137 research outputs found
Vitamin D3-loaded electrospun cellulose acetate/polycaprolactone nanofibers: Characterization, in-vitro drug release and cytotoxicity studies
Vitamin D deficiency is nowa global health problem; despite several drug delivery systems for carrying vitaminD
due to low bioavailability and loss bioactivity. Developing a new drug delivery system to deliver vitamin D3 is a
strong incentive in the current study. Hence, an implantable drug delivery system (IDDS) was developed from
the electrospun cellulose acetate (CA) and Δ-polycaprolactone (PCL) nanofibrous membrane, in which the core
of implants consists of vitamin D3-loaded CA nanofiber (CAVD) and enclosed in a thin layer of the PCL membrane
(CAVD/PCL). CA nanofibrousmat loadedwith vitaminD3 at the concentrations of 6, 12, and 20% (w/w) of vitamin
D3 were produced using electrospinning. The smooth and bead-free fibers with diameters ranged from 324 to
428 nm were obtained. The fiber diameters increased with an increase in vitamin D3 content. The controlled
drug release profile was observed over 30-days, which fit with the zero-order model (R2 > 0.96) in the first
stage. The mechanical properties of IDDS were improved. Young's modulus and tensile strength of CAVD/PCL
(dry) were161 ± 14 and 13.07 ± 2.5 MPa, respectively. CA and PCL nanofibers are non-cytotoxic based on the
results of the in-vitro cytotoxicity studies. This study can further broaden in-vivo study and provide a reference
for developing a new IDDS to carry vitamin D3 in the future
Amorphous formulations of indomethacin and griseofulvin prepared by electrospinning
Following an array of optimization
experiments, two series of electrospun
polyvinylpyrrolidone (PVP) fibers were prepared. One set of fibers
contained various loadings of indomethacin, known to form stable glasses,
and the other griseofulvin (a poor glass former). Drug loadings of
up to 33% w/w were achieved. Electron microscopy data showed the fibers
largely to comprise smooth and uniform cylinders, with evidence for
solvent droplets in some samples. In all cases, the drug was found
to exist in the amorphous physical state in the fibers on the basis
of X-ray diffraction and differential scanning calorimetry (DSC) measurements.
Modulated temperature DSC showed that the relationship between a formulationâs
glass transition temperature (<i>T</i><sub>g</sub>) and
the drug loading follows the GordonâTaylor equation, but not
the Fox equation. The results of GordonâTaylor analysis indicated
that the drug/polymer interactions were stronger with indomethacin.
The interactions between drug and polymer were explored in more detail
using molecular modeling simulations and again found to be stronger
with indomethacin; the presence of significant intermolecular forces
was further confirmed using IR spectroscopy. The amorphous form of
both drugs was found to be stable after storage of the fibers for
8 months in a desiccator (relative humidity <25%). Finally, the
functional performance of the fibers was studied; in all cases, the
drug-loaded fibers released their drug cargo very rapidly, offering
accelerated dissolution over the pure drug
Electro-spun hydroxyethyl cellulose nanofibers: the relationship between structure and process
Nanofibers as carrier systems for antimicrobial microemulsions. II. Release characteristics and antimicrobial activity
Potential utilization of recycled PET in comparison with liquid crystalline polymer as an additive for HDPE based composite fibers: Comparative investigation on mechanical performance of cross-ply laminates
Electrospun Cellulose Acetate Fiber Mats as Carriers for Crude Extracts From Phyllanthus Emblica Linn. Fruits
Fruit of Phyllanthus emblica Linn (PE) was extracted with methanol and then partitioned into diethyl ether, ethyl acetate, butanol, and water fractions. The diethyl ether fraction showed the highest antibacterial activity against two pathogenic bacteria including Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923). The PE extract from diethyl ether fraction was then loaded into 17%w/v cellulose acetate (CA) solution prepared in 2:1 v/v acetone/N, N-dimethylacetamide at concentrations of 1, 3, and 5% w/w (based on the weight of CA). The PE extract-loaded electrospun CA fiber mats were fabricated by electrospinning. The morphological appearance of both the neat and the PE extract-loaded electrospun CA fibers were smooth with the average diameters in a range of 335-694 nm. The amounts of water retention and release characteristics of PE extract from fiber mats in an acetate buffer (pH 5.5) were studied and compared with the corresponding cast-films fabricated by the solvent casting method. The amount of water retention of the PE extract-loaded fiber mats was about 112-205% which was higher than that of the cast films (i.e. 25-35%). The study of release characteristics of PE extract from fiber mats and films was carried out by total immersion method in an acetate buffer at 32°C for 72 h. The PE extract-loaded fiber mats exhibited greater amount of extract released than those of the cast films. The maximum amounts of PE extract released from fiber mats and films were about 40-80% and 18-23%, respectively
Effects of drug solubility, state and loading on controlled release in bicomponent electrospun fibers
Bicomponent fibers of two semi-crystalline (co)polymers, poly(É-caprolactone), and poly(oxyethylene-b-oxypropylene-b-oxyethylene), were obtained by electrospinning. Acetazolamide and timolol maleate were loaded in the fibers in different concentrations (below and above the drug solubility limit in polymer) in order to determine the effect of drug solubility in polymer, drug state, drug loading and fiber composition on fiber morphology, drug distribution and release kinetics. The high loadings fibers (with drug in crystalline form) showed higher burst and faster release than low drug content fibers, indicating the release was more sustained when the drug was encapsulated inside the fibers, in amorphous form. Moreover, timolol maleate was released faster than acetazolamide, indicating that drug solubility in polymer influences the partition of drug between polymer and elution medium, while fiber composition also controlled drug release. At low loadings, total release was not achieved (cumulative release percentages smaller than 100%), suggesting that drug remained trapped in the fibers. The modeling of release data implied a three stage release mechanism: a dissolution stage, a desorption and subsequent diffusion through water-filled pores, followed by polymer degradation control
Electrospun starch acetate nanofibers: Development, properties, and potential application in drug delivery
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