Preparation And Characterization Of Rifapentine-Loaded Poly (E-Caprolactone) Microspheres

Objective:Preparation a new drug delivery system based on Rifapentine (RFT)-poly(ε-caprolactone) (PCL) release microspheres (MS) for long-term suppression of bone and joint tuberculosis. Physical and chemical properties, in vitro release properties, antibacterial properties and degradation have been investigated. An experimental basis for the new sustained-release formulations has been provided for the treatment of bone tuberculosis.Methods:1. RFT-PCL-MS were fabricated by oil-in-water (O/W) solvent evaporation method as a long-time control-released system. The effect of technological parameters such as stirring speed of the emulsion, the volume ratio of drug and the concentration of PVA on the properties of the microspheres were evaluated by the morphology, size distribution, drug loading and entrapment efficiency.2. The RFT-PCLMS were characterized by using SEM, FTIR, XRD, in vitro drug release behavior and in vitro degradation systematically.3,2-fold dilution method was using for the determination of trace drug-loaded microspheres Mycobacterium tuberculosis MIC values and loaded microspheres with Mycobacterium tuberculosis in co-culture medium Roche drug effected on microspheres antibacterial properties.Results:1. The optimal preparation conditions were as follows:speed of mechanical stirring was 300 r·min-1, quantity of drug was 20 mg, and polyvinyl alcohol concentration was 2 wt%. The RFT-PCL micro sphere display an average particle size of 27.249±0.256μm with 3.098±0.011 wt% drug loading amount and 34.078±0.123% entrapment efficiency, while presenting spherical shape, microporous surface, uniform size distribution and narrow particle size distribution.2. The results indicated that in vitro release process of drug-laded PCL microspheres was divided into a sudden release and slow release phase, of that 2 d drug cumulative release was 30.962% and 12 d drug cumulative release was 62.42%. PCL microspheres degraded slowly and pH value of degradable product did not change apparently on the contrast of PLGA microspheres with a lot of acid materials released in vitro degradation.3. The encapsulated method did not affect the bacteriostatic ability of rifampicin because the effective concentration at different time point is larger than the minimum bacterio stasis concentration of drug.Conclusion:Poly(ε-caprolactone) is an ideal carrier material for rifapentine to prepare a controlled release delivery system for long term suppression. Drug-loaded microspheres prepared promise for the treatment of bone and joint tuberculosis.