| Summary: | 碩士 === 嘉南藥理科技大學 === 生物科技系暨研究所 === 91 === This study described the preparation and characterization of hydrogel
nanoparticles containing the neurochemical messenger norepinephrine (NE). NE
as a model drug was encapsulated in hydrogel nanospheres using homogenizer.
The size of the NE-hydrogel nanoparticles was evaluated by using Zetasizer
3000HS particle size analyzer. The rheological properties of ointments
including NE-hydrogel nanoparticles were characterized by Cone and Plate
Viscometer. All drug-polymer interactions and the skins were assessed by
Differential Scanning Calorimetry (DSC). For these nanoparticles, drug
loading, in vitro release of drug from the nanoparticles, drug concentration
after transdermal absorption , cumulative amount of drug in skin and long-term
stability determination were quantified by high performance liquid
chromatography (HPLC). The results revealed that particle size, encapsulation
efficiency, in vitro release and transdermal absorption properties of the
nanoparticles were affected by various hydrogels, preparative processes,
surfactants and drug concentrations. The measured particle size distribution
was ranged from 40nm to 500nm. The time-depentent behavior of ointments
including NE-hydrogel nanoparticles was mentioned to as 〝Dilatant〞 flow and
showed a shear-thickening liquid. In regard to the long-term stability, the
results suggested that the product containing NE nanoparticles ought to be
stored in the condition of lyophilized powder at lower temperature and
recovered by adding double deionized water before used. The DSC determinations
indicated that the physical and chemical interaction did not occur among the
components during manufacturing process and reconstituted lyophilized powders.
The encapsulation efficiency of NE in hydrogel nanoparticles was reached to 81.
32%. On the basis of in vitro release study, it revealed that NE was
encapsulated in the hydrogel matrix, following the initial burst release of
30% to 40%, the release was sustained over the 24-hours study period. For in
vitro transdermal absorption study, the skins were treated as well as the
ointments were added with and without different concentrations (0.5% and 1%)
of various surfactants (benzalkonium chloride, sodium lauryl sulfate and tween
80), the experimental results revealed that the rapid permeability was
correlated with surfactants and drug concentration, the skin barrier property
was significantly compromised with benzalkonium chloride and sodium lauryl
sulfate treatment, tween 80 had a lesser effect on skin barrier property
compared to benzalkonium chloride and sodium lauryl sulfate ( 1% > 0.5%,
benzalkonium chloride > sodium lauryl sulfate > tween 80).
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