Formulation development

In case of API potency calculation during product development, which one is preferable whether lod/water by kf?

LOD is better than water content by KF.


Dear Ankurji,
Thanks for your reply and May i know the reason for that.

both are important.
LOD= Moisture content+Residual solvents

LOD: water+other residual solvents
K.F: water only
finally you should refer to pharmacopoeial reference

LOD may sufficient since residual solvents have their limits.

In formulation development LOD is preferable .

LOD is preferable

Based on route of synthesis/Input put material of API , API manufacture decide which method to be use for API calculation method.

Example:If API manufacture with solvent , its prefer to use LOD method rather then KF method.

Note : LOD method more prefer than KF method for formulation department.

In my opinion, both are different. It is based on manufacturing process. If the material consumed any other solvent than water or with water, then LOD test will be the part of specifications. If only water is used then, water by KF will be part of specifications. e.g. Moxifloxacin/Ciprofloxacin HCl are prepared by reacting Moxifloxacin/Ciprofloxacin bases with solution of HCl in water. so mostly you will see the water by KF in the monograph of these material.

it depends on the individual monograph of that perticular API. You have to follow whatever mentioned in the pharmaceutical monograph if it is mentioned water then use water content otherwise LOD.

Because, LOD will give the both bound and unboung water content of the substance.

Where as water content by KF, will measure only unbound water content of the substance.

Hi sir,
How to fix the average weight for the tablet.
While, trial and error method.
And what are the factors to be considered to fix the average weight for tablets

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Average wt depend upon many factors like
Wt of active/tab(potency)
Tooling(compression punches +Blister Dies)
Nature of excipients.
One common method is as follow
Potency is 250mg
Target weight is 450mg then
mean we have to add 250 mg of excipients
if we add 6% disintegrant that is 30mg
3% binder 15mg
2% glident+lubricant 10mg
so total excipients are 30+15+10=55mg
200-55=145mg add diluent/filler.
Depending upon results amount of disintegrnt,binder etc is increased or decreased by adjusting the amount of filler.

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