DSC Studies Research Articles

Pickering Dry Emulsion System for Improved Oral Delivery of Fenofibrate.

The current study reports a Pickering dry emulsion (PDE) system for improved oral delivery of fenofibrate, a poorly water-soluble model drug. The silica nanoparticles were modified by surface modifiers and explored as a stabilizer for emulsion. The wetting property of modified silica nanoparticles was evaluated by contact angle study. Emulsion was spray-dried to obtain PDE. PDE was evaluated for particle size analysis, drug loading, TGA, DSC, XRPD, FEG-SEM, in vitro dissolution study, and in vivo pharmacodynamic study. The particle size of liquid emulsion was found within the range of 0.3-0.6 μm; after spray drying, the particles agglomerated and exhibited an increase in particle size (1.5 μm). The high drug loading (13% w/w) was found in PDE. DSC and XRD study confirmed the amorphous form of fenofibrate. SEM study showed the formation of a spherical porous microcapsule structure. In vitro dissolution exhibited significant enhancement in drug release for the PDE system as compared to plain fenofibrate. The PDE significantly lowered serum lipid level as compared to plain fenofibrate in a Triton-based hypercholesterolemia model in rats, which ultimately confirmed the enhancement in bioavailability. Thus, the PDE system has good potential in the drug delivery area.

Interaction mechanism of three egg protein derived ACE inhibitory tri-peptides and DPPC membrane using FS, FTIR, and DSC studies.

Understanding the interaction of food derived angiotensin converting enzyme (ACE) inhibitory peptides and intestinal epithelial cell membrane may help to improve their absorption. This research aimed to study the molecular interaction of ACE inhibitory tri-peptides ADF, FGR, and MIR with DPPC membrane during absorption process. The DPPC liposome was prepared and characterized, then used as a model membrane. The permeability of tri-peptides across the membrane was investigated using Fluorescence spectroscopy. The effect of tri-peptides on the structure and dynamics of DPPC bilayers was determined using Fourier transform infrared spectroscopy. The effect of tri-peptides on the phase transition temperature in the DPPC membrane was also analyzed using Differential scanning calorimetry. The results showed that ACE inhibitory tri-peptides ADF, FGR, and MIR can penetrate into both the membrane-water interface and hydrophobic region of DPPC bilayer, and the tri-peptide FGR have higher permeability across the membrane.

Antigen-adjuvant interactions, stability, and immunogenicity profiles of a SARS-CoV-2 receptor-binding domain (RBD) antigen formulated with aluminum salt and CpG adjuvants

ABSTRACT Low-cost, refrigerator-stable COVID-19 vaccines will facilitate global access and improve vaccine coverage in low- and middle-income countries. To this end, subunit-based approaches targeting the receptor-binding domain (RBD) of SARS-CoV-2 Spike protein remain attractive. Antibodies against RBD neutralize SARS-CoV-2 by blocking viral attachment to the host cell receptor, ACE2. Here, a yeast-produced recombinant RBD antigen (RBD-L452K-F490W or RBD-J) was formulated with various combinations of aluminum-salt (Alhydrogel®, AH; AdjuPhos®, AP) and CpG 1018 adjuvants. We assessed the effect of antigen-adjuvant interactions on the stability and mouse immunogenicity of various RBD-J preparations. While RBD-J was 50% adsorbed to AH and <15% to AP, addition of CpG resulted in complete AH binding, yet no improvement in AP adsorption. ACE2 competition ELISA analyses of formulated RBD-J stored at varying temperatures (4, 25, 37°C) revealed that RBD-J was destabilized by AH, an effect exacerbated by CpG. DSC studies demonstrated that aluminum-salt and CpG adjuvants decrease the conformational stability of RBD-J and suggest a direct CpG-RBD-J interaction. Although AH+CpG-adjuvanted RBD-J was the least stable in vitro, the formulation was most potent at eliciting SARS-CoV-2 pseudovirus neutralizing antibodies in mice. In contrast, RBD-J formulated with AP+CpG showed minimal antigen-adjuvant interactions, a better stability profile, but suboptimal immune responses. Interestingly, the loss of in vivo potency associated with heat-stressed RBD-J formulated with AH+CpG after one dose was abrogated by a booster. Our findings highlight the importance of elucidating the key interrelationships between antigen-adjuvant interactions, storage stability, and in vivo performance to enable successful formulation development of stable and efficacious subunit vaccines.

