Biomedical Engineering Reference
In-Depth Information
Fig. 3
Niosomal drug
delivery system
variation in purity in their manufacturing with phospholipids as compared to
liposomes (Fang et al.
2001
). Niosomes are promising vehicles for drug delivery
because they are nonionic, resulting in less toxicity, and they are more specific
(Alam et al.
2009
). The hydrophilic core of the molecule provides an ideal domain
for hydrophilic drugs. In addition, lipophilic compounds can incorporate into their
hydrophobic domain (Fig.
3
). In addition, modification of niosomes can direct them
to specific targets. Niosomal systems can target antibiotics to the surface of
bacterial biofilms. Based on the vesicle size, niosomes can be divided into three
groups. These are small unilamellar vesicles (SUV, size
μ
¼
0.025-0.05
m),
μ
multilamellar vesicles (MLV, size
¼ >
0.05
m), and large unilamellar vesicles
(LUV, size
m).
Opinions about the usefulness of niosomes in the delivery of drugs vary
depending on the use, e.g., encapsulating toxic drugs such as anti-AIDS drugs,
anticancer drugs, antiviral drugs, and antimicrobial drugs. However, they do pro-
vide a promising carrier system in comparison with ionic drug carriers, which are
relatively toxic. However, the technology utilized in niosomes is still in its infancy.
Hence, future research is required to develop an appropriate technology for large
production (Kazi et al.
2010
).
0.10
μ
¼ >
3 Polymer-Based Drug Delivery Systems
Polymer-based drug delivery systems consist of hydrophilic and hydrophobic
regions. The hydrophobic part forms a polymeric core containing the drugs, while
the hydrophilic segment protects the core from degradation. A variety of biode-
gradable polymers have been used to form the hydrophobic polymeric core, includ-
ing poly(lactic acid) (PLA), poly(glycolic acid) (PGA), poly(lactide-co-glycolide)
(PLGA), poly(carprolactone) (PCL), and poly(cyanoacrylate) (PCA), whereas
polyethylene glycol (PEG) has been commonly used for the hydrophilic segment.
Polymer-based drug delivery systems possess several unique characteristics for
antimicrobial drug delivery. They are structurally stable and can be synthesized
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