[The effect of additives on the availability of atropine in transdermal therapeutic systems]

The present paper investigates the effect of 13 liquid and semisolid additives on the pharmaceutical availability of atropine from dermal silicone matrices. The hydrophobic additives isopropylmyristate, linseed oil, methylsilicone oil, olive oil, liquid paraffin, the tensides Abil B 8842, Spans 20, 40, 60, Tweens 40 and 80, and the hydrophilic additives polyethylene glycol 200 and 400 were employed for the study. The additives were incorporated into the silicone matrices in the amount of 5%. The paper aimed to replace polyethylene glycol, used in dermal silicone matrices at present, with a different additive. When using liquid or semisolid additives, a 2 to 3.5-fold increase in pharmaceutical availability of atropine in contrast to the control sample was achieved. The highest values of pharmaceutical availability were obtained with the use of isopropylmyristate, polyethylene glycol 400, olive and linseed oils, and Span 20. The paper discusses the effect of the individual additives on the mechanism of release of atropine from silicone matrices.