Stability Studies Research Articles

An antibiotic efficacy comparative study between market-prescribed and solid-lipid fluoroquinolone ophthalmic nanoformulation against conjunctivitis

Besifloxacin hydrochloride (BSF) drug substance (DS), is effective against gram-positive and gram-negative microorganisms. BSF (liquid suspension form) is already available in two different market brands: Besivance and Besix. Both of these commercialized drug products (DP) have lower mucoadhesive characteristics, therefore they spend less time in contact with various ocular tissues (cornea and conjunctiva). This research work emphasized the design, development, and optimization of BSF-loaded solid-lipid nanoparticles (BSF@SLN) to increase antibacterial activity by enhancing drug absorption through passive diffusion techniques in the ocular organ compared to conventional dosage forms. The SLN was prepared through a very simple process hot homogenization process using glyceryl monostearate and polysorbate-80 along with poloxamer-188 and water for injection. Various characterization techniques like FTIR, DSC, and XRD were performed to check the compatibility between DS and excipients. The preliminary formulation of SLN was characterized through zeta potential, polydispersity index, and particle size techniques. The developed SLN was optimized following 32 factorial designs. Surface morphology and size of optimized BSF@SLN ophthalmic DP were confirmed by using advanced microscopic techniques such as SEM. In-vitro release of optimized BSF@SLN ophthalmic DP was performed by using two chambers of Franz diffusion cell. Stability studies of optimized BSF@SLN ophthalmic nanoformulations were tested for up to 6 months at 25°C ± 2°C/60% ± 5% RH. The antimicrobial activity of optimized ophthalmic nanoformulation was found 2.76 times more effective compared to the Besix eye drop. In-vivo study of BSF@SLN ophthalmic nanoformulations was carried out with an eye irritancy test and compared with marketed DP (Besix). and found significant pharmacological.

Preparation and Preliminary Analysis of Several Nanoformulations Based on Plant Extracts and Biodegradable Polymers as a Possible Application for Chronic Venous Disease Therapy

Nanotechnology is one of the newest directions for plant-based therapies. Chronic venous disease often predisposes to long-term and invasive treatment. This research focused on the inclusion of vegetal extracts from Sophorae flos (SE), Calendulae flos (CE), and Ginkgo bilobae folium (GE) in formulations with PHB and PLGA polymers and their physicochemical characterization as a preliminary stage for possible use in the development of a complex therapeutic product. The samples were prepared by an oil–water emulsification and solvent evaporation technique, resulting in suspensions with high spreadability and a pH of 5.5. ATR-FTIR analysis revealed bands for stretching vibrations (O-H, C=O, and C-H in symmetric and asymmetric methyl and methylene) in the same regions as the base components, but switched to high or low wavenumbers and absorbance, highlighting the formation of adducts/complexes between the extracts and polymers. The obtained formulations were in the amorphous phase, as confirmed by XRD analysis. AFM analysis emphasized the morphological peculiarities of the extract–polymer nanoformulations. It could be noticed that, in the case of SE-based formulations, the dominant characteristics for SE-PHB and SE-PLGA composition were the formation of random large (SE-PHB) and smaller uniform (SE-PLGA) particles; further on, these particles tended to aggregate in the case of SE-PHB-PLGA. For the CE- and GE-based formulations, the dominant surface morphology was their porosity, generally with small pores, but larger cavities were observed in some cases (CE- and GE-PHB). The highest roughness values at the (8 µm × 8 μm) scale were found for the following samples and succession: CE-PHB < SE-PLGA < SE-PHB-PLGA. In addition, by thermogravimetric analysis, impregnation in the matrix of compression stockings was evaluated, which varied in the following order: CE-polymer > SE-polymer > GE-polymer. In conclusion, nine vegetal extract–polymer nanoformulations were prepared and preliminarily characterized (by advanced physicochemical methods) as a starting point for further optimization, stability studies, and possible use in complex pharmaceutical products.

