Purpose:
To develop a transdermal betahistine (BTH) delivery
system using different pressure sensitive adhesives (PSAs)
including acrylics, polyisobutylene and styrenic rubber
solution.
Methods:
Formulations were prepared
by solvent casting and adhesive transfer method. PSAs -
acrylate vinylacetate (AVA), hydrophilic acrylate (HA),
acrylic non-curing (ANC), polyisobutylene (PIB), and
tackified styrenic rubber solution (TSR) - were
evaluated for their suitability in terms of miscibility,
maximum drug loading, effect on tack property and in
vitro permeation through excised guinea pig skin.
Furthermore, one of the PSAs was tested in relation to
effect of penetration enhancers on tack property, in
vitro permeation, in vivo patch adhesion performance and
stability.
Results:
Only formulations prepared with AVA and HA were stable.
Increased drug loading in these PSAs significantly
reduced tack. In vitro permeation data across guinea pig
skin demonstrated that BTH flux from from the
formulation containing HA (F1) was significantly (p <
0.001) higher than that containing AVA (F2).
Formulations containing 2 % enhancer showed good tack.
Specifically, the formulation containing 2 % oleic acid
as enhancer not only showed the highest permeation but
also good tack property, non-irritancy for up to 36 h
and stability under accelerated conditions.
Conclusion:
The formulation
containing HA as the PSA and 2 % oleic acid as enhancer
demonstrated a good potential for further development to
an adhesive-type transdermal delivery system for BTH.
Keywords:
Meniere’s syndrome, Transdermal delivery, Betahistine,
Pressure-sensitive adhesives, Penetration enhancers.
