| abstract |
Methods are provided for purification of peptides and proteins by incorporation of the peptide or protein into a diketopiperazine or antagonist complexing agent to facilitate removal of one or more contaminants, i.e., unwanted components, or components. In a preferred embodiment, a peptide such as insulin, containing one or more impurities, e.g. zinc ions are trapped in diketopiperazine to form a peptide / diketopiperazine / impurity precipitate, which is then washed with a solvent to remove the impurity, which is a non-solvent of diketopiperazine. Recommendations and methods are also provided for improved transport of active agents along biological membranes, leading, for example, to a rapid increase in the concentration of the agent in the blood. The recommendations include microparticles formed by (i) the active agent, which may be charged or neutral, and (ii) a transport enhancer that covers the agent's charge and / or forms hydrogen bonds with the target biological membrane in order to facilitate it. the transfer. In a preferred embodiment, insulin is administered by pulmonary delivery of microparticles comprising fumaryl diketopiperazine and insulin in its biologically active form. The load on the insulin molecule is covered by hydrogen bonding to diketopiperazine, thereby allowing insulin to pass through the target membrane. This method |