مجال
التميز
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تميز دراسي و بحثي
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البحوث المنشورة
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البحث (1):
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عنوان البحث:
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Rapidly dissolving polymeric microneedles
for minimally invasive intraocular drug delivery
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رابط إلى البحث:
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Click here
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تاريخ النشر:
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05/10/2016
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موجز عن البحث:
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In this study, dissolving microneedles (MNs) were used to enhance
ocular drug delivery of macromolecules. MNs were fabricated using
polyvinylpyrrolidone (PVP) polymer of various molecular weights (MWs)
containing three model molecules of increasing MW, namely fluorescein sodium
and fluorescein isothiocyanate–dextrans (with MW of 70 k and
150 k Da). Arrays (3 × 3) of PVP MNs with conical shape
measuring about 800 μm in height with a 300 μm base diameter, containing
the model drugs, were fabricated and characterized for their fracture forces,
insertion forces (in the sclera and cornea), depth of penetration (using OCT
and confocal imaging), dissolution time and in vitro permeation. The average
drug content of the MNs (only in MN shafts) ranged from 0.96 to 9.91 μg,
and the average moisture content was below 11 %. High MW PVP produced
MNs that can withstand higher forces with minimal reduction in needle height.
PVP MNs showed rapid dissolution that ranged from 10 to 180 s, which was
dependent upon PVP’s MW. In vitro studies showed significant enhancement of
macromolecule permeation when MNs were used, across both the corneal and
scleral tissues, in comparison to topically applied aqueous solutions.
Confocal images showed that the macromolecules formed depots within the
tissues, which led to sustained permeation. However, use of MNs did not
significantly benefit the permeation of small molecules; nevertheless, MN
application has the potential for drug retention within the selected ocular
tissues unlike topical application for small molecules. The material used in
the fabrication of the MNs was found to be biocompatible with retinal cells
(i.e. ARPE-19). Overall, this study reported the design and fabrication of
minimally invasive rapidly dissolving polymeric MN arrays which were able to
deliver high MW molecules to the eye via the intrastromal or intrascleral
route. Thus, dissolving MNs have potential applications in enhancing ocular
delivery of both small and macromolecules.
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البحث ( 2):
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فصل في كتاب بعنوان:
Hydrogels: Design, Synthesis and Application
in Drug Delivery & Regenerative Medicine
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عنوان البحث:
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In-Situ Forming Phase-inversion Injectable
Hydrogels for Controlled Drug Release
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رابط إلى البحث:
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Click
here
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تاريخ النشر:
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30/11/2017
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موجز عن البحث:
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Retention
within the selected ocular tissues unlike topical application for small
molecules. The material used in the fabrication of the MNs was found to be
biocompatible with retinal cells (i.e. ARPE-19). Overall, this study reported
the design and fabrication of minimally invasive rapidly dissolving polymeric
MN arrays which were able to deliver high MW molecules to the eye via the
intrastromal or intrascleral route. Thus, dissolving MNs have potential
applications in enhancing ocular delivery of both small and macromolecules.
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المؤتمرات العلمية:
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المؤتمر (1):
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عنوان المؤتمر:
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9th
Saudi students’ Conference
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تاريخ الإنعقاد:
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13-14/02/2016
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مكان
الإنعقاد:
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Birmingham, UK
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طبيعة المشاركة:
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Poster presentation
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عنوان المشاركة:
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DISSOLVING MICRONEEDLES AS A NOVEL OCULAR DRUG
DELIVERY SYSTEM
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ملخص المشاركة:
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Polyvinylpyrrolidone
(PVP) K29/32 30% w/w gel was used to fabricate the MN arrays and PVP K90 15%
w/w gel was used to form the MN baseplates. A 3×3 MN array with conical shape
MNs measuring about 800 µm in height and 300 µm base diameter, containg the
model drug (Fluorescein sodium at 0.2% w/w) was prepared using casting
method. MN arrays were characterized in terms compression forces, dissolution
time, insertion force into the sclera and insertion depth, and tansscleral
drug permeation in comparison with topical drug solution application. In this
study scleral tissues were dissected from porcine eye that was obtained from
local slaughterhouse. Permeation studies across sclera were conducted at 37
°C using Franz-Type diffusion cells uisng PBS as a receptor solution. Either
10 µL of 0.2% Fluorescein sodium aqueous solution or MN containing
Fluorescein Sodium at the same concentraition were applied onto the scleral
tissues. 150 µL samples were collected at predetermined intervals over 24
hours and percentage drug permeation was quantified.