Development and Evaluation of Topical Herbal Formulation for Infectious Eczema

The study Development and Evaluation of Topical Herbal Formulation for Infectious Eczema presents a comprehensive investigation into the preparation and assessment of a herbal gel aimed at addressing infectious eczema. The research methodology involved meticulous plant collection, extraction, and subsequent physicochemical and phytochemical analyses. Murraya koenigli leaves were collected, identified, dried, and ground into a fine powder before undergoing successive extraction with solvents of increasing polarity. The resulting extracts were concentrated and stored for future use. Physicochemical constants of the powdered drug were determined, including moisture content, total ash value, and extractive values, providing insights into the composition and quality of the herbal material. Preliminary phytochemical evaluations were conducted to identify the presence of specific phytoconstituents such as alkaloids, saponins, flavonoids, phenols, and triterpenoids. These evaluations involved various qualitative tests, each confirming the presence of specific compounds indicative of potential bioactivity. Subsequently, a herbal gel was formulated using the plant extract and Carbopol-934 as a gelling agent, along with other excipients. The gel formulations were evaluated for pH, spreadability, extrudability, and stability over time. Results indicated suitable pH values, spreadability, and extrudability across different formulations, suggesting their potential for dermatological applications. Stability studies demonstrated consistent physical appearance, rheological properties, spreadability, pH, and drug levels over a one-month period, affirming the formulations' stability and therapeutic potential. Overall, this study provides valuable insights into the development of effective herbal formulations for managing infectious eczema, contributing to the advancement of natural-based therapies in dermatology and offering promising avenues for further research and clinical application

Development and Evaluation of Chemometric Models for the Estimation of Sumatriptan in the Presence of Naproxen and a Degradation Product Using UV Spectrophotometry.

Chemometrics is a discipline that allows the spectral resolution of drugs in a pharmaceutical formulation along with degradation product and it is as an alternative to chromatographic methods. Sumatriptan (SUM) is co-formulated with naproxen (NAP) and used in acute migraine attacks. SUM which has physiological importance has not been subjected to any stability-indicating chemometric approaches yet so there is a need for accurate and safe method for the assay of the cited drug in their preparation. SUM was determined in pharmaceutical formulation along with NAP and in presence of alkali-induced degradation product with simple and cost-effective multivariate approaches using spectrophotometric data. The greenness and blueness assessment was applied using different ecological metrics, including green analytical procedure index (GAPI), analytical greenness metric (AGREE), analytical eco-scale (AES) & new "blueness" evaluation using BAGI tool, respectively. Three chemometric approaches were applied for the stability-indicating determination of SUM in presence of NAP. Classical least squares (CLS), Partial least squares (PLS) and Principal components regression (PCR), three multivariate calibration numerical models that were performed on the UV- spectra of the mixtures, were used to achieve the best resolution. Sumatriptan was analyzed with mean accuracies for PLS (100.29 ± 1.318) and for PCR (100.60 ± 1.564). The presented methods were compared and validated for their quantitative analyses. Moreover, statistical comparison between the results obtained by the proposed models and the official methods showed no significant differences. The proposed multivariate calibrations were accurate and specific for quantitative analysis of the studied component. PLS is the best method that has the capacity for qualitative analysis of SUM and it is suitable for routine analysis and stability studies of it in quality control laboratories. Various ecological assessment metrics confirmed the long-standing eco-friendliness of the suggested models.

A multiparametric study for size and stability of hybrid Fe 2 O 3 -NiO nanoparticles and their statistical transformation

A multiparametric study for size and stability of hybrid Fe ₂ O ₃ -NiO nanoparticles and their statistical transformation

Exploring the Effectiveness of Carboxymethylated and Crosslinked Albizia procera Gum in Diltiazem Hydrochloride Matrix Tablets: A Comparative Analysis.

This study investigates the efficacy of modified Albizia procera gum as a release-retardant polymer in Diltiazem hydrochloride (DIL) matrix tablets. Carboxymethylated Albizia procera gum (CAP) and ionically crosslinked carboxymethylated Albizia procera gum (Ca-CAP) were utilized, with Ca-CAP synthesized via crosslinking CAP with calcium ions (Ca2+) using calcium chloride (CaCl2). Fourier Transform (FT) IR analysis affirmed polymer compatibility, while differential scanning calorimetry (DSC) and X-ray diffraction (XRD) assessed thermal behavior and crystallinity, respectively. Zeta potential analysis explored surface charge and electrostatic interactions, while rheology examined flow and viscoelastic properties. Swelling and erosion kinetics provided insights into water penetration and stability. CAP's carboxymethyl groups (-CH2-COO-) heightened divalent cation reactivity, and crosslinking with CaCl2 produced Ca-CAP through -CH2-COO- and Ca2+ interactions. Structural similarities between the polymers were revealed by FTIR, with slight differences. DSC indicated modified thermal behavior in Ca-CAP, while Zeta potential analysis showcased negative charges, with Ca-CAP exhibiting lower negativity. XRD highlighted increased crystallinity in Ca-CAP due to calcium crosslinking. Minimal impact on RBC properties was observed with both polymers compared to the positive control as water for injection (WFI). Ca-CAP exhibited improved viscosity, strength, controlled swelling, and erosion, allowing prolonged drug release compared to CAP. Stability studies confirmed consistent six-month drug release, emphasizing Ca-CAP's potential as a stable, sustained drug delivery system over CAP. Robustness and accelerated stability tests supported these findings, underscoring the promise of Ca-CAP in controlled drug release applications.

