April Journal-2009.p65 - Association of Biotechnology and Pharmacy

Current Trends in Biotechnology and Pharmacy
Vol. 3 (2) 188-196, April 2009. ISSN 0973-8916
increased, the amount of drug permeated was
increased. This may be a result of the initial rapid
dissolution of the hydrophilic polymers when the
patch is in contact with the hydrated skin, which
results in accumulation of high amounts of drug
on the skin surface and thus leads to the saturation
of the skin with drug molecules at all times (26).
Drug release rate from films containing higher
proportions of lipophilic polymer ERL 100 and
ERS 100 may be contributed to the relatively
hydrophobic nature of polymer which has less
affinity for water. This results in decrease in the
thermodynamic activity of the drug in the film
and decreased drug permeation.
Comparison between the best
formulations of respective series (A-3 and B-4)
revealed that extent of drug release was higher
in case of A-3 (polymers ERL 100 and HPMC)
than B-4 (polymers ERS 100 and HPMC). The
maximum drug permeation from formulation A-3
might be due to higher permeability characteristics
of ERL 100 in comparison to ERS 100. The
formulation A-3 showed an increase in
permeation than the A-4 may be due to decreased
in path length to the movement of drug, as it is
inversely proportional to diffusion rate.
Any vehicle can have three models of
penetration enhancement that is by changing
thermodynamic activity or by improving skin/
vehicle partition coefficient or by altering the
barrier property of stratum corneum.
Propylene glycol (PG) action as a sorption
promoter has been explained in the literature on
the basis of its co solvency effect. Where
thermodynamic activity is considered as main
driving force and also by carrier mechanism, in
which PG partition into the skin and thereby
promotes the movement of the drug into and
through the skin. PG shows penetration
enhancement activity towards 5-fluorouracil (27),
progesterone (28) and estradiol (29).
194
Conclusions
Ex vivo permeation of A-HCl shows that
patches of ERL 100:HPMC is suitable compared
to ERS 100:HPMC patches. The results of the
study show that A-HCl could be administered
transdermally through the matrix type TDDS for
effective control of ADHD. Further work is
recommended in support of its efficacy by long
term pharmacokinetics and pharmacodynamic
studies on human beings.
Acknowledgements: The authors are grateful
to the management of the institute, Sultan-Ul-
Uloom Educational Society, Banjarahills,
Hyderabad for providing the facilities. The gift
samples of Atomoxetine HCl, Eudragit RL 100
and Eudragit RS100 by Aurobindo
Pharmaceuticals, Hyderabad, India is highly
acknowledged.
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