Review on transdermal patches: optimization in drug administration

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Regulatory Science

Background:

• Transdermal patches provide sustained drug delivery and improve patient adherence.
• However, real-world effectiveness is limited by biological variability, improper patient use, and inconsistent regulatory standards.
• Adhesion is a key attribute, but current testing methods lack standardization and clinical correlation.

Purpose of the Study:

• To consolidate technical, clinical, and regulatory knowledge on transdermal patches.
• To identify existing gaps hindering the safe and effective application of transdermal drug delivery systems.

Main Methods:

• A comprehensive literature search was conducted across databases (PubMed, Scopus, ScienceDirect, Google Scholar).
• Regulatory agency websites (FDA, EMA) and pharmacopeial documents (USP-NF, European Pharmacopoeia) were consulted.
• The review included published reviews, primary studies, regulatory guidance, and pharmacopeia standards, excluding non-authoritative sources.

Main Results:

• Real-world performance of transdermal systems is impacted by biological variability, patient misuse, and fragmented regulatory requirements.
• Adhesion testing methods are inconsistent, with limited correlation between in vitro results and clinical outcomes.
• Fragmented regulatory frameworks pose challenges to the consistent development and approval of transdermal products.

Conclusions:

• Enhanced harmonization of adhesion and bioequivalence standards is essential for transdermal products.
• Improved patient education and testing under realistic conditions are necessary.
• These measures will ensure the quality, safety, and interchangeability of both innovator and generic transdermal patches.