Kopolimeme micele: terapijski sustav za primjenu lijeka

Professional paper - Review paper

• Author: Ivan Pepić
• Author's institution: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmaceutical technology)
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract (english)

Block copolymers are generally defined as macromolecules with linear and/or radial
arrangement of two or more different blocks of varying monomer composition. The increasing
interest in block copolymers arises mainly from their unique solution and associative
properties as a consequence of their molecular structure. ln fact when a block copolymer
is dissolved in a liquid that is a thermodynamically good solvent far one block
and a precipitant for the other, the copolymer chain may associate reversibly to form micellar
aggregates. The micelles consist of a more or less swollen core of the insoluble
blocks surrounded by a flexible corona of soluble blocks. lt can in general be assumed that
block copolymers in selective solvent fonn micelles via an association process, characterised
by a certain CMC, below which only moleculary dissolved copolymer is present in
solution, usually as unimers. Above CMC, multimolecular micelles are in equilibrium
with the unimers. Concerning the kinetics of micellization in solution, it could be show
that two relaxation processes have to be considered for block copolymer micellar systems.
All individual methods of micelle preparation can be divided into two large groups: the
direct dissolution method and the dialysis method. The method of drug incorporation
employed will depend mosdy on the method of micelle preparation used for the particular
block copolymer. The incorporated drug may lie within the micelle core, at the interface
between the micelle core and the corona or even within the corona itself. The stability
of block copolymer micelles includes two different concepts: thermodynamic stability
and kinetic stability. Micelles as drug carriers are able to provide a set of advantages: they
can solubulize poorly soluble drugs and those increase their bioavailability, they can stay
in the body (in the blood) long enough providing gradual accumulatiori. in the required
area, their size permits them to accumulate in body region with leaky vasculature, they
can be targeted by attachment of a specific ligand to the outer surface, and they can be
prepared in large quantities easily and reproducibly. Being in a micellar form, the drug is
well protected from possible inactivation under the effect of biological surroundings, it
does not provoke undesirable side effects, and its bioavailability is usually increased.

• Keywords (croatian): kopolimerne micele; oslobađanje lijeka; terapiski sustav za primjenu lijeka; blok kopolimeri
• Language: croatian
• Publication type: Professional paper - Review paper
• Publication status: Published
• Peer review: Peer review - domestic
• Publication version: Published version
• Journal title: Farmaceutski glasnik
• Numbering: vol. 61, no. 5, pp. 295-315
• p-ISSN: 0014-8202
• URN:NBN: urn:nbn:hr:163:567372
• Publication: 2005
• Type of resource: Text
• Access conditions: Open access
• Created on: 2021-02-16 14:34:31