Biological Barriers in Drug Delivery: Strategies to Enhance Penetration

Abstract

The effective delivery of therapeutic agents to target sites within the body is often hindered by biological barriers that impede their penetration. These barriers, including the blood-brain barrier, epithelial barriers, and extracellular matrix, pose significant challenges to drug delivery systems. This review explores various strategies aimed at enhancing the penetration of drugs across these biological barriers. First, the intricacies of each barrier are examined, highlighting their unique structural and functional characteristics. Subsequently, a comprehensive overview of existing drug delivery approaches is provided, encompassing both conventional and emerging techniques. These include the use of nanocarriers, liposomes, microneedles, and chemical modifications of drug molecules to improve their bioavailability and tissue penetration.