Formulations and Methods of Administration of Cephalotaxines, Including Homoharringtonine

A process for producing homoharringtonine, comprising:

• a) contacting a Cephalotaxus plant with citric acid to obtain an extraction mixture;
• b) adjusting the pH of the extraction mixture of a) to between about 8 and 9 with ammonia;
• c) extracting said extraction mixture of b) with chloroform;
• d) applying reduced pressure to the extraction mixture of c) to remove said chloroform;
• e) contacting the extraction mixture of d) with a silica gel column and eluting a purified extraction product;
• f) concentrating the purified extraction product of e);
• g) drying the concentrated purified extraction product of f);
• h) contacting the dried extraction product of g) with methanol to obtain a precipitate;
• and
• i) collecting said precipitate, wherein said precipitate comprises homoharringtonine.