Gels are often used for the delivery of drugs because they have rheological properties that will give a long residence time. Most pharmaceutical gels consist of 99% water and a polymer matrix that will not hinder the release of drugs with a small molecular weight. To fully take advantage of the residence time, it is necessary to have a sustained drug release. In this paper it is suggested that surfactant micelles can be used to control the release from gels. The in vitro release under physiological conditions of ®ve parabens from four different poly(acrylic acid) gels (Carbopol 934, 940, 1342) and one gellan gum (Gelrite) gel was measured using a USP dissolution bath modi®ed for gels, and the diffusion coef®cients were calculated. The diffusion coef®cient of uncharged parabens was generally lower in gels with lipophilic modi®cations, such as C1342, and the greatest effect was seen for butylparaben, with a diffusion that was 25% lower than that in C934 (lacking lipophilic modi®cation). Addition of surfactant micelles to gels delayed the release of all the uncharged drugs in all types of gels studied. The slowest release was seen for butylparaben in a lipophilically modi®ed gel with micelles present. The diffusion coef®cient in such a system was almost 30 times smaller than that in C934 without micelles.