Validated HPLC Method Research Articles

Chitosan Nanoparticles Embedded in In Situ Gel for Nasal Delivery of Imipramine Hydrochloride: Short-Term Stage Development and Controlled Release Evaluation.

Imipramine hydrochloride (IMP), a tricyclic antidepressant used for major depression, enuresis, and neuropathic pain, is limited by gastrointestinal complications, low oral bioavailability (44%), and complex dosing requirements. This study aimed to explore a novel non-invasive nasal delivery system using chitosan nanoparticles (Cs NPs) embedded in an in situ gel to address the limitations of oral IMP administration. Cs NPs loaded with IMP were synthesized via ionic gelation and assessed for precision in drug concentration using a validated HPLC method. The particles were integrated into a thermoresponsive polymer, Pluronic F127, to form an in situ gel suitable for nasal administration. The formulation was characterized for gelation temperature, duration, viscosity, mucoadhesive strength, and overall gel robustness. Drug release kinetics and the controlled release mechanism were studied using ex vivo permeation tests with Franz diffusion cells and nasal sheep mucosa. The optimized nanoparticle formulation (F4-50) exhibited a consistent PS of 141.7 ± 2.2 nm, a zeta potential (ZP) of 16.79 ± 2.1 mV, and a high encapsulation efficiency of 67.71 ± 1.9%. The selected in situ gel formulation, F4-50-P1, demonstrated a gelation temperature of 33.6 ± 0.94 °C and a rapid gelation time of 48.1 ± 0.7 s. Transform-attenuated total reflectance infrared spectroscopy (ATR-IR) confirmed the compatibility and effective encapsulation of IMP within the formulation. The release profile of F4-50 included an initial burst release followed by a sustained release phase, with F4-50-P1 showing improved control over the burst release. The flux rates were 0.50 ± 0.01 mg/cm2/h for F4-50 and 0.33 ± 0.06 mg/cm2/h for F4-50-P1, indicating effective permeation. The developed chitosan nanoparticle-based in situ gel formulation provides a promising approach for the controlled release of IMP, enhancing therapeutic efficacy and patient compliance while mitigating the disadvantages associated with oral delivery.

Imipramine in dogs: A pharmacokinetic study following oral administration under fasted and fed conditions

This study investigates the pharmacokinetics (PK) of imipramine, a tricyclic antidepressant used in human psychiatric disorders and increasingly considered in veterinary medicine. Despite its longstanding use in canines, prior research on imipramine's PK in dogs is lacking. This study aimed to determine the PK of imipramine in dogs in regards to feeding conditions, and to ascertain whether desipramine (active metabolite) is formed or not. In this study, six male Labrador dogs underwent oral administration (1.5 mg/kg) of imipramine tablets (10 mg each; Tofranil®, Novartis) in both fasted and fed conditions. Dogs were randomly allocated to one of two treatment groups, employing an open, single-dose, two-treatment, two-phase, cross-over design, with a washout period of one week. Blood was drawn from the left cephalic vein to heparinized tubes at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, 24, and 48 h. Plasma concentrations were quantified using a validated HPLC method, and the data were analyzed using PKanalix™ software with a non-compartmental approach.Concentrations of imipramine remained quantifiable up to 1.5 hr after administration under both conditions. Desipramine, in both feeding states, was detectable for a short duration, but not quantifiable. No significant differences were observed in the PK parameters of imipramine between the fasting and fed states. The rapid attainment of maximum concentration (Cmax) occurred within 0.25 h, indicating a swift absorption rate. Notably, the terminal half-life in dogs was remarkably short at 0.25 h, prompting a re-evaluation of dosing strategies. Considering the recommended therapeutic plasma concentrations in humans, the administered dose might result in effective levels for a brief period of time. Future research should explore intravenous administration, multiple-dose studies, and metabolic investigations to further elucidate imipramine's PK in dogs.

