Temporally controlled drug delivery systems: coupling of pH oscillators with membrane diffusion.
A novel approach to modulate the release of a drug or an active ingredient that avoids the need for external power sources or electronic controllers is described. By changing the pH of a solution relative to the pKa, a drug, enhancer, or solubilizer may be rendered charged or uncharged. Because only the uncharged form of a drug can permeate across lipophilic membranes, a temporally modulated delivery profile may be obtained with a pH oscillator in the donor solution. Ionizable permeants have a buffer capacity, so the feasibility of coupling the mixed Landoldt pH oscillator with membrane diffusion of nicotine or benzoic acid is demonstrated for a single oscillation.
Giannos
S A
SA
Ciba-Geigy Corporation, Ardsley, NY 10502, USA.
Dinh
S M
SM
Berner
B
B
D001565:Benzoates / Q000737:chemistry; D019817:Benzoic Acid; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration; D008433:Mathematics; D008567:Membranes, Artificial; D013464:Sulfuric Acids / Q000737:chemistry; D013885:Thiosulfates; D013997:Time Factors
D001565:Benzoates; D008567:Membranes, Artificial; D013464:Sulfuric Acids; D013885:Thiosulfates; D019817:Benzoic Acid; C033158:sulfuric acid