DRUG TRANSPORT ACROSS NYLON-610 FILMS - INFLUENCE OF SYNTHESIS VARIABLES

Nylon 610 is a hydrophilic polymer with considerable potential as a me mbrane for drug microencapsulation. To better understand drug transpor t through such membranes, the influence of the solvents and monomers u sed in the synthesis of nylon films were examined using a full factori al study. Nylon 610 films were synthesized by an interfacial polyconde nsation reaction using hexamethylenediamine (HD) in the water phase an d sebacoyl chloride (SC) in the organic phase, which was a solvent ble nd of chloroform and trichlorotrifluoroethane at ratios of 1:1, 1:4, a nd 4:1. Monomer concentrations studied were 0.2, 0.4, and 0.6 M with r espect to their appropriate phase, while the monomer ratios were 1:1, 3:1, and 1:3. The molecular weight, porosity, thickness, and crystalli nity of the films were characterized. The transport of potassium chlor ide, hydrocortisone, and m-cresol was studied at 25 degrees C as a fun ction of the syntheses variables. Potassium chloride was selected to m easure the porosity of the membrane. Hydrocortisone and m-cresol, a kn own solvent for nylon 610, were used to study pore and solution-diffus ion transport, respectively. The molecular weight of the films was pro portional to the chloroform concentration. As the molecular weight inc reased, film thickness, porosity, and hydrocortisone permeability incr eased. As the molecular weight decreased, film thickness and porosity decreased, while m-cresol permeability increased. These results can be explained on the basis of HD ability to readily partition into a good solvent such as chloroform permitting high molecular weight polymer t o form before precipitation.