Chitosan-PVA-PVP/nano-clay composite: a promising tool for controlled drug delivery.

In this study, chitosan, polyvinyl alcohol (PVA), and polyvinyl pyrrolidone (PVP) were used to create ternary blends reinforced with organically modified montmorillonite nanoclay. Tramadol was used as a model drug to assess the efficacy of these ternary blends as drug delivery systems. The current work demonstrated the highly controlled release of tramadol via transdermal administration. The results of the FTIR investigation revealed the compatibility of the blending components. Among non-drug-loaded formulations, MC6 is the most stable with a 17.6% weight residue at 505 °C and MC11 is the most stable of all the drug-loaded and non-drug-loaded formulations with a weight residue of 22.0% at 505 °C. The XRD studies of the prepared formulations showed crystalline behavior. However, the SEM analysis revealed that no gaps or mixing components were uniformly dispersed in the nanocomposites. Pharmaceutical tests, such as swelling, dissolution, and permeation rates, revealed a strong influence of the PVA concentration. There was a uniform distribution of drug throughout the films with maximum encapsulation efficiency found for MC7 (96.09 ± 0.31) and minimum encapsulation efficiency for MC11 (90.56 ± 0.34)%. Compared to the sodium acetate (pH 4.5) and potassium phosphate buffers (pH 6.8) the swelling and erosion were higher in hydrochloric acid buffer (pH 1.2). An increase in PVA concentration (or decrease in PVP concentration) increases the swelling, dissolution, and permeation rates. In addition, erosion increased with increasing PVP concentration. Furthermore, the nanoclay-reinforced composite showed high permeation. Based on the obtained results, it can be concluded that the produced nanocomposite could be used as an efficient transdermal drug delivery system.

Non-enzymatic amperometric glucose sensing on CuO/mesoporous TiO2 modified glassy carbon electrode.

The present study illustrates the fabrication of a glucose sensing electrode based upon binary composite of copper oxide and mesoporous titanium dioxide on glassy carbon (CuO/TiO2/GCE). The X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis evidently showed the phase pure monoclinic CuO nanoparticles and anatase TiO2. N2 adsorption-desorption analysis verified the mesoporosity in TiO2 with specific surface area greater than 105 m2 g-1. Electrochemical impedance spectroscopic analysis proved the remarkable decrease in the charge transfer resistance and facilitation of electron transfer process on the fabricated electrode. The optimum weight ratio of CuO to TiO2 was 1 : 1, and the optimum potential was 0.6 V vs. saturated calomel electrode. The chronoamperometric measurements displayed a detection limit of 1.9 µM, and sensitivities of 186.67 µA mM-1 cm-2 and 90.53 µA mM-1 cm-2 in two linear ranges of 0.05 to 5.2 mM and 5.2 to 20 mM, respectively. The amperometric analysis further showed good reproducibility, high specificity and outstanding stability of the modified electrode.

Nanoclay Reinforced Ternary Blends Based on Biodegradable Polymers for Drug Delivery Application.

In this study, ternary blends based on chitosan, polyvinyl alcohol, and polyethylene glycol reinforced with organically modified montmorillonite (nanoclay) clay were synthesized. These ternary blends were evaluated as transdermal drug delivery patches using tramadol as a model drug. The FTIR study showed interaction among important functional groups and compatibility among the mixing components. Among drug-loaded formulations, composite MA12 shows maximum thermal stability with 27.9% weight residue at 540°C. The prepared formulations exhibited crystalline nature as observed by XRD analysis. SEM studies revealed that there are no gaps and cracks in prepared films and nanoclay was found dispersed in the formulations. The swelling ratio was higher in pH 1.2 as compared to pH 4.5 and pH 6.8 buffers, and there was an increase in swelling with an increase in PVA concentration. Moreover, the drug release test performed in phosphate buffer pH 6.8 showed that tramadol release from nanocomposite films increases with an increase in PEG concentration. Permeation studies indicated that the rate of permeation increased with a decrease in PVA concentration. The permeation rate was found to be higher for samples without nanoclay. The overall results suggest nanocomposite films as excellent candidates for transdermal drug delivery application.

Evaluation of the Synergistic Effect of Graphene Oxide Sheets and Co3O4 Wrapped with Vertically Aligned Arrays of Poly (Aniline-Co-Melamine) Nanofibers for Energy Storage Applications.

