Spectroscopic and computational insights into theophylline/β-cyclodextrin complexation: inclusion accomplished by diverse methods

The dissolution of p-methoxycinnamic acid-β-cyclodextrin inclusion complex produced with microwave irradiation

Background: p-methoxycinnamic acid (pMCA) is an ethyl p-methoxycinnamic derivative, which is the largest active ingredient in the rhizome of the kencur (Kaempferia galanga L) plant. Several studies reported that the compound has anti-inflammatory activity but has low solubility in water. The formation of a pMCA-β-cyclodextrin (βCD) inclusion complex with a molar ratio of 1:1 can increase its solubility. The formation of inclusion complexes with conventional methods requires a long time and the yield value is not optimal. Objective: This study aims to evaluate the dissolution of the pMCA-βCD inclusion complex produced using the microwave irradiation method. Methods: The product was manufactured with chloroform solvent and a power of 400 watts (power 80%). It was then evaluated using the Differential Thermal Analysis (DTA) every 2 minutes until the 8th minute. The reaction was complete after 4 minutes of treatment with a yield of 96.5%. The obtained inclusion complexes were evaluated using DTA, FTIR, and PXRD. Subsequently, a dissolution test was carried out using a type 2 apparatus in distilled water medium of pH 6.8±0.05 at 37±0.5°C. Results: The results showed that there was a change in the melting temperature profile, infrared spectra, and crystallinity of the product. An 89.18% dissolution was also obtained within 60 minutes, which was twice that of pMCA compounds. Conclusion: From the results of the study, it can be concluded that the formation of pMCA-βCD inclusion complexes using the microwave irradiation method is capable of providing high-yield values in a short time.

Application of molecular docking in elaborating molecular mechanisms and interactions of supramolecular cyclodextrin

The cyclodextrin (CD)-based supramolecular nanomedicines have attracted growing interest because of their superior characteristics, including desirable biocompatibility, low toxicity, unique molecular structure and easy functionalization. The smart structures of CD impart host-guest interaction for meeting the multifunctional needs of disease therapy. However, it faces challenges in formulation design and inclusion mechanism clarification of the functional supramolecular assemblies owing to the complicated structures and mechanisms. Fortunately, molecular docking helps the researchers to comprehend the interaction between the drug and the target molecule for achieving high-through screening from the database. In this review, we summarized the category and characteristics of molecular docking along with the properties and applications of CD. Significantly, we highlighted the application of molecular docking in elaborating molecular mechanisms and simulating complex structures at molecular levels. The issues and development of CD and molecular docking were also presented to provide beneficial reference and new insights for supramolecular nano-systems.

Application of Molecular Dynamics Simulations in the Analysis of Cyclodextrin Complexes

Cyclodextrins (CDs) are highly respected for their ability to form inclusion complexes via host-guest noncovalent interactions and, thus, ensofance other molecular properties. Various molecular modeling methods have found their applications in the analysis of those complexes. However, as showed in this review, molecular dynamics (MD) simulations could provide the information unobtainable by any other means. It is therefore not surprising that published works on MD simulations used in this field have rapidly increased since the early 2010s. This review provides an overview of the successful applications of MD simulations in the studies on CD complexes. Information that is crucial for MD simulations, such as application of force fields, the length of the simulation, or solvent treatment method, are thoroughly discussed. Therefore, this work can serve as a guide to properly set up such calculations and analyze their results.