-cyclodextrin is hydrophobic, making it favorable for the encapsulation of hydrophobic drug molecules with suitable shapes and sizes. Due to the enhanced hydrophilicity of -cyclodextrin, the solubility of poorly soluble drugs in water is increased. This, in turn, significantly improves the dissolution rate and bioavailability of the formulated drugs. Danshensu is a lipophilic quinone compound extracted from Salvia miltiorrhiza, exhibiting strong antimicrobial and antiviral activities. However, its poor solubility in water and low absorption have limited its efficacy and clinical application. Studies by Zhang Zhe and others involved the formation of -cyclodextrin
Enhancing drug stability: -Cyclodextrin inclusion complexes can be viewed as molecular capsules, isolating drug molecules within the cavity of cyclodextrins. This isolation helps prevent hydrolysis, oxidation, isomerization, and polymerization of drug molecules, thereby protecting them from interactions with surrounding molecules and improving their stability. For instance, Leonurine is an active ingredient in traditional Chinese medicine Leonurus heterophyllus, exhibiting various biological activities such as antibacterial, antiviral, and anti-inflammatory effects. Due to its instability, efforts by Hou Xiaolin and others involved preparing leonurine hydroxypropyl- -cyclodextrin inclusion complexes, leading to a significant improvement in leonurine's stability.
Masking the unpleasant odor of drugs, facilitating intake: After being encapsulated by -cyclodextrin, Chinese herbal medicines with bitter or pungent tastes can have their undesirable flavors masked, improving palatability. Acorus oil, with strong antiviral activity against pseudorabies virus in pigs and Newcastle disease virus in chickens, is insoluble in water, bitter in taste, and poorly absorbed. Yang Chu and colleagues prepared Acorus oil -cyclodextrin inclusion complexes, not only masking the odor and taste but also rendering the complex soluble in water. Stability experiments under high temperature, high humidity, and intense light showed improved formulation stability. The inclusion complex not only exhibited high bioavailability but also demonstrated a certain sustained-release effect.