NATURAL BIODEGRADABLE CIPROFLOXACIN MICROSPHERES: OPTIMIZATION STUDY BY FACTORIAL DESIGN

Oral drug delivery is the most popular method of control and release of therapeutic agents for the management of diseases. The colon specific drug delivery systems are considered to attain targeted drug delivery to the large intestine specifically at colon. They provide local delivery for the treatment of colonic diseases like inflammatory bowel disease. The present investigation is based on response of percent drug release as dependent variable for the study at Y axis with two different variables-concentration of surfactant (X1) and stirring speed (X2). A 32 full factorial design was used for complete reading of blending of polymers. The effects of surfactant concentration and stirring speed were evaluated by different parameters as entrapment efficiency, particle size, surface characteristics, micromeritic properties, DSC study and in vitro drug release studies. The present investigation reveals that galactomannan gum containing microspheres are promising as a carrier for colon targeted delivery of ciprofloxacin.

Synthesis and Application of Reactive Acrylic Latexes: Effect of Particle Morphology.

The aim of the study is the synthesis and characterization of epoxy functional reactive polyacrylic latexes, e.g., poly (BA-co-MMA-co-AN-co-GMA) with core/shell and non-structured (random) particle morphologies. Additionally, their performance as binders and coating ability in leather finishing were studied. The epoxy functional polymers were synthesized via the seeded emulsion polymerization technique and the obtained latexes were characterized by means of particle size, zeta potential, FTIR, TEM, DSC, DMTA, and TGA. The results showed that the particle size and zeta potential values were very similar for both latexes, except core/shell latex had slightly higher particle size. DSC, TEM, and DMTA studies verified the successful synthesis of core/shell latex morphology. The copolymer films were elastic in nature and had low Tg values (−13 and −20 °C). The performance results showed some different behavior for core/shell and random copolymer coatings. The abrasion resistance of the leather finish with random copolymer as binder exhibited slightly better values, especially in wet conditions. On the other hand, the leathers finished with core/shell binder showed better performance in flexing endurance and the water spotting test.

Preparation and Evaluation of Sustained Release Microbeads Containing Ibuprofen

The current study was carried out in order to prepare sustain release multiparticulate drug delivery system of Ibuprofen which is also known as 2-(4-isobutylphenyl) propionic acid. From the drug excipient study it was found that the drug and polymer were compatible with each other and there was no disappearance, new formation of peaks on the FTIR study. From the DSC study it was seen that there was no change in the melting point of drug when mixed with the polymers. The method applied was Ionotropic gelation. The Microbeads were prepared by employing sodium alginate as a coating agent with HPMC as release retardant and calcium chloride as a cross linking agent. The prepared microbeads were evaluated for various parameters such as micromertics, loose surface crystal study, percentage yield, percent cumulative drug release and surface morphology. From the various evaluated parameters it was revealed that the prepared microbeads were having a good flow property. The percentage yield was found to be in the range of 65.23% - 79.45%, the drug release was found to be in the range of 4.96% - 96.08%. The batch of B7 was the optimized one as it contain higher amount of drug content and shows better amount of drug release then the other batches. The surface morphology study revealed that the optimized formulation was having small cracks or fractures on the surface. From the study we can conclude that this method can be employed for preparing microbeads of Ibuprofen without any difficulty and this formulation can utilized for reducing the dose frequency of Ibuprofen which will not hinder the GIT.

Enhanced stability and oral bioavailability of erlotinib by solid self nano emulsifying drug delivery systems

