Reservoir drug release systems were produced by coating drug loaded Carbopol 934P disks with polymer films containing Eudragit RL and dika fat at varying proportions. Uncoated disks produced maximal drug release after 5 hrs at pH 1.2 or 13 hrs at pH 6.8. Under these conditions, drug release occurred mainly by gel erosion and/or Fickian diffusion. Coating the disks with films of the polymer blends, predictably, led to more controlled drug release rates. But the ratio of the polymers in the coatings was found to be the modifying factor in the drug release mechanism. Systems containing less than 50% dika fat in the film coatings had a predominantly zero order release mechanism.
Effect of dika fat content of a barrier film coating on the kinetics of drug release from swelling polymeric systems. Available from: https://www.researchgate.net/publication/12487681_Effect_of_dika_fat_content_of_a_barrier_film_coating_on_the_kinetics_of_drug_release_from_swelling_polymeric_systems [accessed Dec 28, 2015].