Inclusion Complexation with Randomly Methylated β-Cyclodextrin – An Opportunity to Achieve Greater Solubility of Dimenhydrinate

Dimenhydrinate is widely used as an antiemetic drug, but its low solubility leads to inadequate absorption rate, causing low bioavailability after oral administration of pharmaceutical dosage forms. Embodiment of dimenhydrinate into the internal cavity of cyclodextrin may be helpful to overcome this drawback. This work aimed to establish whether dimenhydrinate can form inclusion complex with randomly methylated β-cyclodextrin to achieve solubility enhancement and masking of bitter taste of dimenhydrinate. Phase solubility analysis was conducted to assess the stochiometric relation in assumptive inclusion complex of dimenhydrinate and randomly methylated β-cyclodextrin, evaluate their binding properties and determine the stability of the newly formed complex. Inclusion complex was made by kneading method in molar ratio 1:1. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR/FTIR) is a widely used method for detection of complex formation and complex characterization in solid state. The proof of complex formation could be changes in shape, position and intensity of the specific absorption peaks of guest and host molecules. ATR/FTIR spectra of pure drugs, their physical mixture and newly formed complex were compared to confirm inclusion complexation.