Manufacturing and Filling of Inhalers and Sprays (Aerosols) in pharmaceutical Industry

Spray and Inhalers require two main steps in manufacturing process:

  1. Mixture of Active Ingredients and Excipients
  2. Propellant


Propellants are the chemical substances that are burnt or decomposed to produce propellant gases or Propellants are liquids that can readily be vaporized into gas form. In Spray and Inhalers, propellants are used in form of pressurized gas and liquid form at its equilibrium state and used to produce movement of mixture. Propellants build pressure inside container to expel mixture outside container. When some amount of propellant is excel out with ingredients, liquid propellant evaporates to maintain pressure inside can. Propellants have prime role in filling and manufacturing of Spray and Inhalers.

Equipment Used are:

  • Mixing Equipment
  • Filling Machine (Cold filling Machine, Pressure Filling Machine, Compressed Gas Filling, Rotary Filling Machine)
  • Sealing Machine
  • Labeling & Packaging

Technical Staff:

Non Technical Staff:

  • Machine Operator
  • Helpers

Section Required:

  • Raw Material Stock Section
  • Propellant Stock Section
  • Mixing and Preparation Section
  • Filling and Sealing Section
  • Packaging Section

Procedure for Filling Aerosols:

  • Dispensing of Raw material and Excipients
  • Preparation of Mixture
  • Filling of Mixture into aerosol container
  • Filling of propellant into container
  • Sealing
  • Testing (Leakage, Strength, Pressure handing, Dose Determination etc)
  • Capping, Labeling and Packaging

Method used for filling Aerosols:

  • Cold Filling
  • Pressure Filling
  • Compressed gas filling
  • Rotary Filling Machine 

Cold filling Method:

In cold filling method, an apparatus consists of insulated box and cooled by copper tubing which is filled with dry ice or acetone.

Two ways are used to fill spray in cool filling method:

In first method, material and propellant is separately chilled. Material is chilled to -30 to -400 F. This chilled material is filled into chilled aerosol container. Then chilled propellant is added through valves presents at aerosol container. Seal the container and conduct test for leakage & strength. Then container will move to capping, labeling and packaging.

In another method, material and propellant are mixed together & chilled to -30 to -400 F. This mixture is added to chilled aerosol container. Seal the container and conduct test for leakage & strength. Then container will move to capping, labeling and packaging.

Pressure Filling Method:
In pressure filling method, an apparatus consists of a measuring device which is capable of measuring the amount of propellant and material to be added into container at room temperature. Material and propellant are added separately or together with the help of inlet valves under pressure created by a cylinder of nitrogen or compressed gas is attached to the top of the valve and pressure of nitrogen results the movement of material and propellant into container till pressure inside container becomes equal to outside pressure. Seal the container and send for testing. Then container will move to capping, labeling and packaging.

Compressed Gas Filling Method:
In Compressed Gas Filling Method, A compressed gas propellant is used. Compressed Gas Propellant is filled into aerosol container through pressure gauge from large container. Before filling compressed gas propellants, material is filled inside aerosol container and assembly is fitted at it place. Air inside container is then removed through vacuum and compressed air is filled through pressure reducing valve attached to gas cylinder.

Rotary Filling Machine Method:
Rotary Filling method is new and fastest way to fill aerosol which allows propellant to be added around and through valve stems. 

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