Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 5 Articles
Solubility parameter-dependent drug releasing property is essential in practical drug\ndelivery systems (DDS), and how to combine magnetic nanoparticles(NPs) and suitable polymer\ncoating towards DDS is always a crucial and valuable challenge in biomedical application. Herein,\na controllable drug delivery model with a surface having a chemically tunable solubility parameter is\npresented using hollow magnetite/polyacrylic acid (Fe3O4/PAA) nanocomposites as nanocarrier\ntowards DDS. This composite is prepared by simply coating the modified hollow Fe3O4 with PAA.\nThe coating amount of PAA onto the surface of Fe3O4 (measured by TGA) is about 40% (w/w). Then,\nRhodamine 6G (R6G) is selected as model drug in drug delivery experiment. The efficiency of drug\nloading and drug release of these Fe3O4/PAA nanocarriers are evaluated under various temperature,\nsolvent and pH values. As a result, the best drug releasing rate was achieved as 93.0% in pH = 7.4\nPBS solution after 14 h. The releasing efficiency is 86.5% in acidic condition, while a lower releasing\nrate (30.0%) is obtained in aqueous solution, as different forms (polyacrylic acid and polyacrylate) of\nPAA present different solubility parameters, causing different salt and acid effects in various solvents,\nswelling property of PAA, and binding force between PAA and R6G. Therefore, by changing the\nsolubility parameter of coating polymers, the drug delivery properties could be effectively tuned.\nThese findings prove that the DDS based on magnetic particle cores and polymer encapsulation could\nefficiently regulate the drug delivery properties by tuning surface solubility parameter in potential\ncancer targeting and therapy....
Different from traditional solid dispersion (SD) for improving the dissolution rates of poorly water-soluble drugs, the\nupgraded 4th SD was developed to furnish a drug sustained-release profile. In this work, two different kinds of 4th SDs\nwere fabricated using two electrospinning processes. One is a ternary SD (nanofibers F2) that consisted of ethyl cellulose\n(EC), polyethylene glycol 1000 (PEG), and tamoxifen citrate (TAM) from a modified coaxial process, and the other is a\nbinary SD (nanofibers F1) which is comprised of EC and TAM from a single-fluid blending process. Scanning electronic\nmicroscopic observations demonstrated that F2 (330 �± 50 nm) showed a better quality than F1 (870 �± 230 nm) in terms of\nsize and size distribution although both of them had a smooth surface morphology and a cross section. X-ray diffraction\npatterns verified that both SDs were amorphous nanocomposites owing to the favorable secondary interactions among these\ncomponents, as suggested from the results of FTIR. In vitro dissolution experiments indicated that F2 could furnish an improved\ndrug sustained-release characteristics compared to F1, exhausting all the contained TAM and having weaker leveling-off late\nrelease. The molecular behaviors of drug sustained-release from the binary 4th SD were suggested. The protocols reported\nhere paved an alternative way for developing novel functional nanomaterials for effective delivery of poorly water-soluble\ndrugs....
Ball-milling is usually used to prepare co-amorphous drugââ?¬â??amino acid (AA) mixtures.\nIn this study, co-amorphous drugââ?¬â??AA mixtures were produced using spray-drying, a scalable\nindustrially preferred preparation method. The influence of the solvent type and solvent composition\nwas investigated. Mixtures of indomethacin (IND) and each of the three AAs arginine, histidine,\nand lysine were ball-milled and spray-dried at a 1:1 molar ratio, respectively. Spray-drying was\nperformed at different solvent ratios in (a) ethanol and water mixtures and (b) acetone and water\nmixtures. Different ratios of these solvents were chosen to study the effect of solvent mixtures on\nco-amorphous formulation. Residual crystallinity, thermal properties, salt/partial salt formation,\nand powder dissolution profiles of the INDââ?¬â??AA mixtures were investigated and compared to pure\ncrystalline and amorphous IND. It was found that using spray-drying as a preparation method,\nall INDââ?¬â??AA mixtures could be successfully converted into the respective co-amorphous forms,\nirrespective of the type of solvent used, but depending on the solvent mixture ratios. Both ball-milled\nand spray-dried co-amorphous samples showed an enhanced dissolution rate and maintained\nsupersaturation compared to the crystalline and amorphous IND itself. The spray-dried samples\nresulting in co-amorphous samples were stable for at least seven months of storage....
In the framework of Quality-by-Design (QbD), the inline determination of process\nparameters or quality attributes of a product using sufficient process analytical technology (PAT) is a\ncenter piece for the establishment of continuous processes as a standard pharmaceutical technology.\nIn this context, Twin-Screw-Extrusion (TSE) processes, such as Hot-Melt-Extrusion (HME), are one key\naspect of current research. The main benefit of this process technology is the combination of different\nunit operations. Several of these sub-processes are linked to the Residence Time Distribution (RTD)\nof the material within the apparatus. In this study a UV/Vis spectrophotometer from ColVisTec\nwas tested regarding the suitability for the inline determination of the RTD of an HME process.\nTwo different measuring positions within a co-rotating Twin-Screw-Extruder were compared to\nan offline HPLCââ?¬â??UV as reference method. The obtained results were overall in good agreement\nand therefore the inline UV/Vis spectrophotometer is suitable for the determination of the RTD in\nTSE. An influence of the measuring position on repeatability was found and has to be taken into\nconsideration for the implementation of PATs. An effect of the required amount of marker on process\nrheology is not likely due to the low Limit-of-Quantification (LoQ)....
In contrast to traditional drug administration, targeted drug delivery can prolong, localize,\ntarget and have a protected drug interaction with the diseased tissue. Drug delivery carriers,\nsuch as polymeric micelles, liposomes, dendrimers, nanotubes, and so on, are hard to scale-up,\ncostly, and have short shelf life. Here we show the novel fabrication and characterization of\nphotopatternable magnetic hollow microrobots that can potentially be utilized in microfluidics and\ndrug delivery applications. These magnetic hollowbots can be fabricated using standard ultraviolet\n(UV) lithography with low cost and easily accessible equipment, which results in them being easy to\nscale up, and inexpensive to fabricate. Contact-free actuation of freestanding magnetic hollowbots\nwere demonstrated by using an applied 900 G external magnetic field to achieve the movement\ncontrol in an aqueous environment. According to the movement clip, the average speed of the\nmagnetic hollowbots was estimated to be 1.9 mm/s...
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