The magnetic properties and the crystal structure of MgV2O4 and Mg(V0.85Al0.15)2O4 have been studied. Both compounds are the normal cubic spinels with highly frustrated magnetic lattice. Around T2=65 K, MgV2O4 has magnetic orders accompanied with the cubic-tetragonal transition. Below T2, the susceptibility shows complex behavior. In Mg(V0.85Al0.15)2O4, the spin-glasslike state appears. The V51-Knight shift of MgV2O4 has an anomalous temperature dependence, which is not simply related by that of the susceptibility.

Drugs are most often administered by the oral route. However, more than 40% of new chemical entities exhibit poor aqueous solubility, resulting in unsatisfactory oral drug delivery. Recently, much attention has been focused on selfemulsifying drug delivery systems (SEDDS) to improve the oral bioavailability of poorly aqueous soluble drugs. SEDDS are isotropic mixtures of oil, surfactants, solvents and co-solvents/surfactants. The principal characteristic of these systems is their ability to form fine oil-in-water (o/w) emulsions or microemulsions upon mild agitation following dilution by an aqueous phase. For lipophilic drugs, which display dissolution rate-limited absorption, SEDDS may be a promising strategy to improve the rate and extent of oral absorption. This article gives an overview of the new excipients used in SEDDS and biopharmaceutical aspects of SEDDS. The application of SEDDS and closely related lipid-based systems as drug delivery vehicles is also introduced, with particular emphasis being placed on the application of SEDDS in traditional Chinese medicine (TCM).

Purpose: The present study was to formulate curcumin solid lipid nanoparticles (Cur-SLNs) with P-gp modulator excipients, TPGS and Brij78, to enhance the solubility and bioavailability of curcumin. Methods: The formulation was optimized by Plackett-Burman screening design and Box-Behnken experiment design. Then physiochemical properties, entrapment efficiency and in vitro release of Cur-SLNs were characterized. In vivo pharmacokinetics study and in situ single-pass intestinal perfusion were performed to investigate the effects of Cur-SLNs on the bioavailability and intestinal absorption of curcumin. Results: The optimized formulations showed an average size of 135.3 ± 1.5 nm with a zeta potential value of À24.7 ± 2.1 mV and 91.09% ± 1.23% drug entrapment efficiency, meanwhile displayed a sustained release profile. In vivo pharmacokinetic study showed AUC 0!t for Cur-SLNs was 12.27-folds greater than curcumin suspension and the relative bioavailability of Cur-SLNs was 942.53%. Meanwhile, T max and t 1/2 of curcumin for Cur-SLNs were both delayed comparing to the suspensions (p50.01). The in situ intestinal absorption study revealed that the effective permeability (P eff ) value of curcumin for SLNs was significantly improved (p50.01) comparing to curcumin solution. Conclusion: Cur-SLNs with TPGS and Brij78 could improve the oral bioavailability and intestinal absorption of curcumin effectively. KeywordsCurcumin, in situ intestinal absorption, oral bioavailability, P-glycoprotein, solid lipid nanoparticles History

(2015) Enhanced oral bioavailability of piperine by selfemulsifying drug delivery systems: invitro,invivo and insitu intestinal permeability studies, Drug Delivery, 22:6, 740-747, DOI: 10.3109/10717544.2014 AbstractThe main purpose of this work was to develop and evaluate a self-emulsifying drug delivery system (SEDDS) of piperine to enhance its solubility and bioavailability. The formulation was optimized by solubility test and ternary phase diagrams. Then physiochemical properties and in vitro release of SEDDS were characterized. In vivo pharmacokinetics study and in situ singlepass intestinal perfusion were performed to investigate the effects of SEDDS on the bioavailability and intestinal absorption of piperine. The optimized formulation was composed of ethyl oleate, Tween 80 and Transcutol P (3:5.5:1.5, w/w), with the level of the piperine reached 2.5% (w/w). The in vitro dissolution rates of piperine SEDDS were significantly higher than the self-prepared capsules. In vivo pharmacokinetic study showed C max1 , C max2 and area under the curve of piperine after oral administration of SEDDS in rats were 3.8-, 7.2-and 5.2-fold higher than the self-prepared capsules, respectively, and the relative bioavailability of SEDDS was 625.74%. The in situ intestinal absorption study revealed that the effective permeability and the effective absorption rate values of piperine for SEDDS were significantly improved comparing to solutions (p50.01). So SEDDS formulation could improve the oral bioavailability and intestinal absorption of piperine effectively.

Multidrug resistance (MDR) is a major obstacle to successful and effective chemotherapeutic treatments of cancers. This study explored the reversal effects of vitamin E on MDR tumor cells in vitro and in vivo, elucidating the potential mechanism of this reversal. VE at a concentration of 50 μM exhibited a significant reversal of the MDR effect (compared to only PTX in DMSO, p < 0.05) in two human MDR cell lines (H460/taxR and KB-8-5). The MDR cell xenograft model was established to investigate the effect of VE on reversing MDR in vivo. Mice intravenously injected with Taxol (10 mg/kg) with VE (500 mg/kg, IP) showed an ability to overcome the MDR. VE and its derivatives can significantly increase intracellular accumulation of rhodamine 123 and doxorubicin (P-gp substrate), but not alter the levels of P-gp expression. These treatments also did not decrease the levels of intracellular ATP, but were still able to inhibit the verapamil-induced ATPase activity of P-gp. The new application of VE as an MDR sensitizer will be attractive due to the safety of this treatment.