Fast Stability Indicating UPLC Method for Quantitative Analysis of Dronedarone in Pharmaceutical Dosage Form: Force Degradation Study

A simple, precise, rapid reproducible, selective, and stability indicating reverse phase UPLC method has been developed for the estimation of dronedarone in pharmaceutical dosage form. Estimation of dronedarone hydrochloride was achieved on Acquity BEH C18 (100 mm*2.1 mm) 1.7 μm column using buffer [20 mM KH2PO4 + 1 mL Triethylamine (pH=2.5 by orthophosphoric acid)] and methanol in ratio of 40 : 60 as mobile phase at 30°C. The flow rate was 0.4 mL/min and effluents were monitored at 290 nm. The method was validated with respect to linearity, accuracy, precision, LOD, LOQ, and robustness. The method was linear over the concentration range 0.38–90 μg/mL (r2=0.999), with a limit of detection and quantification of 0.1 and 0.38 μg/mL, respectively. Dronedarone was subjected to acid and alkali hydrolysis, chemical oxidation, dry heat degradation, and photo (sunlight) degradation. The degraded product peaks were well resolved from the drug peak with significant difference in their retention time value.

Development and Validation of HPTLC Method for Simultaneous Estimation of Diosgenin and Quercetin in Fenugreek Seeds (Trigonella foenum-graceum)

A sensitive, fast, and reproducible high performance thin-layer chromatographic method has been developed for simultaneous analysis of diosgenin and quercetin from fenugreek seeds, using TLC aluminium plates precoated with silica gel G60F254. Among the different combinations of mobile phases used, best separation was achieved in Toluene-ethyl acetate-formic acid (5 : 4 : 1, v/v/v). Densitometric scanning of the plates directly at 275nm was used for analysis of quercetin. While as for analysis of diosgenin, plates were scanned at 450nm after spraying with anisaldehyde-sulphuric acid reagent. The retardation factorvalue of diosgenin and quercetin was found to be 0.69 ± 0.02 and 0.57 ± 0.02, respectively. The method was validated for specificity, precision (intraday and interday), accuracy, and robustness. Accuracy of the method was checked by recovery study of three different levels with the average percentage recovery of 99.13 ± 0.26 for diosgenin and 99.63 ± 0.34 for quercetin, respectively. Dried fenugreek seed samples were found to contain diosgenin in the range of 0.113–0.135% (w/w) and quercetin in the range of 0.009–0.012% (w/w). The present method is being reported for the first time and can be used for routine quality control and quantification of these marker compounds in various plant samples, extracts, and market formulations.

A Rapid Reversed-Phase HPLC Method for Analysis of Trans-Resveratrol in PLGA Nanoparticulate Formulation

A rapid reversed-phase high performance liquid chromatography (RP-HPLC) method was developed for the determination of trans-resveratrol (t-RVT) in PLGA nanoparticle formulation. A new formulation of t-RVT loaded PLGA nanoparticles (NPs) with potential stealth properties was prepared by nanoprecipitation method in our laboratory. The desired chromatographic separation was achieved on a Phenomenex C18 column under isocratic conditions using UV detection at 306 nm. The optimized mobile phase consisted of a mixture of methanol: 10 mM potassium dihydrogen phosphate buffer (pH 6.8): acetonitrile (63 : 30 : 7, v/v/v) at a flow rate of 1 mL/min. The linear regression analysis for the calibration curves showed a good linear correlation over the concentration range of 0.025–2.0 μg/ml, with determination coefficients, R2, exceeding 0.9997. The method was shown to be specific, precise at the intraday and interday levels, as reflected by the relative standard deviation (RSD) values, lower than 5.0%, and accurate with bias not exceeding 15% and percentage recovery was found to be in the range between 94.5 and 101.2. The limits of detection and quantification were 0.002 and 0.007 μg/ml, respectively. The method was successfully applied for the determination of t-RVT encapsulation efficiency.

Development and Validation of Stability Indicating RP-HPLC Method for Estimation of Satranidazole from Its Formulation

Satranidazole is a new nitroimidazole derivative with potent antiamoebic action and is available in market in the form of tablet and dry syrup either alone or in combination with Ofloxacin. The present study involves the development of simple, accurate, precise, and reproducible reversed phase high performance liquid chromatography (RP-HPLC) method for determination of Satranidazole from its granular dosage form. Isocratic elution at a flow rate of 1.0 mL/min was employed on BDS Hypersil C18 (250 mm × 4.6 mm, 5 μm) column at 25°C temperature. The mobile phase consists of 0.16% v/v orthophosphoric acid solution, pH 3: acetonitrile in the ratio of 60 : 40 v/v. The UV detection wavelength was 320 nm, and 20 μL sample was injected. The retention time for Satranidazole was about 4.3 minutes. The method was validated for various parameters such as system suitability, precision, recovery, robustness, and ruggedness as per ICH guidelines. The validated RP-HPLC method was found to be specific, linear, precise, and accurate and can be successfully employed for the assay of Satranidazole taste masked granules coated with Eudragit E100 and marketed tablets.

