Abstract
In this study, quality engineering (Taguchi Methods) was applied to the formulation of an ointment. ln order to obtain good ointment permeability through skin, the "in vitro" permeability was measured as the duality characteristic. The excised skins from rats and micro-pigs were used in the permeation test. All ingredients in the model ointment were selected as control factors and assigned to an L18 orthogonal array. Animal species were considered as the noise factor conditions so that the optimum condition would be robust against species. For the generic function, it was considered that the cumulative amount of penetration should be proportional to time. Zero point proportional equation, Y= βT was used, where Y, β and T denote the cumulative drug penetration per uniｔ, constant, and time respectively. As a result, excellent permeability was obtained under the optimum condition with little dependency on different species. Such success was accomplished with a single repetition in the test, in contrast to traditional testing with many repetitions in animal experimentation.
