PURPOSE: 

To ensure that DHS must be validated and they meet their design criteria and existing ovens must be rechecked, when they are significantly changed.

RESPONSIBILITY :

1. Production Manager

PROCEDURE

1. Maximum loads of vials or ampoules are washed as validation has to be carried on maximum load.

2. Washed vials or ampoules are arranged inverted in SS boxes.

3. Boxes are loaded on carriage as per the standard loading pattern.

4. Place a minimum of 10 previously calibrated probes of the multiprobe digital temperature indicator throughout the chamber but not inside the articles to be sterilized. Note the location the SS boxes and the probes.

5. Load the carriage into the sterilizer and check that the following switches are ‘ON’

-Blower

-Door Alarm

– Temperature Recorder

– Thermostat and HEPA Filter

6. Set the Temperature at 260 °C and set the time as per the vial/ampoule load. 7. Switch ‘ON’ the sterilizer main switch, heater, and timer switch and begin the cycle. Check amperage of electric current in the three phases. It should be above 35 – 38

PURPOSE: 

To ensure that DHS must be validated and they meet their design criteria and existing ovens must be rechecked, when they are significantly changed.

RESPONSIBILITY :

1. Production Manager

PROCEDURE

1. Maximum loads of vials or ampoules are washed as validation has to be carried on maximum load.

2. Washed vials or ampoules are arranged inverted in SS boxes.

3. Boxes are loaded on carriage as per the standard loading pattern.

4. Place a minimum of 10 previously calibrated probes of the multiprobe digital

temperature indicator throughout the chamber but not inside the articles to be sterilized. Note the location the SS boxes and the probes.

5. Load the carriage into the sterilizer and check that the following switches are ‘ON’

-Blower

-Door Alarm

– Temperature Recorder

– Thermostat and HEPA Filter

6. Set the Temperature at 260 °C and set the time as per the vial/ampoule load.

7. Switch ‘ON’ the sterilizer main switch, heater, and timer switch and begin the cycle. Check amperage of electric current in the three phases. It should be above 35 – 38 amperes.

8. Note the temperature readings of all probes using the probe selector switch at the interval every five minutes.

9. Record the readings in the following format.

10. Note the time at which the built in temperature indicator and the thermograph reach 260 °C an also note the temperature at which all probes reach 220 °C.

11. Continue recording the temperature readings every five minutes till the end of the cycle.

12. From the temperature readings identify the location of the coldest spot in the oven for that particular loading pattern and use this information for heat penetration studies.

1. A new oven should be capable of maintaining a temperature differential of ± 5 °C and older ovens may have a larger temperature differential.
2. The heat distribution test is performed initially one time for each standard load and repeated whenever there is a change in the loading pattern or whenever there is a
3. Significant change (major maintenance) in the existing oven:
4. A maximuin load is used for the test. If maximum loads have been tested satisfactorily, then loads of the same materials but less than maximum need not be tested, however, subsequent maximum loads must have the same loading pattern as used during the validation.

HEAT PENETRATION TEST

Vials and ampoules required to fill sterile solution are sterilized and depyrogenated in dry heat sterilizer at 220 °C for 90 minutes. The temperature of the load at any location should be maintained at 220 °C for 90 minutes. In heat penetration test, the thermocouples are placed inside the items being sterilized to measure the amount of heat delivered. At least one thermocouple is placed in the coolest location as determined by the heat distribution test. Even the item located at the coolest location must reach the required cycle temperature and remain at that temperature for the length of time required by the approved cycle.

PROCEDURE

1. Maximum load of vials or ampoules are washed as validation has to be carried out on the maximum loads.

2. Washed vials or ampoules are arranged inverted in SS boxes.

3. Boxes are loaded on carriage of the sterilizer as per the standard loading pattern.

4. Probes are inserted into the vials or ampoules at different locations of the full load. Note the locations of SS box and probe.

5. At least one probe should be inserted into a box kept at the cold spot in the dry heat sterilizer.

6. Load the carriage into the sterilizer and check that the following switches are on

– Blower

– Door Alarm

– Temperature Recorder

– Thermostat and

– HEPA Filter

7. Set the temperature at 260 °C and set the time as per the vial / ampoule load.

8. Switch on the sterilizer main switch, heater and timer switch to begin the cycle and check amperage of electric current in three phases. It should be above 35-38 amperes.

9. Note temperature readings of all probes using probe selector switch at the interval of every five minutes.

10. Record the readings in the following format:

11. Note the time at which the built in temperature indicator and thermograph has reached 260 °C.

12. Continue recording temperature readings at the interval of every five minutes till all probes reach 220 °C.

13. After all the probes have reached 220 °C, continue to take readings to confirm that temperature has been maintained at 220 °C till the sterilization cycle is over i.e. 90 minutes after all the probes have reached 220 °C.

14. Allow the sterilization cycle to complete.

15. Depending upon the loading pattern and location of probes, the sterilization cycle may change.

16. Determine the sterilization cycle time for 220 °C for 90 minutes from the data, after all probes recorded at 220 °C.

17. Pre and post validation calibration of 12 point thermocouple used for the validation should be – done at 160 °C, 200 °C and 240 °C.

Items for which validation is performed on the maximum load.

a. 2 ml tubular vials and 2 ml moulded vials

b. 3 ml tubular vials

c. 1 ml flint glass ampoules

d. 1.5 ml flint glass ampoules

e. 2 ml flint glass ampoules –

f. 3 ml flint glass ampoules

FREQUENCY : ANNUALLY FOR EACH LOAD

 (Review date on or  before 12 months from date of authorization)