Reconstitution of lyophilised peptides (revision 2)
Old revision·20:27, 23 Jun 2024·DrTitration
| Reconstitution of lyophilised peptides | |
|---|---|
| Reverses | Lyophilisation |
| Common diluents | Bacteriostatic water, Sterile water for injection |
| Consequence | Solution stability is far shorter than powder stability |
| Analytical method infobox · conventions | |
Reconstitution is the dissolution of a lyophilised peptide cake in a liquid diluent. The dried solid is the stable form: once in solution the peptide is exposed to hydrolysis, deamidation, oxidation and aggregation, all of which proceed far faster in the liquid phase.[1]
Two quantities determine the resulting concentration: the mass of peptide actually present in the vial, and the volume of diluent added. The first is not the number printed on the label unless content, water and fill mass are known — a vial nominally containing 5 mg may contain appreciably less peptide. See Underfilling.[2]
Mechanics
[edit]Diluent is directed against the vial wall rather than onto the cake. A jet striking the cake dissolves it violently, generating the air–liquid interfaces and shear at which peptides unfold and aggregate; running the liquid down the wall lets the cake dissolve from beneath.[1]
Dissolution is completed by gentle swirling or by leaving the vial to stand. Shaking is the practice most likely to produce visible haze, for the same interfacial reason. A cake that has not fully dissolved after several minutes should be given time rather than agitation.