Generic and additional names: Ethambutol; (+)-2,2′-(ethylenediimino)di-1-butanol; d-N,N′-bis(1-hydroxymethylpropyl)ethylenediamine; EMB

CAS name: 2, 2′-(1,2-Ethanediyldiimino)bis-1-butanol

CAS registry #: 74-55-5

Molecular formula: C₁₀H₂₄N₂O₂

Molecular weight: 204.31

Intellectual property rights: Generic, first used in TB treatment in 1966

Brand names: Aethambutolum, D-Ethambutol, Dadibutol, Diambutol, EMB, Ethambutol HCL, Etibi, Myambutol, Tibutol

Solubility: Dihydrochloride: Soluble in water, DMSO; sparingly soluble in ethanol; difficult to dissolve in acetone and chloroform [Merck Index]

Polarity: Log P −0.14 [DrugBank]

Acidity/basicity: ETH HCl has two apparent dissociation constants, pKa₁ = 6.35, pKa₂ = 9.35. In solution at neutrality the monohydrochloride predominates¹

Melting point: ETH, 88ºC; ETH HCl, 200ºC [Merck Index]

Formulation and optimal human dosage: Available as 100 and 400 mg tablets. 15 mg/kg daily or up to 25 mg/kg but risk of ocular toxicity. Weekly dose, 30 mg/kg 3 times/week [FDA label].