In the early 2000s, a method for cross-linking cyclodextrins (CDs) with citric acid (CTR) was developed. This method was nontoxic, environmentally friendly, and inexpensive compared to the others previously proposed in the literature. Since then, the CD/CTR biopolymers have been widely used as a coating on implants and other materials for biomedical applications. The present review aims to cover the chemical properties of CDs, the synthesis routes of CD/CTR, and their applications as drug-delivery systems when coated on different substrates. Likewise, the molecules released and other pharmaceutical aspects involved are addressed. Moreover, the different methods of pretreatment applied on the substrates before the in situ polymerization of CD/CTR are also reviewed as a key element in the final functionality. This process is not trivial because it depends on the surface chemistry, geometry, and physical properties of the material to be coated.
Karen Escobar, Karla A Garrido-Miranda, Ruth Pulido, Nelson Naveas, Miguel Manso-Silván, Jacobo Hernandez-Montelongo (2023) Coatings of Cyclodextrin/Citric-Acid Biopolymer as Drug Delivery Systems: A Review. Pharmaceutics 15(1):296. doi: 10.3390/pharmaceutics15010296.