(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.

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

Highlights(1) Tide amplitude decreases in the lowermost channel and tidal flats of the Yellow River Delta as river discharge increases.(2) The river discharge changes can reshape the shear front zone dynamics near the active Yellow River delta.(3) The barrier effect of the tidal shear front zone combined with strong longshore tidal currents significantly restrict the sediment dispersal and river mouth deposits.

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Abstract. Multidrug resistance (MDR) is a main clinical hurdle for chemotherapy of cancer, and overexpression of P-glycoprotein (P-gp) is a key factor. In the present study, a new co-delivery system for reversing MDR was designed and developed. The system was composed of curcumin (Cur) and piperine (Pip) encapsulated in solid lipid nanoparticles (SLNs) with tocopheryl polyethylene glycol succinate (TPGS) and Brij 78 [(Cur+Pip)-SLNs]. TPGS and Brij 78 could sensitize MDR tumors by inhibiting the P-gp drug efflux system. The combination of Cur and Pip, when administered in SLNs formulations, resulted in a significant enhancement in cytotoxicity and allowed efficient intracellular delivery of the drugs in drug-resistant A2780/Taxol cells. This dual inhibitory strategy may have significant potential in the clinical management of MDR in cancer.

In this study, we observed that a Aconitum coreanum polysaccharide (CACP) exhibited an effective inhibitory effect on H22 cell growth in vitro and in vivo via the induction of apoptosis. Further, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting assays revealed that the expression of pituitary tumor transforming gene 1 (PTTG1), one proto-oncogene, was evidently suppressed in both transcript and protein levels in H22 cell model or mice after CACP treatment. Particularly, CACP (40 μg/ml) treatment or transfection with PTTG1 small interfering RNA (siRNA) could greatly reduce the phosphorylation of Akt (p-Akt) but increase phospho-p38 mitogen-activated protein kinase (p-p38 MARK) protein levels in H22 cells as compared with vehicle-treated cells. Likewise, following treatment of H22-tumor-bearing mice with CACP (100 mg/kg), doxorubicin (DOX, 3 mg/kg), and their combination, tumor tissues showed an attenuated p-Akt protein expression, but a striking p-p38 MARK level when compared with those in model mice. Taken together, we demonstrated here the inhibitory effect of CACP on the growth of H22 cells in vitro and in vivo, which may be through, at least partly, repression of PTTG1 and then followed by the inactivation of P13/Akt and activation of p38 MARK signaling pathways. These findings offered a novel approach for the treatment of hepatocellular carcinoma (HCC) in the future.

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