Formulation to deter abuse of drugs by smoking

A method of deterring abuse of an oral dosage form of a drug, which can be abused by smoking, which method comprises incorporating into the oral dosage form of the drug a formulation comprising, a physical barrier, which is (i) an additive selected from a molecular sieve, a mesoporous silica, an activated carbon, or a combination thereof, and (ii) a polymeric network of microspheres having an average diameter from about 1.5 μm to about 4.0 μm and comprising a polymeric blend consisting of polylactic acid (PLA) and polycaprolactone (PCL) in a ratio ranging from about 1:9 to about 9:1, wherein, upon heating of the oral dosage form above the melting point of the microspheres, the microspheres melt and entrap the drug, thereby deterring abuse of the oral dosage form of the drug by smoking.