In vitro and in vivo evaluation of optimized sustained release Ketoprofen niosome for once daily administration

The present work aimed to use niosomes for achieving sustained release of Ketoprofen in tablet form to be administered once daily. Ketoprofen niosomes were prepared by lipid hydration and formed from mixed surfactants (Span 20 and Span 60) and cholesterol in the molar ratio 0.66:1. The prepared niosomes were characterized for entrapment efficiency and particle size. After lyophilization, 185 mg of the dried niosomes (Equivalent to 100 mg Ketoprofen) was mixed with 282.5 mg of Avicel PH 101, 2.5 mg of Cab-o-Sil (0.5%), 25 mg of Starch (5%), and 5 mg of Magnesium stearate (1%). A single dose of the tested Ketoprofen niosomal tablets was orally administered to 12 healthy volunteers and the Ketoprofen plasma levels were compared with those obtained in the same subjects after administration of one dose of the commercial Ketofan® capsules. The results showed that the mean Cmax values were 4.64 and 5.6 µg/ml and Tmax values were 2 and 4 hr for the tested tablet formulation and the reference Ketofan® capsule respectively. During a 24 h period after administration, mean Ketoprofen plasma levels never fell to 1 µg/ml with the tested Ketoprofen tablet whereas with Ketofan® capsule they sometimes fell below the therapeutic threshold during the final 4 h. The percentage of relative bioavailability (RB %) for the tested tablet formulation was found to be 123.06 %. In conclusion, the new sustained release 100 mg Ketoprofen niosomal tablet formulation can ensure therapeutic Ketoprofen plasma levels for the entire 24 h period with a constant release of Ketoprofen guaranteeing the efficacy of once-daily 100 mg Ketoprofen administration.