Current Issue : January - March Volume : 2019 Issue Number : 1 Articles : 5 Articles
Hydrogels are among the most common materials used in drug delivery, as polymeric\nmicelles are too. They, preferentially, load hydrophilic and hydrophobic drugs, respectively. In this\npaper, we thought to combine the favorable behaviors of both hydrogels and polymeric micelles with\nthe specific aim of delivering hydrophilic and hydrophobic drugs for dual delivery in combination\ntherapy, in particular for colon drug delivery. Thus, we developed a hydrogel by UV crosslinking\nof a methacrylated (MA) amphiphilic derivative from inulin (INU) (as known INU is specifically\ndegraded into the colon) and vitamin E (VITE), called INVITEMA. The methacrylated micelles\nwere physicochemically characterized and subjected to UV irradiation to form what we called the\nâ??nanogridsâ?. The INVITEMA nanogrids were characterized by DSC, SEM, TEM, water uptake and\nbeclomethasone dipropionate (BDP) release. In particular, the release of the hydrophobic drug\nwas specifically assessed to verify that it can spread along the hydrophilic portions and, therefore,\neffectively released. These systems can open new pharmaceutical applications for known hydrogels\nor micelle systems, considering that in literature only few examples are present....
In this study, dissolving polymeric microneedle (MN) patches composed of gelatin and\nsodium carboxymethyl cellulose (CMC) were used to localize insulin. Their in vitro skin insertion\ncapabilities were determined using tissue-marking dye to stain the skin after patches removal.\nScanning electron microscopy (SEM) was used to determine changes in the MNs over time, and optical\ncoherence tomography (OCT) was used to monitor their real-time penetration depth. Confocal\nmicroscopy images revealed that rhodamine 6G gradually diffuses from the puncture sites to deeper\ndermal tissue. Using an in vivo imaging system (IVIS), skin areas that received FITC-insulin-loaded\nMNs were found to present strong fluorescent signals that greatly decreased 1 h after application.\nResults show that dissolving MNs rapidly release FITC-insulin, and it then gradually diffuses into\nthe skin. This study verifies that using a gelatin/CMC MN patch for insulin delivery achieves\nsatisfactory relative bioavailability compared to a traditional hypodermic injection and can be a\npromising delivery device for poorly permeable protein drugs such as those used to treat diabetes.\nInsertion tests on human cadaveric skin demonstrate that dissolving MNs could serve as efficient\ndevices for transdermal drug delivery in clinical practice and that the volar aspect of forearm skin is\nthe ideal location for their applications....
Curcumin is a naturally occurring substance with various pharmacological activities. It has\nnot been developed as a drug because of its low bioavailability due to its low solubility and absorption.\nPiperine is a natural enhancer that is popularly used to increase the absorption of curcumin in oral\napplications; however, it has not been applied for transdermal curcumin delivery. This study aims to\ndevelop a transdermal curcumin delivery system using piperine as a skin permeation enhancer in the\nform of composite double-layer membrane; the upper layer consisted of curcumin and the lower layer\nconsisted of piperine. The amount of curcumin was fixed, but the amount of piperine varied at three\nlevels from 1.96% to 7.41%. The composite membrane had moderate mechanical strength (15â??22 MPa)\nwith a good swelling degree (~435%). From an in vitro skin permeation study, piperine had the\neffect to increase the permeation of curcumin. The permeation rate was related to the amount of\npiperine. The composite membrane containing piperine at 7.41% could increase the permeation rate of\ncurcumin by about 1.89 times compared with non-piperine contained membrane. Bacterially-derived\ncellulose containing curcumin and piperine may have the potential for transdermal curcumin delivery\nin order to improve curcuminâ??s bioavailability....
Transdermal drug administration presents several advantages and it is therefore favorable\nas an alternative drug delivery route. However, transdermal delivery of biopharmaceutical drugs is\nmade difficult by the skin barrier. Microneedle application and iontophoresis are strategies which\ncan be used to overcome this barrier. Therefore, recombinant human growth hormone (rhGH)\nwas used as a model macromolecular drug and was transdermally delivered using microneedle\napplication and iontophoresis. Methylene blue staining, stereomicroscopy and scanning electron\nmicroscope (SEM) imaging were used to characterize the microchannels produced. To optimize the\niontophoresis protocol, the effects of molecular charge and current density on transdermal delivery\nwere evaluated in an in vitro permeation study using excised rat skin tissues. Using the optimized\niontophoresis protocol, the combination effects of iontophoretic delivery via microchannels were\nevaluated in three different experimental designs. The flux obtained with anodal iontophoresis\nin citrate buffer was approximately 10-fold higher that that with cathodal iontophoresis in\nphosphate buffered saline (PBS). Flux also increased with current density in anodal iontophoresis.\nThe combination of iontophoresis and microneedle application produced higher flux than single\napplication. These results suggest that anodal iontophoresis with higher current density enhances\nthe permeation of macromolecules through microchannels created by microneedles. In conclusion,\nthe combination of iontophoresis and microneedles is a potential strategy for the enhancement of\ntransdermal delivery of macromolecular drugs....
One drawback of traditional forms of medical ocular dosage is drug dilution by tear;\nmoreover, drugs are rapidly drained away from pre-corneal cavity by tear flow and lacrimo-nasal\ndrainage. Prolonging contact time with different strategies and mucoadhesive vehicles will help to\ncontinuously deliver drugs to the eyes. For this study, we prepared and evaluated the effects of a\nnanostructure lipid carrier (NLC) on propranolol hydrochloride as a hydrophilic drug model for\nrabbit corneal permeation. Propranolol hydrochloride NLC was prepared using cold homogenization.\nThe lipid was melted, then the drug and surfactant were dispersed and stirred into the melted lipid.\nThis fused lipid phase was scattered in aqueous solution containing the cosurfactant at 4 C and\nthen homogenized. We evaluated particle size, drug loading, drug release, and NLC permeability\nthrough rabbit cornea as well as the formulaâ??s effect on the cornea. Our results show that drug\nloading efficiency depended on the surfactant/lipid ratio (S/L) and the percentages of liquid lipid\nand Transcutol (Gattefosse, Saint-Priest, France) (as solubilizer). Drug release data were evaluated\nwith the Higuchi model and a significant correlation was shown between the S/L ratio and the\namount of drug released after 4 and 48 h. NLC formulations improved propranolol hydrochloride\npermeation. We conclude that the effect of the NLC formulations was due to mucoadhesive and film\nforming properties....
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