Injectables can be sterilized using several methods, most commonly through terminal sterilization techniques.
Terminal Sterilization Methods for Injectables
Terminal sterilization, applied to the final product within its packaging, is a common and cost-effective way to sterilize injectables. This is because it requires less specialized equipment compared to other methods.
Here's a breakdown of terminal sterilization methods, as per the provided reference:
| Sterilization Method | Description | Advantages | Disadvantages |
|---|---|---|---|
| Dry Heat | Exposing the injectable to high temperatures for a specified period. | Simple, effective for heat-stable substances. | May degrade heat-sensitive drugs. |
| Moist Heat (Autoclaving) | Using pressurized steam to kill microorganisms. | Highly effective, reliable, and relatively quick. | Not suitable for heat-labile materials. |
| Radiation (Gamma Rays) | Using gamma radiation to disrupt the DNA of microorganisms. | Effective, can penetrate packaging. | May cause degradation of some drugs; specialized equipment required; safety concerns regarding radiation exposure. |
| Gases (Ethylene Oxide) | Exposing the injectable to ethylene oxide gas. | Effective for heat-sensitive materials. | Potential toxicity; requires careful removal of gas residues; potential for polymer degradation. |
Examples and Practical Insights:
- Cost-effectiveness: Terminal sterilization with heat is typically less expensive than aseptic processing (manufacturing under sterile conditions) because it uses less specialized equipment and facilities. According to the reference, terminal sterilization made using these methods is less specialised and costs less to produce.
- Material Compatibility: The choice of sterilization method depends largely on the properties of the drug substance and the packaging materials. Heat-sensitive drugs, for instance, cannot be sterilized by autoclaving.
- Validation: Regardless of the method chosen, the sterilization process must be thoroughly validated to ensure that it consistently achieves the desired level of sterility.
