Virus Inactivation
The goal of virus inactivation is the irreversible
loss of viral infectivity.
Inactivation of virus is superior to removal: the exact and careful determination of the inactivation kinetics allows for a highly reliable and precise performance and validation of the inactivation process.
In general, non-invasive physical methodologies such as High Temperature Short Time (•HTST•) heat treatment are preferred over invasive methodologies using chemical agents, which have to be removed and require expensive analytical monotoring.
The loss of the infectivity does not necessarily mean the complete destruction or disintegration of the virion - which might be most desirable -, but is already given by the irreversible denaturation of distinctive viral components which are essentially required by the virion in order to be able to infect a host cell. Hence, the inactivation procedure should again cover a broad range of virus species featuring various degrees of resistance. Some popular inactivation processes like the solvent-detergent (S/D-) treatment or acid treatment are solely feasible for a limited range of virus species; small non-enveloped viruses such as Polio, SV40 and Parvo (B19) remain unaffected.
HTST Virus Inactivation
The introduction of High
Temperature Short Time (•HTST•) heat treatment
offers for the first time a substantial inactivation of small
non-enveloped viruses while fully maintaining the integrity of the protein
product. With respect to the concept of validation of viral clearance, the
High Temperature Short Time (•HTST•)
heat treatment features the unique opportunity to spike and re-collect a
virus sample of a volume as low as 20 - 30 ml into the fluid pathway using
a designed sample applicator under operational conditions for the
manufacturing process ( flow rate 35 - 80 Lh-1, peak
temperature 60 - 165oC) at full scale. The complete pathway is
disposable, hence offering an extraordinary validation opportunity as well
as a multi-product use and avoiding any potential cross contamination.
| Viral Clearance and
Validation
|
©1999 Charm Bioengineering, Inc.