Prodrug Approach: An Alternative to Improve Pharmacokinetic Properties

Prodrugs are the masked forms of active drugs that are designed to be activated once they have been administered into the body by an enzymatic or chemical means. It is a well known molecular modification strategy that aims to optimize the physicochemical and pharmacological properties of drugs to improve their undesirable pharmacokinetic properties and decrease their toxicity. In most of the cases, prodrugs design involves the introduction of carrier/promoiety by a metabolic liable linkage so that after biotransformation by one or two chemical or enzymatic steps it will lead to the active parent drug. However, some prodrugs lack an obvious promoiety but instead result from a molecular modification of the prodrug itself, which generates a new active compound. This review introduces in depth the rationale behind the use of the promoiety, and also considers the possible problems that can arise from inadequate activation of prodrugs