Neglected aspect of the strategy for human breast diseases: trans-areolar drug delivery

A Comprehensive Review on Current Knowledge and Future Potential of Topical Therapies in Breast Cancer Treatment

Breast cancer remains one of the most prevalent malignancies among women globally. Despite advances in therapeutic options, the prognosis often remains challenging. Breast cancer typically originates in the epithelial lining of glandular tissue ducts (85%) or lobules (15%). Initially confined to these areas (in situ), it generally remains asymptomatic and poses little risk of metastasis. The primary treatments for breast cancer include surgery, radiation therapy, chemotherapy, hormone therapy, and targeted therapy. Although these interventions have advanced significantly and have improved patient survival rates, they are connected with numerous im mediate and long-term side effects. Effective breast cancer treatment aims to maximize efficacy while minimizing adverse effects. Given that many breast cancers are specific to the breast, developing safe and targeted therapeutic strategies will be of benefit. This review examined the current literature on the effectiveness of topical therapies for breast cancer. Studies and clinical trials were evaluated that have investigated these treatments, focusing on their safety, ease of application, and patient acceptance. Recently, topical drug delivery is transforming breast cancer therapy, offering precision and reduced systemic toxicity. Emu oil-enhanced tamoxifen showed superior transdermal effectiveness, while raloxifene gel achieved 2.77 times greater bioavailability than oral forms. Tamoxifen nanoemulgels and microneedle arrays with resveratrol further enhanced localized delivery, These therapies have gained patient acceptance due to their non-invasive nature, lack of gastrointestinal side effects, ease of application, and favourable safety and therapeutic profiles and setting a new benchmark for innovative and patient-friendly treatments. This review summarizes the findings from various studies, highlighting the benefits and limitations of topical therapies. Topical therapies offer a promising noninvasive option for breast cancer treatment with fewer side effects. These treatments have shown favorable therapeutic and safety profiles, making them an attractive option for patients.

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.

Influence of Hydroalcoholic Vehicle on In Vitro Transport of 4-Hydroxy Tamoxifen Through the Mammary Papilla (Nipple)

Majority of breast cancers originate from epithelial cells in the duct and lobules in the breast. Current systemic treatments for breast cancer are associated with significant systemic side effects, thus warranting localized drug delivery approaches. The aim of this study was to investigate the influence of hydroalcoholic vehicle on topical delivery of 4-hydroxy tamoxifen (4-HT) through the mammary papilla (nipple). The in vitro permeability of 4-HT through porcine mammary papilla was studied using different hydroalcoholic vehicles (0, 33.33, and 66.66% alcohol). Nile red was used as a model lipophilic dye to characterize the drug transport pathway in the mammary papilla. The penetration of 4-HT through the mammary papilla increased with increase in alcohol concentration in the vehicle. The solubility of 4-HT was enhanced by increasing alcohol concentration in the vehicle. On the other hand, the epidermis/vehicle partition coefficient decreased with increase in alcohol concentration. The mammary papilla served as a depot and slowly released 4-HT into the receptor medium. Highest drug penetration was observed with saturated drug solution in 66.66% alcohol, and 4-HT levels were comparable to IC₅₀ value of 4-HT. Results from this study demonstrate the possibility of using mammary papilla as a potential route for direct delivery of 4-HT to the breast.

Transpapillary drug delivery to the breast

The study was aimed at investigating localized topical drug delivery to the breast via mammary papilla (nipple). 5-fluorouracil (5-FU) and estradiol (EST) were used as model hydrophilic and hydrophobic compounds respectively. Porcine and human nipple were used for in-vitro penetration studies. The removal of keratin plug enhanced the drug transport through the nipple. The drug penetration was significantly higher through the nipple compared to breast skin. The drug’s lipophilicity had a significant influence on drug penetration through nipple. The ducts in the nipple served as a major transport pathway to the underlying breast tissue. Results showed that porcine nipple could be a potential model for human nipple. The topical application of 5-FU on the rat nipple resulted in high drug concentration in the breast and minimal drug levels in plasma and other organs. Overall, the findings from this study demonstrate the feasibility of localized drug delivery to the breast through nipple.