Application to determine the proportion of peptide in the micelle (Chamieh et al. 2019)
The aim of this study is to quantify the free fraction of peptides in ion pair SEDDS formulations using TDA and leuprorelin and desmopressin as model peptides. The influence of the ionic strength on peptide release is also evaluated.
In the case of leuprorelin the radius decreases exponentially from about 11.9 nm to 2.8 nm at 150 mM ionic strength, suggesting the release of a large amount of peptide.
In the case of desmopressin, the radius decreases from about 4.1 nm to 0.7 nm at 150 mM ionic strength, showing a total release of the peptide.
The proportion of free peptide as a function of ionic strength could be deduced.
Desmopressin appears to be totally released from the SEDDS at physiological saline conditions (150 mM), whereas leuprorelin is released at 80%.