Hyuk Jun Cho

Layer-by-layer coated lipid-polymer hybrid nanoparticles designed for use in anticancer drug delivery

Polyelectrolyte multilayers created via sequential adsorption of complimentary materials may be useful in the delivery of small molecules such as anti-cancer drugs. In this study, layer-by-layer (LbL) nanoarchitectures were prepared by step-wise deposition of naturally derived chitosan and hyaluronic acid on negatively charged hybrid solid lipid nanoparticles (SLNs). A doxorubicin/dextran sulfate complex was incorporated into the SLNs. This resulted in the production of spherical nanoparticles ∼ 265 nm in diameter, with a zeta potential of approximately -12 mV. The nanoparticles were physically stable and exhibited controlled doxorubicin (DOX) release kinetics. Further pharmacokinetic manipulations revealed that in comparison with both free DOX and uncoated DOX-loaded SLNs, LbL-functionalized SLNs remarkably enhanced the circulation half-life and decreased the elimination rate of the drug. Cumulatively, our results suggest that this novel LbL-coated system, with a pH-responsive shell and molecularly targeted entities, has the potential to act as a vehicle to deliver medication to targeted tumor regions.

Fabrication and evaluation of pH-modulated solid dispersion for telmisartan by spray-drying technique.

The present study was undertaken to overcome the problems associated with solubility, dissolution and oral bioavailability of a poorly water-soluble ionizable drug, telmisartan (TMS). For these purposes, a solubility test was carried to select the appropriate formulation composition from various carriers and alkalizers. Solid dispersions (SDs) of TMS were prepared at different drug-to-carrier ratios by the spray-drying technique, and were characterized by dissolution and aqueous solubility studies. The optimum formulation was investigated by dissolution studies at different pH and water media and its solid state characterisations were performed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. In solubility and dissolution tests, all TMS-loaded pH-modulated SDs (pH(M)-SDs) exhibited marked improvement in the dissolution behavior when compared with crystalline TMS powder. The optimum formulation of pH(M)-SD consisted of TMS/PVP (polyvinylpyrrolidone) K30/Na(2)CO(3) at a weight ratio of 2/0.5/3 and showed significant improvement in the aqueous solubility and dissolution rate by approximately 40,000- and 3-fold, respectively, compared to TMS powder. Solid-state characterization revealed the changed in crystallinity of TMS into amorphous state. Furthermore, area under the drug concentration time-curve (AUC) of TMS from the pH(M)-SD increased by 13.4- and 2.1-fold, compared with TMS powder and commercial product, respectively. According to these observations, taken together with dissolution and pharmacokinetic behaviors, pH-modulated SD in the presence of an alkalizer for a poorly water-soluble ionizable drug, TMS, appeared to be efficacious for enhancing its bioavailability.

Application of Box–Behnken design in the preparation and optimization of fenofibrate-loaded self-microemulsifying drug delivery system (SMEDDS)

Abstract This study was designed to optimize a fenofibrate-loaded self-microemulsifying drug delivery system (SMEDDS) by using a response surface methodology. Box–Behnken design (BBD) and its desirability function were used to optimize the SMEDDS. The independent factors were the amounts of Labrafil M 1944 CS, Labrasol, and Capryol PGMC and the dependent variables were droplet size, cumulative percentage of drug released in 30 min and equilibrium solubility of fenofibrate in SMEDDS. Various response surface graphs were used to understand the effects of each factor, and the desirability function was then adjusted to optimize SMEDDS formulation. The experimental values of optimized formulation were in close agreement with predicted values. Furthermore, in vivo pharmacokinetic study of the optimized formulation showed significant increase in relative oral bioavailability compared to that of the powder suspension. In conclusion, the BBD demonstrated its effectiveness in optimizing the SMEDDS formulation and in identifying the effects of formulation variables.

Optimization of self-microemulsifying drug delivery system for telmisartan using Box-Behnken design and desirability function.

To develop and optimize the novel self‐microemulsifying drug delivery system (SMEDDS) formulation for enhanced water solubility and bioavailability of telmisartan (TMS) using the Box–Behnken design (BBD) and desirability function.

Preparation and characterization of spray-dried gelatin microspheres encapsulating ganciclovir

AbstractThe aim of this study was to prepare ganciclovir (GCV)-loaded cross-linked gelatin microspheres by spray-drying method. The microspheres were characterized in terms of particle size, surface morphology, loading efficiency, thermal behavior, physical characteristics, swelling properties, and the release profile in vitro. The major process and formulation parameters were optimized to obtain smaller particles with high loading capacity. The physical state examination confirmed the molecular-level dispersion of drug in the polymer. The loading efficiency determined by high-performance liquid chromatography (HPLC) was around 68%. The in vitro release experiments revealed that the GCV released from the gelatin microspheres was related to the extent of swelling, which was proportional to the drug-to-polymer ratio. These results suggest that cross-linked gelatin microspheres could be a suitable drug-delivery system for GCV.

Effects of Noscarna™ on hypertrophic scarring in the rabbit ear model: Histopathological aspects

In this study, we evaluated the effects of silicone-based gel on the healing of hypertrophic scars in the rabbit ear model. After 4-week application of silicone-based gel containing allantoin, dexpanthenol and heparin (Noscarna™) to scars in a rabbit ear model of hypertrophic scarring, significant improvements in hypertrophic scar healing and a great loss of skin pigment were observed compared to the non-treated control, base or silicone control-treated scars. Furthermore, histological analysis of Noscarna™-treated scars revealed a significant reduction in scar elevation index (SEI), anterior skin and epithelial thicknesses, inflammatory cells, vessels, collagen disorganization and fibroblasts compared to all control hypertrophic scars. Furthermore, Noscarna™ showed more favorable effects on hypertrophic scars than a commercial product, Contractubex®. Therefore, these results clearly demonstrated that the newly developed silicone-based gel, Noscarna™, could be a promising formulation as an effective therapeutic agent for hypertrophic scars.