Powder injection

Highest Inhalation aerosols Injectables Sterile powders Injection ... 

Powder injection molding (PIM) ceramics processing, 5 651 titanium, 24 857... 

The Alka/Sorb air pollution control system is designed to remove dioxin, furans, toxic metals, acid gases, and particulates from industrial and medical incinerator off-gas. The Alka/Sorb system consists of a dry treatment/wet scrubbing process during which incinerator off-gas is cooled, contacted with an alkaline powder, injected with a sorbent, filtered by a baghouse and then wet-scrubbed for final removal of trace acid gases. Two central parts of the Alka/Sorb system include a wet-acid scrubber and a patented sorbent called Diox-Blok, which prevents the formation of dioxins and furans in air emissions. 

Powder injection applies many of the principles of pulmonary delivery of dry powders to the lungs The drug has to be in the form of very small particles, is dispensed from a reservoir, and is delivered as an aerosol i.e., particles are dispersed in a gas. Liquid or dissolved drug can be delivered by precipitation or adsorption onto carrier particles. The big difference with pulmonary delivery is the momentum at which the particles are delivered. Driven by a high-pressure helium gas stream, the particles travel fast enough to penetrate the outer layer of the skin, the stratum corneum. The design of devices to deliver needle-free injection of solids was pioneered by researchers at the University of Oxford who founded PowderJect Pharmaceuticals PLC in 1993 (now PowderMed Ltd.) to develop the only powder-based technology so far. Since that... 

Figure 8.15 Histological demonstration of dermal powder injection in the pig. The stratum corneum (SC), dermis (D), and particles delivered to the epidermis (ED) are clearly shown. The particles consist of swellable, slowly soluble polysaccharide microspheres (50 pm diameter when dry). [With modifications from Hickey (2001). Reproduced with permission from Euromed Communications.]...

Figure 8.16 Cross-sectional diagram of a single-use disposable powder injection system highlighting the major components. When the actuator button is depressed, the driver gas (He) is released into the surrounding rupture chamber. At a specific pressure, the plastic membranes of the drug cassette burst and the drug particles are entrained in the gas flow, which is accelerated through the convergent-divergent nozzle. [From Hickey (2001). Reproduced with permission from Euromed Communications.]...

Device development for powder injection also may gain much more momentum with the successful market introduction and penetration of a first product, most likely a hepatitis B vaccine. Of course, this product has to compete with other dosage forms and has to prove superiority to gain acceptance and become more than a niche product. Multiple-dose devices for powder injection probably will take much longer to market. Similar to inhalation devices, such systems will require advanced features such as dose counting and logbook functions. 

Hickey, P. L. Powder injection A novel mode of drug delivery opening the way for new modes of therapy. Drug Del Syst. Sci. 1 25-29, 2001. 

Knights, M., Metal-Powder Injection Molding Moves Into Large Parts, PT, Feb. 2003. 

The debinding of powder injection molding workpieces, which consist of about 60 vol.% of a solid matrix (metal or ceramic powders) and thermoplastic polymer binders, was examined by extraction with scC02 [1]. By this technique the debinding time could be reduced from 1-2 days for pyrolysis to 1-2 hours for SFE. 

C2oHi7F2N303 HCI Antibacterial agent Oral Powder Injection (Embryonated broiler eggs, Chicken, Turkey) 91296-87-6 Aug. 1995/ Abbott Laboratories... 

Unlimited possibilities in tool design by CAD/CAM and subsequent realization by P/M techniques (near net shape production, powder injection molding, etc.)-... 

Zauner, R., Micro powder injection moulding, Microelectr. Eng. 83 (2006) 1442-1444. 

Data reported in the literature indicate that sodium compounds are considerably more reactive than calcium compounds when injected into flue gas as dry powders, although reactivities of the calcium compounds (particularly lime) are increased when they are injected via a spray dryer system. The study described in this paper was confined to dry-powder injection tests with sodium bicarbonate, nahcolite (a sodium bicarbonate mineral), and trona (a sodium carbonate/bicarbonate mineral). 

This study has confirmed that high levels of SO2 removal can be achieved via dry powder injection of NaHC03-bearing sorbents into the flue gas of coal-fired boilers. The mineral nahcolite is particularly effective. Commercially produced sodium bicarbonate is slightly less reactive than nahcolite. The mineral trona was found to be less effective, probably due to the lower bicarbonate content of this material. With all three sorbents, SO2 removal efficiencies in excess of 90 percent could be achieved, although in some cases at fairly low sorbent utilization efficiencies. 

The feed rate for powders injected into the economizer outlet for boilers firing high-sulfur oil (2% or greater S) and operating with low excess air is 165-621 lb MgO equivalent per 1000 barrels of oil. The feed rate for oil-based magnesia dispersions is 127 lb MgO equivalent per 1000 bbl of oil. Coal-fired boilers, using a high-sulfur bituminous coal, typically require... 

WjN (30) W powders injected down stream the arc (500 mesh) N, 5 6 Cold quenching tube (1/4" o.d.) below the powder feed ring 25 % conversion to WjN 261) (1960)... 

Perugini, G. Analysis of dynamic fusion phenomena of ceramic and metallic powders injected into an argon plasma jet, 3d Internat. Meet. Modem Ceramics Technologies, Rimini, Italy... 

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