The present investigation demonstrates the preparation of solid self nanoemulsfying drug delivery system (sSNEDDS) to enhance stability and bioavailability of Erlotinib (ERL) via the oral route. Capmul®MCM EP (CPM EP, oil), Cremophor® RH 40 (CMR RH 40, surfactant), and LBF CS (LBF CS, cosurfactant) were chosen as chief components for preparing Liquids SNEDDS (L-ERL-SNEDDS) based on solubility and emulsion forming ability. Pseudo ternary phase diagram and constrained mixture designs were applied to identify the self-emulsifying area and it was found that CPM EP, CMR RH 40, and LBF CS in the ratio of 59:11:30 showed optimized particle size (110.08 nm), with narrow PDI (0.114) and high ERL loading capacity (14.31 mg/g). Adsorption method was implemented for solidification of L-ERL-SNEDDS. Among various solid carriers were studied, Aerosil® 200 (A200) was finalized based on free flowing property and reconstitution ability. DSC and XRD studies revealed that crystallinity of drug was reduced in developed system. The developed formulation (named as, A200-ERL-sSNEDDS) showed increased cytotoxicity and apoptosis in PANC-1 and MIA PaCa-2 cells. Pharmacokinetic studies revealed ∼2.2 times increase in AUC0-∞values in case of A200-ERL-sSNEDDS as compared to free ERL. Thus current strategy can be extrapolated for delivering of poorly soluble drugs via oral route.

Antioxidant performance of bio-oils in oxidative stability of base lubricating oil determined through TGA and PDSC techniques

Lube oil suffers from thermo-oxidative degradation in the engine during its service. In order to improve its service life and avoid oxidative degradation, antioxidants are added into the lube oil. The present study focuses on the utilization of low-cost biomass extracts as antioxidant additives and monitoring the level of degradation of lube oil by thermal analysis. The antioxidants used were MeOH extracts of rice husk (BO-I) and wood saw dust (BO-II). The oxidation of the lube oil samples were performed at 100 °C and 200 °C for 6 h separately in the presence of 5% of biomass extract according to modified IP method. Programmed Thermo Gravimetric Analysis was carried out in both oxygen and nitrogen atmospheres to evaluate the antioxidant characters of the BO-I and BO-II from indicators like Tonset, Toffset, mass loss as fast volatiles and weight gain. In DSC study, the indicators of degradation used were, oxidation induction temperature (OIT), percent change in OIT and variance. In case of oxidation at 100°C, the percent differences determined for MBO-I were found to be 0.87% and 0.00% and for MBO-II were 2.67% and 1.63% in O2 and N2 atmospheres, respectively. Similarly, for oxidation at 200 °C, the percent differences in T onset for the NMBO, MBO-I and MBO-II were calculated and found to be 27.77%, 9.52% and 12.74%, respectively under O2 atmosphere, whereas under N2 atmosphere were; 19.80, 12.21 and 13.76%, respectively. The percent changes in OIT values for NMBO, MBO-I and MBO-II samples in comparison with the control sample were found to be 46.99, 29.90, and 3.95%, respectively. Among the two bio-oils, the antioxidant character of the BO-I was found to be excellent compared to BO-II at 100 °C and 200 °C. The biomass extracts can be effectively used as antioxidant additives in lube oil on commercial scale.

Formulation and in-vivo evaluation of nanosponges based tramadol HCL C/R tablets using design of experiment

The current study was aimed to develop a controlled release formulation of tramadol utilizing the cyclodextrin based nanosponges. Box-Behnken design was employed to study the effect of each independent variable on dependent variables. Five types of nanosponges from β-cyclodextrin (NS1-NS5) were purposely designed. The prepared nanosponges by freeze drying method were characterized and formulated into tablets and evaluated for in-vitro and in-vivo studies. The particle sizes of tramadol-nanosponges are in between 34.38 to 134.26 nm, encapsulation efficiency of 41.13-86.72% and drug release% at 6h of 52.34-81.12%. More than 90 % of drug was found to be released from nanosponge formulations. The FTIR, DSC and XRPD studies confirmed the interaction of Tramadol with nanosponges. The nanosponges Cmax of 915.24±1.67 ng/ml was significantly higher (p&lt;0.05) than the marketed product's Cmax of 411.5±1.25 ng/ml. Both the nanosponges formulation and the commercial product had Tmax values of 1.5±0.06 and 2.0±0.05 hours, respectively. When compared to the marketed product (342.6±0.65 ng h/ml), the AUC0-t of the nanosponges formulation (643.2±0.56 ng h/ml) was substantially greater (p&lt;0.05) indicating better systemic drug absorption from nanosponges formulation. Cyclodextrin based nanosponges showed enhanced solubility with increased bioavailability of poorly soluble Tramadol for controlled drug delivery.

