The General Requirements as given in SCHEDULE M – GMP – PART 1 of this Schedule relating to requirements of Good Manufacturing Practices for Premises and materials for pharmaceutical products shall be complied for the manufacture of Metered-Dose-Inhalers (MDI). In addition to these requirements, the following Specific Requirement shall also be followed.



Manufacture of Metered-Dose-Inhalers shall be done under conditions which shall ensure minimum microbial and particulate contamination. Assurance of the quality of components and the bulk product is very important. Where medicaments are in suspended state, uniformity of suspension shall be established.

Building and Civil Work
  • The building shall be located on a solid foundation to reduce risk of cracking walls and floor due to the movement of equipment and machinery.
  • All building surfaces shall be impervious, smooth and non-shedding. Flooring shall be continuous and provided with a cove between the floor and the wall as well as the wall to the ceiling. Ceiling shall be solid, continuous and covered to walls. Light fittings and air-grills shall be flush with the ceiling. All service lines requiring maintenance shall be erected in such a manner that these accessible from outside the production area.
  • The manufacturing area shall be segregated into change rooms for personnel, container preparation area, bulk preparation and filling area, quarantine area and spray testing and packing areas.
  • Secondary change rooms shall be provided for operators to change from factory clothing to special departmental clothing before entering the manufacturing and filling area.
  • Separate area shall be provided for de-cartoning of components before they are air washed.
  • The propellants used for manufacture shall be delivered to the manufacturing area distribution system by filtering them through 2µ filters. The bulk containers of propellants shall be stored, suitably identified, away from the manufacturing facilities.

Environmental Conditions
  • Where products or clean components are exposed, the area shall be supplied with filtered air of Grade C.
  • The requirements of temperature and humidity in the manufacturing area shall be decided depending on the type of product and propellants handled in the facility. Other support area shall have comfort levels of temperature and humidity.
  • There shall be a difference in room pressure between the manufacturing area and the support areas and the differential pressure shall be not less than 15 Pascals (0.06 inches or 1.5mm water gauge).
  • There shall be a written schedule for the monitoring of environmental conditions. Temperature and humidity shall be monitored daily.

  • Personnel in the manufacturing and filling section shall wear suitable single-piece-garment made out of non-shedding, tight weave material. Personnel in support areas shall wear clean factory uniforms.
  • Gloves made of suitable material having no interaction with the propellants shall be used by the operators in the manufacturing and filling areas. Preferably, disposable gloves shall be used.
  • Suitable department-specific personnel protective equipment like footwear and safety glasses shall be used wherever hazard exists.

  • There shall be written procedures for the sanitation of the MDI manufacturing facility. Special care should be taken to handle residues and rinses of propellants.
  • Use of water for cleaning shall be restricted and controlled. Routinely used disinfectants are suitable for sanitizing the different areas. Records of sanitation shall be maintained.

  • Manufacturing equipment shall be of closed system. The vessels and supply lines shall be of stainless steel.
  • Suitable check weights, spray testing machines and labeling machines shall be provided in the department.
  • All the equipment shall be suitably calibrated and their performance validated on receipt and thereafter periodically.

  • There shall be approved Master Formula Records for the manufacture of metered close inhalers. All propellants, liquids and gases shall be filtered through 2µ filters to remove particles.
  • The primary packing material shall be appropriately cleaned by compressed air suitably filtered through 0.2µ filter. The humidity of compressed air shall be controlled as applicable.
  • The valves shall be carefully handled and after de-cartoning, there shall be kept in clean, closed containers in the filling room.
  • For suspensions, the bulk shall be kept stirred continuously.
  • In-process controls shall include periodical checking of weight of bulk formulation filled in the containers. In a two-shot-filling process (liquid filling followed by gaseous filling), it shall be ensured that 100% check on weight is carried out.
  • Filled containers shall be quarantined for a suitable period established by the manufacturer to detect leaking containers prior to testing, labeling and packing.


In addition to the routine good manufacturing practices documentation, manufacturing records shall show the following additional information:-

  • 1) Temperature and humidity in the manufacturing area.
  • (2) Periodic filled weights of the formulation.
  • (3) Records of rejections during on line check weighing.
  • (4) Records of rejection during spray testing.

Reference : Drugs and Cosmetics act 1940