ABSTRACT
OBJECTIVE: To investigate the preparation of sustained release drug-loaded nanofibers by using a modified coaxial electrospinning process, in which only solvent is exploited as sheath fluid. METHODS: Ethanol was used as sheath fluid and ethyl cellulose (EC) and ferulic acid (FA) were taken as filament-forming matrix and active pharmaceutical ingredient, respectively. RESULTS: Drug-loaded EC nanofibers were smoothly and continuously generated without any clogging through the coaxial process. Field-emission scanning electron microscopic observations demonstrated that the nanofibers' diameters could be manipulated through adjusting the flow rate of sheath fluid. The composite nanofibers were in essential a molecular solid dispersion of EC and FA based on the hydrogen bonding between them, as verified by XRD and FTIR results. In vitro dissolution tests showed that FA in the nanofibers had a fine sustained release profile via a typical Fickian diffusion mechanism. CONCLUSION: The modified coaxial electrospinning with solvent as sheath fluid can be a useful tool for developing novel sustained release drug delivery systems.
ABSTRACT
The improving effect of electrospun drug-loaded nanofibers on the solubility of poorly water-soluble drug was investigated in the present research. Drug-loaded nanofibers were successfully prepared using electrospinning process with helicid as the poorly water-soluble model drug and polyvinylpyrrolidone K60 (PVP K60) as the filament-forming matrix. Scanning electron microscopy observation demonstrated that the nanofibers had a three-dimensional continuous web structure, and had well smooth surface and a diameter between 400-600 nm. X-ray diffraction results suggested that helicid lost its original crystal structure but highly distributed into the nanofibers in an amorphous state, resulting from the hydrogen bonding interactions between the carboxylic group of PVP K60 and the hydroxyl groups of helicid. The drug-loaded nanofibers obviously improved helicid's solubility, and were able to completely release the whole drug in 60 s. Electrospun drug-loaded nanofibers can improve the solubility and release profiles of poorly water-soluble drug.
Subject(s)
Benzaldehydes , Chemistry , Drug Carriers , Drug Compounding , Electrochemical Techniques , Methods , Microscopy, Electron, Scanning , Nanofibers , Chemistry , Pharmaceutical Preparations , Chemistry , Povidone , Chemistry , Solubility , Spectrophotometry, Ultraviolet , X-Ray DiffractionABSTRACT
<p><b>OBJECTIVE</b>To investigate the improvement of taurine (Tau) in learning and memory ability of rats exposed to lead.</p><p><b>METHODS</b>Forty Wistar rats were randomly divided into control group: treated with distilled water; lead group: treated with lead acetate (40 mg.kg(-1).d(-1)); lead-taurine group 1, 2, 3: lead acetate (40 mg.kg(-1).d(-1)) + different concentrations of taurine (100, 400, 800 mg.kg(-1).d(-1)). The ability of learning and memory of rats were measured weekly by spatial water maze test from the 5th to 8th week. At the end of the experiment, the rats were killed, the samples of blood and brain were taken for test.</p><p><b>RESULTS</b>(1) The time of seeking anchorage of lead-Tau 800 mg group in the 6th, 7th, 8th week and that of lead-Tau 400 mg group in the 6th week were significantly lower than that of lead group (P<0.05). (2) Blood lead contents in lead-Tau 100 mg and lead-Tau 400 mg group [(510.9 +/- 57.56) microg/L, (485.40 +/- 98.85) microg/L] were different from those in lead group (P<0.05). (3) The content of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), nitric oxide synthase (NOS), acetylcholinesterase (AChE) in brain of lead-Tau 800 mg group and lead-Tau 400 mg group were also different from those in lead group (P<0.05 or P<0.01). The content of GSH and the activity of GSH-Px in lead-Tau 800 mg group were different from those in lead group (P<0.05) as well.</p><p><b>CONCLUSION</b>Taurine could improve learning and memory ability of rats exposed to lead and may play a protective role in brain.</p>