Improved Physical, thermal, and conductivity strength of ternary nanocomposite films of PVDF/PMMA/GO NPs for electrical applications

Polymer nanocomposites samples polyvinylidene fluoride/Polymethyl methacrylate (PVDF/PMMA) mixed with various concentrations of graphene oxide nanoparticles (GO NP's) were created using solution casting and ultrasonic-assisted solution casting processes. The characteristics of the manufactured polymer samples were studied using XRD, FTIR, TEM, TGA, and DSC. The AC conductivity, dielectric constant, and dielectric loss of PVDF/PMMA-GO nanocomposites were examined as a function of GO concentrations. XRD analysis demonstrates the semicrystalline PVDF/PMMA and shows that the doped PVDF/PMMA films have a lower crystallinity degree (Xc) than the pure blend. The interaction between the GO ions and the PVDF/PMMA matrices is demonstrated by significant fluctuations in the FTIR spectra. TEM revealed that the GO nanoparticles were produced in spherical and cubic shapes, with an average size of 18.6 nm. The energy gap of nanocomposite films reduced as the GO NP's concentration in the polymer mix increased, decreasing from 4.24 eV to 3.71 eV for the indirect transition. The PVDF/PMMA exhibits a single glass transition temperature (Tg) according to the DSC study, showing that the PVDF and PMMA are miscible. The melting point of the nanocomposite films increased from 244.39 °C to 251.56 °C, increasing their thermal stability. Thermogravimetric analysis (TGA) curves showed that the PVDF/PMMA polymeric matrix had increased thermal stability. Dielectric constant and loss analyses have been performed to gain a better knowledge of charge storage properties and conductivity relaxation. The highest ionic conductivity of PVDF/PMMA blended with 0.08 wt. GO NP's is ~7.23 × 10–5 S/cm. These findings are expected to have a considerable effect on a wide range of applications, such as polymer solar cells, nanoelectronics, polymer organic semiconductors, and energy storage.

Development and in vitro Evaluation of Atazanavir Microcrystals for Intranasal Delivery

Abstract: Background: Nasal route of drug administration has gained popularity nowadays specially for drugs acting on nasopulmonary area. Atazanavir is an antiviral drug which has proved efficacy in different viral infection including COVID-19. Therefore the hypothesis is, if given through intra nasal route this formulation will be able to prevent the viral infection like COVID-19 by directly acting on the virus at its entry point. Objectives: This study aims to prepare a stable mucoadhesive microcrystal formulation of this antiviral drug with good permeation for intra nasal delivery. Materials and Methods: The formulation was prepared by high-speed homogenization process. Prepared microcrystals were estimated for in vitro drug release and permeation, drug excipient interaction study by DSC, FTIR and in vitro mucoadhesiveness study on agar gel plate. A short-term stability study was conducted on all formulations for 6 months. Results: The melting point and absorbance maxima of atazanavir were found as 200.9°C and 248 nm. The DSC and FTIR study results confirmed no drug excipient interaction was there in the formulation. The particle size of the formulations was found as 5-11 μm in range. Drug release was better and faster from the microcrystals as compare to pure powder drug. The flux for microcrystal formulation was found to be 100 whereas flux for the pure drug powder was 24. Formulations had sufficient mucoadhesive strength due to incorporation of HPMC 400 polymer and they were found stable after six months stability study. Conclusion: Lastly, it can be concluded that this formulation would be a promising system for the delivery through intra nasal route as it showed good drug release and permeation during a short time span in in vitro nasal condition with a particle size range suitable for intranasal delivery. However, further in vivo studies are required to confirm the hypothesis. Key words: COVID-19, Atazanavir, Protease inhibitor, Naso-pulmonary, Intranasal, Antiviral.

