ABSTRACT
OBJECTIVE: To evaluate the effects of different pretreatment ways on microneedle onits penetration enhancing effect for ramosetron hydrochloride paches in microneedle-assisted transdermal drug delivery. METHODS: Skin penetration experiments were carried out using excised guinea pig skin. Microneedle pretreatment ways including needle type, needle length, needle acting force and acting time were taken as the influencing factors. The main effects and interaction effects of influencing factors in skin penetration enhancement were analyzed. RESULTS: Microneedle length had the most significant impact on drug skin penetration. When the length changed from 200 μm to 300 μm, the steady-state permeation rate and the cumulative permeation amount within 48 h displayed marked increase. Additionally, there was interaction between the penetration enhancing effects of the microneedle length and acting force. When the acting time and needle type were fixed and the microneedle length was 200 μm, no significantly different impacts occurred if the acting force varied between 3 and 5 N. However, if the microneedle length was 300 μm, the penetration enhancing effects became more significant when increasing acting force from 3 to 5 N. CONCLUSION: This studies suggeste that microneedle pretreatment ways may result in different effects on penetration of drugs through skin, and there may exist interaction effect between different microneedle pretreatment ways.This study provides a reference for the selection of microneedle pretreatment in microneedle-assisted transdermal drug delivery.