Biomedical Engineering Reference
In-Depth Information
could.be.due.to.an.increase.in.the.meloxicam.contents.of.the.polymer.providing.a.reduc-
tion.of.the.relative. amount.of.polymer.as.a.diffusion. barrier,. resulting.in.an.increase.of.
meloxicam.release.
59
23.3.1.3 Antibiotic Drugs
Kenawy. et. al.
60
. prepared. electrospun. iber. mats. from. either. poly(lactic. acid). (PLA). or.
poly(ethylene-co-vinyl-acetate).(PEVA),.with.a.blend.ratio.of.50:50,.as.carriers.for.delivery.
of.tetracycline.hydrochloride..The.release.characteristics.from.the.electrospun.iber.mats.
were. compared. to. a. commercially. available. drug. delivery. system. (Actisite
®
),. as. well. as.
to.the.corresponding.cast.ilms..Drug.release.from.the.PEVA.iber.mats.showed.a.higher.
release.rate.than.that.from.the.50/50.PLA/PEVA.and.pure.PLA.iber.mats..Moreover,.the.
PEVA. and. 50/50. PLA/PEVA. iber. mats. exhibited. relatively. smooth. release. of. the. drug.
over.about.5.days,.and.also.had.a.release.rate.similar.to.that.of.Actisite..Hence,.the.melt.
processing. of. Actisite. could. be. avoided. by. using. electrospining,. which. is. important. for.
heat-sensitive.drugs..In.addition,.the.PLA.iber.mats.exhibited.some.instantaneous.release.
of.drug.due.to.the.partial.crystallinity.of.PLA,.which.limits.the.diffusion.of.water.into.the.
polymer.matrix.and.diffusion.of.the.drug.from.the.polymer.matrix.
60
Zong. et. al.
61
. fabricated. electrospun. biodegradable. amorphous. poly(D,L-lactide).
(PDLA).and.semicrystalline.poly(L-lactic.acid).(PLLA).fiber.mats.for.biomedical.appli-
cation.. They. investigated. the. effect. of. various. parameters. in. electrospinning. on. the.
structure.of.these.fiber.mats..They.also.used.an.antibiotic.drug.(Mefoxin
®
).incorpo-
rated.in.these.fiber.mats.to.study.release.behaviors..The.results.showed.that.the.effect.
of.Mefoxin.on.the.obtained.fiber.was.a.uniform.structure.with.an.average.diameter.
of. 160. nm.. The. burst. release. of. Mefoxin. was. observed. within. 3. h,. which. is. an. ideal.
drug.release.profile.for.the.prevention.of.post-operation-induced.adhesion,.since.most.
infections.occur.in.the.first.few.hours.after.surgery.
61
.In.2008,.Thakur.et.al.
62
.fabricated.
dual.drug.release.PLLA.fiber.mats.containing.lidocaine.hydrochloride.(an.anesthetic.
drug). and. mupirocin. (an. antibiotic. drug). by. using. dual. spinneret. electrospinning..
Lidocaine.hydrochloride-loaded.PLLA.electrospun.fiber.mats.showed.an.initial.burst.
release.followed.by.a.plateau.after.the.first.few.hours,.whereas.mupirocin.exhibited.
only. 5%. release. in. the. first. hour. followed. by. a. sustained. release. for. over. 72. h.. The.
dual.spinneret.electrospinning.process.was.able.to.achieve.the.required.dual.release.
profiles.used.in.wound.dressing.applications.by.allowing.lidocaine.chloride.to.crys-
tallize.in.other.PLLA.fibers.and.maintaining.mupirocin.in.the.noncrystallized.form.
within.the.PLLA.fibers.
Highly.water-insoluble.drugs.such.as.itraconazole.and.ketanserin.were.used.to.incor-
porate.polyurethane.(PU).iber.mats.into.a.segment.for.use.in.topical.drug.administration.
and. wound. healing.
63
. The. release. behaviors. of. PU. iber. mats. containing. either. itracon-
azole.(i.e.,.10.or.40.wt%).or.ketanserin.(i.e.,.10.wt/%).were.investigated..The.results.showed.
that.both.poorly.water-soluble.itraconazole.and.ketanserin.were.released.from.the.water-
insoluble.PU.iber.mats.into.aqueous.solutions..Moreover,.ketanserin.was.released.more.
rapidly.from.the.PU.iber.mats.within.the.irst.4.h.than.itraconazole..The.burst.release.of.
ketanserin.could.be.due.to.several.factors,.including.higher.drug.solubility.in.the.polymer.
and.increased.drug.diffusivity.in.the.polymer..In.addition,.the.imperfection.on.the.iber.
of.ketanserin.resulted.in.the.formation.of.aggregate.on.the.iber.surface,.which.might.dis-
solve.more.rapidly.than.the.drug,.which.is.embedded.in.the.iber.
63
.The.antibiotic.drug.
cefoxitin.sodium.(Mefoxin),.a.hydrophilic.drug.used.for.the.prevention.of.infection.after.
surgery,. was. used. in. electrospun. poly(lactide-co-glycolide). (PLGA)-based. iber. mats.
30
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