Formulation, Optimization and Evaluation of Ticagrelor Loaded Self Microemulsifying Chewable Tablets

Abstract: Ticagrelor is a new generation Adenosine diphosphate receptor inhibitor drug which is highly lipohilic having poor aqueous solubility used in the treatment of Acute Coronary Syndrome and prevention of Thrombotic events like Stroke and Heart Attack. An approach has been made to develop Chewable tablets of drug loaded on Self-microemulsifying drug delivery systems (SMEDDS), screen suitable adsorbent for solidification of formulated SMEDDS and to study the effect of superdisintegrants in chewable tablets. Methods: On basis of Pseudoternary diagrams constructed for selected oil, surfactant and cosurfactant, SMEDDS formulation was formulated using Capmul MCM EP oil with surfactant (Cremophor RH 40) and co-surfactant (PEG 400) which was solidified using selected adsorbent. Chewable tablets were compressed by direct compression method using superdisintegrants. Results: IR Studies and DSC studies revealed compatibility and stability of drug in formulation. Compression blend containing Solidified SMEDDS possessed good flow and compressibility. Chewable tablets compressed using Soy Polysaccharides as super disintegrant showed least wetting and disintegration time, drug release of 97.68% within 30 min. Short term stability studies revealed no significant change in physical and chemical properties. Conclusion: These results suggest that the Ticagrelor loaded self microemulsifying chewable tablets can be a promising oral drug delivery system to improve the solubility and dissolution profile of Ticagrelor. Key words: Ticagrelor, SMEDDS, Adsorbents, Chewable tablets, Acute coronary syndrome.

Thermal degradation of various types of polylactides research. The effect of reduced graphite oxide on the composition of the PLA4042D pyrolysis products

This study was aimed to investigate the effect of reduced graphene oxide (rGO) on the pyrolysis of polylactide composites (PLA4042D/rGO) prepared in solution. GC-MS analysis of PLA4042D/rGO pyrolysis products showed that introduction of rGO into the composition with PLA leads to a significant change in the ratio of main degradation products. A sharp decrease of five-membered dioxolanones accompanied by a growth in the content of lactides and cyclic oligomeric lactides was observed in PLA4042D/rGO pyrolysis products as compared with pristine PLA. DSC studies of PLA4042D crystallization in the melt showed that the adsorption of PLA macromolecules on rGO surface can cause the decrease in their segmental mobility. Apparently, a decrease in the segmental mobility of PLA chains hinders the formation of dioxolanones via the intramolecular nonradical ester interchange reaction. At the same time, the role of intermolecular reactions with the formation of cyclic oligomers of lactides increases.

Statistical optimization of voriconazole nanoparticles loaded carboxymethyl chitosan-poloxamer based in situ gel for ocular delivery: In vitro, ex vivo, and toxicity assessment.

The research study reflects the development of novel voriconazole (VCZ) loaded nanoparticles (NPs) for prolonged delivery for the management of ocular diseases. The in situ ophthalmic gel was prepared by incorporating NPs into carboxymethyl chitosan (CMCh) and poloxamer. The central composite design was used to optimize the process for the preparation of nanoparticles by the o/w solvent evaporation method. The developed nanoparticles were evaluated for the encapsulation efficiency (89.6 ± 1.2%), particle size (219.3 ± 1.8nm), polydispersity index (PDI, 0.1), zeta potential (- 21.1 ± 1.12mV), saturation solubility, DSC study, and drug release. The etherification process grafts carboxyl surface functional groups, on chitosan, and was confirmed by FTIR and NMR studies. The developed CMCh-poloxamer based gelling system was found to be clear and transparent with gelation temperature varying from 33 to 40°C. The nanoparticle-loaded gel containing CMCh demonstrated enhanced antifungal activity against Candida albicans. The optimized batch containing CMCh showed improved mucoadhesion by 2.86-fold compared to VCZ nanosuspension. The drug release was prolonged up to 8h with an ex vivo study suggesting the enhanced permeation across goat cornea estimated via fluorescent microscope. The hen's egg chorioallantoic membrane study revealed that the formulation was non-irritant and tolerated by the chorioallantoic membrane. The present study concludes that the VCZ loaded nanoparticulate in situ ophthalmic gel using CMCh may act as a potential alternative for traditional eye drops.

