[2] Different methods of attaching the drug to the carrier have been implemented, including adsorption, integration into the bulk structure, encapsulation, and covalent bonding.
The addition of an amphiphilic block copolymer effectively lowers this critical micelle concentration by shifting the monomer exchange equilibrium.
[2] These carriers are comparable to liposomes, however the lack of an aqueous core makes polymeric micelles less accommodating to a wide variety of drugs.
Microspheres are hollow, micron-sized carriers often formed via self-assembly of polymeric compounds which are most often used to encapsulate the active drug for delivery.
Some of the research currently being done uses advanced assembly techniques, such as precision particle fabrication (PPF), to create microspheres capable of sustained control over drug release.