Comparative Study of Itopride Hydrochloride in-Vitro Drug Release in Various Brands of Sustained Release Capsules By RP-HPLC

Background: The World Health Organisation has advocated the use of generic medicines to make them accessible and affordable but studies have revealed that marketed products do not produce same therapeutic effects and hence are not interchangeable. Dissolution testing of generic solid dosage forms serves as a valuable tool for acquiring dissolution profiles and for assessing the similarity or dissimilarity between the formulations under examination. Objectives: To evaluate the in-vitro drug release profiles of different generic brands of Itopride Sustained release capsules that are commercially available in Indian market and compare them with the innovator product using model dependant and as well as model independent methods. To determine whether same medicine manufactured by different brands are interchangeable. Materials & Methods: In this study Eight generic brands of Itopride 150mg sustained release capsules available in the Indian market were evaluated using dissolution test with the aim to assess their bioequivalence with the innovator product (Ganaton OD). Dissolution studies were performed using USP type II apparatus at 100 rpm in 900 ml 0.1N HCl while maintaining a temperature of 37±0.5 ºC. The samples were estimated by a validated HPLC method. Dissolution test results were statistically evaluated by employing both model dependant and model independent methods. In model dependant experimental data obtained for each dissolution profile were transformed by applying the equations of different kinetic models and the best-fit model was selected whereas in model independent approach fit factors, dissolution efficiency and mean dissolution times were calculated. Results: The Weibull model best explained the release of drugs from all the brands. Upon statistical evaluation of dissolution test results its was found that while similarity factor f2 was within the limits for all generic brands, difference factor f1 of two brands was out of acceptable range thus questioning their bioequivalency with the innovator product. Also the dissolution efficiency of four out of the brands was out of acceptable limits. Keywords: bioequivalence, difference factor (f1), similarity factor (f2), dissolution profile, comparison and evaluation..

Stability-indicating RP-HPLC method development and validation for the quantification of amlodipine besylate and valsartan tablets in solid oral dosage form.

The present study discusses the development of simple, rapid, specific, precision, accuracy, stability indicating the HPLC method for the analysis of amlodipine besylate and valsartan tablet dosage form. The chromatographic separation was achieved using phosphate buffer with 1% triethyl amine (pH3.0) as mobile phase-A and mixed Methanol and buffer in the ratio of (65:35)(v/v) as mobile phase-B. The detection of components was made at 237 nm for amlodipine besylate and valsartan. Analytical techniques should enrich sensitivity and specificity for the estimation of pharmaceutical drug products. Evaluated stress studies under different types of ICH conditions. The optimized HPLC method was validated as per the current ICH guidelines. The validated HPLC method was obtained highly specific with linearity ranging between 25 and 200 μgmL-1 of amlodipine besylate and 40-320 μgmL-1 of valsartan and both components correlation coefficient was > 0.999. The method showed high accuracy more than 97%. In stress studies, amlodipine besylate and valsartan were found to be sensitive to acid stress conditions and oxidation stress conditions. The method was found to be suitable for the quality control of amlodipine besylate and valsartan in the tablet as well as in stability-indicating studies. The method was applied to the analysis of stability samples.

Stability-Indicating HPLC Method Development and Validation for the Simultaneous Determination of Vildagliptin and Dapagliflozin in Pharmaceutical Dosage Form.

Vildagliptin (VD) and Dapagliflozin (DP) were determined simultaneously by RP-HPLC using an ultraviolet (UV) detector, a Hypersil Gold C18 (250 × 4.6 mm) column, 5 µm and a mobile phase of acetonitrile: water (adjusted with O-Phosphoric acid to pH 3) in ratio 40: 60% v/v. The estimation wavelength was chosen to be 213 nm. VD and DP were shown to have retention times of 2.9 and 8.3 minutes, respectively. Q2 (R1) ICH guidelines were followed during the validation process. VD and DP correlation coefficient R2 values are 0.9993 and 0.999, respectively. While DP’s linearity range is 1 to 6 µg/mL, VD’s is 10 to 60 µg/mL. The precision and accuracy studies show %relative standard deviation (%RSD) below 2%. Recovery% was assessed to meet the ICH Q2 (R1) guidelines criteria. The presented research on forced degradation showed stability indicating studies. The findings also demonstrated that the suggested method is suitable for determining VD and DP precisely and accurately.

