In vitro transdermal delivery of caffeine, theobromine, theophylline and catechin from extract of Guarana, Paullinia Cupana

Heard, C.M., Johnson, S., Moss, G.P. and Thomas, C.P. (2006) In vitro transdermal delivery of caffeine, theobromine, theophylline and catechin from extract of Guarana, Paullinia Cupana. International Journal of Pharmaceutics (1). pp. 26-31. ISSN 0378-5173