Aerosol metered

USP24. <601 > Aerosols, Metered Dose Inhalers, and Dry Powder Inhalers. The United States Pharmacopoeia and National Formulary 1895-1912, 2000. 

Inhalation drug products include inhalation aerosols (metered dose inhalers) inhalation solutions, suspensions, and sprays (administered via nebulizers) inhalation powders (dry powder inhalers) and nasal sprays. The CMC and preclinical considerations for inhalation drug products are unique in that these drug products are intended for respiratory tract-compromised patients. This is reflected in the level of concern given to the nature of the packaging components that may come in contact with the dosage form or the patient. 

Cromolyn sodium (disodium cromoglycate) and nedocromil sodium are stable but extremely insoluble salts (see structures below). When used as aerosols (metered-dose inhalers), they effectively inhibit both antigen- and exercise-induced asthma, and chronic use (four times daily) slightly reduces the overall level of bronchial reactivity. However, these drugs have no effect on airway smooth muscle tone and are ineffective in reversing asthmatic bronchospasm they are only of value when taken prophylactically. 

Additional multiple-unit containers are in widespread use such as collapsible tubes, metered-dose inhalers, and aerosol containers. The f/j / /AF provides standards for aerosols and containers used for aerosols in Aerosols, Metered-Dose Inhalers, and Dry Powder Inhalers (601) and Pharmaceutical Dosage Forms (1151). Commonly used for ointments and pastes, the collapsible tube container is often constructed of plastic, metal, or some lamination of plastic and metallic layers. Although such preparations can be packaged in jars or bottles, collapsible tubes can offer better protection from contamination and from environmental hazards. The metered-dose inhaler and aerosol container are other specific multiple-unit dosage form examples that are commonly fabricated from metal and are closely tied to the process of medication administration. " ... 

Aerosols, Metered-Dose Inhalers, and Dry Powder Inhalers... 

Interim Guidance for Documentation of in Vivo Bioequivalence of Albuterol Inhalation Aerosols (Metered Dose Inhalers). Division of Bioequivalence, Office of Generic Drugs, Center for Drug Evaluation and Research, FDA, January 27,1994. 

Keywords Medical aerosols Metered dose inhaler Nebulizer Pharmaceutical aerosols Respiratory drug delivery... 

The aerosol container has enjoyed commercial success ia a wide variety of product categories. Insecticide aerosols were iatroduced ia the late 1940s. Additional commodities, including shave foams, hair sprays, antiperspirants, deodorants, paints, spray starch, colognes, perfumes, whipped cream, and automotive products, followed ia the 1950s. Mediciaal metered-dose aerosol products have also been developed for use ia the treatment of asthma, migraine headaches, and angiaa. 

The use of metered-dose valves in aerosol medical appHcations permits an exact dosage of an active dmg to be deHvered to the respiratory system where it can act locally or be systemicaHy absorbed. For example, inhalers prescribed for asthmatics produce a fine mist that can penetrate into the bronchial tubes (see Antiasthmatic agents). 

Pharmaceutical powder aerosols have more stringent requirements placed upon the formulation regarding moisture, particle size, and the valve. For metered-dose inhalers, the dispensed product must be deflvered as a spray having a relatively small (3—6 -lm) particle size so that the particles can be deposited at the proper site in the respiratory system. On the other hand, topical powders must be formulated to minimize the number of particles in the 3—6-p.m range because of the adverse effects on the body if these materials are accidently inhaled. 

In the United States, use of CEC propeUants, designated as PropeUants 11, 12, and 114, is strictly limited to specialized medicinal aerosol products such as metered-dose inhalers. The physical properties and chemical names of these propeUents are given in Table 2. 

Annex 10 Manufacture of Pressurised Metered Dose Aerosol Preparations for Inhalation Annex 11 Computerised Systems... 

Here B is the world average burden of anthropogenic sulfate aerosol in a column of air, in grams per square meter. The optical depth is then used in the Beer Law (which describes the transmission of light through the entire vertical column of the atmosphere). The law yields I/Iq = where I is the intensity of transmitted radiation, Iq is the incident intensity outside the atmosphere and e is the base of natural logarithms. In the simplest case, where the optical depth is much less than 1, (5 is the fraction of light lost from the solar beam because of... 

Formulation(s) aerosol inhalation 20 fig/metered inhalation, 40 pg/metered inhalation inhalation sol. 250 pg/... 

An alternative method of calibration involves the dispersion of monodisperse polystyrene microparticles. This has recently been made an efficient process by the incorporation of these particles in pMDI suspension to allow for metering of small well-dispersed boluses sufficient for use as aerosol calibration standards [43]. 

AJ Hickey, RM Evans. Aerosol generation from propellent-driven metered dose inhalers. In AJ Hickey, ed. Inhalation Aerosols. New York Marcel Dekker, Inc., 1996, pp. 417-439. 

ALBUTEROL INHALATION AEROSOL 17GM CONTAINER 200 METERED SPRAYS 6505011169245 PG 3.18 ... 

Graepel, P. and D.J.Alexander. 1991. CFC replacements safety testing, approval for use in metered dose inhalers. J. Aerosol Med. 4 193-200. 

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