Nebulizers prevention

Because all inhaled corticosteroids are equally effective if given in equipotent doses, product selection should be individualized based on the available dosage form, delivery device, and patient preference. In infants, administration may require the use of a nebulizer or spacer/holding chamber with a facemask. Caregivers should use a soft, damp cloth to wipe the face of infants receiving an inhaled corticosteroid via a facemask to prevent topical candidiasis.18... 

Airway clearance therapy is usually accompanied by bron-chodilator treatment [albuterol (also known as salbutamol outside the United States) by nebulizer or metered-dose inhaler] to stimulate mucociliary clearance and prevent bronchospasm associated with other inhaled agents. A mucolytic agent may be administered to reduce sputum viscosity and enhance clearance. 

The use of the aerosol route for delivery of antibiotics for pulmonary infections remains controversial. The majority of pediatric studies have been conducted in children with cystic fibrosis. In these patients distribution of the antibiotic to the desired tissue site is impeded because of the viscosity of the sputum in patients with acute exacerbations of their pulmonary infections [91,92], Long-term studies have demonstrated preventive benefits of aerosolized antibiotics in children with cystic fibrosis who are colonizing Pseudomonas aeruginosa in their lungs but are not acutely ill [93,94], Cyclic administration of tobramycin administered by nebulizer has received FDA approval [95],... 

The digestion of solid samples to produce a solution is discussed in Section 13.2. For solution-based ICP MS analysis, the liquid is taken up through a thin tube via a peristaltic pump. This feeds directly into the instrument nebulizer, where argon gas is introduced into the liquid and a fine mist of droplets is expelled from the tip of the nebulizer. This sample aerosol is sprayed into the condenser to reduce the size of the droplets, ensuring an even sample loading and preventing cooling of the plasma. About 1% of the sample solution uptake is transported to the plasma torch, and any unused solution is drained away and may be recycled. 

When using PFT with a neutral selector, it is quite difficult to avoid any entrance of the chiral selector into the ionization source, particularly at a high pH, where EOF is important. The use of BGE at low pH and/or coated capillary to minimize EOF is therefore mandatory. However, the coaxial sheath gas, which generally assists the ionization process, leads to an aspirating phenomenon of the chiral selector in the MS direction. Javerfalk et al. were the first to apply PFT with a neutral methyl-/i-CD for the separation of racemic bupivacaine and ropivacaine with a polyacrylamide-coated capillary and an acidic pH buffer (pH 3). Cherkaoui et al. employed another neutral CD (HP-/1-CD) with a PVA-coated capillary for the analysis of amphetamines and their derivatives. To prevent a detrimental aspiration effect, analyses were carried out without nebulization pressure. Numerous other studies presented excellent results such as the enantioselective separation of adrenoreceptor antagonist drugs using tandem mass spectrometry (MS/MS) the separation of clenbuterol enantiomers after solid-phase extraction (SPE) of plasma samples or the use of CD dual system for the simultaneous chiral determination of amphetamine, methamphetamine, dimethamphetamine, and p-hydroxymethamphetamine in urine. 

Patients suffering from cystic fibrosis often use various aerosolized drugs. To reduce the viscosity of the mucus in the airways, recombinant human deoxyribonuclease is used. This enzyme is the first recombinant protein that has been developed for specific delivery to the lungs via the airways. It has a local action on the mucus in the airways and its absorption is minimal. Another drug that decreases the viscosity of the mucus is acetylcysteine. Aerosolized antibiotics are a further group of therapeutics that is widely used by cystic fibrosis patients. Solutions of antibiotics like tobramycin or colistin are used in nebulizers to prevent exacerbation of the disease. Pentamidine has been used for the prophylaxis of Pneumocystis pneumonia in patients infected with HIV virus, while chronic rejection of lung transplants provided a reason to develop an aerosol formulation of cyclosporine A. 

Prevention of acute bronchospasm nha e 20 mg (1 amp/vial) administered by nebulization shortly before exposure to the precipitating factor. 

Prevention of PCP - 300 mg once every 4 weeks administered via the Respirgard II nebulizer by Marquest. 

Prevention of bronchospasm Inhalation (nebulization) 20 mg within I hr before exercise or exposure to allergens, Aerosol Spray 2 sprays within I hr before exercise or exposure to allergens... 

These compressed air nebulizers produce polydisperse aerosols. After the aerosol is produced, the size distribution may change due to evaporation of liquid from the droplets. In addition, the particles may be electrically charged due to an ion imbalance in the droplets as they form if such charges become further concentrated due to evaporation, the particle may break up into smaller particles. Thus electrical neutralization of the aerosol, for example, by exposure to a radioactive source, is usually necessary to prevent electrostatic effects from dominating the particle motion, coagulation, and other behavior. 

