Cyclodextrins are macrocyclic structures mainly consisting of carbohydrate building blocks. A novel application has recently been approved for cyclodextrin called sugammadex, which acts as a scavenger for the neuromuscular agent rocuronium. Sugammadex consist of eight identical carbohydrate molecules.
The linker chain used between the carboxylate groups in sugammadex has the following advantages:
1. There is a good sense in making carbohydrate as molecular tag because more structural variations are possible for carbohydrates than other types of structure.
2. If proteins are used as drugs, they are large enough to stimulate the immune responses.
3. The current 4 atom linker chain aids in encapsulating the steroid molecule inside the cyclodextrin ring.
4. The diameter of sugammadex is 7.5 to 8.3(angstrom), which is exactly matching to the width of ruccoronium and it helps in targeting the drug.
Hence, shorter or longer chains will not help in encapsulating the steroid inside the cyclodextrin rings and thus cannot lock and drug targeting is not possible.