Surface Activity and Emulsifying Effect of Non-Toxic Starch Nanocrystal.

The purpose of this study is to investigate the surface activity of starch nanocrystals (SNC), material derived from starch, and confirm their usefulness as a surfactant. In order to evaluate the surface activity, the surface tension change of suspended SNC solution via the Wilhelmy plate method was measured and the values were compared with various synthetic surfactants. The effect of SNC as emulsifier was evaluated on emulsion formation and physical stability. The surface tension of the SNC-dispersed solution was decreased while its concentration was increased. When the 5.0% (w/v) of SNC was added, the surface tension was decreased from 70.3 to 49.5 mN/m. It was confirmed that the physical stability of the emulsion prepared by adding the SNC was improved compared to that of surface inactivity material (PEG 400). The phase separation was observed within 1 hour after preparation of the emulsion containing PEG 400, but the emulsion containing SNC was stable for 5 hours or more. To summarize this study, SNC, a natural-derived and non-toxic material, exhibits sufficient surface activity, thereby confirming the possibility of being applied to the food and pharmaceutical industry.

Preparation and Evaluation of Nanostructured Lipid Carrier for Topical Delivery of Velutin: Synthetic Tyrosinase Inhibitor.

The purpose of this study is to produce nanostructured lipid carrier (NLC) that can solubilize poorly water-soluble velutin and verify an improved tyrosinase synthesis inhibition. A solubility test for velutin was conducted. Cetyl palmitate and caprylic/capric triglyceride were selected as solubilizer. The lipid matrix was produced using the ultrasound dispersion method. The morphology and size distribution of the produced NLC was analyzed through scanning electron microscopy (SEM) and dynamic light scattering (DLS), and the release and tyrosinase inhibition of velutin was evaluated through the Franz diffusion cell method and tyrosinase inhibition assay. Lipid matrix nanoparticles showed an average size of approximately 250 nm and polydispersity of 0.2, and it was confirmed that the velutin incorporated within nanoparticles sustained release at a constant rate over 36 hours. Due to extremely low aqueous solubility, the tyrosinase synthesis inhibition of velutin suspension was 0%, and the value of velutin incorporated within the NLC formulation was greatly improved 56.5% (40 µg/mL). As a result, it was verified that lipid-based NLC nanoparticles are an efficient formulation for the topical delivery of poorly water-soluble flavonoids such as velutin.

Development and Evaluation of Poorly Water-Soluble Celecoxib as Solid Dispersions Containing Nonionic Surfactants Using Fluidized-Bed Granulation.

The purpose of this study is to develop a solid dispersion system with improved dissolution, absorption, and patient compliance of poorly water-soluble celecoxib (CXB). Instead of sodium lauryl sulfate (SLS), an anionic surfactant used in the marketed product (Celebrex®), solubilization was performed using non-ionic surfactants with low toxicity. Cremophor RH40 (Cre-RH) was selected as the optimal solubilizer. Granules and tablets containing CXB and Cre-RH were prepared via fluid-bed and tableting processes, respectively. The morphology, crystallinity, flowability, dissolution, and pharmacokinetics for CXB-solid dispersion granules (SDGs) and the hardness and friability for CXB-solid dispersion tablets (SDTs) were evaluated. The solubility of CXB was found to be increased by about 717-fold when using Cre-RH. The dissolution of granules containing Cre-RH was found to be increased greatly compared with CXB API and Celebrex® (66.9% versus 2.3% and 37.2% at 120 min). The improvement of the dissolution was confirmed to be the same as that of granules in tablets. The CXB formulation resulted in 4.6- and 4.9-fold higher AUCinf and Cmax of CXB compared with those of an oral dose of CXB powder in rats. In short, these data suggest that the solid dispersion based on Cre-RH-a non-toxic solubilizer, non-ionic surfactant- may be an effective formulation for CXB to enhance its oral bioavailability and safety.