Aerosol delivery vaporizer

The solvent precipitation method utilizes the unique properties of nonsolvent at a critical temperature and pressure to precipitate solid particles of drugs from solutions. Carbon dioxide, which exhibits remarkable solvent power at its critical temperature of 31.1°C and pressure of 70 bar for high molecular weight and low vapor pressure solids, is an ideal nonsolvent choice. CO2 is also nontoxic, inexpensive, and readily available. The technology has been successfully applied to the production of fine particles for aerosol delivery. ... 

Metered dose inhaler has been the most popular aerosol delivery device for the treatment of respiratory diseases, which is attributable to its portability and simple operation. Although seemingly easy to use, the MDI is a sophisticated device in design. The drug(s) are suspended or dissolved in a liquefied propellant system, which may also contain excipients such as cosolvents or surfactants. The formulation is kept pressurized in a small canister, sealed with a metering valve. Upon actuation through an actuator, the valve opens and the metered dose is dispensed as an aerosol spray from the expansion and vaporization of the propellant under ambient pressure. The inhalers may be used alone or with spacer devices, the electrostatic issues of which are considered in a later section. The present discussion focuses on the inherent charging of particles produced from MDIs. 

Urine (Matusiewicz and Barnes, 1985) - NIOSH-NBS freeze dried urine is reconstituted in water. 50 nL samples are determined. Instrumentation Plasma-Therm model 5000D ICP-AES spectrometer. Instrumentation Laboratory FASTAC II pneumatic nebulizer/aerosol delivery system to deliver sample to a model IL655 furnace for graphite furnace vaporization at 2500°C. Argon plasma, 40.68 MHz, A = 231.60 nm, pyrolytically coated graphite tube with platform. Detection limit 0.9 hqIL (45 pg Ni) by peak area, 12 /peak height. Urine reference material found 1.05 mg/L (RSD 2.1%), expected 1.01 0.11 mg/L. 

Gather important information the agent used was it aerosol, liquid, gas, powder or vapor location method of delivery do you have the necessary personal protective equipment (PPE) to deal with the hazard, or have you called for assistance by a specialized team are you sure that anyone who enters a contaminated area has the proper PPE and is trained in its use be sure to establish control — keep all victims, non-victims and bystanders at the crime scene (if there is any suspicion of an attack) until it is determined who among them may be a terrorist or a witness perform decontamination, triage if necessary, isolation, quarantine, search and locate evidence, maintain chain of control, and collect samples. 

The chemical structures of the currently available inhaled anesthetics are shown in Figure 25-2. The most commonly used inhaled anesthetics are isoflurane, desflurane, and sevoflurane. These compounds are volatile liquids that are aerosolized in specialized vaporizer delivery systems. Nitrous oxide, a gas at ambient temperature and pressure, continues to be an important adjuvant to the volatile agents. However, concerns about environmental pollution and its ability to increase the incidence of postoperative nausea and vomiting (PONV) have resulted in a significant decrease in its use. 

Aerosol-assisted CVD introduces rapid evaporation of the precursor and short delivery time of vapor precursor to the reaction zone. The small diffusion distance between the reactant and intermediates leads to higher deposition rates at relatively low temperatures. Single precursors are more inclined to be used in AACVD therefore, due to good molecular mixing of precursors, the stoichiometry in the synthesis of multicomponent materials can be well controlled. In addition, AACVD can be preformed in an open atmosphere to produce thin or thick oxide films, hence its cost is low compared to sophisticated vacuum systems. CVD methods have also been modified and developed to deposit solid phase from gaseous precursors on highly porous substrates or inside porous media. The two most used deposition methods are known as electrochemical vapor deposition (EVD) and chemical vapor infiltration (CVI). 

Direct metering of liquids/solids, followed by immediate vaporization in a vessel, also can be used. For metering of liquids (either neat, or as solutions of solids), flowmeters and various dispensing pumps are available (Figs. l-2a,b and 1-3, Tables 1-1 and 1-2). The final vaporization takes place in, for instance, a hot box - a vessel containing objects held at high temperature. This process should be differentiated from aerosol CVD (see Sect. 1.3.1.5). For some compositions, direct solid feed systems have been proven as a delivery mode (Fig. 1-4, Table 1-3). 

Various alternative precursor delivery processes have been designed specifically to circumvent the low volatility and low thermal stability problems associated with (Ba(dpm)2 (see Sect. 2.4.1.2). The first method involves the dissolution of Y(dpm)j, Ba(dpm)2 and Cu(dpm)2 precursors in solvents such as butylacetate [188], THF [153, 156], toluene [189], decane [190] and supercritical carbon dioxide [191]. According to this process, termed aerosol-assisted CVD (AACVD), the multicomponent precursor solution is atomized or vaporized into a carrier gas stream or directly into the reaction chamber, with deposition occurring on a heated substrate. Some attractive features of AACVD include deposition at atmospheric pressure, the ability to use thermally sensitive precursors, and a high precursor transport rate [189]. Figure 2-30 shows a sum-... 

Because of its vapor pressure properties, phenol is present in both the particulate phase and the vapor phase of cigarette MSS aerosol. Thus, it is amenable to removal from the vapor phase by selective filtration and to reduction of its level in the particulate phase by all the technologies whereby MSS particulate phase or tar delivery is reduced, for example, filtration efficiency, air dilution (increased paper porosity, filter-tip ventilation), and inclusion of expanded tobacco in the blend. 

The vapor pressure and the design of the canister nozzle determine the aerosol jet and eventually impaction. Low vapor pressure increases drng delivery from a particular spacer due to a reduced jet and therefore rednced impaction. Airomir salbutamol pMDl containing HFA propellant delivered less drug as fine particles (MMAD < 5 pm) compared with the Ventolin salbutamol pMDI containing chloroflnorocarbon (CFC) propellant but a higher output from a spacer, probably due to a lower jet velocity (29). 

For the above agents, a particularly threatening means of delivery, on which both military offensive and protective programs and the committee s considerations have concentrated, is as vapors or aerosols designed to cause poisoning or disease as a result of inhalation. Nevertheless, it would be a mistake to assume that terrorists will not be able to use other agents, even novel ones, or other means of delivery, including contamination of food or water supplies. 

One of the constant concerns of numerous industries where either aerosols or toxic vapors are produced is the effects of these upon workers. A variety of health problems arise because of the workers inhaling gases and aerosols of irritant or toxic fibers which are produced in the normal course of activities. A less obvious hazard arises from the attachment of trace molecular species to particles. If these trace species are radioactive or chemically toxic, the particles, which effectively concentrate them, provide a vehicle for delivery deep within the body causing a health hazard far beyond that suggested by their gross molecular concentration in the air [1.31,32]. Kinetic theory, thermodynamics, and interaction forces, all enter into descriptions of the attachment process. 

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