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Drug Delivery Device (drug + delivery_device)
Selected AbstractsLocalized transmeningeal muscimol prevents neocortical seizures in rats and nonhuman primates: Therapeutic implicationsEPILEPSIA, Issue 4 2009Nandor Ludvig Summary Purpose:, To determine whether muscimol delivered epidurally or into the subarachnoid space can prevent and/or terminate acetylcholine (Ach),induced focal neocortical seizures at concentrations not affecting behavior and background electroencephalography (EEG) activity. Methods:, Rats (n = 12) and squirrel monkeys (n = 3) were chronically implanted with an epidural or subarachnoid drug delivery device, respectively, over the right frontal/parietal cortex, with adjacent EEG electrodes. Recordings were performed in behaving rats and chaired monkeys. Via the implants, either a control solution (artificial cerebrospinal fluid, ACSF) or muscimol (0.25,12.5 mm) was delivered locally as a "pretreatment," followed by the similar delivery of a seizure-inducing concentration of Ach. In five additional rats, the quantities of food-pellets consumed during epidural ACSF and muscimol (2.5 mm) exposures were measured. In a last group of four rats, muscimol (0.8,2.5 mm) was delivered epidurally during the ongoing, Ach-induced EEG seizure. Results:, In contrast to ACSF pretreatments, epidural muscimol pretreatment in rats completely prevented the seizures at and above 2.5 mm. In the monkeys, subarachnoid muscimol pretreatments at 2.5 mm completely prevented the focal-seizure,inducing effect of Ach, whereas similar deliveries of ACSF did not affect the seizures. Furthermore, 2.5 mm epidural muscimol left the eating behavior of rats intact and caused only slight changes in the EEG power spectra. Finally, muscimol delivery during Ach-induced EEG seizures terminated the seizure activity within 1,3 min. Conclusions:, The results of this study suggest that muscimol is a viable candidate for the transmeningeal pharmacotherapy of intractable focal epilepsy. [source] The cigar as a drug delivery device: youth use of bluntsADDICTION, Issue 10 2003Stephen Soldz ABSTRACT Aims, Blunts are hollowed-out cigars used to smoke marijuana (and perhaps other substances) in the United States. We investigated rates of blunt use; whether cigar use reported in surveys may actually be blunt use; the relationship of blunt to cigar use; characteristics of blunt users; brands of cigars used to make blunts; and drugs added to blunts. Design, A school-based survey of youth, the Cigar Use Reasons Evaluation (CURE). Setting, Eleven schools across Massachusetts. Participants, A total of 5016 students in grades 7,12. Measurements, CURE items assessing blunt, cigar and cigarette use, brands used to make blunts, drugs added to blunts and demographics were used. Findings, Life-time blunt use was reported by 20.0% of the sample, with use greater among high school (25.6%) than middle school (11.4%) students, and among males (23.7%) than females (16.6%). Self-reported cigar use rates were not influenced strongly by blunt use being misreported as cigar use. In a multivariate model, blunt use was associated with male gender, higher grade in school, lower GPA, truancy, lower school attachment, not living in a two-parent family, being of ,other' race/ethnicity and current use of both cigarettes and cigars. ,Phillies' was the most popular brand of cigar for making blunts, used by 59.$% of users. ,Garcia y Vega' (18.0%) was the second most popular. Twenty-eight per cent of blunt users had added drugs other than marijuana to blunts. Conclusions, The use of blunts as a drug delivery device is a serious problem. Efforts to address it will require the cooperation of the tobacco control and substance abuse prevention systems. [source] Contact lenses as a drug delivery device for epidermal growth factor in the treatment of ocular woundsCLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 2 2010Clyde L Schultz PhD Background:, This work was conducted to investigate the uptake and release of epidermal growth factor (EGF) from hydrogel contact lenses and to determine whether the released protein would be therapeutically active in a rabbit corneal epithelial defect model of ocular trauma, prior to use in humans. Methods:, The uptake and release of EGF from hydrogel contact lens materials were determined by high-pressure liquid chromatography. Contact lenses composed of vasurfilcon A or lotrafilcon A (containing silicone) were incubated in a source solution containing 0.4 ppm EGF for seven hours. To determine the kinetics of drug uptake into the contact lens matrix, drug concentration in the source solution was measured at zero, one, 60, 240 and 420 minutes. To determine the kinetics of release, loaded contact lenses were immersed in a recipient solution of phosphate-buffered saline. Therapeutic activity in vivo was investigated by placing prepared lenses on the surface of abraded corneas of New Zealand White rabbits, with abraded corneas of contralateral eyes used as controls. Control eyes were treated with contact lenses placed in