Experimental study of graphene-based nanofluid dispersions stability for efficient heat transmission within a concentric tube heat exchanger

This study undertook the experimental enhancement of dispersion stability in graphene-based nanofluids to boost the performance of concentric counterflow heat exchangers. Emphasis was placed on the characterization and preparation of graphene suspensions by evaluating their dispersion properties in various solvents: water, ethanol, acetone, and dimethylformamide (DMF). The graphene powder underwent comprehensive analysis using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR). Subsequently, graphene suspensions were prepared and uniformly mixed using both a magnetic stirrer and an ultrasonic vibrator. The investigation confirmed that solvent type significantly influences the stability and solubility of the suspensions. Solutions of reduced graphene oxide (rGO) in water, ethanol, and DMF exhibited remarkable long-term stability, contrasting with those in acetone. Water emerged as the superior solvent for developing the thermal transport fluid. The addition of graphene resulted in a conductivity increase of approximately 48.15% at φ = 0.5% concentration, while the best thermal efficiency was attained at φ = 0.35% and a flow rate of 3 L/min. Furthermore, at lower flow rates, it is advisable to avoid higher concentrations to maintain optimal thermal efficiency.

Activity, stability, and kinetic study of CuO/TiO2 Janus photocatalyst for Rhodamine B degradation

ABSTRACT The CuO/TiO2 photocatalyst was synthesized using hydrothermal and sonochemical methods and subsequently applied to degrade rhodamine B in wastewater. The best synthesis conditions were established, determining Cu(NO3)2 solution concentration of 2.5 wt.% and calcination temperature of 500 °C. The CuO/TiO2 photocatalyst underwent characterization through various techniques, including ICP, photoluminescence, X-ray diffraction, ASAP, scanning electron microscope (SEM), EDAX, transmission electron microscopy (TEM), and diffuse reflectance spectroscopy. TEM and SEM analyses revealed the presence of TiO2 nanowires and CuO nanoparticles. The Box–Behnken design, encompassing 27 experimental runs, assessed the impact of process variables such as initial dye concentration, pH, UV lamp power, and catalyst dose on the degradation process. The model's R2 value of 0.9893 indicated a high precision in fitting the predicted data to their actual values. Analysis of variance results highlighted UV irradiation power as the most significant variable within the design space. In addition, the CuO/TiO2 photocatalyst demonstrated efficacy under visible light irradiation. Light-expanded clay aggregate beads were chosen as the substrate for photocatalyst immobilization, which enhanced the reaction rate. The stability of CuO/TiO2 was evidenced by about 2% reduction in efficiency after four degradation cycles.

Egg yolk peptide‐iron chelate: preparation, conformational structure, chelating mechanism and stability in vitro

SummaryIn this study, a method to produce iron‐chelating peptides derived from egg yolk proteins was developed and optimised. The egg yolk proteins were enzymolysed and ultrafiltered to prepare egg yolk peptide (EYP), and then the EYP was chelated with Fe to produce egg yolk peptide‐Fe (EYP‐Fe). The optimised mass ratio of peptide to iron, pH, temperature and reaction time were found at 8:1, pH 8.0, 40 °C and 30 min, respectively. The mean particle size of EYP‐Fe was 389.2 ± 2.61 nm, and the chelating ratio was 95.38 ± 1.93%. The measurements of FTIR, X‐ray photoelectron spectroscopy (XPS) and NMR showed that ferrous ions mainly combined with the amino and carboxyl of EYP to form EYP‐Fe. In vitro stability studies have shown that the iron release rate of the EYP‐Fe is maintained at around 5% under alkaline conditions, and there is no significant difference in iron release rate under conditions of 30 °C–80 °C; besides, it has a lower iron release rate (18%) in gastrointestinal digestion compared to FeSO4 (97.93%), indicating that the EYP‐Fe has good heat tolerance, alkalinity and digestion tolerance. The above results provide a scientific basis for the use of EYP‐Fe derived from egg yolk protein as a potential alternative to iron supplements.

