遗传算法在经皮给药微乳载体处方优化中的应用

以萘普生为模型药物，用遗传算法优化经皮给药微乳载体的处方。用伪三元相图法确定由Tween 80、IPM、乙醇和水组成的微乳区域。用3因素3水平的中心设计法制备载药量为1.12%的萘普生模型微乳，并进行离体兔皮的体外渗透实验。以稳态渗透速率的二次回归模型为目标函数，用遗传算法对中心设计结果进行优化，筛选出具有最大透皮速率的萘普生微乳载体处方。所得优化处方的组成为：21.41% Tween 80、15.17%乙醇、4.14% IPM和59.28%水，预计的稳态渗透速率为183.57 μg·cm^-2·h^-1。回代试验表明，以优化处方制备的萘普生微乳，其稳态渗透速率的平均值为189.43 μg·cm^-2·h^-1，高于预测值。结果表明，用遗传算法筛选微乳经皮给药载体处方，方法可行，结果合理、可靠。

Application of genetic algorithm in formulation optimization of microemulsion for transdermal delivery

Using naproxen as model drug, the formulation of microemulsion vehicle for transdermal delivery was optimized by genetic algorithm. The ranges of microemulsion composed of Tween 80, IPM, alcohol and water, were defined through construction of the pseudo-ternary phase diagrams. Systematic model microemulsions containing naproxen 1.12% were prepared by a three-factor, three-level center design method, and their diffusion studies via excised rabbit skin were performed. Using the quadratic regression model of steady-state permeation rate (J_s) of naproxen as objective function, the consequence of center design experiment was optimized by genetic algorithm, and the formulation of microemulsion with highest permeation rate for naproxen was screened. The optimum formulation was composed of 21.41% Tween 80, 15.17% alcohol, 4.14% IPM, and 59.28% water, and the anticipated J_s was 183.57 μg·cm^-2·h^-1. The results of back substitution test showed the steady-state permeation rate of naproxen microemulsion prepared according to optimum formulation was 189.43 μg·cm^-2·h^-1, which was higher than anticipated value. This result demonstrated optimizing formulation of microemulsion for transdermal delivery by genetic algorithm is feasible, reliable and reasonable.