In Vivo Drug Release Profiles

Micelles introduced into the circulation are exposed to a vast array of proteins, blood cells, and other blood components. A high affinity between the drug and major blood components commonly results in an acceleration of drug release from the micelles in vivo that, in turn, leads to a rapid elimination of the drug from the body (Figure 17.6c).16 Studies have shown that the in vivo release profile of drug from micelles is largely determined by the compatibility between the drug and the core-forming block as well as the affinity between the drug and plasma proteins.36,120,146,147 Ramaswamy et al. investigated the distribution of paclitaxel in vitro in human plasma samples following incubation of free drug or drug incorporated in PEG-b-PDLLA micelles with the plasma. In this study, similar plasma distribution profiles were obtained following incubation of free and micelle-formulated paclitaxel with lipoprotein deficient and lipoprotein rich fractions. 7 In this way, this study clearly illustrates the extent to which the in vivo retention of drugs in colloidal carriers may be determined by the drugs' affinity for plasma components. Therefore, the microenvironment within the delivery system must have the capability to compete with the various plasma components in order to achieve prolonged drug retention within the micelles in vivo.

Diabetes Sustenance

Diabetes Sustenance

Get All The Support And Guidance You Need To Be A Success At Dealing With Diabetes The Healthy Way. This Book Is One Of The Most Valuable Resources In The World When It Comes To Learning How Nutritional Supplements Can Control Sugar Levels.

Get My Free Ebook


Post a comment