Chitosan-based buccal mucoadhesive bilayer tablets enhance the bioavailability of tizanidine hydrochloride by bypassing the first-pass metabolism

Tizanidine hydrochloride (TZN) is an antimuscarinic agent used in the treatment of pain-related spasms, multiple sclerosis, and stroke-related spasticity. It has low oral bioavailability (40 %) due to excessive first-pass metabolism in the liver. The aim of this project was to enhance the systemic bioavailability of TZN by developing buccal mucoadhesive bilayer tablet formulations using chitosan salts with molecular weights of 136 kDa (7 cP) and 169 kDa (10 cP). Structural characterisation of chitosans and their salts was performed by FTIR, 1H NMR, DSC, TGA, and XRD analyses. Soluble chitosan salts, chitosan glutamate and chitosan chloride, for the adhesive layer, and insoluble ethyl cellulose for the impermeable backing layer were selected as polymers to fabricate the buccal tablets by direct compression method. The tablets containing TZN demonstrated high swelling and good mucoadhesion characteristics as well as released all the drug within 8 h. While TC10, formulated with 10 cP chitosan chloride, showed the highest swelling properties, TG10, prepared with 10 cP chitosan glutamate, exhibited the highest mucoadhesion. Chitosan glutamate tablets (TG7 and TG10) demonstrated better mucoadhesive characteristics and stability than chitosan chloride ones (TC7 and TC10) in the buccal medium based on the results of swelling and drug release studies. The permeability studies performed by Franz diffusion cell demonstrated that the amount of TZN passing through the bovine buccal mucosa was between 13.4 and 14.4 %. Stability studies conducted at 5 ± 2 °C, 25 ± 2 °C and 40 ± 2 °C for 6 months showed that no changes in the content uniformity and pH were observed. The in vivo comparative bioavailability studies in female New Zealand rabbits were performed and TZN-containing buccal mucoadhesive bilayer tablets fabricated with both chloride (TC10) and glutamate (TG10) salts of chitosan demonstrated three times higher bioavailability than the commercial TZN product (Sirdalud® oral tablet) administered by the gastrointestinal route.

A first-principles study of HfB2 anisotropic surface stability and its oxygen adsorption behavior

In this work, the HfB2 anisotropic surface stability, and the adsorption behavior of oxygen molecule on the most likely exposed HfB2 surface were investigated based on density functional theory. The study found that the HfB2(0001) surface terminated by Hf (labeled as: Hf-(0001)) is more stable, and more likely interact with oxygen. By rotating the oxygen molecule orientation and changing the adsorption site, all possible high and low-symmetry adsorption configurations are considered. The results show that the low symmetry structure is unstable, and eventually turn into the high symmetry ones. For the highly symmetric structures, oxygen molecule tends to be adsorbed in parallel, and the dissociated oxygen molecule tends to be located at the bridge and hollow site of the Hf-(0001) surface, and there is no energy barrier to this process. Charge density difference and partial density of states proved that oxygen absorbed structures present similar electronic interaction characteristics, and oxygen adsorption process mainly affects the Hf atom at the outmost layer of the Hf-(0001) plane. Oxygen atoms bind to the Hf-(0001) surface mainly in the form of ionic bonds and covalent bonds, originating from the orbital hybridization of O-p and Hf-d. The oxidation of HfB2 starts from the interaction between oxygen and Hf.

Irregular network of extended defects in graphene and a new criterion of the crystal lattice melting

Investigation of graphite defects has long and rich history. However, it turned out, that most point defects in graphene, such as vacancies or topological Stone-Wales defect, have high formation energies, preventing them from formation in large quantities. Recently, we have proposed a new type of extended defects in graphene, with formation energy per atom only slightly above the melting temperature. This means, that these planar defects may occur near the melting temperature in sufficient quantities to influence the thermodynamic properties of graphene. Still, there is discrepancy between thermodynamic properties of these defects and their topology, which can be successfully resolved by proposition of a new defects' type – irregular network of extended defects, which will be described in this paper. The study of network stability from these defects enables us to formulate a new criterion of crystal lattice melting, which supersedes the Lindemann/Born criteria.

