ABSTRACT
Response Surface Methodology (RSM) models combined with experimental designs became popular in recentyears. Their advantages to analyze the interactive effects among different factors and the efficiency considerationsencouraged more researchers to conduct natural product research employed with these models. A review about basicprinciples of factorial designs, central composite designs, Box–Behnken designs, and Doehlert designs which utilizedalong with the RSM and their applications in natural product research is presented. The objective of this reviewwas to report various experimental design techniques and their applications in the field of natural product research.Furthermore, the characteristic of each design is also presented and the trends of RSM applications in natural productresearch are also discussed in this paper.
ABSTRACT
RESUMO: Nesse trabalho, objetivou-se recuperar o óleo presente na borra oleosa por processo de extração, a fim de reutilizá-lo como combustível. Foram aplicados dois planejamentos experimentais: fatorial fracionado e Doehlert. Através da caracterização da borra oleosa (análises físico-químicos, elementar CHN e S, orgânicas e inorgânicas), constatou-se que a borra oleosa utilizada é constituída de 36,2% de óleo, 16,8% de cinzas, 40% de água e 7% de compostos voláteis. A eficiência média do processo de extração foi 70%. Entretanto, a análise estatística mostrou que o modelo quadrático não se ajustou bem ao processo, devido à complexidade do material estudado. Por outro lado, aplicando-se a modelagem de RNA, o coeficiente de determinação foi de 87,5%, mostrando-se bastante satisfatório.
ABSTRACT: This work aimed to recover the oil present in oily sludge by extraction process in order to reuse it as fuel. Two experimental designs were applied: fractional factorial and Doehlert. Through characterization of the oily sludge (physico-chemical analysis, CHN and S elemental, inorganic and organic), it was found that the oily sludge used consists of 36.2% oil, 16.8% ash, 40% water and 7% volatile compounds. The efficiency obtained in the oil extraction process was 70%, in average. However, statistical analysis showed that the quadratic model did not satisfactorily the process due to the complexity of the studied material. By the other hand, applying ANN the coefficient of determination became 87.5% that is quite satisfactory.
ABSTRACT
Objective: To optimize the preparation technology of paeoniflorin microcapsule (PM), and to study its behavior of in vitro release. Methods: Using encapsulation efficiency and drug loading as indicators, the PM were prepared by complex agglutination method, the preparation technology of PM was optimized by Doehlert design. The dissolution volume of PM within 20 h and the release curve were measured by HPLC, afterwards its morphology and particle size were studied by electron microscopy. Results: The encapsulation efficiency and drug loading were significantly related to the ratio of coating material, stirring speed, and pH value. The optimal conditions were as follows: the ratio of coating material to paeoniflorin was 4.3:1, the stirring speed was 305 r/min, and the pH value was 4.0. The obtained microcapsules were smooth round capsule-shaped, with non-adhesions and uniform particle size, the encapsulation efficiency was up to 83.81%, the drug loading was 24.24%, and the microcapsule diameter was below 200 μm, with sustained-release effect. Conclusion: The complex agglutination method is simple and reliable to prepare PM, and the product is stable. As a new formulation, microcapsule has a broad prospect for development.