Dry Heat Sterilization Cycle Design & Development at lower temperature

There are standards and references available for people wanting to establish dry heat sterilization cycles at lower temperature. While these standards help in learning, it is indeed a challenge when you are asked to establish dry-heat sterilization process for steroidal API.

This is the story of a project of VIENNI™. The project started like others with initial trials conducted by the client’s in-house validation team. The results were not satisfactory. The challenge persisted while a few facts were overlooked. The product, process and procedures needed an expert’s touch!

The basic challenges:

1.   Product safety and efficacy has to be retained

2.  Development of an effective sterilization cycle recipe

3. Presentation of microbiological results

Vienni was brought-in to support for design and to develop the dry-heat sterilization cycle. The initial gap analysis revealed some interesting facts in the sterilization cycle design process. The most important gaps identified were taken stock of and assessed through discussions. Some of them are as listed below:

      1. Arrangement pattern of containers used to keep load item (The API)

            2.  Use of non-uniform perforated containers
      3.   Location of the containers
      4.  Packing of the load item (the API)
      5.  Cycle parameter establishment
      6.   Product stability at the stated temperature
      7. Temperature profile

The above gaps were systematically addressed and closed. The new process and parameters determined were implemented.

The very first step in the implementation was to address the arrangement pattern of containers, uniform perforated containers, arrangement and location of the containers, optimized packing of the load item, hence, first four challenges were overcome! The next step was to set the physical parameters of the cycle. These parameters were found to be inconsistent and performing above the limit, during initial trials and were identified to be a recurring problem. The Eureka-moment was when the temperature in the load items was reduced to below the temperature recorded during initial trials and the set parameters were revised accordingly. Finally, after a few science-and data-based trials, the temperature inside the product was recorded within the limits.

The last challenge was to prove acceptance through the microbiological studies i.e. BI-incubation and the sterility test. The results of the microbiological studies results were also found as per the pre-determined specifications. A trial run was conducted to evaluate and establish the come-up time, which was found to be insufficient after which some more trials were required to determine the optimum come up time, sterile hold and cool down time. The runs passed the sterility test and the incubation test in flying colours.

The exposure time and temperature of the cycle was set based on the D-value calculation of the biological indicator.

Experience, expertise, rigor and patience helped us establish, develop and design a dry-heat sterilization cycle in a record time. Yet another feather in our cap!