Abstract
We investigated the effect of low-molecular-weight β-cyclodextrin (β-CyD) polymer on in vitro release of two drugs with different lipophilicities (i.e., lidocaine and ketoprofen) from mucoadhesive buccal film dosage forms. When β-CyD polymer was added to hydroxypropylcellulose (HPC) or polyvinylalcohol (PVA) film dosage forms, the release of lidocaine into artificial saliva (pH 5.7) was reduced by 40% of the control. In contrast, the release of ketoprofen from the polymer film was enhanced by addition of β-CyD polymer to the vehicle. When lidocaine and ketoprofen was incubated with β-CyD polymer in the artificial saliva, concentration of free lidocaine molecules decreased in a β-CyD polymer concentration-dependent manner. The association constant with β-CyD polymer was 6.9±0.6 and 520±90 M−1 for lidocaine and ketoprofen, respectively. Retarded release of the hydrophilic lidocaine by β-CyD polymer might be due to the decrease in thermodynamic activity by inclusion complex formation, whereas enhanced release of the lipophilic ketoprofen by the β-CyD polymer might be due to prevention of recrystallization occurring after contacting the film with aqueous solution. Thus, effects of low-molecular-weight β-CyD polymer to the drug release rate from film dosage forms would vary according to the strength of interaction with and the solubility of active ingredient.
