Tablets based on compressed zein microspheres for sustained oral administration: design, pharmacokinetics, and clinical study.

In our previous study, we reported a novel tablet based on compressed zein microspheres as a universal drug delivery system using the hydrophobic protein zein, which shows zero-order release in the presence of pepsin. However, this formulation had difficulty with disintegration under physiological conditions within 48 h, and thus could not be used directly for oral administration. In the present study, a formulation of ivermectin (IVM) tablets based on compressed zein microspheres was improved as a new dosage form. The plasma disposition pharmacokinetics of IVM tablets based on compressed zein microspheres after oral administration was studied over a 7-day period with six dogs (Canis familiaris), using a commercial IVM tablet (5 mg/piece, Yilijia(®) ) as a control. Clinical efficacy was tested using 270 dogs presented as veterinary patients for the treatment of demodicidosis. A formulation with disintegration time within 15 min could be obtained. The acquired C( max), T(max), and AUC were 9.89 ± 0.34 ng/mL, 11.33 ± 2.63 h, and 883.87 ng h/mL for IVM tablets based on compressed zein microspheres and 9.64 ± 1.05 ng/mL, 7.26 ± 2.09 h, and 666.30 ng h/mL for Yilijia(®), respectively. The bioavailability of the tablets based on compressed zein microspheres was 132.65% that of Yilijia( ®). Efficacy for the dogs in all the IVM tablets based on compressed zein microspheres-treated groups reached 100% at 7, 14, and 21 days post administration.

Preparation and immunological effectiveness of a Swine influenza DNA vaccine encapsulated in PLGA microspheres.

Optimal preparation conditions of DNA vaccine against swine influenza encapsulated in Poly (D,L)-lactic-co-glycolic acid (PLGA) microspheres were determined. The microspheres were prepared by an emulsion-evaporation method using PLGA as the biodegradable matrix forming polymer. Using the optimal preparation conditions, PLGA microspheres containing the DNA vaccine were produced with good morphology as evident from scanning electron micrographs, high encapsulation rate and high stability. The transfection test indicated that the vaccine could be expressed as an antigen in cells and maintained good bioactivity. Moreover, these results demonstrated that the PLGA microspheres containing DNA vaccine can be used to achieve prolonged release of plasmid DNA. These results have laid a foundation for further development before ultimate industrial application.

Comparison of cytocompatibility of zein film with other biomaterials and its degradability in vitro.

UNLABELLED: Cytocompatibility of particle zein (Pzein) and film zein (Fzein) was evaluated and compared with polyhydroxybutyrate (PHB), its copolymer poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), polylactic acid (PLA), and collagen, using HL-7702 cells, in terms of cell attachment rate within 3 h, and cell viabilities at 3 and 6 days determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. The zein degradation test was carried out using collagenase and trypsin, and the degradation product was added to the culture medium at different concentrations in order to examine the concentration-dependent cytotoxic effect. RESULT: The adhesion rate of the HL-7702 cells on both Pzein and Fzein was higher than that on collagen film. Cell viabilities were higher on both Pzein and Fzein than on films of PLA, PHB, PHBV, and collagen from fish skin. Zein can be degraded by both trypsin and collagenase, and the degradation product can enhance cell viability within a certain range of concentrations.