Novel antimicrobial peptides based on Protegrin-1: In silico and in vitro assessments

The development of antibiotic resistance has caused significant health problems. Antimicrobial peptides (AMPs) are considered next-generation antibiotics. Protegrin-1 (PG-1) is a β-hairpin AMP with a membrane-binding capacity. This study used twelve PG-1 analogs with different amino acid substitutions. Coarse-grained molecular dynamics (MD) simulations were used to assess these analogs, and their physicochemical properties were computed using the Antimicrobial Peptide Database. Three AMPs, PEP-D, PEP-C, and PEP-H, were chosen and synthesized for antibacterial testing. The microbroth dilution technique and hemolytic assays evaluated the antimicrobial efficacy and cellular toxicity. The checkerboard method was used to test the combined activity of AMP and standard antibiotics. Cell membrane permeability and electron microscopy were used to evaluate the mode of action. The chemical stability of the selective AMP, PEP-D, was assessed by a validated HPLC method. PEP-D consists of 16–18 amino acid residues and has a charge of +7 and a hydrophobicity of 44 %, similar to PG-1. It can efficiently inactivate bacteria by disrupting cell membranes and significantly reducing hemolytic activity. Chemical stability studies indicated that AMP was stable at 40 °C for six months under autoclave conditions. This study could introduce the potential therapeutic application of selective AMP as an anti-infective agent.

Quality characteristics and HPLC detection of phosphodiesterase inhibitors in some herbal capsules indicated for male sexual disorders in Ghana

BackgroundHerbal medicines used for male sexual disorders are widespread across the globe and have been noted as likely candidates for adulteration. To assure access to safe and quality herbal products, this study aimed at sampling some herbal capsules indicated for male vitality for quality analytical checks.MethodsHerbal capsules sampled from two regions were subjected to physicochemical assessment, using pharmacopeial and regulatory standards. Microbial quality analysis was also performed on the selected products. A validated HPLC method for simultaneous analysis of sildenafil citrate and tadalafil was used to detect and quantify the possible presence of phosphodiesterase inhibitors in the selected products.ResultsOut of a total of 57 herbal capsules, 19 were indicated for male sexual related illnesses of which only 8 fulfilled the inclusion criteria of being used exclusively for male vitality. The majority (62.5%) of the herbal products failed the weight uniformity test but all of them disintegrated within the acceptable limit of 30 min. The moisture and heavy metal contents were within limits of acceptability. Majority (87.5%) of the herbal products failed the test for the aerobic bacteria count; however, none of the isolated bacteria was pathogenic. Sildenafil citrate was detected in the majority (87.5%) of the herbal products in concentrations of 0.98–33.95 mg/g. Two products contained both sildenafil and tadalafil. High batch-to-batch variability was recorded in some physicochemical parameters and pharmaceutical adulterants.ConclusionHigh incidence of quality fails and adulteration of herbal capsules for sexual disorders observed means there is a real risk of unintended dosing with phosphodiesterase inhibitors. This represents a public health issue and necessitates tighter monitoring of production standards by the regulator.

Microencapsulation for the delivery of terazosin hydrochloride: design, development, and characterization

The aim of the work. Terazosin HCL, which is a selective alpha-1 antagonist, has been recommended for the treatment of benign prostatic hyperplasia-related medical conditions, including hypertension and urinary tract disorders. The purpose of this research was to create microparticles that would have a prolonged release of terazosin hydrochloride (TZ). However, TZ is a medicine that is readily soluble and has a high capability of dissolving in water. Materials and methods. A validated HPLC method was established to assess TZ. The TZ microparticles were produced using the process of melt dispersion by utilising cetyl palmitate (CP), myristic acid (MA), Glycerol monostearate 4055 (type II) or Kolliwax® GMS II (GMS), polyethylene glycol 400 (PEG 400) as a plasticizer, and tween 80 as a stabilizing agent. Different formulations of TZ microparticles were evaluated with regard to particle size, zeta potential, and release, and morphological scanning was performed. Results. A zeta potential that falls between -22.9 and -29.4 mV is possessed by TZ microparticles. Furthermore, the size of TZ microparticles falls between 2.11 and 5.60 µm, and the polydispersity index (PDI) was between 0.24 to 0.41. In addition, the formula (F4) that included CP, GMS, PEG 400, and Tween 80 in the proportions of 0.8:0.2:1:0.5 had the highest zeta potential (ZP) and dissolved more than 85 % of TZ after 8 hours. Therefore, F4 was chosen for the purpose of conducting morphological research. Conclusion. Employing the use of CP, GMS, PEG 400, and Tween 80 in a ratio of 0.8:0.2:1:0.5 could result in the generation of microparticles of TZ that are the most acceptable

