Polymer microspheres for controlled drug release.

International journal of pharmaceutics (2004-09-01)
S Freiberg, X X Zhu

Polymer microspheres can be employed to deliver medication in a rate-controlled and sometimes targeted manner. Medication is released from a microsphere by drug leaching from the polymer or by degradation of the polymer matrix. Since the rate of drug release is controlled by these two factors, it is important to understand the physical and chemical properties of the releasing medium. This review presents the methods used in the preparation of microspheres from monomers or from linear polymers and discusses the physio-chemical properties that affect the formation, structure, and morphology of the spheres. Topics including the effects of molecular weight, blended spheres, crystallinity, drug distribution, porosity, and sphere size are discussed in relation to the characteristics of the release process. Added control over release profiles can be obtained by the employment of core-shell systems and pH-sensitive spheres; the enhancements presented by such systems are discussed through literature examples.

Product Number
Product Description

NanoFabTx materials screening kit, for synthesis of polymeric nanoparticles
NanoFabTx PEGylated nanoparticle formulation screening kit
NanoFabTx PEG-PLA drug formulation screening kit, for synthesis of PEGylated nanoparticles
NanoFabTx PLA-nano, for synthesis of 100 and 200 nm particles