An outlook on hold time procedures which help in determining the effectiveness of the cleaning process and sampling & analytical methods
1.0 Introduction
Hold time procedures are crucial as they prevent the degradation of products and also protect it from contamination which may be hard to remove through common cleaning procedure. They are integrated with cleaning procedures.
Mainly three types of hold times are used; they are Dirty Hold time, Clean Hold Time and Sampling delay time
Dirty Hold Time (DHT): The time period where equipment is stored at appropriate conditions before cleaning is called Dirty hold time
Clean Hold Time (CHT): The time period between cleaning & reusing of equipment is called clean hold time.
Sampling delay time (SDT): The time period from cleaning till the samples residues are measured is called Sampling delay time.
1.1 Dirty Hold Time (DHT):
Every cleaning protocol has dirty hold time as its integral part where the effectiveness of cleaning process is evaluated. It may be of short duration.
In some cases DHT may not be effective like in the end of manufacture it may be difficult to clean solid oral product on tablet press. In such situations the worst case may not be represented by DHT. If the solid represents hygroscopic substance then it can be considered to be significant.
In cases where liquid dries up on surface then it may be difficult to clean where the DHT may not be significant
DHT focuses on soils on equipment surfaces at the start of cleaning process.
1.2 Clean Hold Time (CHT)
CHT is significant when there is microbial contamination after equipment is cleaned. If the equipment remains in wet condition then microbial proliferation can be possible. Sometimes the equipment may be visually clean but later develop microbial contamination which can be combated if protected after cleaning by closing or wrapping it.
CHT may be conducted independent of protocol to evaluate the effectiveness of cleaning procedure.
The bioburden data serves as baseline data for microbial contamination.
1.3 Sampling Delay Time (SDT)
This method is used for swab sampling or separate sampling rinse. For grab sample of final process rinse this hold time is not applicable.
The protocol should specify that the sampling of surface is to be done within a timeframe after cleaning.
Sampling recovery studies should notify the acceptable time.
SDT focuses on residue sampling on surface of the equipment at the end of cleaning process.
SDT evaluates the effectiveness of sampling & analytical methods.
Equipment, hold time issues,
