Drying time management

Dear Experts;
Can you tell me what should be the time to fix for drying in next bathes.
The details of validation batches are as follows
Batch no Drying temp Drying time Remark
(Lim: 45 to 50°C) (to comply the results)

12001 47-49 10 hours

12002 45 - 48 12 hours

12003 42-48 15 hours ;
During drying of batch no 12003 temp found lower than range due to manual error.

Thanking you…
G. Kumar

What kind dryer equipment do you have?

If it is a fluid bed dryer, most of them have a process end-point programmable for exhaust air temperature. If you use a fixed inlet air temp, the exhaust air temperature is directly correlatable to the level of humidity present in your batch.

It is a Tray dryer.

[COLOR="#000000"]An accurate prediction of commercial drying cycle time can be valuable for product quality and estimating manufacturing costs.
Drying is a science no matter you use in API production facility or in formulation facilities where you dry granules.
Drying time is evaluated based on Solvent content in the Product Vs drying time.
It will be useful if you plot a curve rather than going by emperical calculations which lead to spoilage of both product and process ultimately causing loss of revenue and time to your company.
A product is dried till it attains its critical moisture content.
This is based on the API added, Excipients and method of granulation using solvents like IPA and or Starch paste.
The temperature stability of the product must be considered in setting the operating conditions to ensure that it will not be heated above the allowable limit.
This time must be re-evaluated at your pilot lab or R&D labs.
We do not know the amount of moisture content that is initially present and also mositure content that it must retain.
Your technology transfer should optimize this parameter.
Your tech and R&D guys can help you out based on your product charecterestics.
Do not waste your time here on this issue.
Better spend your valuable time in lab and obtain correct parameter.
Drying is a very Critical Step and a in-process control step in manufacturing operation.[/color]

The same principle applies. Drying is a mass and heat transfer process. The temperature of your product will be that of the wet bulb temperature indicated by the vapor concentration in the drying atmosphere and the dry bulb temperature (the temperature that you are applying) plus the excess heat that isnt used to evaporate the solvent.

In short therms, as long as it is wet, the product temperature will be the same, then when its humidity content lowers (be it of any solvent), the temperature will rise quickly. So, you need to monitor the product temperature and keep sampling at different time intervals and determine humidity content. With this info at hand, you can easily create a drying graph that will give the optimum time, given a fixed heating temperature.

But, as Durga Prasad says, maybe its work for another department.