A gel plaster in the form of nipple cover: A comfortable and safe transdermal delivery method for mammary hyperplasia

Hyperplasia of mammary glands (HMG) is considered a precancerous condition with a risk of malignant transformation, highlighting the necessity of proactive treatment in the early stages. Transdermal drug delivery offers significant advantages such as painlessness, absence of first-pass effect, and good patient compliance. However, the unique structure of the breast requires transdermal formulations for treating mammary hyperplasia to exhibit higher levels of safety and comfort. We have formulated an ancient topical formula called ’Muxiang Bing,’ comprising traditional Chinese medicines Aucklandiae Radix (AR) and Rehmanniae Radix (RR), for the treatment of HMG. This formula has been transformed into a gel paster in the form of nipple cover for trans-nipple-areola delivery. In our investigations, we observed that the optimal formulation of the Muxiang gel plaster demonstrated enhanced permeation facilitated by AR’s effect on RR. Furthermore, pre-treatment with the Muxiang gel plaster improved mammary tissue morphology, hormone levels, oxidative stress, aberrant cell proliferation, and damage in rat models, thus preventing and ameliorating mammary hyperplasia. The Muxiang gel plaster exhibited low skin irritability in rats, and long-term use did not cause harm to their internal organs or blood cells, indicating its safety and efficacy.