This could be a start to what you are looking for.
http://texastechnologies.com/moisture-control/desiccant/unit-sized-desiccant-requirements.htm
"Desiccant is sold in unit size bags according to Mil-D-3464E. A unit is the amount of desiccant which will adsorb at least 3 grams of moisture vapor at 20% relative humidity, and at least 6 grams of moisture vapor at 40% relative humidity at 25°C.
If the container you need to protect is 950cc or less in volume, a gram-size desiccant requirement chart is available here.
We also have a calculator which will give an estimate of the number of units of Clay or Silica Gel desiccant required for any size Moisture Barrier Bag. Desiccant Estimator
The amount of desiccant/adsorbent required will depend upon the chemical characteristics of the product as well as the volume contents and physical properties of the container. We recommend a stability study be performed to determine exact amounts required. Samples available upon request."