Prodrugs & Codrugs
A codrug, also known as a drug-drug conjugate, consists of two or more drug compounds linked to one another via a labile covalent bond. The drugs are usually selected to provide synergistic treatment of the target disease or disorder. The linker moiety typically contains a carbonyl functionality such as an ester, amide, urea, carbonate, carbamate, or thioester group and is chosen on the basis of having high enzymatic lability at physiological pH 7.4 and hence reverting back to the parent compounds in vivo. The advantages of using a codrug over the parent compounds include lower water solubility and hence better cellular absorption leading to more efficient delivery and lower toxicity. Codrugs may be administered by themselves or in the form of bioerodible or nonbioerodible sustained release drug delivery formulations. At Oak Crest, we are synthesizing a library of novel codrugs for the treatment of a wide range of infectious diseases. An important component of these efforts includes the development of new sustained release systems for targeted delivery of these substances.