Quercetin-Loaded Solid Lipid Nanoparticle Dispersion with Improved Physicochemical Properties and Cellular Uptake.

The objective of this study was to formulate and characterize properties of solid lipid nanoparticle (SLN) dispersion containing quercetin. SLN was prepared by ultrasonication method using tripalmitin and lecithin as lipid core and then the surface was coated with chitosan. Entrapment efficiency was greater than 99%, and mean particle size of SLN was 110.7 ± 1.97 nm with significant increase in the coated SLN (c-SLN). Zeta potential was proportionally increased and reached plateau at 5% of chitosan coating with respect to tripalmitin. Differential scanning calorimetry showed disappearance of endothermic peak of quercetin in SLNs, indicating conversion of crystalline state to amorphous state. FTIR study of SLNs showed no change in the spectrum of quercetin, which indicates that the lipid and chitosan were not incompatible with quercetin. When coating amount was greater than 2.5% of tripalmitin, particle size and zeta potential were very stable even at 40°C up to 90 days. All SLN dispersions showed significantly faster release profile compared to pure quercetin powder. At pH 7.0, the release rate was increased in proportion to the coating amount. Interestingly, at pH 3.0, chitosan coating of 5.0% or greater decreased the rate. Cellular uptake of quercetin was performed using Caco-2 cells and showed that all SLN dispersions were significantly better than quercetin dispersed in distilled water. However, cellular uptake of quercetin from c-SLN was significantly lower than that from uncoated SLN.

Design and in vitro evaluation of finasteride-loaded liquid crystalline nanoparticles for topical delivery.

In this study, liquid crystalline nanoparticles (LCN) have been proposed as new carrier for topical delivery of finasteride (FNS) in the treatment of androgenetic alopecia. To evaluate the potential of this nanocarrier, FNS-loaded LCN was prepared by ultrasonication method and characterized for size, shape, in vitro release, and skin permeation-retention properties. The particle size ranged from 153.8 to 170.2 nm with a cubical shape and exhibited controlled release profile with less than 20% of the drug released in the first 24 h. The release profile was significantly altered with addition of different additives. Formulation with lower monoolein exhibited higher skin permeation with a flux rate of 0.061±0.005 µg cm(-2) h(-1) in 24 h. The permeation however, significantly increased with glycerol, propylene glycol, and polyethylene glycol 400, while it declined for the addition of oleic acid. A similar trend was observed with skin retention study. In conclusion, FNS-loaded LCN could be advocated as a viable alternative for oral administration of the drug.

Novel self-nanoemulsifying drug delivery system for enhanced solubility and dissolution of lutein.

Self-nanoemulsifying drug delivery system (SNEDDS) containing oil (Phosal 53 MCT), surfactant (Labrasol), and cosurfactant (Transcutol-HP or Lutrol-E400) was prepared to enhance solubility and dissolution of lutein. Ternary phase diagram of the SNEDDS was constructed to identify the self-emulsifying regions following which the percentage of oil, surfactant, and cosurfactant in the SNEDDS were optimized in terms of emulsification time and mean emulsion droplet size. The optimized SNEDDS consists of 25% oil, 60% surfactant, and 15% cosurfactant. When measured using USP XXIII dissolution apparatus II, the emulsification time of the SNEDDS prepared with Transcutol-HP as cosurfactant was less than 20 sec, and it was 20-30 sec in the SNEDDS prepared with Lutrol-E400. Mean emulsion droplet size was slightly smaller when Transcutol-HP was used as cosurfactant (80 +/- 6 nm), compared to when Lutrol- E400 was used (93 +/- 6 nm). Dissolution of lutein from the solid SNEDDS (physical mixture of the optimized SNEDDS and Aerosil 200) took place immediately (less than 5 min) in distilled water, and, once dissolved, no precipitation or aggregation of the drug were observed. In contrast, no drug was released from lutein powder or from the commercial product (Eyelac(R)) until 3 h of the study duration.

The effect of coenzyme Q10 on the pharmacokinetic parameters of theophylline.

Interaction of a drug with other drugs and dietary supplements is becoming an emerging issue for patients and health insurance authorities due to awareness of adverse drug event. In this study, we examined the effects of coenzyme Q10 (CoQ10), one of the most popular dietary supplements, on the pharmacokinetic parameters of theophylline in rats. The pharmacokinetic parameters of theophylline changed significantly when the drug was administered after five consecutive days of pretreatment with CoQ10. Time to reach maximum plasma concentration of theophylline delayed when the drug was administered after the pretreatment with CoQ10. Maximum plasma concentration and area under the curve of theophylline were about two-fold increased and other pharmacokinetic parameters such as half-life and volume of distribution were also changed significantly. Therefore, although CoQ10 is generally considered a safe dietary supplement, it appears that patients on theophylline therapy should use caution when they take CoQ10.