Immediate release three-layered chewing gum tablets of fenoprofen calcium: preparation, optimization and bioavailability studies in healthy human volunteers

A three-layered gum tablet (1800 mg), containing 200 mg of Fenoprofen Calcium (Fn) with an inner core containing the drug, and two external layers containing antiadherent lubricant, has been prepared using direct compression. A 23 factorial plan has been designed to evaluate the effect of formulation variables namely, Pharmagum (R) M concentration, Maltodextrin type, and Co-adjuvant type on the release characteristics of Fn from the prepared tablets. The formula consisting of 65% Pharmagum (R) M, 75% Maltodextrin DE 39 and 5% Talc comparatively exhibited the highest release (66.59% +/- 2.39) in the mouth after 5 min of chewing. Binary and ternary beta-cyclodextrin (beta-CD) complexation was adopted to enhance the release of Fn from the selected gum tablet. The highest significant release (p < 0.05) was achieved from the lyophilized ternary complex containing 100 mg of Fn in presence of polyvinylpyrrolidone (PVP K-25), exhibiting a release of 88.25% +/- 0.93 after 5 min of chewing. The relative bioavailability of the selected gum tablet was found to be 166.06% compared to Nalfon (R) 200 mg capsules. Reduction of the dose to 100 mg exhibited faster absorption rate than Nalfon (R) capsules. The obtained results suggest the possibility of reducing the dose of Fn in chewing gum.