Amphiphilic Block Copolymers: A Novel Substance for Bitter-Masking in Aqueous Solutions

Area of Science:

• Pharmaceutical Science
• Materials Science
• Colloid Science

Background:

• Suppressing bitterness in liquid formulations, especially for pediatric use, is a significant challenge due to the high dispersibility of bitter molecules.
• Current methods relying on sweeteners often lead to an unsatisfactory taste profile and do not effectively mask bitterness.
• The three-point contact theory explains bitterness perception, but effective masking strategies remain limited.

Purpose of the Study:

• To introduce and investigate the application of amphiphilic block copolymers (ABCs) for suppressing the bitterness of liquid preparations.
• To elucidate the mechanism by which ABCs inhibit bitterness based on molecular interactions.
• To evaluate the impact of ABCs on the pharmacokinetic and pharmacodynamic properties of bitter drugs.

Main Methods:

• Utilized amphiphilic block copolymers (ABCs) as a novel approach for bitterness suppression.
• Investigated the self-assembly behavior of ABCs in aqueous solutions to form association colloids.
• Analyzed the interaction between ABCs and bitter substances using principles of molecular encapsulation and electrostatic interactions.
• Assessed the pharmacokinetic and pharmacodynamic profiles of bitter drugs in the presence of ABCs.

Main Results:

• ABCs demonstrated broad efficacy in inhibiting the bitterness of four representative bitter substances.
• The mechanism involves the self-assembly of ABCs into association colloids that entrap bitter components, reducing their availability to taste receptors.
• Bitter molecules were found to embed within the hydrophobic cavities of ABCs, with interactions that dispersed the positive electrostatic potential of bitter groups.
• Co-administration of ABCs with bitter drugs did not significantly alter their pharmacokinetic or pharmacodynamic parameters.

Conclusions:

• Amphiphilic block copolymers represent a promising new strategy for effective bitterness inhibition in liquid formulations.
• The self-assembly of ABCs into association colloids provides a physical barrier and molecular interaction mechanism for taste masking.
• This approach offers a viable alternative to sweeteners for improving the palatability of bitter medicines without compromising therapeutic efficacy.