Vigorous agitation generates shear forces and an air-liquid interface that promote peptide aggregation, and it produces foam that traps material away from the solution
Zhang Q., Yan L., Lu J., Zhou X
BASIC INFORMATION ON CARNITINE L-Carnitine is a conditionally essential amino acid found predominantly (95%) in skeletal muscle and synthesized endogenously in the body from amino acids lysine and methionine
The other crucial modification that increases its stability is substituting the eighth residue , an alanine, with amino-isobutyric acid (AIB) which has an additional methyl group making the alpha carbon quaternary
Vrang N, Larsen PJ
Because native GLP-1 is highly susceptible to degradation by Dipeptidyl-Peptidase IV (DPP-4), which is abundantly expressed in the endothelium of capillaries adjacent to the L-cells 16, 17 , two types of GLP-1-based drugs are developed