I am working on a sepiolite-based clay nanocomposite for a targeted drug delivery system. Nearly all drug quantity is loaded into sepiolite when the drug EPI is loaded into sepiolite. But when the PBS or acetate buffer is used very little amount of EPI has been released. On the other hand, if the DMSO is used as a dissolution medium, a comparatively huge amount of EPI is released.

What could be the reason that sep is not releasing EPI on PBS 7.4 or acetate buffer (pH4) or pH buffer (pH 1.2), but releasing a large amount of EPI in DMSO?

Your help in this regard would be highly appreciated.

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