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المؤتمر (2):
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عنوان المؤتمر:
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7th
APS International PharmSci Conference
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تاريخ الإنعقاد:
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07/09/2016
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مكان
الإنعقاد:
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Glasgow, UK
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طبيعة المشاركة:
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Poster presentation
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عنوان المشاركة:
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Effect of Different Molecular Weights of
FITC-dextran Release from PLGA/NMP-based Injectable In Situ Forming Implants
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ملخص المشاركة:
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The focus of this study is to
investigate the effect of different molecular weights (MWs) of fluorescein
isothiocyanate–dextran (FITC-dextran) (Mw 150kDa, 70kDa, and 4kDa) on the in
vitro release and implant forming property of phase inversion-based in situ
forming implants (ISFI) that are composed of poly(lactic-co-glycolic acid)
(PLGA75/25) and N-Methyl-2-pyrrolidone (NMP). Implants were formed by
injecting 50 µL of PLGA75/25/NMP 30%w/w gel in 5 mL of PBS. In vitro
FITC-dextran release of different MWs was quantified using fluorescence
spectrophotometer. Implant morphology and outer shell thickness was studied
using scanning electron microscope (SEM). Mean thickness of the outer shell
of the implants was 819 µm ±16. In vitro FITC-dextran release study shows
high burst release followed by prolonged release of FITC-dextran of Mw
150kDa, 70kDa, and 4kDa as model drugs for greater than 21 days. Increase in
the MW of FITC-dextran caused reduction in percentage of cumulative release.
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المؤتمر (3):
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عنوان المؤتمر:
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The 39th
All Ireland Schools of Pharmacy Conference
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تاريخ الإنعقاد:
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24-25/04/2017
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مكان
الإنعقاد:
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Cork, The Republic of Ireland
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طبيعة المشاركة:
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Poster presentation
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عنوان المشاركة:
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Preparation, Characterization, and in
vitro Drug Release from a Biodegradable in situ forming Implant
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ملخص المشاركة:
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Phase
inversion ISFI consists of hydrophobic polymer dissolved in a biocompatible
organic solvent. The rate of drug release from these implants can be
attributed to a number of parameters and molecular weight of drug is one of
them. This mode of in situ implant formation has numerous benefits compared
to other types of implants that require external trigger such as change in
pH, temperature, or ionic strength. Administration by this method allows the
injection of a liquid material into the body which then solidifies to form a
depot which in turn controls the drug delivery. PLGA is a FDA-approved
biodegradable and biocompatible polymer that has been extensively used in the
fabrication of ISFI. NMP is preferred biocompatible organic solvent due to
its pharmaceutical precedence over other solvents.
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المؤتمر (4):
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عنوان المؤتمر:
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The association for research in vision and
ophthalmology annual meeting ARVO 2017
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تاريخ الإنعقاد:
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08/05/2017
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مكان
الإنعقاد:
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Baltimore, USA
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طبيعة المشاركة:
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Poster presentation
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عنوان المشاركة:
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Phase Inversion-based in situ Forming
Ocular Implants for Sustained Drug Delivery
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ملخص المشاركة:
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PI-ISFI formulations were
prepared by dissolving the required amount of different molecular weights
(MWs) of the drug in the solvent to produce a 0.5% w/w solution before the
addition of 30 % w/w of gel. PI-ISFI were formed by injecting 0.05mL of the
gel in 5 mL of phosphate buffer solution (PBS) (pH 7.4 ± 0.2), as a release
media. As a result, a solid, spherical implant was formed. Release samples
were quantified using fluorescence spectrophotometer. Implants were imaged
using scanning electron microscope (SEM) to investigate the microstructure of
the implants. Syringeability (work of syringeability (WoS), and maximum force
of expulsion (MFE)) was conducted using Texture Analyser. The required force
to inject different volumes (10, 25, and 50 µL) of PLGA75/25/NMP (30% w/w)
and different PLGA/75/25 concentrations (20%, 30%, and 40% w/w) was evaluated
using a 27 G needle. All samples were analyzed in triplicate.
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