naeemeh yousefi faculty of pharmacy, tehran university of medical sciences, tehran, iran arash rashidian tehran university of medical sciences fatemeh soleymani food and drug laboratory research center, food and drug organization. moh&me iran, tehran, national committee on rational drug use, food and drug organization, ministry of health and medical education

md nazrul islam mondal 1. laboratory of computational statistics and operations research, institute for mathematical research university putra malaysia, 43400 upm serdang, selangor darul ehsan , malaysia ; 2. dept. of population science and human resource development; university of rajshahi , rajshahi, bangladesh. mahendran shitan 1. laboratory of computational statistics and operations research, institute for mathematical research university putra malaysia, 43400 upm serdang, selangor darul ehsan , malaysia ; 3. dept. of mathematics, faculty of science, university putra malaysia; 43400 upm serdang, selangor darul ehsan , malaysia.

J.M. Nduko , M.C. Mwende, W.N. Wanjala,