Nestea
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Registered: 13-11-2018
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API content determination via titration
Hello,
i have 2 different brands of an antidiarrheal medication containing Loperamide hydrochloride. 2 mg per tablet.
One is original Immodium and the other one is a generic brand.
My personal experience is, that the generic ones have a much weaker effect than the original one.
And now i am thinking that the generic one maybe contains less than 2mg active ingredient.
I m sure i can determine the content by titration of the HCl salt with NaOH with an pH indicator.
Molar mass of Loperamide hydrochloride is 513,5 g/mol
My plan is to crush up 10 pills (20mg) containing 0.00003894839 mol of HCl and than titrate with a 0,01 mol/L standard solution of NaOH.
To fully neutralize the HCl i should need 3,894839 ml of NaOH solution.
If the Loperamide HCl content is lower, i should need less.
My question is, can i use a pH indicator for this titration like bromothymol blue?
Phenolphthalein changes color at pH 8 , but maybe this can be an option too?
What do you think? would this procedure work, or do you have a better idea?
I know this is a pretty easy task, but i just want to be sure.
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Tsjerk
International Hazard
Posts: 3022
Registered: 20-4-2005
Location: Netherlands
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Mood: Mood
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Depends on what else is in those pills
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Nestea
Harmless
Posts: 15
Registered: 13-11-2018
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Thats a goo question. There are different fillers.
Lactose monohydrate, corn strach, talcum, magnesium stearate in the immodium brand capsule
sodium starch glycolate, microcrystalline cellulose in the generic brand.
can the magnesium stearate interfere the titration? formation of magnesium hydroxide/ Sodium stearate?
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