challenges

Prodrugs are unique due to special features in contrast to drugs. The primary goal of prodrug design is to conceal harmful drug features, such as low solubility in water or lipid membranes, low target selectivity, chemical instability, undesirable taste, irritation or pain after local administration, presystemic metabolism and toxicity. The prodrug approach emphasizes on the improvements accomplished by developing the prodrug as compared to the free or parent drug. By determining market exclusivity, assessing viability and finding an optimum development pathway such as that offered by the 505(b)(2) process, developers may find that prodrugs present an ideal alternative to new drug development. There is no guidance on the acceptable development path for prodrugs. A clear understanding of what the classification means in terms of the studies required to support clinical development is needed.