Stability Indicating Simultaneous Validation of Telmisartan and Cilnidipine with Forced Degradation Behavior Study by RP-HPLC in Tablet Dosage Form

A simple, precise, and accurate RP-HPLC method has been developed and validated for the simultaneous assay of Telmisartan and Cilnidipine in tablets. Isocratic RP-HPLC method was developed on Waters C18 250×4.6 mm, 5 μm column using mobile phase as acetonitrile (ACN): buffer pH 3.0 with orthophosphoric acid (68 : 32) at a flow rate of 1.0 mL/min and the detection was carried out at 245 nm using photodiode array detector. Forced degradation study was carried out by oxidation, hydrolysis, photolysis, and heating the drug. The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The method was found to be linear in the concentration range of 40–160 μg/mL with correlation coefficient of 0.9990 for Telmisartan and 10–40 μg/mL with correlation coefficient of 0.9989 for Cilnidipine. Degradation products produced as a result of stress studies did not interfere with the detection of agomelatine; therefore, the assay can be considered to be stability indicating.

Cefpodoxime Proxetil: A New Stability Indicating RP-HPLC Method

The present work describes the development of a sensitive and economic stability indicating high performance liquid chromatographic (HPLC) method for the determination of cefpodoxime proxetil (CP) as bulk drug and as pharmaceutical formulation. Both R and S isomers of the drug were separated using Phenomenex ( mm, 5 μm particle size) ODS column with a flow rate of 1 mL min−1 and an SPD 20 A UV detector to monitor the eluate at 252 nm. The isocratic method used a mobile phase consisting of methanol and phosphate buffer of pH 4.0 in the ratio 65 : 35. The linear regression analysis data for the calibration plots showed good linear relationship with in the working concentration range of 5–100 μg mL−1. The LOD and LOQ were 53 and 160 ng mL−1, respectively. CP was subjected to stress degradation using acid, alkali, hydrogen peroxide, dry heat, wet heat, and UV light. The standard drug peaks were well resolved from the degradation products’ peaks with significantly different retention time (Rt), and the resolution factor for the R and S isomers of CP was found to be greater than 2.

Metal Species in Biology: Bottom-Up and Top-Down LC Approaches in Applied Toxicological Research

Since the inception of liquid chromatography (LC) more than 100 years ago this separation technique has been developed into a powerful analytical tool that is frequently applied in life science research. To this end, unique insights into the interaction of metal species (throughout this manuscript “metal species” refers to “toxic metals, metalloid compounds, and metal-based drugs” and “toxic metals” to “toxic metals and metalloid compounds”) with endogenous ligands can be obtained by using LC approaches that involve their hyphenation with inductively coupled plasma-based element specific detectors. This review aims to provide a synopsis of the different LC approaches which may be employed to advance our understanding of these interactions either in a “bottom-up” or a “top-down” manner. In the “bottom-up” LC-configuration, endogenous ligands are introduced into a physiologically relevant mobile phase buffer, and the metal species of interest is injected. Subsequent “interrogation” of the on-column formed complex(es) by employing a suitable separation mechanism (e.g., size exclusion chromatography or reversed-phase LC) while changing the ligand concentration(s), the column temperature or the pH can provide valuable insight into the formation of complexes under near physiological conditions. This approach allows to establish the relative stability and hydrophobicity of metal-ligand complexes as well as the dynamic coordination of a metal species (injected) to two ligands (dissolved in the mobile phase). Conversely, the “top-down” analysis of a biological fluid (e.g., blood plasma) by LC (e.g., using size exclusion chromatography) can be used to determine the size distribution of endogenous metalloproteins which are collectively referred to as the “metalloproteome”. This approach can provide unique insight into the metabolism and the plasma protein binding of metal species, and can simultaneously visualize the dose-dependent perturbation of the metalloproteome by a particular metal species. The concerted application of these LC approaches is destined to provide new insight into biochemical processes which represent an important starting point to advance human health in the 21st century.

Profiling of Phytochemicals in Tissues from Sclerocarya birrea by HPLC-MS and Their Link with Antioxidant Activity

High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to investigate the differences in phytochemicals in roots, bark, and leaf of Sclerocarya birrea (marula) for methanol and water extracts that exhibited the best antioxidant activities. As many as 36 compounds were observed in the extracts of these tissues of which 27 phenolic compounds were tentatively identified. The HPLC-MS/MS results showed flavonoid glycosides were prominent in leaf extracts while the galloylated tannins were largely in bark and root extracts. Four flavonoid glycosides that were reported for the first time in the marula leaf have been identified. The HPLC-MS/MS studies also illustrated different degrees (highest degree = 3) of oligomerisation and galloylation of tannins in the bark and root extracts.

Development and Validation of a Stability Indicating RP-HPLC Method for the Determination of Two Sun Protection Factors (Koptrizon and Tinosorb S) in Topical Pharmaceutical Formulations Using Experimental Designs

A novel, simple, validated stability indicating HPLC method was developed for determination of Koptrizon and Tinosorb S. Stability indicating power of the method was established by forced degradation study. The chromatographic separation was achieved with Waters X Bridge column, by using mobile phase consisting of a mixture of acetonitrile : tetrahydrofuran : water (38 : 38 : 24, v/v/v). The method fulfilled validation criteria and was shown to be sensitive, with limits of detection (LOD) and quantitation (LOQ) of 0.024 and 0.08 μg for Koptrizon and 0.048 and 0.16 μg for Tinosorb S, respectively. The developed method is validated for parameters like precision, accuracy, linearity, solution stability, specificity, and ruggedness as per ICH norms. Design expert with ANOVA software with linear model was applied and a 23 full factorial design was employed to estimate the model coefficients and also to check the robustness of the method. Results of the two-level full factorial design, 23 with 10 runs including two-centre-point analysis based on the variance analysis (ANOVA), demonstrated that all three factors, as well as the interactions between retention time of Koptrizon, Tinosorb S, and USP plate count for Koptrizon, are statistically significant.