PREPARATION AND EVALUATION OF NANOSPONGES BASED TRAMADOL HCL C/R TABLETS USING DESIGN OF EXPERIMENT

Objective: The goal was to develop a controlled release formulation of tramadol utilizing the cyclodextrin-based nanosponges as a nanocarrier. Methods: Based on the preliminary trials a 3-factor, 3-level Box-Behnken design was employed. Five types of nanosponges from β-cyclodextrin (NS1-NS5) were purposely designed. Tramadol was loaded into nanosponges by the freeze-drying method. The prepared nanosponges were characterized and formulated into tablets and evaluated. Results: The particle sizes of tramadol-loaded nanosponges are in between 34.38 to 134.26 nm, encapsulation efficiency of 41.13-86.72% and drug release% at 6h of 52.34-81.12%. In vitro release studies showed that more than 90 % of the drug were released from nanosponge formulations as compared to only around 20% from free drug suspension after 24 h. The FTIR, DSC and XRPD studies confirmed the interaction of Tramadol with nanosponges. TEM image revealed the spherical structure of drug-loaded nanosponges. The drug-loaded in the nanosponge structure can be retained and released slowly over time. The nanosponges were formulated into tablets and evaluated for weight variation, hardness, friability and disintegration studies and obtained satisfactory results. In vitro release of drug from tablet showed controlled release behavior for a period of 12 h. The percentage of tramadol released from nanosponges tablets after was 87.48 percent and stability studies indicated no significant changes within 6 months. Conclusion: Cyclodextrin-based nanosponges showed superior complexing ability with increased solubility of poorly soluble Tramadol tablets made for controlled drug delivery, which can reduce dosing frequency.

Synthesis, Characterization and Photocatalytic Activities of Co3O4 - MnO2 - ZnO Ternary Nanoparticles

Co3O4 - MnO2 - ZnO NPs were synthesized by making use of the equimolar solutions of cobalt chloride, manganese(II) sulfate and zinc sulfate in aqueous sodium hydroxide and refluxed at elevated temperature. The synthesized mixed nano oxides were characterized by FT-IR, XRD, UV - Vis DRS, TEM, SAED, SEM, EDAX, AFM, TG/DTG and DSC. The FTIR spectra confirm the presence of M-O bonds (M = Co, Mn, Zn). The size of the Co3O4 - MnO2 - ZnO NPs are found to be 10.13 - 25.65nm through XRD studies. The XRD patterns also expose that the particle size is significantly increased with increasing concentration of the precursors. UV-Vis diffuse reflectance spectra (DRS) show that the ternary nanoparticles can be activated by UV and visible light illumination. The TEM, SEM and AFM micrographs of 0.1M Co3O4 - MnO2 - ZnO NPs show roughly spherical shape with size ranging from 10 - 30nm. EDAX analysis confirms the presence of Co, Mn, Zn and O. From TG-DTG and DSC studies, it is found that Co3O4 - MnO2 - ZnO NPs are thermally stable. The photocatalytic activity of Co3O4 - MnO2 - ZnO NPs was determined for degradation of methylene blue (MB) under sunlight. Among the samples, 0.1M Co3O4 - MnO2 - ZnO NPs exhibits the best performance (91.98%) for the degradation of MB in 90 min of irradiation time under sunlight. The factors influencing the photocatalytic activity are pH of dye solution, photocatalyst particle size, photocatalyst dosage and dye concentration.

Design and Development of Solid SMEDDS and Liquisolid Formulations of Lovastatin, for Improved Drug Dissolution and In vivo Effects-a Pharmacokinetic and Pharmacodynamic Assessment.

Lovastatin (Lov) is a lipid-lowering agent, with 5% bioavailability (BA) due to extensive first pass metabolism and poor solubility. To enhance dissolution and in vivo effects, Lov solid self microemulsifying drug delivery system (SMEDDS) and liquisolid systems were developed and evaluated to select superior one. Solubilities were determined in oils, surfactants, and cosurfactants. Ternary phase diagrams were constructed and selected the one which showed maximum emulsion zone. In vitro dissolution, DSC, SEM and PXRD studies were used to characterize the developed formulations. In vivo studies were conducted on optimal formulations in wistar rats. Based on solubilities, Capmul PG8 and Capmul MCM were preferred as oils, Labrasol and Transcutol P as surfactant and cosurfactant. Here, Syloid XDP carrier showed better adsorption capacity among others, hence was used in optimal solid SMEDDS (SX) and liquisolid (LS) formulations. Dissolution study results showed significant improvement in release when compared to pure drug. DSC, SEM, and PXRD results indicated the loss of drug crystallinity in optimal formulations. In pharmacokinetic (PK) study, SX and LS showed 2.57 and 1.43 fold improvements in AUC, when compared to that of coarse suspension (CS). In pharmacodynamic (PD) study, hyperlipidemia was induced by Triton X-100. CS and LS treatments showed a decline in hyperlipidemic levels at 4h. But, SX-treated group showed early onset of decline at 2h. Further, the duration of anti-hyperlipidemia was at least 12h extra when compared to CS and LS. This study confirmed the superiority of SX over LS in PK and PD effects.

