Dear all.
What is the justification of different dissolution medium for Loperamide hydrochloride capsule and loperamide hydrochloride tablet in USP, though both are oral solid dosage form?
Dear Atanu,
The media for lopramide tablets and capsules are:
Capsules: buffer pH 4.7
Tablets 0.1N HCl
As you know, that tablets must undergo disintegration before dissolution.Disintegration should be carried out in the stomach (the best medium for lopramide HCl disintegration), hence the use of 0.1N HCl. Capsules undergo dissolution without the need to be disintegrated and since this opiate derivative acts on the gut wall, dissolution should occur in the gut pH which is close to 4.7 (5.0).
Hoping this will be helpful,
Rafik
Dear Rafik,
Thanks for answer. I think disintegration will be applicable to both the dosage form. So why the dissolution medium is different ? and both are having same absorption window.
Thank you Behera for question and Rafiq and Patil for answers. If the dissolution medium is pH 4.7 for "modified/controlled/enteric coated" tablet, then Rafiq's answer is correct. Not otherwise.
Both tablet and capsule shell will have to disintegrate for dissolution of drug. As the transit time of stomach is 3-4 hrs, I think dissolution of simple capsule and simple tablet will occur in stomach at pH 1.2.
Dear Jagadevappa S Patil, can you please elaborate this issue little more. I believe that what is in USP is true, but I am not able to understand yet.
It is necessary to understand that what is selected for dissolution testing in the USP is somewhat arbitrary. It is not based on science p- it is based on the submissions to the FDA for product approval. The dissolution test is a long way away from actually being a biomimetic test procedure and that is why we find many methods in the USP that have no physiological logic behind them. In this case I would guess that the capsule and tablet were developed by different companies and therefore they were separate submissions to the FDA and, on the approval of the FDA submission, the USP has no alternative but to accept whatever was in the registration files.
Just to let you know - there is a specialist group on Linked In for dissolution which might be of interest
Yes can you please name it, i will be glad to join...Once again thanx a lot...
Hi Atanu,
Did you ever face issue like drop in dissolution of loperamide tablet upon storage?
Hi Jitendra,
R u got probable cause of drop in dissolution ? Also lets know which media selected for dissolution
- Badges
- Science topic
- Similar topics
- Statistics
- Survey