A method of preparing a pharmaceutical composition comprising the steps of: (a-1) wet granulating at least one active ingredient that is a compound of formula: or a pharmaceutically acceptable salt thereof, wherein: R a is selected from the group consisting of C 1-3 aliphatic, C 1-3 fluoroaliphatic, -R 1, -T-R 1, -R 2, and -T-R 2; T is a C 1-3 alkylene chain optionally substituted with fluoro; R 1 is an optionally substituted aryl, heteroaryl, or heterocyclyl group; R 2 is selected from the group consisting of halo, -C≡C-R 3, -CH=CH-R 3, -N(R 4) 2, and -OR 5; R 3 is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; each R 4 independently is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; or two R 4 on the same nitrogen atom, taken together with the nitrogen atom form an optionally substituted 5- to 6-membered heteroaryl or 4- to 8-membered heterocyclyl ring having, in addition to the nitrogen atom, 0-2 ring heteroatoms selected from N, O, and S; R 5 is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; R b is selected from the group consisting of fluoro, chloro, -CH 3, -CF 3, -OH, -OCH 3, -OCF 3, -OCH 2 CH 3, and -OCH 2 CF 3; and optionally one or more pharmaceutically acceptable excipients independently selected from the group consisting of surfactants, binders, and disintegrants in the presence of a suitable solvent to form a wet mixture; (a-2) drying the wet mixture from step (a-1), to form dried granules; (a-3) milling the dried granules from step (a-2), to form milled granules; and (a-4) blending the milled granules from step (a-3) with a buffer and optionally one or more pharmaceutically acceptable excipients independently selected from the group consisting of surfactants, binders, disintegrants, lubricants and glidants; wherein a filler is added during step (a-1), during step (a-4), or during both steps (a-1) and (a-4). (a-1) wet granulating at least one active ingredient that is a compound of formula: or a pharmaceutically acceptable salt thereof, wherein: R a is selected from the group consisting of C 1-3 aliphatic, C 1-3 fluoroaliphatic, -R 1, -T-R 1, -R 2, and -T-R 2; T is a C 1-3 alkylene chain optionally substituted with fluoro; R 1 is an optionally substituted aryl, heteroaryl, or heterocyclyl group; R 2 is selected from the group consisting of halo, -C≡C-R 3, -CH=CH-R 3, -N(R 4) 2, and -OR 5; R 3 is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; each R 4 independently is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; or two R 4 on the same nitrogen atom, taken together with the nitrogen atom form an optionally substituted 5- to 6-membered heteroaryl or 4- to 8-membered heterocyclyl ring having, in addition to the nitrogen atom, 0-2 ring heteroatoms selected from N, O, and S; R 5 is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; R b is selected from the group consisting of fluoro, chloro, -CH 3, -CF 3, -OH, -OCH 3, -OCF 3, -OCH 2 CH 3, and -OCH 2 CF 3; and optionally one or more pharmaceutically acceptable excipients independently selected from the group consisting of surfactants, binders, and disintegrants in the presence of a suitable solvent to form a wet mixture; and -T-R 2; T is a C 1-3 alkylene chain optionally substituted with fluoro; R 1 is an optionally substituted aryl, heteroaryl, or heterocyclyl group; R 2 is selected from the group consisting of halo, -C≡C-R 3, -CH=CH-R 3, -N(R 4) 2, and -OR 5; R 3 is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; each R 4 independently is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; or two R 4 on the same nitrogen atom, taken together with the nitrogen atom form an optionally substituted 5- to 6-membered heteroaryl or 4- to 8-membered heterocyclyl ring having, in addition to the nitrogen atom, 0-2 ring heteroatoms selected from N, O, and S; R 5 is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, or heterocyclyl group; R b is selected from the group consisting of fluoro, chloro, -CH 3, -CF 3, -OH, -OCH 3, -OCF 3, -OCH 2 CH 3, and -OCH 2 CF 3; (a-2) drying the wet mixture from step (a-1), to form dried granules; (a-3) milling the dried granules from step (a-2), to form milled granules; and (a-4) blending the milled granules from step (a-3) with a buffer and optionally one or more pharmaceutically acceptable excipients independently selected from the group consisting of surfactants, binders, disintegrants, lubricants and glidants;