Pronobesh Chattopadhyay

Interpenetrating polymer network (IPN) hydrogel microspheres for oral controlled release application.

Interpenetrating polymer network (IPN) hydrogel microspheres of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA) were prepared by water-in-oil (w/o) emulsion crosslinking method for oral controlled release delivery of a non-steroidal anti-inflammatory drug, diclofenac sodium (DS). The microspheres were prepared with various ratios of NaCMC to PVA, % drug loading and extent of crosslinking density at a fixed polymer weight. The prepared microspheres with loose and rigid surfaces were evidenced by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the IPN formation. Differential scanning calorimetry (DSC) study was performed to understand the dispersion nature of drug after encapsulation. The in vitro drug release study was extensively evaluated depending on the process variables in both acid and alkaline media. All the formulations exhibited satisfactory physicochemical and in vitro release characteristics. Release data indicated a non-Fickian trend of drug release from the formulations. Based on the results of this study suggest that DS loaded IPN microspheres were suitable for oral controlled release application.

Development of solid lipid nanoparticles (SLNs) of lopinavir using hot self nano-emulsification (SNE) technique.

Solid lipid nanoparticles (SLNs) of poor orally bioavailable drug lopinavir were prepared using hot self nano-emulsification (SNE) technique. Hot isotropic mixture of stearic acid, poloxamer and polyethylene glycol was spontaneously self nano-emulsify in hot water and SLNs were formed with subsequent rapid cooling. Self nano-emulsification ability of stearic acid, poloxamer and polyethylene glycol mixture was assessed by ternary phase diagram study. Optimized SLNs were having particle size of 180.6 ± 2.32 nm (PDI=0.133 ± 0.001), 91.5 ± 1.3% entrapment efficiency and zeta potential of -13.4 ± 0.56 mV. SLNs were evaluated by transmission electron microscopy (TEM) and atomic force microscopy (AFM) for morphological study. Further, Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) of SLNs were also performed for checking solid state characterization. Higher oral bioavailability was found for lopinavir loaded SLNs in comparison to bulk lopinavir due to higher lymphatic drug transport (p<0.05). Results indicate that SLNs of higher fatty acids can be successfully prepared by hot SNE technique.

One step preparation of a biocompatible, antimicrobial reduced graphene oxide–silver nanohybrid as a topical antimicrobial agent

A reduced graphene oxide–silver nanohybrid (Ag–RGO) was prepared by simultaneous reduction of graphene oxide and silver ions, using the aqueous extract of the Colocasia esculenta leaf. The nanohybrid demonstrated better antimicrobial activity than the individual nanomaterials. Excellent cytocompatibility was observed for peripheral blood mononuclear cells (PBMCs) and mammalian red blood cells (RBCs). An acute dermal toxicity study on wistar rats confirmed no induction of direct or indirect toxicity to the host. Thus, this nanohybrid holds potential for applications as a non-toxic topical antimicrobial agent in dressings, bandages, ointments etc.

Bio-based Biodegradable and Biocompatible Hyperbranched Polyurethane: A Scaffold for Tissue Engineering

Hyperbranched polyurethanes are synthesized using TDI, PCL diol, butanediol, and pentaerythritol (1-5 wt%) as the B(4) reactant with and without the monoglyceride of sunflower oil. The biodegradation, physico-mechanical, and thermal properties are found to be tailored by varying the percentage weight of the branching unit. An MTT/hemolytic assay and subcutaneous implantation in Wistar rats followed by cytokine/ALP assay and histopathology studies confirm a better biocompatibility of HBPU with MG than without MG. HBPU supports the proliferation of dermatocytes with no toxic effect in major organs, in addition the in vitro degraded products are non-toxic. Cell adherence and proliferation endorse the bio-based HBPU as a prospective scaffold material in the niche of tissue engineering.

Al3+ ion cross-linked interpenetrating polymeric network microbeads from tailored natural polysaccharides.

Interpenetrating network (IPN) microbeads of sodium carboxymethyl locust bean gum (SCMLBG) and sodium carboxymethyl cellulose (SCMC) containing diclofenac sodium (DS), a non steroidal anti-inflammatory drug were prepared by single water-in-water (w/w) emulsion gelation process using AlCl(3) as cross-linking agent in a complete aqueous environment. The influence of different variables like total polymer concentration, gelation time and crosslinker content on in vitro physico-chemical characteristics and drug release rate in different media was investigated. Drug loaded microbeads were evaluated through Fourier transform infra-red (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses. Scanning electron microscopy (SEM) micrograph of the beads suggested the formation of spherical particles. FTIR analysis indicated the stable nature of the drug in the blend microbeads. DSC and XRD analysis revealed amorphous state of drug after encapsulation. The drug release profile in acidic medium was considerably less in comparison to alkaline media. Formulations showed non-Fickian type transport mechanism. These tri-valent ion crosslinked beads not only improve drug encapsulation efficiency but also enhance drug release in phosphate buffer.

Biocompatible high performance hyperbranched epoxy/clay nanocomposite as an implantable material

Polymeric biomaterials are in extensive use in the domain of tissue engineering and regenerative medicine. High performance hyperbranched epoxy is projected here as a potential biomaterial for tissue regeneration. Thermosetting hyperbranched epoxy nanocomposites were prepared with Homalomena aromatica rhizome oil-modified bentonite as well as organically modified montmorillonite clay. Fourier transformed infrared spectroscopy, x-ray diffraction and scanning and transmission electron microscopic techniques confirmed the strong interfacial interaction of clay layers with the epoxy matrix. The poly(amido amine)-cured thermosetting nanocomposites exhibited high mechanical properties like impact resistance (>100 cm), scratch hardness (>10 kg), tensile strength (48-58 MPa) and elongation at break (11.9-16.6%). Cytocompatibility of the thermosets was found to be excellent as evident by MTT and red blood cell hemolytic assays. The nanocomposites exhibited antimicrobial activity against Staphylococcus aureus (ATCC 11632), Escherichia coli (ATCC 10536), Mycobacterium smegmatis (ATCC14468) and Candida albicans (ATCC 10231) strains. In vivo biocompatibility of the best performing nanocomposite was ascertained by histopathological study of the brain, heart, liver and skin after subcutaneous implantation in Wistar rats. The material supported the proliferation of dermatocytes without induction of any sign of toxicity to the above organs. The adherence and proliferation of cells endorse the nanocomposite as a non-toxic biomaterial for tissue regeneration.

