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I am formulating a drug which shows pH dependant solubility, having
higher solubility in basic pH. The drug is also soluble in acidic pH
but with SLS.
The addition of SLS does increase the solubility but also cause
gelling of the drug. The reference product contains more than 60%
drug. Would the gelling phenomenon observed in solution have a role
over drug absorption and bioavailability?
Literature says that the drug shows variable absorption. Is the
gelling tendency a reason for such a phenomenon.
Thank you in anticipation.
Regards,
Ankur
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I am formulating a drug which shows pH dependant solubility, having
higher solubility in basic pH. The drug is also soluble in acidic pH
but with SLS.
The addition of SLS does increase the solubility but also cause
gelling of the drug. The reference product contains more than 60%
drug. Would the gelling phenomenon observed in solution have a role
over drug absorption and bioavailability?
Literature says that the drug shows variable absorption. Is the
gelling tendency a reason for such a phenomenon.
Thank you in anticipation.
Regards,
Ankur
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Ankur,
Whats the percentage of SLS you are using? As the amount of SLS
increases, more viscous gel network will be formed which will reduce
the drug release.
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Dear Ankur,
Ph dependent solubility profile gives you a window of opportunity to
try to prepare base addition salt of this drug, if the pKa is
preferably >8. Getting it solubilized in the presence of a surfactant
does not offer a useful option. The gelling phenomena may contribute
to variation in exposure. However. high variability could be due to
its being a substrate of pgp efflux transporter and/or gut
metabolizing enzymes and may not be directly connected with bio-
pharmaceutical issues.
regards,
V. Sihorkar
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Dear Ankur,
Kindly read the pKa of the drug as <8 (or preferably <4) for formation
of a stable base addition salt.
regards,
Vaibhav
Vaibhav Sihorkar, Ph.D
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