The Formulation, Development And Evaluation Of Ointment For Anti-Inflammatory Activity

The search for safer anti-inflammatory agents has led to exploration of natural sources such as curcumin and fenugreek. Curcumin, derived from Curcuma longa, and α-linolenic acid from Trigonella foenum-graecum, exhibit significant anti-inflammatory properties. This study focuses on formulating an ointment utilizing these extracts for topical application. Molecular docking techniques were employed to assess the binding affinities of curcumin and α-linolenic acid. The ointment was prepared using various bases and preservatives, and its physicochemical properties were evaluated. Stability studies revealed consistent properties under different temperature conditions. Characterization of the drug extracts and ointment formulations was conducted to ensure efficacy and safety. The ointment showed promising results in terms of stability and efficacy, particularly formulation F2, suggesting its potential as a topical anti-inflammatory therapy with improved patient compliance

FORMULATION AND STABILITY EVALUATION OF ANTI-OBESITY NUTRACEUITCAL BLEND OF WHITE KIDNEY BEAN EXTRACT (PHASEOLUS VULGARIS L.), PROPOLIS ETHANOLIC EXTRACT AND CRPIC3

Objective: This study aimed to formulate and evaluate the stability profile of an anti-obesity nutraceutical combination in different dosage forms. Methods: Active and inactive ingredients were formulated into pharmaceutical dosage forms. The quality parameters of the dosage forms were determined, followed by accelerated stability testing (40±2 °C and 75±5% Relative Humidity (RH)) for 180 d was completed to evaluate their physical, chemical and microbiological attributes throughout the storage period. Results: Pre-formulation parameters of the powder blend of active and inactive ingredients for each dosage form showed a satisfactory flowability with Hausner's ratio falling between 1.16 and 1.18, average angle of repose between 22.29° and 22.90° and acceptable compressibility with Carr’s index below 25%. Tablets assessments were acceptable with a mean friability value of 0.21±0.03%, hardness of 4.12±0.09 kg/cm2. The average disintegration time of 5 min 10 sec for tablets and 4 min and 30 sec for capsules. The accelerated stability study revealed that tablet dosage forms are stable for longer period that can reach up to 180 d (24 mo real-time), while sachets and capsules are stable for a period of 135 d (18 mo real-time). Conclusion: The anti-obesity blend of White Kidney Bean Extract (WKBE), Propolis Ethanolic Extract (PEE) and CrPic3 can be successfully formulated in acceptable and convenient dosage forms that can be stable for 18-24 mo.

Long-term storage for reanalysis purposes: A stability study of extracts from post-explosion/burning residues of fuel-oxidizer explosive mixtures

Post-explosion residue analysis is vital in forensic chemistry, providing valuable insights into incidents involving explosives. One significant challenge in this field is preserving samples for long-term storage for reanalysis. Presently, many laboratories conducting post-explosion analyses worldwide do not retain samples for reanalysis purposes, since the extraction process for sample preparation often necessitates the complete consumption of the scarce material. Even in cases where a portion of the material remains, such as a swab, it is difficult to ensure its representativeness and select a specific portion for preservation. One possible solution to overcome this challenge is to consider preserving the extracts used in the analyses for potential reanalysis. However, the stability characteristics of these extracts are currently unknown. The results presented in this article provide valuable insights into the feasibility of long-term storage for samples containing target analytes in extracts from post-explosion/burning residues of frequently encountered fuel-oxidizer explosive mixtures, such as flash powder, explosive emulsion, and black powder. These results shed light on the potential viability of preserving such extracts for future reanalysis, offering promising prospects for enhancing forensic investigations in this field. Based on the current findings, it has been demonstrated that the aqueous extracts can be effectively preserved as long-term storage samples for a minimum of 24 months, encompassing all the studied explosives. Only cyanate ion showed significant degradation among the 27 compounds studied. Additionally, the organic extract, specifically in the case of emulsion explosive, can be maintained for at least 12 months.

