Practical issues on PFS sterilization: an analysis of critical aspects

Introduction

Prefilled syringes (PFS) offer several advantages over traditional packaging in vials. For example, microbial contamination is minimized due to less manipulation.This presentation discusses a method for sterilizing PFSs through a moist heat process, the most common and approved method used by pharmaceutical facilities for this type of products. The main issues to consider while sterilizing PFSs with a moist heat process are described.

What happens when a sealed container with aqueous solution is heated?

Inside every sealed container, the internal pressure increases during the heating phases
of the sterilizing process.

1 – Water evaporates in the head space

                    Vapor pressure of the liquid, because of a one-to-one correspondence, depends on               temperature and is indipendent from the quantity of product.

2 – Dissolved gases leave the solution

They will partially contribute to pressure rise in the head space.

3 – Gases (air) initially present in the head space increase their pressure

Their pressure will rise proportionally to the absolute increasing temperature.

4- […]