[An evaluation method for physical properties of medicinal film and its application in screening film formulation of Trillium tschonoskii total saponins].

At present, the evaluation methods for pharmaceutical properties of Chinese medicinal films have many problems, such as poor objectivity for the indexes and no quantitative and standardized evaluation methods. This study established a new method using three important physical property parameters, i.e., flow index, weight loss rate, and elongation rate, which were closely related to the pharmaceutical properties of films. On this basis, the above parameters were taken as indicators to optimize the film formulation of Trillium tschonoskii total saponins and verify the feasibility and suitability of the established method and parameters in formulation optimization. A self-made flow distance detection device and a viscometer were used to measure and characterize the fluidity, where the flow index refers to the ratio of the flow distance per unit time to the viscosity. The weight loss rate was measured by the 3 M transpore~(TM) surgical tape. The film-forming property was characterized by the weight loss rate of the sample within a certain period of time. An electronic tension machine was employed to measure the elongation rate after drying, which was used to characterize the ductility of the film. The results showed that the established method for the determination of flow index, weight loss rate, and elongation rate was stable and reliable. The optimal film formulation of T. tschonoskii total saponins could be obtained by optimization with those indicators. As demonstrated, the above evaluation indicators(flow index, weight loss rate, and elongation rate) can guide the optimization and design of formulation, and the new evaluation method constructed based on this shows a good application prospect in formulation optimization and formulation quality evaluation of medicinal films.