DESIGN, DEVELOPMENT AND IMPROVEMENT OF AN EMULGEL CONTAINING SILVER NANOPARTICLES AND VITAMIN D-3 FOR ITS POTENTIAL TO ACCELERATE THE HEALING OF WOUND

Objective: The aim of this research work was to prepare a topical emulgel based dosage form incorporated with vitamin D-3 and silver nanoparticles to reduce the wound healing time in any kind of wound. Methods: Central Composite Design (CCD) was applied for the optimization of emulgel by using Design expert software. Three responses (pH, viscosity, and in vitro drug release) and two factors (Carbopol concentration and stirring duration) were chosen, and Statistical Analysis of Variance (ANOVA) revealed that all the factors were significantly affecting the responses. Silver Nanoparticles (SNPs) was prepared with Green Tea Extract (GTE) and evaluated for particle size, Poly Dispersity Index (PDI), zeta potential and Fourier Transform Infra-red (FTIR) spectroscopy and revealed that SNPs of desired range and stability have been synthesized. Here excision wound model was used to evaluate the wound healing activity of formulation in vivo. Results: Maximum in vitro release 88.2±2.1 has shown by the optimized formulation F13, pH and viscosity were also found in optimum range i.e., 6.2±0.4 and 1672±33 respectively, followed by Korsmeyer and Peppas model. Total eight groups were designed for animal study and silver sulphadiazine was used as marketed formulation. F13 formulation was further evaluated for in vivo data, it was revealed that emulgel loaded with high dose of vitamin D-3 along with silver nanoparticles has shown 100.5±1.7% wound contraction, while marketed formulation has shown 103.7±1.1% wound contraction, which was much similar with test formulation. Cytotoxic cell study was done using assay on chicken egg, formulation has not shown any cytotoxic behaviour like haemolysis and cell damage on chick embryo’s blood vessels. Accelerated stability study of the optimized formulation was also performed to check whether the formulation was stable or not and it was revealed that optimized formulation was found stable for the period of six months. Conclusion: It was revealed that emulgel loaded with high dose of vitamin D-3 and SNPs found suitable to accelerate wound healing and showed almost similar response in wound contraction on comparison with marketed formulation. This emulgel promised to controlled the delivery of the drug for the longer duration.

QbD Enabled Development and Evaluation of Pazopanib Loaded Nanoliposomes for PDAC Treatment.

Pancreatic ductal adenocarcinoma (PDAC) is one of the highly fatal types of cancer with high mortality/incidence. Considering the crucial role of vascular endothelial growth factor (VEGF) in PDAC progression, its inhibition can be a viable strategy for the treatment. Pazopanib, a second-generation VEGF inhibitor, is approved for the treatment of various oncological conditions. However, due to associated limitations like low oral bioavailability (14-39%), high inter/intra-subject variability, stability issues, etc., high doses (800mg) are required, which further lead to non-specific toxicities and also contribute toward cancer resistance. Thus, to overcome these challenges, pazopanib-loaded PEGylated nanoliposomes were developed and evaluated against pancreatic cancer cell lines. The nanoliposomes were prepared by thin-film hydration method, followed by characterization and stability studies. This QbD-enabled process design successfully led to the development of a suitable pazopanib liposomal formulation with desirable properties. The % entrapment of PZP-loaded non-PEGylated and PEGylated nanoliposomes was found to be 75.2% and 84.9%, respectively, whereas their particle size was found to be 129.7nm and 182.0nm, respectively. The developed liposomal formulations exhibited a prolonged release and showed desirable physicochemical properties. Furthermore, these liposomal formulations were also assessed for in vitro cell lines, such as cell cytotoxicity assay and cell uptake. These studies confirm the effectiveness of developed liposomal formulations against pancreatic cancer cell lines. The outcomes of this work provide encouraging results and a way forward to thoroughly investigate its potential for PDAC treatment.

Nanofiber-based Delivery of Luliconazole: Fabrication, Characterization, and Therapeutic Performance Assessment.

