Plasticizers are used mainly for oral solid dosage forms. Plasticizers are added to the polymers used as film forming agents in order to make the polymer pliable and soft, enhancing the flexibility and plasticity of the films. They play a vital role in the formulations like gastro-retentive films, ocular films, transdermal films, buccal films, oro-dispersible films and are added to these products to reduce the glass transition temperature facilitating the thermal stability of the drug and other ingredients. They are considered effective in retarding drug release in acid media.