Propyl Starch Derivatives enable a Controlled and Sustained Release of Hydrophobic Drugs inDependence on the Degree of Hydrophobic Modification

摘要

Maize starch hydrophobically modified by covalentbinding of propyl chains has been used as raw material forthe preparation of novel drug delivery systems.Specifically, two starch derivatives with a degree ofsubstitution (Ds) of 1.07 (PS 1) and 1.45 (PS 1.45) wereselected to prepare the nanoparticles by an emulsiondiffusionprocess. Afterwards, nanoparticles werephysicochemically characterized showing nanometric sizeand low polydispersity. Both systems had highencapsulation efficiency (EE) for the tested drugs(Flufenamic acid, Testosterone and Caffeine),independently of the physicochemical characteristics ofthe encapsulated drug. Nevertheless, the hydrophobicinteractions drug-polymer had a clear influence on therelease profile, showing the hydrophobic drugs a close tolinear release avoiding the undesirable initial burst effect.