Inhalation Preparation | Aerosol | MDI and Standard Test

Inhalation preparations OR Pressurized Metered-Dose Preparation (MDI) are liquid or solid dosage forms intended for administration as vapors or aerosols to the lung to obtain a local or systemic effect. They contain solutions or dispersions of one or more active ingredients which may be dissolved or dispersed in a suitable vehicle.

Inhaler.

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Inhalation preparations intended to be administered as aerosol (dispersion of solid or liquid particles of active ingredients in a gas) are administered by pressurized metered-dose inhalers or powder inhalers. Pressurized Metered Dose Inhalers are dosage forms containing therapeutically active ingredients that are packed under pressure in a sealed container and are released as a fine mist o spray upon actuation of a suitable valve system.

Types of Hydro fluoroalkane inhalers (Pressurized Metered Dose Inhalers or MDI):

1. Two-phase system consisting of gas and liquid.

2. Three-phase system consisting of gas, liquid, and solids or liquids.

Standard Tests or Evaluation for Inhalation Preparation:

1. Pressurized Metered-Dose Preparation (MDI)
2. Description: It should comply with the Specification of Products.
3. Content of active ingredient delivered per actuation Shall comply with the specification.
4. Uniformity of delivered dose: The Preparation complies with the test if 9 out of 10 results lie between 75 to 125 % of the average value and all lie in between 65 to 135 %. If 2 or 3 values lie outside the 75 — 125 % limit, repeat the test for two more inhalers. Not more than 3 of the 30 values lie outside the limits of 65 —135 %.
5. Particle Size. The number of particles longer than 20-micron meter does not exceed 50, and no particles exceed 100-micron meters in length.
6. The number of deliveries per container: The number of deliveries so discharged in the test for particle size is not less than the number stated on the label.
7. Deposition of emitted dose: As per IP or other specifications.
8. Leak Test. The average leakage rate of the 12 containers should not be more than 3.5 per container, and none of the containers leaks more than 5% of the net fill weight per year.

Related Post: Capsules, Types, and formulation

1. Powder For Inhalation preparation or Dry Powder Inhalation (DPI)

Powder for Inhalation preparation is presented as single-Dose powders or multi-dose powders Fo pre-meter inhalers. The inhaler is loaded with powders pre-dispensed in capsules or other suitable pharmaceutical dosage forms.

1. Description: It should comply with the Specification of Products.
2. Uniformity of delivered dose: The Preparation complies the test if 9 out of 10 results lie in between 75 to 125% of average value & all lie in between 65 to 135 To. If 2 or 3 values lie outside the 75 -125 % limit, repeat the test for two more inhalers. Not more than 3 of the 30 values lie outside the limits of 65 -135 %.
3. Uniformity of content: As given in capsules.
4. The number of deliveries per container: The number of deliveries so discharged in the test for particle size is not less than the number stated on the label.
5. Microbial contamination: Total viable aerobic bacterial count shall be not more than 100 CF per g of the powder. E. coli – absent in 10g of the powder. Salmonella – Absent in 50 g of the powder. S.Aureus – absent in 10 g of the powder. P. aeruginosa – absent in 10 g of the powder.