Dimeric drug depot forms for photo-induced drug release

摘要

Photochemically controlled drug release systems require quite special linker systems for the photocleavable attachment of a drug to a polymer backbone. Such linkers must be photochemically cleavable exactly at that point where a detachment of the drug molecule is possible without any added chemical groups in order not to influence its therapeutic properties. The need for such special linker systems is a bottleneck. The photochemical cleavage of chemical bonds requires energies in the UV and may be accomplished either by single-photon or two-photon absorption. We found that dimers of drugs like 5-fuorouracil (5-FU) show significant changes in their physico-chemical properties like solubility in polymer matrices compared to their monomers. Due to this differences they may be used as drug depot forms without the need of any linker system at all. Upon photochemical cleavage of the dimer, either by single-photon or two-photon absorption, the active monomer form of the drug is released without any residual groups attached. Synthesis, chemical and photochemical characterization of dimeric 5-FU is reported and potential applications in polymer systems for medical applications are outlined.