Inhaled Ivermectin-Loaded Lipid Polymer Hybrid Nanoparticles: Development and Characterization.

Ivermectin (IVM), a drug originally used for treating parasitic infections, is being explored for its potential applications in cancer therapy. Despite the promising anti-cancer effects of IVM, its low water solubility limits its bioavailability and, consequently, its biological efficacy as an oral formulation. To overcome this challenge, our research focused on developing IVM-loaded lipid polymer hybrid nanoparticles (LPHNPs) designed for potential pulmonary administration. IVM-loaded LPHNPs were developed using the emulsion solvent evaporation method and characterized in terms of particle size, morphology, entrapment efficiency, and release pattern. Solid phase characterization was investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Using a Twin stage impinger (TSI) attached to a device, aerosolization properties of the developed LPHNPs were studied at a flow rate of 60 L/min, and IVM was determined by a validated HPLC method. IVM-loaded LPHNPs demonstrated spherical-shaped particles between 302 and 350 nm. Developed formulations showed an entrapment efficiency between 68 and 80% and a sustained 50 to 60% IVM release pattern within 96 h. Carr's index (CI), Hausner ratio (HR), and angle of repose (θ) indicated proper flowability of the fabricated LPHNPs. The in vitro aerosolization analysis revealed fine particle fractions (FPFs) ranging from 18.53% to 24.77%. This in vitro study demonstrates the potential of IVM-loaded LPHNPs as a delivery vehicle through the pulmonary route.

Effects of geographical variation on the phytochemicals gallic acid, corilagin, and ellagic acid, as well as medicinal properties of Emblica officinalis Gaertn (Fruit)

Geographical variation can significantly influence the abundance and distribution of phytochemicals within the raw drug, which in turn may affect its medicinal efficacy and potential health benefits. Understanding these variations is crucial for optimizing cultivation practices and harnessing the full therapeutic potential of herbal raw drug. Owing to the lack of availability of the comprehensive study on the effects of geographical variation on phytochemicals & micronutrient content and antioxidant & antibacterial potential of Emblica officinalis (EO), in the current study, EO fruit samples from different terrestrial regions of India were analyzed to identify variations in certain phytochemicals and nutrients content. A broad study including the identification, substantiation and phytochemical analysis of EO has been performed via a validated HPLC method. The complete profiling of various volatile metabolites present in the sample has been done by GC-MS/MS technique. The observed range of phytochemicals present in different EO samples using validated HPLC-DAD method are 4.38 to 69.41 mg/g for Gallic acid, 0.50 to 5.54 mg/g for Corilagin and 3.92 to 15.34 mg/g for ellagic acid. The total phenolic content (TPC) and total flavonoid content (TFC) for different samples of EO ranged from 52.86–175.47 mg GAE/g of wt. and 1.28–13.88 mg QCE/g of wt. respectively. ICP-OES analysis depicts substantial amount of various essential micronutrients such as Fe, Cu, Mn and Zn. In antibacterial assay, methanolic extracts of EO obtained from Pune zone exhibited promising activity against S. aureus, S. typhi and MRSA strains with inhibition zones of 28, 23 and 28 mm, respectively. Further, the antioxidant, antidiabetic and anti-inflammatory activities of EO on the basis of analyzed phytochemicals have also been evaluated through molecular docking study.

