Development and characterization of poly(lactic-co-glycolic) acid nanoparticles loaded with copaiba oleoresin.

Copaiba oleoresin (CPO), obtained from Copaifera landgroffii, is described as active to a large number of diseases and more recently in the endometriosis treatment. In this work, poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing CPO were obtained using the design of experiments (DOE) as a tool to optimize the production process. The nanoparticles optimized by means of DOE presented an activity in relation to the cellular viability of endometrial cells. The DOE showed that higher amounts of CPO combined with higher surfactant concentrations resulted in better encapsulation efficiency and size distribution along with good stability after freeze drying. The encapsulation efficiency was over 80% for all produced nanoparticles, which also presented sizes below 300 nm and spherical shape. A decrease in viability of endometrial stromal cells from ectopic endometrium of patients with endometriosis and from eutopic endometriotic lesions was demonstrated after 48 h of incubation with the CPO nanoparticles. The nanoparticles without CPO were not able to alter the cell viability of the same cells, indicating that this material was not cytotoxic to the tested cells and suggesting that the effect was specific to CPO. The results indicate that the use of CPO nanoparticles may represent a promising alternative for the treatment of endometriosis.

Poly ɛ-caprolactone nanoparticles loaded with Uncaria tomentosa extract: preparation, characterization, and optimization using the Box-Behnken design.

PURPOSE: The aim of this research was to develop and optimize a process for obtaining poly ɛ-caprolactone (PCL) nanoparticles loaded with Uncaria tomentosa (UT) extract. METHODS: Nanoparticles were produced by the oil-in-water emulsion solvent evaporation method. Preliminary experiments determined the initial conditions of the organic phase (OP) and of the aqueous phase (AP) that would be utilized for this study. Ultimately, a three-factor three-level Box-Behnken design (BBD) was employed during the optimization process. PCL and polyvinyl alcohol (PVA) concentrations (X(1) and X(2), respectively) and the AP/OP volume ratio (X(3)) were the independent variables studied, while entrapment efficiency (Y(1)), particle mean diameter (Y(2)), polydispersity (Y(3)), and zeta potential (Y(4)) served as the evaluated responses. RESULTS: PRELIMINARY EXPERIMENTS REVEALED THAT THE OPTIMAL INITIAL CONDITIONS FOR THE PREPARATION OF NANOPARTICLES WERE AS FOLLOWS: OP composed of 5 mL ethyl acetate/acetone (3/2) mixture containing UT extract and PCL, and an AP of buffered PVA (pH 7.5) solution. Statistical analysis of the BBD results indicated that all of the studied factors had significant effects on the responses Y(1), Y(2), and Y(4,) and these effects are closely described or fitted by regression equations. Based on the obtained models and the selected desirability function, the nanoparticles were optimized to maximize Y(1) and minimize Y(2). These optimal conditions were achieved using 3% (w/v) PCL, 1% (w/v) PVA, and an AP/OP ratio of 1.7, with predicted values of 89.1% for Y(1) and 280 nm for Y(2). Another batch was produced under the same optimal conditions. The entrapment efficiency of this new batch was measured at 81.6% (Y(1)) and the particles had a mean size of 247 nm (Y(2)) and a polydispersity index of 0.062 (Y(3)). CONCLUSION: This investigation obtained UT-loaded nanoparticle formulations with desired characteristics. The BBD approach was a useful tool for nanoparticle development and optimization, and thus should be useful especially in the realm of phytotherapeutics, in which varied compositions may be assessed in quantitative and qualitative terms.