Valproic acid (VPA; valproate; di-n-propylacetic acid, DPA; 2-propylpentanoic acid, or 2-propylvaleric acid) was first synthesized in 1882, by Burton. FDA approved valproic acid for the treatment of manic episodes associated with bipolar disorder, for the monotherapy and adjunctive therapy of complex partial seizures and simple and complex absence seizures and adjunctive therapy in patients with multiple seizure types that include absence seizures and for the prophylaxis of migraine headaches. The mechanisms of VPA which seem to be of clinical importance in the treatment of epilepsy include increased gamma-aminobutyric acid (GABA)-ergic activity, reduction in excitatory neurotransmission, and modification of monoamines. Recently, it was discovered that the VPA is a class I selective histone deacetylase inhibitor. This activity can be distinguished from its therapeutically exploited antiepileptic activity.

Aspirin is a nonsteroidal anti-inflammatory drug. Aspirin is unique in this class of drugs because it irreversibly inhibits both COX-1 and COX-2 activity by acetylating a serine residue (Ser529 and Ser516, respectively) positioned in the arachidonic acid-binding channel, thus inhibiting the synthesis of prostaglandins and reducing the inflammatory response. The drug is used either alone or in combination with other compounds for the treatment of pain, headache, as well as for reducing the risk of stroke and heart attacks in patients with brain ischemia and cardiovascular diseases.

Methyl salicylate (or methyl 2-hydroxybenzoate), also known as wintergreen oil, is a natural product and is present in white wine, tea, porcini mushroom Boletus edulis, Bourbon vanilla, clary sage, red sage and fruits including cherry, apple, raspberry, papaya and plum. Methyl salicylate is topically used in combination with methanol and under brand name SALONPAS to temporarily relieves mild to moderate aches and pains of muscles and joints associated with: strains, sprains, simple backache, arthritis, bruises. The precise mechanism of action of methyl salicylate is not known, but there is suggested, that it cause dilation of the capillaries thereby increasing blood flow to the area.

Gentisic acid is an active metabolite of salicylic acid degradation, which possesses a broad spectrum of biological activity, such as anti-inflammatory, antirheumatic and antioxidant properties. The antioxidant activity and radioprotective properties of gentisic acid are exerted by its phenoxyl group. It is also used in cosmetics as a skin-whitening agent for the treatment of skin pigmentary disorders by influencing the synthesis of melanin through inhibition of melanosomal tyrosinase activity Gentisic acid is also a biomarker of Renal Cell Carcinoma.

Guacetisal (Broncaspin) is a bronchomucotropic synthesized by the Bayer Italia S.p.A. Research Laboratories. It is obtained from the esterification of acetylsalicylic acid with guaiacol. Guacetisal was used for the treatment of chronic bronchitis and other inflammatory diseases of the respiratory tract. Guacetisal, used rectally, proved to be a valuable instrument for anti-inflammatory and anti-cough treatment in acute diseases of the airways in infancy.