Synthesis of a Frost-Resistant Siloxane Rubber and an Elastomer on its Basis

A synthetic route to frost-resistant siloxane rubbers is developed on the basis of the anionic block copolymerization of a mixture of cyclooctamethyltetrasiloxane, hexaethylcyclotrisiloxane, and 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane in the presence of KOH. The resulting rubbers were used to produce frost-resistant elastomers. According to the results of DSC studies, the glass-transition temperature of the frost-resistant rubber is –129 °C; no crystallization or melting processes of the samples are detected on the thermograms. The elastomer obtained based on the siloxane rubber retains its operational characteristics even at the temperature as low as –123 °C.

Elucidation of chickpea hydration, effect of soaking temperature, and extent of germination on characteristics of malted flour.

Germination is a biochemical process that has been widely used to improve the nutritional quality, functional properties, and bioavailability of the protein. Soaking is the preliminary step for germination. Effect of soaking temperature on germination parameters was studied to select the suitable soaking temperature for germination. The effect of germination time on nutritional, functional, and microstructural properties of chickpea flour was evaluated. The soaking temperature was selected as 30°C depending on the germination percentage, vigor value, and mean germination time. Physico-chemical composition, antioxidant activity, ascorbic acid, total phenolic, and total flavonoid were investigated over 4 days of germination. It was found that protein content increased on dry matter basis, whereas carbohydrate and fat content decreased during germination. Ascorbic acid content was found to increase to about 3.52 times. Antioxidant activity increased from 24.14% to 58.50% after 4 days of germination. Water absorption capacity was found to decrease, whereas oil absorption capacity increased. XRD pattern depicted a decrease in crystallinity due to the degradation of amylopectin and increased amylose content. SEM was used to study the microstructural changes with increase in germination time. DSC studies were also carried out to study the effect of germination on thermal properties of chickpea flour. PRACTICAL APPLICATION: This research work gives an outline of the available literature on the mechanism of hydration and germination process with the associated chemical and biochemical changes in the bioactive components along with the special emphasis on the health benefits. The present work is an effort toward the development of chickpea-based meal-replacement beverages.

Functionalized chitosan nanoparticles for cutaneous delivery of a skin whitening agent: an approach to clinically augment the therapeutic efficacy for melasma treatment

The increase in the production of melanin level inside the skin prompts a patient-inconvenient skin color disorder namely; melasma. This arouses the need to develop efficacious treatment modalities, among which are topical nano-delivery systems. This study aimed to formulate functionalized chitosan nanoparticles (CSNPs) in gel form for enhanced topical delivery of alpha-arbutin as a skin whitening agent to treat melasma. Ionic gelation method was employed to prepare α-arbutin-CSNPs utilizing a 24 full factorial design followed by In vitro, Ex vivo and clinical evaluation of the nano-dispersions and their gel forms. Results revealed that the obtained CSNPs were in the nanometer range with positive zeta potential, high entrapment efficiency, good stability characteristics and exhibited sustained release of α-arbutin over 24 h. Ex vivo deposition of CSNPs proved their superiority in accumulating the drug in deep skin layers with no transdermal delivery. DSC and FTIR studies revealed the successful amorphization of α-arbutin into the nanoparticulate system with no interaction between the drug and the carrier system. The comparative split-face clinical study revealed that α-arbutin loaded CSNPs hydrogels showed better therapeutic efficacy compared to the free drug hydrogel in melasma patients, as displayed by the decrease in: modified melasma area and severity index (mMASI) scores, epidermal melanin particle size surface area (MPSA) and the number of epidermal monoclonal mouse anti–melanoma antigen recognized by T cells-1 (MART-1) positive cells which proved that the aforementioned system is a promising modality for melasma treatment.