Molecular interactions and release mechanisms of Finasteride in β-CD and Trimethyl-β-CD complexes: A computational and experimental approach

The low water solubility of Finasteride (Fin) presents a significant challenge to its effective use in patients. To address this issue, the trimethyl-β-cyclodextrin (TM-β-CD) was prepared to encapsulate Fin, improving its aqueous solubility and release, along with other physical characteristics. Additionally, an inclusion complex of β-CD with Fin was prepared to provide a comparison between both carriers. The complexes were characterized using BET, XRD, FT-IR, TGA, FE-SEM, and DLS techniques. The formation of the encapsulated drug was studied computationally through GaussView 5.0.8. The encapsulation efficiency study showed a higher yield for β-CD/Fin. Furthermore, the in vitro release study of Fin from both carriers demonstrated a sustainable cumulative release for β-CD/Fin. The kinetic study revealed a non-Fickian and case II release mechanism for TM-β-CD/Fin and β-CD/Fin. These findings suggest TM-β-CD for applications requiring improved Fin water solubility and β-CD to prolong the release process for different purposes. The data obtained from computational methods confirmed the experimental findings and provided insight into the rationale behind these phenomena. Furthermore, a simulation study suggested that Fin enters the CDs` cavities via its pyridine ring and forms hydrogen bonds with TM-β-CD.