A process for preparing a crystalline rapamycin analog includes: combining the rapamycin analog with an organic medium to form a mixture incubating the mixture until the rapamycin analog crystallizes and recovering the crystalline rapamycin analog. The organic medium can be a solvent, and the process can include causing the rapamycin analog to dissolve into the solvent, and incubating the solvent until the rapamycin analog crystallizes. The following can also be performed: forming a slurry of crystalline rapamycin analog stirring the rapamycin analog mixture until the rapamycin analog crystallizes saturating the rapamycin analog solution forming a supersaturated rapamycin analog solution combining an antisolvent with the rapamycin analog and the solvent to form a biphasic mixture, and incubating the biphasic mixture to cause a liquid-liquid phase split.
