HPLC method. The stability-indicating HPLC assay showed 5-FU completely degraded within 1 hour in basic conditions. No cloudiness or color change was observed during the stability study. Precipitation was observed in the CADD™ cassettes at day 15 in both storage conditions and at day 10 in a single room-temperature CADD™ cassette for 40 mg/mL in 5% dextrose (D5W). HPLC assay revealed the infusions in CADD™ cassettes retained greater than 90% of the initial concentrations of 5-FU for 15 days stored at room temperature (25°C and 60% relative humidity) and for 10 days at refrigeration (2-8°C). Intravia™ bags retained stability through 15 days for all the compounded 5-FU concentrations and both the storage conditions. 5-FU infusions in both CADD™ cassettes and Intravia™ bags were stable for extendable periods in multiple concentrations compared to recommended guidelines for hospital use.

Validation and application of a simple and rapid stability-indicating liquid chromatographic assay for the quantification of caffeine from human saliva

A clinical trial is currently underway to examine the efficacy of using caffeine citrate to prevent intermittent hypoxemia in late preterm neonates. Determining caffeine concentration using saliva in this population would be preferable as it is less invasive than plasma sampling, but a suitable method of analysis is required. This paper presents the development and validation of a rapid, efficient and reproducible stability-indicating high-performance liquid chromatography (HPLC) method and extraction protocol for the quantification of caffeine present in saliva. The stability of extemporaneously prepared caffeine citrate solutions (at 20–25 °C) was determined, along with the stability of caffeine spiked saliva samples (at 20–25 and 2–8 °C), to ensure the suitability of the developed method in the analysis of clinical trial samples. Protein precipitation using acetonitrile ensured the complete removal of salivary proteins and resulted in extraction recovery of ≥95% for all samples. The HPLC assay following extraction was linear (R 2>0.99) over the range 0.3–50 µg/mL (lower limit of quantification 0.3 µg/mL). The accuracy of the quality control samples was 94–100% and the relative standard deviation (RSD) was <7% for all samples. Caffeine-spiked saliva samples were stable for three freeze-and-thaw cycles pre-extraction and up to 72 hr post-extraction. The extraction and HPLC methods described were thus suitable for the analysis of clinical trial samples from the Latte Dosage Trial. All caffeine solutions were physically and chemically stable, with concentrations at the end of the three-month test period being within 4% of the baseline concentrations, indicating appropriateness for use as clinical trial medications.

Physicochemical stability of 20 mg/mL amiodarone hydrochloride oral suspension in SyrSpend® SF PH4 (liquid)

Abstract Objectives Amiodarone hydrochloride is a class III antiarrhythmic drug indicated for the treatment of ventricular and supraventricular tachycardias. Oral amiodarone is only available in a tablet dosage form, which is not suitable for pediatric use. The stability of amiodarone hydrochloride suspension at 5 mg/mL was assessed in SyrSpend® SF PH4 (liquid) but oral amiodarone is typically given as a loading dose of 10–15 mg/kg/day for 4–10 days and then reduced to a maintenance dose of 5 mg/kg/day, making the 20 mg/mL concentration a better option. A hospital preparation of 20 mg/mL amiodarone hydrochloride oral suspension was developed. The purpose of this study was to determine the physicochemical stability of a 20 mg/mL amiodarone hydrochloride oral multidose suspension in a commercial compounding excipient, SyrSpend® SF PH4 (liquid) at ambient temperature and under dark conditions. Methods Three batches of oral suspension were prepared using amiodarone hydrochloride powder and SyrSpend SF PH4 (liquid). The suspensions were stored at room temperature and protected from light (amber glass vials). A sample was withdrawn from each bottle immediately after preparation and at 1, 2, 5, 10, 15, 30, 60, and 90 days. After additional dilution to an expected concentration of 100 μg/mL with methanol, the samples were assayed in triplicate using a stability-indicating high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. The physicochemical properties (pH, osmolality, amiodarone concentration, macroscopic changes) were assessed over 90 days at each day of analysis. Stability was determined by evaluating the percentage of the initial concentration remaining at each time point and defined as retention of at least 95% of the initial concentration of amiodarone hydrochloride. Results After 90 days, the study showed that amiodarone hydrochloride concentrations did not go below 95% of the initial drug concentration. Neither degradation products nor changes of physicochemical properties were detected. Conclusions Compounded oral suspensions of 20 mg/mL amiodarone hydrochloride in SyrSpend® SF PH4 (liquid) were stable for at least 90 days when stored in amber glass bottles at room temperature.

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.

Implementation of Quality by Design Methodology in Development and Validation of a New Stability-Indicating, Reverse Phase High-Performance Liquid Chromatography Method for the Rapid Estimation of Piribedil in Piribedil Prolonged Release Tablets

Piribedil is a diazinane compound used in the treatment of Parkinson’s disease. The objective of the current work was to develop a Quality by design based, stability-indicating High-performance liquid chromatography method, with a short runtime to estimate assay in piribedil prolonged release tablets. The assay is an important critical quality attribute of the drug product, which ensures its efficacy. The critical quality attributes were identified and the quality target method profile was defined. Basis of the initial risk assessment, the separation between piribedil and known/unknown degradation products and the sample preparation procedure's robustness were considered critical factors. Phosphate buffer with 0.01 % triethylamine (pH 2.5; 50 mM) and acetonitrile (80:20, v/v) were used as mobile phase. The peaks were resolved using Hypersil gold C18, (4.6×150) mm, 5 μm column within a runtime of 5 min. The mobile phase was pumped at a flow rate of 1.3 ml/min, whereas the column was maintained at 30°. A 5 μl aliquot of each solution was injected and the peak responses were recorded at 238 nm. The critical chromatographic parameters and sample preparation steps were optimized by using Design of experiments and based on its outcome, method operable design ranges were demarcated. An extensive forced degradation study was executed and all the degradant peaks were well separated from the piribedil peak. Piribedil peak was also found homogenous in all the stressed samples. The developed method was validated and found specific, precise, linear, accurate, rugged and robust.

Development of a Validated Stability-Indicating HPLC Method for Vinpocetine in the Presence of Potential Impurities in Tablet Dosage Form by Multiresponse Optimization.

Vinpocetine has been prescribed for the treatment of ischemic brain diseases for many years. The drug, which has side effects such as headache, flushing, and decreased blood pressure, is not found in nature, but it can be synthesized by several approaches. A simple, rapid, selective, stability-indicating high-performance liquid chromatographic (HPLC) method was developed for the simultaneous estimation of vinpocetine and their potential impurities in a tablet formulation. Optimum HPLC conditions were tried to be determined by a statistical experimental design method. The proposed method was validated as per the ICH guidelines. Stress study was used to demonstrate the stability-indicating ability of the developed method in the quantification of vinpocetine and potential impurities within the same run. According to multiresponse optimization using the Derringer's desirability function, the mobile phase consisted of an acetonitrile-phosphate buffer (pH 6.0) in the ratio of 65:35 (v/v) at a flow rate of 1.7 mL/min. Significant degradations were observed for the drug product under acid hydrolysis and alkali hydrolysis. The new method showed reasonable detection and quantification limits with good selectivity, precision, linearity, and recovery. These validation results have shown that this method is suitable for quantitative determination of vinpocetine and its impurities in quality control laboratories. A reliable and rapid HPLC method optimized with response surface methodology and multiresponse optimization based on Derringer's desirability function was developed for the simultaneous analysis of vinpocetine and its impurities in a tablet formulation.

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.