In the present study, Co3O4 and graphene oxide (GO) are used as reinforcement materials in a copolymer matrix of poly(aniline-co-melamine) to synthesize ternary composites. The nanocomposite was prepared by oxidative in-situ polymerization and used as an electrode material for energy storage. The SEM images revealed the vertically aligned arrays of copolymer nanofibers, which entirely wrapped the GO sheets and Co3O4 nanoparticles. The EDX and mapping analysis confirmed the elemental composition and uniform distribution in the composite. The XRD patterns unveiled composites' phase purity and crystallinity through characteristic peaks appearing at their respective 2θ values in the XRD spectrum. The FTIR spectrums endorse the successful synthesis of composites, whereas TGA analysis revealed the higher thermal stability of composites. The cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy are employed to elucidate the electrochemical features of electrodes. The ternary composite PMCoG-2 displayed the highest specific capacity of 134.36 C/g with 6 phr of GO, whereas PMCoG-1 and PMCoG-3 exhibited the specific capacities of 100.63 and 118.4 C/g having 3 phr and 12 phr GO at a scan rate of 0.003 V/s, respectively. The best electrochemical performance of PMCoG-2 is credited to the synergistic effect of constituents of the composite material.

Synthesis and In Vitro/Ex Vivo Characterizations of Ceftriaxone-Loaded Sodium Alginate/poly(vinyl alcohol) Clay Reinforced Nanocomposites: Possible Applications in Wound Healing.

(1) Background: Nanocomposite films are widely applied in the pharmaceutical industry (e.g., nanodrug delivery systems-NDDS). Indeed, these nanomaterials can be produced at a large industrial scale and display valuable properties (e.g., antibacterial, renewability, biodegradability, bioavailability, safety, tissue-specific targeting, and biocompatibility), which can enhance the activity of conventional marketed drugs. (2) Aim: To fabricate and investigate the in vitro properties of the antibiotic ceftriaxone sodium (CTX) once encapsulated into sodium alginate (SA)/poly(vinyl alcohol)PVA-clay reinforced nanocomposite films. (3) Methods: Different ratios of the polymers (i.e., SA, PVA) and CTX drug were used for the synthesis of nanocomposite films by solvent casting technique. Montmorillonite (MMT), modified organically, was added as a nanofiller to increase their thermal and mechanical strength. The prepared samples were physically characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electronic microscopy (SEM), and energy-dispersive X-ray analysis (EDX). The physicochemical behavior (i.e., swelling, erosion, dissolution/drug release behavior and rat skin permeation) was also assessed. Comparisons were made with the currently marketed free CTX dosage form. (4) Results: TGA of the nanoformulation showed increased thermostability. XRD revealed its semi-crystalline nature. SEM depicted a homogeneous drug-loaded SA/PVA nanocomposite with an average size ranging between 300 and 500 nm. EDX confirmed the elemental composition and uniform distribution of mixing components. The water entrapment efficiency study showed that the highest swelling and erosion ratio is encountered with the nanoformulations S100(3) and S100D15(3). Ex vivo permeation revealed a bi-step discharge mode with an early burst liberation chased by continued drug discharge of devised nanoparticles (NPs). The dissolution studies of the drug-loaded polymer nanocomposites elicited sustained pH-dependent drug release. The cumulative drug release was the highest (90.93%) with S100D15(3). (5) Conclusion: S100D15(3) was the finest formulation. To the best of our knowledge, we also pioneered the use of solvent casting for the preparation of such nanoformulations. Polymers and reinforcing agent, concentrations and pH were rate-deterring features for the preparation of the optimized formulation. Thus, CTX-loaded SA/PVA-MMT reinforced nanocomposite appeared as a promising nanodrug delivery system (NDDS) based on its in vitro physicochemical properties.

Assessment of biological activities of chitosan Schiff base tagged with medicinal plants.

A chitosan Schiff base with an aromatic aldehyde was synthesized and characterized by FTIR and NMR spectroscopies. Furthermore, the degree of substitution was calculated based on the ratios of the area of the proton of the imine (Aimine ) and the area of the peak of the proton of the pyranose ring (AH-2 ). The antimicrobial activities were determined against bacterial and fungal strains, as well as multiple drug-resistant (MDR) bacteria. The chitosan Schiff base was also tagged with medicinal plants, for example, Curcuma longa, Peganum harmala, Lepidium sativam, and cruciferous vegetables, and the biological activities determined against pathogenic bacterial and fungal strains. The chitosan Schiff base showed maximum zone of inhibition of 22 mm against Staphylococcus aureus with a minimum zone of inhibition of 15 mm against Bacillus cereus. The chitosan Schiff base was fused with C longa, isothiocyanates and a combined mixture of P harmala and L sativam that has shown activities against Escherichia coli with a zone of inhibition of 28, 24, and 30 mm, respectively. The Schiff base of chitosan fused with medicinal plants also showed significant inhibitory activities against MDR bacteria.

