HPLC Separation of Acedoben and Inosine on Zodiac HST HB Column

Inosine pranobex is an antiviral agent composed of inosine and dimepranol acedoben—a salt of acetamidobenzoic acid and dimethylaminoisopropanol. While this combination does not act directly on viral particles, it functions as an immunostimulant, and is primarily used in the treatment of subacute sclerosing panencephalitis, a rare complication of measles, especially when combined with intrathecal interferon therapy.

Due to the high polarity of both components, traditional chromatographic retention is challenging. However, both compounds can be effectively retained and separated under anhydrous (water-free) conditions using a Zodiac HST HB column, which operates on hydrogen-bonding interaction. The method utilizes a gradient elution with acetonitrile (ACN) and methanol (MeOH) and includes a volatile buffer system (0.1% formic acid and 0.01% ammonium formate), making the method fully LC/MS-compatible. Detection is typically performed at 270 nm using UV, though LC/MS can also be employed for greater sensitivity.