Aerosols generated by nebulization are directed through a spray chamber, which is usually constructed from glass, or an inert polymer (Fig. 4.9) The spray chamber prevents larger aerosol droplets from reaching the plasma, as... 

The sample is introduced into the ICP as a liquid which must usually contain less than 0.1% dissolved solids to prevent salt build-up on the nickel cones (see Section 5.3). This is in contrast to ICP-AES, which can tolerate up to 1% dissolved solids. The sample is converted to an aerosol by means of a pneumatic nebulizer, and the droplets pass through a spray chamber, into the injector tube of the quartz torch and thence into the central channel of the ICP. These processes are identical with those described for ICP-AES (see Section 4.4.3), and the different types of... 

Pentamidine is an aromatic diamidine (Figure 52-3) formulated as an isethionate salt. Pentamidine is only administered parenterally. The drug leaves the circulation rapidly, with an initial half-life of about 6 hours, but it is bound avidly by tissues. Pentamidine thus accumulates and is eliminated very slowly, with a terminal elimination half-life of about 12 days. The drug can be detected in urine 6 or more weeks after treatment. Only trace amounts of pentamidine appear in the central nervous system, so it is not effective against central nervous system African trypanosomiasis. Pentamidine can also be inhaled as a nebulized powder for the prevention of pneumocystosis. Absorption into the systemic circulation after inhalation appears to be minimal. The mechanism of action of pentamidine is unknown. 

Inhalation solution and suspension drug products are typically aqueous-based formulations that contain therapeutically active ingredients and can also contain additional excipients. Aqueous-based oral inhalation solutions and suspension must be sterile (21 CFR 200.51). Inhalation solutions and suspensions are intended for delivery to the lungs by oral inhalation for local or systemic effects and are used with a specified nebulizer. Unit-dose presentation is recommended for these drug products to prevent microbial contamination during use. The container closure system for these drug products consists of the container and closure and can include protective packaging such as foil overwrap. 

Because memory effects (carryover) from high concentration samples may take place in the nebulizer and in the plasma torch, the system must be flushed between samples. To recognize and prevent memory effects, instrument blanks are analyzed after high concentration samples additional frequent instrument blanks intersperse analytical sequences as a QC measure. 

An aerosol generated by nebulization is directed through a spray chamber (nebulizer chamber). This is usually made of glass, quartz, or inert polymers (Ryton or several fluorine-based polymers), which prevents large aerosol droplets from reaching the plasma. The classical Scott chamber design has been superseded by the cyclonic chamber, which has a 50% better sensitivity. 

Most ultrasonic nebulizers use a somewhat larger sample uptake rate (2-3 mL/min) than pneumatic nebulizers. Typically the spray chamber and/or a tube following the spray chamber is heated to evaporate water partially from the aerosol. Because the aerosol transport efficiency is higher when an ultrasonic nebulizer is used, particularly with a heated spray chamber, a system to remove solvent (typically a condenser and/or membrane separator) is essential to prevent deleterious cooling of the ICP by excess water. 

Slurries have been used to introduce soil samples into an ETV with ICP-MS detection [332] as well as directly into an ICP-MS using a Babington-type nebulizer [333]. Although slurry sample introduction eliminates the problems associated with sample dissolution, care is required to ensure that the slurry particles are small enough to be completely vaporized in the ICP. Agglomeration of particles in the slurry before introduction to the nebulizer must be prevented in order to maintain constant transport efficiency into the ICP... 

The principal methods of interfacing SFC with ICP-MS have been discussed by Carey and Caruso [94]. Where packed SFC columns are used, the SFC restrictor is connected to a heated cross flow nebulizer and the nebulizer gas flow carries the sample to the plasma. For the more commonly used capillary columns, the SFC restrictor is passed through a heated transfer line that is connected directly to the torch of the ICP-MS. For optimal resolution of peaks, the restrictor should be positioned so that it is level with the injector of the ICP torch. This position may be varied slightly (Fig. 10.15). Heat is applied where the transfer line and torch connect to prevent freezing of the mobile phase when it decompresses after exiting the restrictor. To transport the analyte to the plasma efficiently, a gas flow of approximately 0.8-1.0 mL/min is used. This gas flow may also be heated to improve peak resolution. 

IPRATROPIUM BRONCHODILATORS -SALBUTAMOL A few reports of acute angle closure glaucoma when nebulized ipratropium and salbutamol were coadministered Ipratropium dilates the pupil, which i drainage of aqueous humour, while salbutamol t production of aqueous humour Warn patients to prevent the solution to mist or enter the eye. Extreme caution in co-administering these bronchodilators by the nebulized route in patients with a history of acute closed-angle glaucoma... 

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