Small molecule therapeutic-loaded liposomes as therapeutic carriers: from development to clinical applications

While small hydrophilic therapeutic molecules have proved to be exceptionally effective in curing diseases, their in vivo efficacy remains low. Small molecule therapeutics infused in vivo result in uncontrolled bio-distribution that causes dilution and unwanted side effects. Therefore, global research to search for ideal carriers for small molecule therapeutics has gained attention seeking to increase efficiency of targeting desired cells. Liposomes are one class of nanocarriers that could encapsulate both hydrophilic and lipophilic small molecule therapeutics, protect them against physiological degradation and deliver them into targeted cells. In this review, studies done from the past up to the present are summarized, and various methods and mechanisms for encapsulation of small therapeutic molecules in liposomes for targeted delivery and triggered release, as well as their potential in the clinical uses, will be discussed.