Triple-component nanocomposite films prepared using a casting method: Its potential in drug delivery.

The purpose of this study was to fabricate a triple-component nanocomposite system consisting of chitosan, polyethylene glycol (PEG), and drug for assessing the application of chitosan-PEG nanocomposites in drug delivery and also to assess the effect of different molecular weights of PEG on nanocomposite characteristics. The casting/solvent evaporation method was used to prepare chitosan-PEG nanocomposite films incorporating piroxicam-ß-cyclodextrin. In order to characterize the morphology and structure of nanocomposites, X-ray diffraction technique, scanning electron microscopy, thermogravimetric analysis, and Fourier transmission infrared spectroscopy were used. Drug content uniformity test, swelling studies, water content, erosion studies, dissolution studies, and anti-inflammatory activity were also performed. The permeation studies across rat skin were also performed on nanocomposite films using Franz diffusion cell. The release behavior of films was found to be sensitive to pH and ionic strength of release medium. The maximum swelling ratio and water content was found in HCl buffer pH 1.2 as compared to acetate buffer of pH 4.5 and phosphate buffer pH 7.4. The release rate constants obtained from kinetic modeling and flux values of ex vivo permeation studies showed that release of piroxicam-ß-cyclodextrin increased with an increase in concentration of PEG. The formulation F10 containing 75% concentration of PEG showed the highest swelling ratio (3.42±0.02) in HCl buffer pH 1.2, water content (47.89±1.53%) in HCl buffer pH 1.2, maximum cumulative drug permeation through rat skin (2405.15±10.97 µg/cm2) in phosphate buffer pH 7.4, and in vitro drug release (35.51±0.26%) in sequential pH change mediums, and showed a significantly (p<0.0001) higher anti-inflammatory effect (0.4 cm). It can be concluded from the results that film composition had a particular impact on drug release properties. The different molecular weights of PEG have a strong influence on swelling, drug release, and permeation rate. The developed films can act as successful drug delivery approach for localized drug delivery through the skin.

Carrageenan Based Bionanocomposites as Drug Delivery Tool with Special Emphasis on the Influence of Ferromagnetic Nanoparticles.

Over the past few years, considerable attention has been focused on carrageenan based bionanocomposites due to their multifaceted properties like biodegradability, biocompatibility, and nontoxicity. Moreover, these composites can be tailored according to the desired purpose by using different nanofillers. The role of ferromagnetic nanoparticles in drug delivery is also discussed here in detail. Moreover, this article also presents a short review of recent research on the different types of the carrageenan based bionanocomposites and applications.

In Vitro Biological Screening of Hartmannia rosea Extracts.

The present study is focused on the assessment of the medicinal therapeutic potential extracts of H. rosea to investigate their pharmacological implications based upon science proofs. The antioxidant activity of fraction of H. rosea, namely, n-hexane (HR-1), ethyl acetate (HR-2), chloroform (HR-3), and n-butanol (HR-4), was performed by using the DPPH radical scavenging method. The cytotoxicity and enzyme inhibition assessment were also performed. All the extracts showed significant antioxidant, antibacterial, and protein kinase inhibition but none of the extracts exhibited α-amylase inhibition activity. The chloroform extract HR-3 may block a kinase receptor from binding to ATP; the lead molecule will be isolated, which may stop cancerous cell growth and demotion of cell division. It is predicted that ethyl acetate, chloroform, and n-butanol extracts of H. rosea contain polyphenolics, flavonoids, and alkaloids that are biologically effective candidates exhibiting significant cytotoxicity, antioxidant, and antimicrobial activities. They may control oxidative damage in the body tissues and act as potential antidiabetic and anticancer agents. These studies will also be helpful for future drug designing and drug development research.

Formulation and in vitro evaluation of carbopol 934-based modified clotrimazole gel for topical application.

