The objective of the present study is to develop etoricoxib rapidly dissolving tablet formulations by wet granulation and direct compression methods employing starch phosphate, a new modified starch. As per FDA guidelines on biowaivers, drug products containing weakly acidic BCS class II drugs with a dissolution of > 85% in 30 min are eligible for biowaiver. Hence a dissolution of > 85% in 30 min is taken as target dissolution to achieve in the formulation development of etoricoxib tablets. Starch phosphate prepared by reacting starch with di-sodium hydrogen orthophosphate anhydrous at elevated temperatures was insoluble in water and has good swelling (400%) property without pasting or gelling when heated in water. In the micromeritic evaluation, the angle of repose and compressibility index values revealed the excellent flow characteristic of starch phosphate prepared. All the physical properties studied indicated that starch phosphate is a promising pharmaceutical excipient in tablets. FTIR study indicated no drug-excipient interaction between starch phosphate and the drugs studied. Etoricoxib rapidly dissolving tablets with >85% dissolution in 30 min could be formulated employing starch phosphate as directly compressible vehicle by direct compression method (BF3) and also employing etoricoxib-starch phosphate (1:2) solid dispersion by wet granulation method (BF4). Formulations BF3 and BF4 respectively gave 87.59% and 95.14% dissolution in 30 min fulfilling the target dissolution requirement for biowaiver.
