Síntese e caracterização de nanofibras de policaprolactona com adição de progesterona utilizando o solvente ácido acético pelo método de eletrofiação

Abstract

The ideal drug delivery system releases in a prolonged and constant way, depending on the concentration in the target tissue, it's absorption rate, pharmacokinetics and the drug's coating when in situ. Implantable systems that were developed from the polymer polycaprolactone (PCL), in the form of contraceptive implant, have received high consideration in the research of new structures. Several studies involving the incorporation of drugs into polymers by the electrospinning methods are being conducted. Some studies have demonstrated the integrity of the drug and it's better dispersion throughout nanofiber systems. Due to new systems development possibilities for controlled release of drugs, and the few studies with the incorporation of female hormones using nanostructures by the electrospinning process, the purpose of this work was the production of a PCL nanofiber system using acetic acid as the only solvent throughout the process. Samples of the PCL, acetic acid and progesterone system, obtained using different synthesis parameters: solution concentration (polymer and hormone), voltage and injection rate in the electrospinning, were analyzed. In step 1 solutions were prepared with different PCL to acetic acid concentrations: 15%w/w, 20%w/w, 25%w/w and 30%w/w. The electrospinning equipment was adjusted to the injection rates of 4ml/hr and 7ml/hr and the voltages used were 15kV, 20kV and 25kV. In step 2 progesterone was added to the system. It was considered that the sample with the best structural and morphological characteristics was the 20%w/w PCL with the injection rate of 4 ml/hr and a voltage of 20kV. The progesterone to PCL concentrations used in this step were 9%w/w, 16%w/w, 23%w/w, 28%w/w and 33%w/w. In both steps samples were produced in a blanket form with a diameter of 90mm and a total weight of 1g. Structural and in vitro characteristics analysis were conducted to evaluate the effective nanofiber formation, the fiber diameters and the variation of the diameters, the homogeneity of the collected product, the water absorption capacity and the degradation rate of the samples. Samples with 16%w/w and 23%w/w of progesterone showed the best structural and morphological characteristics.