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.

Optimization of Hydroxypropyl Methylcellulose and Dextrin in Development of Dried Nanosuspension for Poorly Water-Soluble Drug.

The purpose of this study is to identify the effects of a stabilizer and matrix former in the development of a celecoxib dried nanosuspension (DNS) for high dissolution rate and drug loading. Tween 80 and Hydroxypropyl Methylcellulose (HPMC) were used as stabilizers in the bead-milling process and dextrin was used as the matrix former in the spray-drying. Various nanosuspensions (NS) were prepared by varying the ratio of HPMC and dextrin, and the physicochemical properties of each formulation were evaluated for particle size, morphology, drug loading, crystallinity, redispersibility, physical stability and dissolution rate. HPMC efficiently stabilized the NS system and reduced the particle size of NS. The mean particle size of the NS with 0.5% HPMC (w/v) was the smallest (248 nm) of all formulations. Dextrin has been shown to inhibit the increase of particle size efficiently, which is known to occur frequently when NS is being solidified. As the dextrin increased in DNS, the dissolution rates of reconstituted NS were significantly improved. However, it was confirmed that more than the necessary amount of dextrin in DNS reduced the dissolution and drug loading. The dissolution of celecoxib in DNS prepared at the ratio (drug:dextrin, 1:2.5) was almost the highest. The dissolution of optimal formulation was 95.8% at 120 min, which was 2.0-fold higher than that of NS dried without dextrin. In conclusion, these results suggest that the formulation based on Tween 80, HPMC and dextrin may be an effective option for DNS to enhance its in vitro dissolution and in vivo oral absorption.