ABSTRACT
OBJECTIVE: To prepare uniform-sized rifabutin-loaded PLGA microspheres and evaluate the characteristics of the microspheres. METHODS: The particle size uniformity of the microspheres prepared by premix membrane emulsification method and homogenization method was compared. Preparation technology was optimized by orthogonal design. Then the drug loading, entrapment efficiency and in vitro drug release were studied. RESULTS: The average particle size and PDI of the microspheres prepared by homogenization method were (4242±175.6) nm and 0.330. The microspheres prepared by premix membrane emulsification method were round, complete and smooth, and their particle sizes were well-distributed with mean value of (1330±64) nm and PDI of 0.168. Besides, the drug loading was (46.83±0.29)% and the entrapment efficiency was (93.66±0.58)%. Accumulative drug release rate was 66% in 15 d. CONCLUSION: The rifabutin-loaded PLGA microspheres prepared by premix membrane emulsification method have narrow particle size distribution, high drug loading, high entrapment efficiency, and ideal in vitro sustained-release effect.
ABSTRACT
PURPOSE: We evaluate in vitro and in vivo efficacy of newly developed gentamicin loaded PLGA microspheres for the treatment of musculoskeletal infection. MATERIALS AND METHODS: Controlled gentamicin sulfate releasing microspheres manufactured from biodegradable PLGA were prepared with an Oil/Oil solvent evaporation method for the treatment of musculoskeletal infection. The in vitro release amount of GS was analyzed by high performance liquid chromatography (HPLC) and the released GS activity was determined by microbiological assay using staphylococcus (S) aureus, respectively. The results of inhibition zone test agree well with the HPLC results obtained from the in vitro release test. RESULTS: The microspheres of different size were obtained with varying the experimental conditions, and the shape of microspheres was smooth and spherical. The PLGA microspheres release gentamicin for 67 days in in vitro test. There was significant inhibition around microphere PLGA from 1 day to 7th week in inhibition zone test The inhibition was reduced after 8th week. and there was no inhibition at 9th week PLGA microspheres. CONCLUSION: It can be suggested that GS/PLGA MSs implantable system that provided a prolonged delivery of GS was found to be effective against S. aureus infection for desired period.
Subject(s)
Chromatography, High Pressure Liquid , Chromatography, Liquid , Gentamicins , Microspheres , Staphylococcus , Staphylococcus aureusABSTRACT
Objective To detect the dynamic changes of antibody and cytokines in the serum induced by single vaccine delivery system (SVDS) of biodegradable microspheres of recombinant glutathione-S-transferase from Schistosoma japonicum (rSjGST) in mice. Methods By using the constructed expression plasmid pET28a(+)-SjGST, rSjGST was expressed by E.coli BL21. After purified through the column of resin,the biodegradable microspheres of rSjGST were prepared with PLGA (Poly lactic-co-glycolic acid, PLGA 75/25).Six-week BALB/c female mice were immunized subcutaneously with a single vaccine, and the blood was collected from eyes on the 6th, 9th, 12th, 15 th, 18th, 21th week respectively. The dynamic levels of serum specific antibody IgG, IL-2 and IFN-? were detected. Results Compared with the control group, there was a significant difference of serum specific antibody IgG of every immune group (P