Learning Objectives The complete aerosol package includes both the product and the container. Hence while studying the stability aspects of aerosols, both the effect of the product on the container and the effect of the container on the product should be studied. Moreover, due to the variety of materials used in making an aerosol valve…
Learning Objective Manufacturing and packaging of aerosols requires specialized equipment and skills, special knowledge and rigid quality control. In addition to the equipment used for the compounding of liquids, suspensions, emulsions, creams and ointments, specialized equipment capable of handling and packaging materials at relatively low temperatures about –40°F or under high pressure must be available.…
Learning Objective Solution System These are also referred to as the two-phase systems—a liquid and a vapor phase. They consist of a solution of active ingredients in pure propellant or a mixture of propellant and solvents. If the active ingredient is soluble in the propellant, no other solvent is necessary. These types of systems are…
It consists of active ingredient or a mixture of active ingredients with other necessary agents such as solvents, antioxidants and surfactants. Propellants can be combined with the active ingredients in many ways producing products with varying characteristics.
Blends of various fluorocarbon propellants are generally used for pharmaceutical aerosols. These mixtures help in obtaining the desirable pressure, delivery and spray characteristics. By varying the proportion of each component, any desired vapor pressure can be achieved. The CFCs have been implicated in having ozone depleting effect, increasing the amount of UV radiations reaching the…
Liquefied gases have been used widely as propellants for most of the aerosol products. In a sealed container such as an aerosol can, the liquefied gas exists in two phases—liquid and gas, behaving as a two-phase system. The molecules in the vapor stage are responsible for exerting the pressure on the contents. As the number…
Liquefied gases are widely used as propellants for most of the aerosol products. These are materials that exist in the gaseous or vapor state at room temperature and atmospheric pressure and are capable of being liquefied easily by lowering the temperature below its boiling point or by increasing the pressure. The compounds chosen generally have…
Compressed gas propellants are widely used in pharmaceutical aerosols. The gases generally used include nitrogen, nitrous oxide and carbon dioxide. They can be used to dispense the product in the form of a solid stream, wet spray or foam. The gas is compressed in the container and occupies the head space above the liquid in…
Learning Objectives A propellant is responsible for developing the pressure within the container and in combination with other components it expels the product in the desired physical form like spray, mist or foam. Propellants may be broadly classified as follows: The types of propellants used for different pharmaceutical applications are listed in Table 12.1. Table…
The aerosol formulation consists of the following two essential components: