Probing the wound healing potential of biogenic silver nanoparticles.

OBJECTIVE: Silver nanoparticles (AgNPs) are known for their antimicrobial profile and wound healing activities. However, cytotoxicity and cosmetic abnormalities associated with silver pose a major challenge in their translation for therapeutic applications. Our objective was to develop biogenic AgNPs, using a single-step green synthesis, and to investigate their in vitro and in vivo behaviour as wound-healing agents. METHOD: AgNPs were prepared using the green synthesis approach with aqueous Bryonia laciniosa leaves extract. The AgNPs were then evaluated for physicochemical properties, stability, and antimicrobial and in vivo wound healing activities. RESULTS: Stable AgNPs with characteristic absorption at 408nm and 15±3nm particle size were generated via the active involvement of Bryonia laciniosa. No loss of stability was detected after 6 months at room temperature. Antibacterial activity was observed against both Gram-negative and Gram-positive bacteria with no cytotoxicity observed in vitro at a concentration of 200 µg/mL and effective cytokine modulation. In vivo wound healing experiments showed improved wound contracting ability in rats where, after 14 days, wound alleviation was 47.1±2.2% in the control groups, compared with 78.1±1.4% and 92.6±6.7% for a silver-based marketed cream and the AgNPs, respectively. CONCLUSION: The developed AgNPs proved to be superior wound healing agents owing to scarless healing with insignificant inflammation and toxicity. DECLARATION OF INTEREST: There were no external sources of funding for this study. The authors have no conflicts of interest to declare.

Gellan gum capped silver nanoparticle dispersions and hydrogels: cytotoxicity and in vitro diffusion studies.

The preparation of highly stable water dispersions of silver nanoparticles using the naturally available gellan gum as a reducing and capping agent is reported. Further, exploiting the gel formation characteristic of gellan gum silver nanoparticle incorporated gels have also been prepared. The optical properties, morphology, zeta potential and long-term stability of the synthesized silver nanoparticles were investigated. The superior stability of the gellan gum-silver nanoparticle dispersions against pH variation and electrolyte addition is revealed. Finally, we studied the cytotoxicity of AgNP dispersions in mouse embryonic fibroblast cells (NIH3T3) and also evaluated the in vitro diffusion of AgNP dispersions/gels across rat skin.

Development of Buccal Adhesive Tablet with Prolonged Antifungal activity: Optimization and ex vivo Deposition Studies.

The purpose of the present work was to prepare buccal adhesive tablets of miconazole nitrate. The simplex centroid experimental design was used to arrive at optimum ratio of carbopol 934P, hydroxypropylmethylcellulose K4M and polyvinylpyrollidone, which will provide desired drug release and mucoadhesion. Swelling index, mucoadhesive strength and in vitro drug release of the prepared tablet was determined. The drug release and bioadhesion was dependent on type and relative amounts of the polymers. The optimized combination was subjected to in vitro antifungal activity, transmucosal permeation, drug deposition in mucosa, residence time and bioadhesion studies. IR spectroscopy was used to investigate any interaction between drug and excipients. Dissolution of miconazole from tablets was sustained for 6 h. based on the results obtained, it can be concluded that the prepared slow release buccoadhesive tablets of miconazole would markedly prolong the duration of antifungal activity. Comparison of in vitro antifungal activity of tablet with marketed gel showed that drug concentrations above the minimum inhibitory concentration were achieved immediately from both formulations but release from tablet was sustained up to 6 h, while the gel showed initially fast drug release, which did not sustain later. Drug permeation across buccal mucosa was minimum from the tablet as well as marketed gel; the deposition of drug in mucosa was higher in case of tablet. In vitro residence time and bioadhesive strength of tablet was higher than gel. Thus the buccoadhesive tablet of miconazole nitrate may offer better control of antifungal activity as compared to the gel formulation.

Compatibility studies between carbamazepine and tablet excipients using thermal and non-thermal methods.

Proper formulation is an important aspect of any dosage form design. As a part of preformulation studies, differential scanning calorimetry (DSC) was used to investigate the physicochemical compatibility between Carbamazepine and various excipients commonly used in tablet manufacturing, supported by Fourier transform infrared (FTIR) and x-ray powder diffraction (XRPD) studies. Compatibility studies were conducted on samples kept at room temperature and at an elevated temperature of 55 degrees C for 3 weeks. Carbamazepine was found to be compatible with all lactose-based components, such as Granulac 230, Flowlac 100, and Microcelac 100. Differential scanning calorimetry studies indicated incompatibility with mannitol, microcrystalline cellulose, starch, and stearic acid. However, XRPD and FTIR studies implied that all the above excipients are compatible with Carbamazepine. X-ray powder diffraction demonstrated incompatibility with stearic acid for samples stored at 55 degrees C for 3 weeks, indicative of formation of a solid solution. Thus, DSC being a thermal method of analysis should not be used singly to detect any inherent incompatibility. It has to be supported sufficiently by other non-thermal techniques, such as XRPD and FTIR.