title: Validation of a flow-through diffusion cell for use in transdermal research.
abstract: A flow-through finite-dose diffusion cell has been designed for use in transdermal drug delivery research. The diffusion cell consists of an upper donor chamber and a lower receiver compartment through which a continuous supply of fresh solvent flows. The flow is directed to an automatic fraction collector. To validate the flow-through cell, its performance was compared directly against that of a conventional single-reservoir Franz cell. Homologous alkyl p-aminobenzoates were diffused through dimethylpolysiloxane membranes, and permeability coefficients increased with increasing chain length, reaching a plateau at the butyrate ester for both types of cells. This behavior suggests a shift from membrane-controlled diffusion to boundary layer control. Permeation of the butyrate and valerate compounds was significantly faster when the flow-through cell was used, suggesting that better mixing is obtained through the flow-through cell design. Considering the advantages offered in terms of time and labor saved through its use, the flow-through cell with automatic fraction collector appears to be a viable alternative to the conventional Franz cell.
mesh_terms: D010129:4-Aminobenzoic Acid / Q000008:administration & dosage / Q000138:chemical synthesis / Q000493:pharmacokinetics*; D000279:Administration, Cutaneous; D062365:Aminobenzoates / Q000493:pharmacokinetics*; D004058:Diffusion; D004129:Dimethylpolysiloxanes; D004864:Equipment and Supplies; D008567:Membranes, Artificial; D010539:Permeability; D012995:Solubility; D012997:Solvents
chemical_list: D062365:Aminobenzoates; D004129:Dimethylpolysiloxanes; D008567:Membranes, Artificial; D012997:Solvents; D010129:4-Aminobenzoic Acid