Enhanced oral bioavailability of 10-hydroxycamptothecin through the use of poly (n-butyl cyanoacrylate) nanospheres.

The article describes the preparation, physicochemical characterization, drug release, and in vivo behavior of 10-hydroxycamptothecin-loaded poly (n-butyl cyanoacrylate) (PBCA) nanospheres (HCPT-PBCA-NSs). HCPT-PBCA-NSs were successfully prepared via emulsion polymerization of n-butyl cyanoacrylate (BCA) monomer in acidic medium with the aid of two colloidal stabilizers (Poloxamer 188 and Dextran 70). The influence of pH, the time of polymerization, and the dosage of the drug on particle size and encapsulation efficiency (EE) were studied. HCPT-PBCA-NSs were of spherical shape and uniformly dispersed with a particle size of 135.7 nm, and zeta potential of -18.18 mV. EE, drug loading (DL), and yield of HCPT-PBCA-NSs were 51.52, 0.63, and 88.25%, respectively. FTIR, 1H NMR, and DSC showed complete polymerization of BCA monomer and HCPT existed in the form of molecular or amorphous in NSs. In vitro release of the drug from HCPT-PBCA-NSs exhibited sustained-release behavior with an initial burst release and about 60% of HCPT was released from the formulation within 24 h of dialysis. The pharmacokinetic study in healthy rats after oral administration showed that encapsulation of HCPT into PBCA-NSs increased the Cmax about 3.84 times and increased AUC0-t about 5.40 times compared with that of HCPT suspension. It was concluded that PBCA-NSs could be a promising drug carrier to load HCPT for oral drug delivery if efforts are made in the future to improve its poor DL capacity.

In vitro and in vivo evaluation of 10-hydroxycamptothecin-loaded poly (n-butyl cyanoacrylate) nanoparticles prepared by miniemulsion polymerization.

In this paper, 10-hydroxycamptothecin (HCPT)-loaded poly (n-butyl cyanoacrylate) nanoparticles (HCPT-PBCA-NPs) co-modified with polysorbate 80, soybean phospholipids, and polyethylene glycol (100) monostearate were successfully prepared via miniemulsion polymerization, and were characterized for particle size, morphology, zeta potential, encapsulation efficiency (EE) and drug loading capacity (DL). The chemical structure of HCPT-PBCA-NPs and the state of HCPT in the PBCA-NPs were investigated by DSC, FTIR and 1H NMR. Additionally, drug release, cytotoxicity, cellular uptake capacity, cellular uptake mechanism, and in vivo behavior of NPs were investigated as well. The particles were 92.7nm in size with a high EE of 94.24%. FTIR, 1H NMR, and DSC demonstrated complete polymerization of BCA monomers and the drug was in a molecular or amorphous form inside the NPs. In vitro release of the drug from HCPT-PBCA-NPs exhibited sustained-release and less than 60% of HCPT was released from the NPs within 24h of dialysis. Cellular uptake study displayed that Caco-2 cell uptake of NPs was governed by active endocytosis, clathrin- and caveolin-mediated process, and increased with the increase of the NPs concentration and the time. The pharmacokinetic study in rats showed that encapsulation of HCPT into PBCA-NPs increased the Cmax and AUC0-t about 6.52 and 7.56 times, respectively, in comparison with the HCPT suspension. It was concluded that HCPT loaded PBCA-NPs prepared by miniemulsion polymerization could be promising in oral drug delivery.

Preparation and oral bioavailability study of curcuminoid-loaded microemulsion.

Curcuminoid, a dietary polyphenolic compound, has poor water solubility and low bioavailability following oral administration. The aim of this study was to develop a formulation of curcuminoid-loaded microemulsion (Cur-ME) to improve its oral bioavailability. The optimized Cur-ME formulation was prepared by using labrafac lipophile WL 1349, cremophor RH 40, and glycerine as the oil phase, the surfactant, and the cosurfactant, respectively. Pharmacokinetics and bioavailability of curcuminoid suspension and Cur-ME were evaluated and compared in rats. Plasma bisdemethoxycurcumin (BDMC), treated as the representing component of curcuminoid, was determined by high-performance liquid chromatography with fluorescence detector. After gavage administration of curcuminoid suspension, the plasma BDMC level was very low, below 5 ng/mL, whereas for Cur-ME, double peak of maximum concentrations were observed. The relative bioavailability of Cur-ME was enhanced in an average of 9.6-fold that of curcuminoid suspension. It was concluded that the bioavailbility of curcuminoid was enhanced greatly by the microemulsion.