An abuse-deterrent pharmaceutical composition has been developed to reduce the likelihood of improper administration of drugs, especially drugs such as opiods. In the preferred embodiment, the
drug is modified to increase its
lipophilicity by forming a salt between the
drug and one or more fatty acids wherein the concentration of the one or more fatty acids is one to 15 times the
molar amount of the
active agent, preferably two to ten times the
molar amount of the
active agent. In one embodiment the modified
drug is homogeneously dispersed within microparticles composed of a material that is either slowly soluble or not soluble in water. In some embodiments the drug containing microparticles or drug particles are coated with one or more
coating layers, where at least one
coating is
water insoluble and preferably
organic solvent insoluble. The abuse-deterrent composition prevents the
immediate release of a substantial portion of drug, even if the
physical integrity of the formulation is compromised (for example, by chopping with a blade or crushing) and the resulting material is placed in water, snorted, or swallowed. However, when administered
as directed, the drug is slowly released from the composition as the composition is broken down or dissolved gradually within the GI tract by a combination of
enzymatic degradation, surfactant action of bile acids, and mechanical
erosion.