REVIEW ARTICLE Drug delivery approaches of an antiviral drug: A comprehensive review

The guanine derivative antiviral drug acyclovir (ACV) is one of the oldest molecules laying successful market until date, being commercially available in various dosage forms for oral, topical and parenteral administrations. Clinical application of this drug is superior to new antiviral agents due to its potential values such as suppression of recurrence, safety profile, minimal drug interactions, and being inexpensive. ACV is slightly water‐soluble, less permeable and poorly bioavailable, yet more potential antiviral molecule, the physicochemical modifications and novel dosage form approaches resulted with more than 100 research works within a decade. The survey of literature showed enormous reports on ACV formulation development, which includes modified tablets, particulate drug delivery, vesicular drug delivery, polymeric nanoparticles, bioadhesive systems, floating dosage forms, in situ gelling systems, transdermal delivery, implantable systems, emulsified dosage forms, polymeric films/patches, etc. As the drug could be administered via multiple routes for effective site targeted action at various doses, and attracted the attention of many researches, the review of the current approaches for the delivery of ACV could be more beneficial for the new scientists. This paper is a review of recent researches highlighting the development of newer techniques and novel dosage forms of ACV for better therapeutic efficacy, which were aimed at enhancing its solubility, permeability and bioavailability. Key words: Acyclovir, bioadhesive, complexation, floating, hydrogel, implant, particulate, vesicular