A dry, flowable and compressible composition comprising: a. a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer; b. a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer; and c. rapamycin; wherein said composition comprises rapamycin and a mixture selected from the group consisting of: i. (a) a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 3650 and a hydrophobe weight percentage of 80% and (b) a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 12,600 and a hydrophobe weight percentage of 30%, having a w/w proportion of a:b of 1: 4 or higher; ii. (a) a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 2750 and a hydrophobe weight percentage of 90% and (b) a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 12,600 and a hydrophobe weight percentage of 30%, having a w/w proportion of a:b of 1:3 or higher; iii. (a) a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 3650 and a hydrophobe weight percentage of 80% and (b) a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 7,700 and a hydrophobe weight percentage of 30%, having a w/w proportion of a:b of 1:4 or higher; and iv. (a) a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 3650 and a hydrophobe weight percentage of 80% and (b) a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 14,600 and a hydrophobe weight percentage of 20%, having a w/w proportion of a:b of 1:3 or higher. a. a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer; b. a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer; and c. rapamycin; i. (a) a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 3650 and a hydrophobe weight percentage of 80% and (b) a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 12,600 and a hydrophobe weight percentage of 30%, having a w/w proportion of a:b of 1: 4 or higher; ii. (a) a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 2750 and a hydrophobe weight percentage of 90% and (b) a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 12,600 and a hydrophobe weight percentage of 30%, having a w/w proportion of a:b of 1:3 or higher; iii. (a) a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 3650 and a hydrophobe weight percentage of 80% and (b) a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 7,700 and a hydrophobe weight percentage of 30%, having a w/w proportion of a:b of 1:4 or higher; and iv. (a) a hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 3650 and a hydrophobe weight percentage of 80% and (b) a hydrophilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer having an average molecular weight of 14,600 and a hydrophobe weight percentage of 20%, having a w/w proportion of a:b of 1:3 or higher.