Phytochemical Screening and Antioxidant Activity of essential oil of Eucalyptus leaf

Abstract Barks, roots, fruits, buds, leaves and other parts of plant are considered as source of essential aromatic oils to cure several ailments. The antioxidant property has been shown to be important in recovery from several diseases. The essential oil extracted from eucalyptus leaves was tested for phytochemical analysis and antioxidant activities. The Eucalyptus oil extracted from the leaves of Eucalyptus globulus family Myrtaceae was screened for the presence of phytochemicals and their effect on 2, 2-Diphenyl-1-picryl-hydrazyl radical (DPPH) and Nitric oxide free radical. Phytochemical screening of the plants showed the presence of flavonoids, terpenoids, saponins and reducing sugars. Eucalyptus globulus is not having any cardiac glycosides and anthraquinones. The free radical scavenging activity of the different concentrations of the leaf oil (10, 20, 40, 60 and 80% (v/v) in DMSO) of E. globulus increased in a concentration dependent fashion. In DPPH method, the oil in 80% (v/v) concentration exhibited 79.55 ± 0.82%. In nitric oxide radical scavenging assay method, it was found that 80% (v/v) concentration exhibited 81.54 ± 0.94% inhibition. It was concluded that leaf oil is potent inhibition of free radicals.

Influence of process variables on essential oil microcapsule properties by carbohydrate polymer–protein blends

Carbohydrate polymer-protein blends Zanthoxylum limonella oil (ZLO) loaded microcapsules were prepared by multiple emulsion solvent evaporation technology and the influence of various processing variables on the properties of ZLO loaded microcapsules were examined systematically. It was found that the internal aqueous alginate phase volume, external aqueous gelatin phase volume and concentration of surfactant in external aqueous gelatin phase have a significant influence on microcapsules properties. The essential oil-loaded microcapsules were smooth and spherical in shape as revealed by scanning electron micrograph. Results of Fourier transform infrared (FTIR) spectroscopy indicated stable character and showed the absence of chemical interaction between the microencapsulated oil and carbohydrate polymer-protein blends. Differential scanning calorimetry (DSC) study revealed the antioxidant nature of ZLO in the microcapsules. The release rate of ZLO loaded microcapsules was analyzed by UV-vis spectrophotometer. 83.80% of oil encapsulation efficiency was obtained depending upon the processing variables. Thus, proper control of the processing variables involved in this technology could allow effective incorporation of essential oil into the core of the carbohydrate polymer-protein blends matrix.

Eleutherine indica L. accelerates in vivo cutaneous wound healing by stimulating Smad-mediated collagen production

ETHNOPHARMACOLOGICAL RELEVANCE Eleutherine indica L. has been used for healing of wound, painful and irregular menstruation, dysentery and lesions, and topically used as antiseptic and antimicrobial agent in folk medicine. In the present study, methanolic extracts of Eleutherine indica was subjected to scientific investigation for in-vivo cutaneous wound healing in wistar rat. MATERIALS AND METHODS In-vivo wound healing activity of Eleutherine indica was evaluated by using circular excision experimental models, followed by histopathological and western blot analysis. The healing potential was comparatively assessed with a reference gentamicin sulfate hydrogel (0.01% w/w). Wound contraction measurement, hydroxyproline estimation and western blot for COL3A1, bFGF, Smad-2, -3, -4, and -7 were performed. RESULTS The methanolic extract of Eleutherine indica showed accelerated wound healing activity as evidenced by fast wound contraction rate and higher hydroxyproline content of granulation tissue. Western blot revealed the Smad-mediated collagen production promoting property of Eleutherine indica methanolic extract. Histopathological examinations also supported the experimental findings. CONCLUSION The study revealed that Eleutherine indica promotes wound healing by augmenting Smad-mediated collagen production in wound granulation tissue.

Acute Dermal Irritation, Sensitization, and Acute Toxicity Studies of a Transdermal Patch for Prophylaxis Against (±) Anatoxin-A Poisoning

The skin irritating, sensitizing, and acute dermal toxicity potential of a novel combinational prophylactic transdermal patch, mainly composed of eserine and pralidoxime chloride as active pharmaceutical ingredients, against (±) anatoxin-a poisoning were investigated in rabbits, guinea pigs, and rats in compliance with the Organisation for Economic Cooperation and Development guidelines. In primary skin irritation test, rabbits were dermally attached with the therapeutically active transdermal patch or with a placebo patch for 72 hours. The transdermal patches did not induce any adverse reactions such as erythema and edema on intact skin sites. The active patch was classified as a practically nonirritating material based on the score in the primary irritation index. In the Buehler test, guinea pigs were sensitized by the active or placebo transdermal patches attached for 24 hours. The patches did not induce any sensitization reactions in contrast to a severe sensitization reaction that occurred in the positive control. Therefore, the active patch and placebo patch were both graded as weak in sensitization score and rate. Acute dermal toxicity test in rats did not produce any overt signs of toxicity following a 14-day treatment period. Taken together, these findings suggest that the transdermal patch does not cause skin irritation, skin sensitization, or dermal toxic effects following dermal application.