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Dear All,
If we want to do the clinical study inorder to test the efficacy of
two products which different appearance of tablet , how could we avoid
the bias that may occur. Some parameters that we will measure are
subjective so if possible we still want to do blind the patients. If
give me some suggestion.
Best Regards,
Wichittra
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Dear Wichittra,
One way of doing this is by what is called the double dummy technique.
In
this, if you have two groups of patients receiving tablets A & B, you
give
placebo of B to patients receiving active A, and placebo of A to
patients
receiving active B. Since both groups of patients receive 2 tablets
each (1
active and 1 placebo), they and the Investigators will be blinded.
Thus you
can avoid bias in your assessments. You can refer to 'A guide to
Clinical
Trials', By Bert & Spilker for details of this design. Hope this helps.
Regards,
Dr Srinivas Sidgiddi
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Dear Wichittra,
We can give similar external coatings to the tablets, which will make
them look similar !!!
Regards
Dr.Sridhar
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1. An assigner/coder apportions subjects to the groups and knows which
subjects get which drug .
2. The doser administers the drug (blind to which drug is being given)
3. The Study Director/Principal Investigator reviews safety
/clinical/cageside observations but is blind to which drug was given)
4. The clinical chemist analyzes samples and must report out of range
results. If the drug is associated with an effect on the safety
measures,
the clinical chemist will also be able to identify group and drug
assignment.
5. The bioanalyst analyzes samples but does not report data to anyone
(drug
will be apparent by analysis, hopefully and data will not be relased
until
the end of the study.
6. At the completion of the study, the clinical/safety/cageside
analyses,
the dosing records and the assigners records and the bioanalytical
results
are collected and collated for the report.
I do not know how you could avoid deductions re drug due to items 3
and 4.
Ed F. O'Connor,PhD
email: efoconnor.at.cox.net
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Hello Forum.
On the subjct of blinding tablets I recently found someone saying that
it's not allowed to use gelatin capsules to cover them. I know that
is the case for critical studies submitted to regulatory bodies, but
this was about designing a study for internal decision making reasons.
It seems to me that the effect of the capsules is negligible unless
you have to use several, when they can stick together en masse in the
stomach and that would slow absorption... but even then the effect is
not large and it applies equally to all treatments, since the capsule
appearance and numbers have to be the same each time.
Does anybody in the forum have any information on the difference that
capsules actually make?
Thanks
Andrew Sutton
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Have the patient be truly blindfolded to them.
Ed F. O'Connor,PhD
email: efoconnor.aaa.cox.net
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Hi Ed,
The trouble with simple blindfolding is that many compounds have a
unique taste and tablets are often different sizes which can lead to
unblinding if, for example the subjects know that there will be 3
doses of one drug and one of another or if there is any effect that is
dose related. Also, volunteers talk to each other and try to guess
what they have received and tell the others before they get the same
dose.
Overall I think it is much the best to make all the doses look, feel
and taste the same if possible and, unlike some regulators I also feel
that easily outweighs any theoretical variation that capsules
introduce into absorption. However, I'd gladly stand corrected if
there is hard evidence that they do make a significant difference.
Cheers
Andrew Sutton
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It gets too complicated to mask with gymnemic acid or jujube extracts.
Capsules seem the best option.
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