Investigation of the mucoadhesivity, swelling and drug release mechanisms of indomethacin buccal tablets: effect of formulation variables
The purpose of this study was to investigate the effect of formulation variables on properties related to critical functionality for their use in indomethacin buccal tablets. Chitosan (CH), carbopol (PAA) and hydroxypropyl methyl cellulose (HPMC) concentration and filler type were evaluated as parameters for describing tablet hardness, swelling index, indomethacin release and mucoadhesion in controlled release buccal tablets.
Moreover, a 32 full factorial design was employed to study the effect of each polymer ratios in CH and PAA combination, which significantly influenced characteristics. A slower indomethacin release and a considerably larger degree of swelling were found for different concentrations of PAA or CH (P < 0.05). The buccal tablets formed a continuous gel layer while in contact with the aqueous medium undergoing a combination of swelling and erosion. In vitro drug release in simulated saliva (pH 6.75) appears to occur both by diffusion and a swelling-controlled mechanism, exhibiting anomalous, Case II type transport or Super Case II type transport.
The diluent present in all study samples, mannitol (MAN), spray dried lactose (SDL) and microcrystalline cellulose (MC) were believed to contribute minimally to hydrogel formation and drug release regulation. The dissolution values for the three co-excipients were a decreasing order mannitol, spray dried lactose and microcrystalline cellulose. In conclusion, the type and concentration of all polymers seem to change the functionality of buccal tablets and it seems important to understand and characterize these excipients to fully predict the drug release, mucoadhesion and swelling of buccal tablets.
Article Information: Ozgur Esim, Ayhan Savaser, Cansel Kose Ozkan, Cetin Tas & Yalcın Ozkan; Drug Development and Industrial Pharmacy, 2020.