Gentiana capitata Buch.-Ham. ex D.Don Cell Suspension Culture as a New Source of Isosaponarin and 3,7,8-Trimethoxy-9-oxo-9H-xanthen-1-yl 6-O-β-D-ribopyranosyl-β-D-allopyranoside and Their Effect on PC-12 Cell Viability.

Some species of the Gentianaceae family are a valuable source of secondary metabolites. However, the phytochemical knowledge of some of these species remains insufficient. Therefore, this work focused on the isolation of the two main secondary metabolites in the methanolic extract from a Gentiana capitata cell suspension using preparative HPLC and the determination of their structure using UHPLC-DAD-IT-MS/MS and NMR methods. Their content in the methanolic extract was quantified using a previously validated HPLC method. The toxicity of the extract and two isolated compounds was also tested on the PC-12 cell line. The structures of the main secondary metabolites were identified as isosaponarin and 3,7,8-Trimethoxy-9-oxo-9H-xanthen-1-yl 6-O-β-D-ribopyranosyl-β-D-allopyranoside by comparing the UHPLC-DAD-IT-MS/MS and NMR results with the literature data. The content of isosaponarin was determined to be 0.76 ± 0.04%, and the content of 3,7,8-trimethoxy-9-oxo-9H-xanthen-1-yl 6-O-β-D-ribopyranosyl-β-D-allopyranoside was found to be 0.31 ± 0.02% in the dry extract. Additionally, a two-fold increase in the viability of the PC-12 cell line was observed compared to the control after treatment with the methanolic extract at a concentration of 500 µg/mL. These results suggest the potential use of G. capitata cell suspension methanolic extract as a new source of isosaponarin and 3,7,8-trimethoxy-9-oxo-9H-xanthen-1-yl 6-O-β-D-ribopyranosyl-β-D-allopyranoside, highlighting their lack of toxicity to the PC-12 (rat pheochromocytoma) cell line.

Exploring montelukast in dogs: A preliminary pharmacokinetic study following oral administration under fasted and fed conditions

This study investigates the pharmacokinetics (PK) of montelukast (MTK), a cysteinyl leukotriene receptor antagonist increasingly being considered in veterinary medicine. In dogs, MTK has found indications mainly for treating atopic dermatitis as an off-label use. Six male Labrador dogs underwent a single oral administration of MTK (40 mg/dog) in both fasted and fed conditions according to an open, single-dose, two-treatment, two-phase, cross-over design, with a washout period of one week. Blood was withdrawn to heparinized tubes at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, and 24 hr. MTK plasma concentrations were quantified using a validated HPLC method, and the data were analysed using PKanalix™ software with a non-compartmental approach.Concentrations remained quantifiable at 24 hr after administration, under both conditions. No significant differences were observed in the PK parameters between the fasted and fed states. MTK was relatively eliminated slowly, with t1/2 values of 8.10 and 7.68 hr after fasted and fed states, respectively. The attainment of maximum concentration (Cmax) occurred at a Tmax of 4 hr, with mean values of 1.98 μg/mL and 2.80 μg/mL under fasted and fed conditions, respectively. Given the unknown therapeutic range of MTK in dogs and the absence of controlled studies proving its efficacy in this species, further dosing adjustments and refinements should be considered based on both the current PK data and the need to establish an effective therapeutic range, if present. Future research should focus on efficacy studies, multiple-dose investigations, and pharmacodynamic assessments to evaluate the suitability of MTK use in dogs.

