Reduction of Bitterness and Enhancing Palatability of Cetirizine Oral Liquid Dosage Forms by Cyclodextrins

The aim of this manuscript is to study cyclodextrins (CDs) as a potential excipient to suppress bitterness and enhance palatability of pediatric liquid preparations for Cetirizine, an extremely bitter drug. Natural α, β and γ CDs; and β CD derivatives such as hydroxyl propyl (HP), randomly methylated (RM) and sulfobutyl ether (SBE) β-CDs were screened in different molar ratios of 1:1, 1:2 and 1:3 for their inhibition of the extremely bitter taste of Cetirizine using the human gustatory sensation test. Cavity size and chemical substitution are dominantly two factors that affect Cetirizine inclusion into natural CDs and β CD derivatives respectively. Syrup and drops formulations were prepared based on the selected α-, γ -and RM β-CDs. The prepared oral liquids were evaluated for palatability, and antimicrobial stability under stress conditions of 40 °C and 75% relative humidity (RH) for three months. Potasium sorbate was found to be an effective preservative for CDs-based oral liquids. RM β-CD-based oral liquids demonstrated dramatic reduction of the bitterness of drops and can be administered without prior dilution as recommended by the manufacturer.