This study introduces and assesses the potential of a Luliconazole-loaded nanofiber (LUL-NF) patch, fabricated through electrospinning, for enhancing topical drug delivery. The primary objectives involve evaluating the nanofiber structure, characterizing physical properties, determining drug loading and release kinetics, assessing antifungal efficacy, and establishing the long-term stability of the NF patch. LUL-NF patches were fabricated via electrospinning and observed by SEM at approximately 200nm dimensions. The comprehensive analysis included physical properties (thickness, folding endurance, swelling ratio, weight, moisture content, and drug loading) and UV analysis for drug quantification. In vitro studies explored sustained drug release kinetics, while microbiological assays evaluated antifungal efficacy against Candida albicans and Aspergillus Niger. Stability studies confirmed long-term viability. Comparative analysis with the pure drug, placebo NF patch, LUL-NF patch, and Lulifod gel was conducted using agar diffusion, revealing enhanced performance of the LUL-NF patch. SEM analysis revealed well-defined LUL-NF patches (0.80mm thickness) with exceptional folding endurance (> 200 folds) and a favorable swelling ratio (12.66 ± 0.73%). The patches exhibited low moisture uptake (3.4 ± 0.09%) and a moisture content of 11.78 ± 0.54%. Drug loading in 1 cm2 section was 1.904 ± 0.086mg, showing uniform distribution and sustained release kinetics in vitro. The LUL-NF patch demonstrated potent antifungal activity. Stability studies affirmed long-term stability, and comparative analysis highlighted increased inhibition compared to a pure drug, LUL-NF patch, and a commercial gel. The electrospun LUL-NF patch enhances topical drug delivery, promising extended therapy through single-release, one-time application, and innovative drug delivery strategies, supported by thorough analysis.

Studies on Quantitative Determination of Polyphenols in Seven Harvesting Times of Salvia deserta Schang Leaves and its Stability Evaluation

Introduction: Leaves of Salvia deserta Schang at seven harvesting times in the same year were collected as the materials. Method: The polyphenols were determined by the Folin–Ciocaileu method and High-Performance Liquid Chromatography (HPLC) to compare the quality of samples. The stability of polyphenols was studied under different conditions (light, temperature, pH, common additives). objective: The contents of total polyphenols in samples of different growth stages were determined by Folin-Ciocaileu colorimetry. The contents of rosmarinic acid and caffeic acid in samples of different growth stages were determined by HPLC. The stability of polyphenols in Salvia deserta Schang Leaves was investigated by measuring the change of polyphenol retention rate in different media (light, temperature, pH, oxidant, sugar, preservative, salt and citric acid) Results: The results showed that the established method is fast, simple and reliable, which is fully validated in terms of outstanding validation data. High Performance Liquid Chromatography (HPLC) for the determination of total polyphenol content can be quickly and accurately detected, reducing the error of manual determination of the content. The study of polyphenol stability was carried out using a UV spectrophotometer (UV) in order to explore the potential factors affecting polyphenol stability as much as possible and to make the study as scientific and rigorous as possible. The results of quantitative determination showed that there are obvious differences in the content of polyphenols in seven samples. The contents of total polyphenols, rosmarinic acid (RA) and caffeic acid (CA) in the samples harvested in July reached the highest level of 41.37, 26.73 and 1.05 mg/g. Conclusion: The results of the stability assay found that light could damage the stability of polyphenols in samples, especially UV light. Polyphenols are quite sensitive to high temperatures. While polyphenols are less stable when exposed to high alkali conditions and salt treatment, they are much more stable when subjected to low concentrations of redox agents, carbohydrates, and preservatives. The developed methods and stability evaluation provide valuable basis information for quality evaluation and the following use of polyphenols in S. deserta Schang leaves.

A hit expansion of 3-benzamidopyrazine-2-carboxamide: Towardinhibitors of prolyl-tRNA synthetase with antimycobacterial activity.

This study presents an exploration of the chemical space around derivatives of 3-benzamidopyrazine-2-carboxamides, previously identified as potent antimycobacterial compounds with predicted binding to mycobacterial prolyl-transfer RNA synthetase. New urea derivatives (Series-1) were generally inactive, probably due to their preference for cis-trans conformation (confirmed by density functional theory calculations and experimentally by nuclear overhauser effect spectroscopy NMR). Series-2 (3-benzamidopyrazine-2-carboxamides with disubstituted benzene ring) demonstrated that substituents larger than fluorine are not tolerated in the ortho position of the benzene ring. This series brought two new compounds (21: R = 2-F, 4-Cl and 22: R = 2-F, 4-Br) with in vitro activity against Mycobacterium tuberculosis H37Rv as well as multidrug-resistant clinical isolates, with minimum inhibitory concentration ranging from 6.25 to 25 μg/mL. The lactone-type derivatives 4H-pyrazino[2,3-d][1,3]oxazin-4-ones (Series-3) were inactive, but solvent stability studies of compound 29 indicated that they might be developed to usable lactone prodrugs of inhibitors of mycobacterial aspartate decarboxylase (PanD).