In vitro antibacterial activity of danofloxacin against Escherichia coli isolated from pigeons and its pharmacokinetic in pigeons

This experiment aimed to investigate the in vitro antimicrobial activity of danofloxacin against Escherichia coli (E. coli) isolated from pigeons, as well as the pharmacokinetics of danofloxacin in pigeons following oral (PO), intramuscular (IM), and intravenous (IV) administration. The minimum inhibitory concentration (MIC) of danofloxacin was first determined for 38 clinical E. coli strains using the micro broth dilution method. Subsequently, 30 healthy pigeons were weighed and randomly divided into 3 groups: IM, IV, and PO, with 10 pigeons in each group. Danofloxacin was given at 5 mg/kg body weight (BW) through 3 different routes. Blood was collected, and plasma was separated at various time points from 0 to 48 h. Plasma samples were analyzed for danofloxacin concentrations using a validated HPLC method. Pharmacokinetic analysis was performed using Phoenix software and a noncompartmental analytical (NCA) method. The results indicated that danofloxacin had a strong antibacterial effect on E. coli, with a MIC50 of 0.5 μg/mL. The noncompartmental analysis showed that after PO and IM administration at 5 mg/kg in pigeons, peak plasma concentrations (Cmax) of 0.61 and 1.62 μg/mL were reached at 4.5 and 0.53 h, respectively. The oral and intramuscular bioavailability (F) were 68.08% ± 24.82% and 87.82% ± 25.36%, respectively. Following IV administration, danofloxacin was widely distributed in pigeons, with volume of distribution (VZ) and volume of distribution at steady state (VSS) values of 6.11 ± 2.01 and 4.65 ± 1.62 L/kg, respectively, and was eliminated slowly, with an elimination half-life (t1/2λz) of 6.41 ± 2.15 h. Based on the calculated ratio values of AUC/MIC, the current IV, IM, and PO doses of 5 mg/kg of danofloxacin would be expected to effectively treat pigeons infected with E. coli strains with MIC values equal to or less than 0.5 μg/mL.

Stability‐Indicating HPLC Method Development and Validation for the Quantification of Tofacitinib Citrate and Its Related Substances Using Hydrophilic Liquid Interaction Chromatography

ABSTRACTA new stability‐indicating RPHPLC method with short run time has been developed and validated for tofacitinib citrate and its related substances. The novel HPLC method integrates hydrophilic interaction liquid chromatography (HILIC) technology as the stationary phase and employs a mobile phase composed of phosphate buffer (pH 7.0) and acetonitrile (45:55, %v/v) at a flow rate of 0.5 mL/min under isocratic elution. Analytes were monitored via a UV detector at 210 nm and with the column oven temperature at 30°C for a 20‐min analysis. Precision (%RSD) for Impurity‐A and Impurity‐B and tofacitinib met specifications at 2.4%, 0.8%, and 0.0%, respectively. Accuracy ranged from 86% to 100% for impurities, with LOD at 0.03% and LOQ at 0.05%–0.06%. Correlation coefficients exceeded 0.999 for impurities and tofacitinib citrate. Solution stability was confirmed for 24 h at room temperature. The method range was extended from LOQ to ∼1.5% for impurities and LOQ to ∼150% for tofacitinib citrate. The method's stability was evaluated under acid and base hydrolysis, oxidative and water hydrolysis, and thermal and photolytic degradation. Introducing HILIC as the stationary phase for this work proved effective, eliminating the need of ion pair reagents, reducing analysis time, and ensuring consistent results.

Advanced stability-indicating gradient elution reverse phase-high performance liquid chromatography method development and validation for simultaneous estimation of rutin and curcumin using an analytical quality by design approach

This research delves into a systematic Analytical Quality by Design (AQbD) approach to develop and validate a stability-indicating robust RP-HPLC method for the simultaneous determination of Rutin and Curcumin, compounds known for their anti-inflammatory, antioxidant, and wound-healing properties. Utilizing QbD principles, critical method parameters (CMPs) were identified and screened using design of experiments (DoE) and optimized via response surface methodology (RSM) with Central Composite Design (CCD). The optimized chromatographic separation used a Phenomenex Luna C18 column with gradient elution, using methanol and 0.1% formic acid, a flow rate of 1 ml/min, and detection at 345 nm (isosbestic point). The retention times were 5.63 mins for Rutin and 17.01 mins for Curcumin. The stability indication of the developed HPLC method was performed, and validation parameters were meticulously conducted following the ICH Q2(R1) guidelines, demonstrating linearity over 2-10 μg/ml for Rutin and 5-25 μg/ml for Curcumin, with correlation coefficients of 0.9999 and 0.9998, respectively. Precision studies showed %RSD within acceptable limits, and accuracies ranged between 97-100%. This validated HPLC method offers a reliable, sensitive approach for simultaneous quantifying Rutin and Curcumin, suitable for routine analysis in pharmaceutical laboratories and quality control.