saline for injection. Wound closure was assessed hourly. Results:, Uptake and release of EGF were demonstrated for vasurfilcon A but not lotrafilcon A contact lens materials. The retention time of EGF released from vasurfilcon A contact lenses was similar to control EGF not exposed to contact lens polymers. The greatest adsorption of EGF into the lens material occurred within approximately 120 minutes, with a flattening of the rate of uptake thereafter. Abraded eyes in rabbits showed a significantly higher overall healing rate for EGF-treated contact lenses compared with control eyes (p < 0.0001). Conclusions:, EGF can be delivered from some but not all hydrogel materials. Lens materials composed of silicone may not be useful for delivering EGF to the eye. EGF-treated contact lenses may be a useful device to facilitate healing of ocular wounds. [source] Development of a Controlled Release System for Risperidone Using Polypyrrole: Mechanistic StudiesELECTROANALYSIS, Issue 4 2010Darren Svirskis Abstract Polypyrrole (PPY) film has been selected as a platform material for drug delivery due to its inherent conductivity, ease of preparation and apparent biocompatibility. PPY films were prepared containing the antipsychotic drug risperidone as a model compound. Drug release profiles could be altered by applying different electrical stimulation to these films. Atomic force microscopy was used to investigate changes in PPY film thickness when different stimuli were applied. The highest levels of drug release were observed when PPY was reduced; this was accompanied by expansion of the film. Technology such as this could be utilized for implantable drug delivery devices, where the dose could be adjusted by external signaling. [source] "Supercritical Carbon Dioxide in Water" Emulsion-Templated Synthesis of Porous Calcium Alginate Hydrogels,ADVANCED MATERIALS, Issue 4 2006S. Partap Controlled-porosity alginate hydrogels are synthesized via a novel organic solvent-free method, "reactive emulsion templating", which utilizes dense-phase carbon dioxide as a reagent and as a templating agent to produce well-defined hydrogels with a narrow macropore-size distribution and high degrees of porosity and interconnectivity (see Figure). These hydrogels may find use in the biomedical field as drug delivery devices, wound dressings, or as supports for tissue engineering applications. [source] Effect of dynamic loading on solute transport in soft gels implication for drug deliveryAICHE JOURNAL, Issue 3 2008F. Urciuolo Abstract Solute transport through soft gels and tissues is intimately coupled to mechanical stress and deformation of the macromolecular network. The aim of this study was to investigate the effect of periodic mechanical stimuli upon solute transport through agarose gels at different concentrations. For this purpose it was experimentally evaluated the materials parameters that govern the coupling between elasto-dynamic and solute transport: hydraulic conductivity (K), elastic modulus (HA), and macromolecular diffusivity (Dg) along with their strain dependence behavior. Mechanical activated solute transport simulation was carried out in order to elucidate the role of amplitude and frequency of soliciting mechanical stimuli on mass kinetics release. Results show that mechanical loading affects the release of macromolecules from a gel in a frequency and strain dependent manner. These findings pave the way for novel strategies for the design and engineering of smart drug delivery devices with transport mechanisms triggered by mechanical stimuli. © 2008 American Institute of Chemical Engineers AIChE J, 2008 [source] Electrostatics of pharmaceutical inhalation aerosolsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2009Philip Chi Lip Kwok Abstract Objectives This review focuses on the key findings and developments in the rapidly expanding research area of pharmaceutical aerosol electrostatics. Key findings Data from limited in-vivo and computational studies suggest that charges may potentially affect particle deposition in the airways. Charging occurs naturally in the absence of electric fields through triboelectrification, that is contact or friction for solids and flowing or spraying for liquids. Thus, particles and droplets emitted from pulmonary drug delivery devices (dry powder inhalers, metered dose inhalers with or without spacers, and nebulisers) are inherently charged. Apparatus with various operation principles have been employed in the measurement of pharmaceutical charges. Aerosol charges are dependent on many physicochemical parameters, such as formulation composition, device construction, relative humidity and solid-state properties. In some devices, electrification has been purposefully applied to facilitate powder dispersion and liquid atomisation. Summary Currently, there are no regulatory requirements on characterising electrostatic properties of inhalation aerosols. As research in this area progresses, the new knowledge gained may become valuable for the development and regulation of inhalation aerosol products. [source] | |||||||||||||