The high-precision filling of aerosols requires technology and rich experience. The accuracy of aerosol filling is directly related to the quality of aerosols, especially for products with special requirements for filling volume, such as pharmaceutical aerosols. Therefore, filling accuracy is one of the parameters that must be controlled in the aerosol production process. Mastering the techniques of aerosol filling can ensure the accuracy of aerosol filling, which is both a technology and an art.

1. Aerosol filling equipment should have regular maintenance plans and daily inspection schedules. The daily maintenance and inspection of aerosol filling machines should include at least the sealing components, control elements, pneumatic circuits, relevant knowledge devices, etc., to ensure that the aerosol filling machine is in good working condition.

2. The pressure control during the filling process includes two aspects: the working pressure of the aerosol filling machine and its booster pump, and the pressure of the propellant delivered to the aerosol filling machine. In general, the working pressure of the pharmaceutical booster pump is stable, and the pressure of the propellant delivered to the aerosol filling machine can be kept stable. Ensuring the stability of these two pressures is a prerequisite for ensuring the accuracy of aerosol filling. At the same time, these two pressures must be set within the appropriate working range during the filling process to ensure that the propellant is always transported and filled in a liquefied state, and to ensure the appropriate filling pressure.

3. Ensure that there are no non liquefiable gases in the quantitative chamber and filling head of the aerosol filling machine. If there is, it must be discharged to ensure the filling accuracy of the aerosol. When using the two-step aerosol filling method, as it is a separate propellant filling, the gas that is not easily compressed in the quantitative chamber and filling head can also be discharged through pre filling; For one-step filling, since the liquid medicine is always in a circulating state, the gas that is not easily liquefied in the quantitative chamber and filling head can be discharged through the circulation of the liquid medicine.

4. Choose the appropriate filling head. The aerosol valves used in the production process may have different filling channels and parameters, such as the sealing part between the filling head and the valve, the downward pressure stroke of the valve stem, etc. Therefore, different valves must use corresponding filling heads to ensure the correct filling of aerosol. At the same time, it is necessary to ensure the correct sealing method between the filling head and the valve during filling, and adjust the height of the filling head appropriately to ensure sufficient compression force is applied to the seal between the filling head and the valve to ensure sealing and prevent leakage during the filling process.

5. The temperature of the propellant. During the filling process, the temperature of the propellant will affect the accuracy of the filling. It should be noted that the temperature of the propellant will affect its density, thereby affecting the accuracy of the filling. In general, for example, for HFA 34a, when the temperature difference is 5 ℃, theoretically the filling difference of the propellant can reach about 1%.

In short, the filling of aerosols requires both corresponding technology and art, which requires continuous exploration and accumulation of experience. The combination of technology and art can achieve high-quality aerosols.