Development and Validation of New HPLC Method for the Determination of Imidazolidinyl Urea in Topical Formulation

Introduction: In this study, a new, simple, selective, and fast liquid chromatographic method has been developed and validated for the determination of imidazolidinyl urea used as an anti-microbial agent in topical formulation. Methods: The developed HPLC method using a diode array detector for the determination of imidazolidinyl urea was applied to the topical formulation. Imidazolidinyl urea in the sample was analyzed in the cyano column (250 x 4,6 mm, 5 μm i.d.) under chromatographic conditions, where the flow rate was determined as 1.0 mL/min. The column oven was 40.0°C, and imidazolidinyl urea was detected at 210 nm. Isocratic application of acetonitrile-water (25:75, v/v) was used as the mobile phase system. The validation of the developed method was performed according to the International Conference on Harmonisation guidelines Q2 (R1). Results: The linearity range of the imidazolidinyl urea was 0.050-0.150 mg/mL, and the limits of detection and quantification were calculated to be 62.5x10-6 mg/mL and 125x10-6 mg/mL, respectively. Assay recovery and precision of imidazolidinyl urea from topical formulation at 0.050, 0.100, and 0.125 mg/mL concentrations were evaluated. The mean recoveries for imidazolidinyl urea in the topical formulation were calculated as 98.857-104.560%. Conclusion: The validated method was successfully applied to the determination of imidazolidinyl urea in a topical formulation. The proposed method is reproducible and reliable and can be used safely for routine analysis.

HPLC Method Development and Validation for Simultaneous Estimation of Tramadol and Piroxicam

HPLC Method Development and Validation for Simultaneous Estimation of Tramadol and Piroxicam

QBD approach in HPLC method development and validation of furazolidone

QbD principles for establishment of a HPLC method for Furazolidone with improved robustness and performance. On the basis of the initial prioritization and factor screening studies, the highly influential factors were identified and subsequently optimized for improving the method robustness. The response surface mapping particularly facilitated improved understanding of the factor–response relationship and interactions associated with them. Extensive validation studies further ensured high degree of method robustness with extreme variation in the key variables influencing the method performance. In addition, the method showed improved sensitivity for the Furazolidone much beyond the values reported in the literature.

Development and Validation of HPLC Method for the Quantification of Impending Genotoxic Impurities in Dapson Drug Substances

Development and Validation of HPLC Method for the Quantification of Impending Genotoxic Impurities in Dapson Drug Substances

Seasonal and Circadian Variation of Non-Volatile Metabolites in Lippia alba Leaves.

The present study describes the seasonal and circadian variations of the major compounds from Lippia alba leaves. SPSS was used to identify, quantify, and associate the variations in the secondary metabolites of this species through HPLC/DAD analysis of the leaves hydroethanolic extracts of six selected L. alba specimens. For the circadian study, the samples were collected at four different daily hours in each year's season. For the seasonal study, the samples were collected monthly from the same individuals for two consecutive years (2018 and 2019). These samples were analyzed and quantified using a validated HPLC method for flavonoids, iridoids, and phenyl ethanoid glycoside. Mussaenoside, acteoside, and tricin-7-O-diglucuronide showed a moderate positive correlation between their biosynthesis and the precipitation index, while epi-loganin had a moderate negative correlation. Acteoside showed a moderate positive correlation between the minimum registered temperature and its production. Compared with previous studies, a drastic reduction (about 95 %) in the production of tricin-7-O-diglucuronide compared with previous study and this difference could be attributed to the plant's aging. Thus, the data demonstrated that lower temperatures and high rainfall could favor the production of the major L. alba active compounds (acteoside and tricin-7-O-diglucuronide) and that older plants harm their production.