title: New mode of drug delivery: long term autonomous rhythmic hormone release across a hydrogel membrane.
abstract: This note demonstrates a novel mode of rhythmic drug delivery, which is independent of external modulation or physiological stimulation. Rhythmic behavior is attributed to negative, nonlinear feedback between the swelling state of a hydrogel membrane and the enzymatic conversion of glucose to hydrogen ion. The system pulsates in the presence of a constant level of glucose, thus distinguishing it from insulin delivery devices that respond to changes in glucose concentration. As an example, gonadotropin-releasing hormone (GnRH) was released in short, repetitive pulses over 1 week.
authors: Department of Pharmaceutics, 9-177 Weaver-Densford Hall, University of Minnesota, 308 Harvard St. S.E., Minneapolis, MN 55455, USA.
authors: Gauri P
authors: GP
authors: Misra
authors: Ronald A
authors: RA
authors: Siegel
mesh_terms: D001692:Biological Transport; D003692:Delayed-Action Preparations / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000295:instrumentation* / Q000379:methods*; D005300:Fertility Agents, Female / Q000493:pharmacokinetics; D007987:Gonadotropin-Releasing Hormone / Q000493:pharmacokinetics*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000493:pharmacokinetics*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D010507:Periodicity; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D005300:Fertility Agents, Female; D008567:Membranes, Artificial; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007987:Gonadotropin-Releasing Hormone