The aim of present study was to enhance topical permeation of clotrimazole gel preparation by using various permeability enhancers such as coconut oil, pistachio oil and sodium lauryl sulphate (SLS). Clotrimazole gel preparations were prepared and optimized by using three factor, five level central composite design. A second-order polynomial equation was generated in order to estimate the effect of independent variables i.e. coconut oil (X1), pistachio oil (X2) and sodium lauryl sulphate (X3) at various dependent variables i.e. flux (Y1), lag time (Y2), diffusion coefficient (Y3), permeability coefficient (Y4), and input rate (Y5) of clotrimazole gel formulations. Ex vivo skin permeation study was performed through rat skin by using modified Franz diffusion cell system. Optimized formulation F8 exhibited highest flux 2.17 µg/cm2/min, permeability coefficient 0.0019 cm/min and input rate 1.543 µg/cm2/min, along with moderate lag time 77.27 min and diffusion coefficient 0.063 cm2/min, which is further supported by anti-fungal activity that exhibited more prominent zone of inhibition against Candida albicans, Aspergillus niger and Mucor. Thus, it can be concluded that permeation of clotrimazole gel was enhanced by various combination of coconut oil, pistachio oil and sodium lauryl sulphate but optimized formulation F8 containing 0.4 ml pistachio oil, 0.8 ml coconut oil and 0.04 g of SLS exhibited more pronounced and promising effect through rat skin.

PHARMACOLOGICAL ACTIVITIES OF PROTOCATECHUIC ACID.

Protocatechuic acid (3,4-dihydroxybenzoic acid, PCA) is a simple phenolic acid. It is found in a large variety of edible plants and possesses various pharmacological activities. This article aims to review the modern trends in phytochemical isolation and extraction of PCA from plants and other natural resources. Moreover, this article also encompasses pharmacological and biological activities of PCA. It is well known to have anti-inflammatory, antioxidant, anti-hyperglycemia, antibacterial, anticancer, anti-ageing, anti-athro- genic, anti-tumoral, anti-asthma, antiulcer, antispasmodic and neurological properties.

Binding strength of porphyrin-gold nanoparticle hybrids based on number and type of linker moieties and a simple method to calculate inner filter effects of gold nanoparticles using fluorescence spectroscopy.

Gold nanoparticle-porphyrin assemblies were formed by binding functionalized porphyrins to gold nanoparticles (Au-NPs). Spectroscopic properties of hybrids and binding strength of porphyrins to Au-NPs were observed based on number and type of linker moieties using fluorescence spectroscopy. Binding appears to be dependent on number rather than type of linker moieties present on the porphyrin molecules, as tetraaminophenyl porphyrin shows the highest binding among the molecules we studied and causes agglomeration of nanoparticles due to presence of four linker groups. The inner filter effects of Au-NPs are considerably high due to their high extinction coefficient and cause large errors in the evaluation of quenching efficiencies. We have described a very simple method to calculate the inner filter effects of Au-NPs by first loading them with porphyrins and then replacing them with nonfluorescent ligands. The difference in the fluorescence of unbound porphyrins in the presence and absence of Au-NPs describes their inner filter effects.

Antioxidant and hypoglycemic effect of Otostegia aucheri methanolic extract in streptozotocin-induced diabetic male long-Evans rats.

Present study is based on the investigation of antioxidant and antihyperglycemic effect of methanolic extract from areal parts of Otostigea aucheri (OA). 2,2-Diphenyl-1 -picrylhydrazyl (DPPH) method was used to measure the antioxidant activity of extract of the species Otostigea aucheri. The observed scavenging activity for the free radicals was significant and it was compared with the standard BHT inhibition method. The IC50 value obtained of methanolic extract was 2.23 microg/mL. The methanolic extract of OA on the blood glucose level was further studied in normal (non-diabetic), streptozotocin (STZ)-induced type I and type II diabetic male Long-Evans rats at postprandial glucose load state. The results revealed that the oral administration of methanolic extract (1.25 g/kg) of OA showed no remarkable hypoglycemic effect in normal and type 1 (IDDM) diabetic rats. However, the methanolic extract significantly lowered (p < 0.005) serum glucose level in type II diabetic (NIDDM) models when simultaneous glucose was administered. This screening for antioxidant activity interprets the pernicious effects of diabetes that have been associated with mediation through the oxidation stress. The study also suggests to introduce natural source of the potential orally active antioxidant and active antihyperglycemic phytochemicals for the future. It may also improve the impaired antioxidant defense system.