Quantification of Risperidone Contained in Precipitates Produced by Tea Catechins Using Nuclear Magnetic Resonance

Area of Science:

• Pharmacology
• Analytical Chemistry
• Food Science

Background:

• Risperidone is an antipsychotic medication.
• Tea catechins are antioxidants found in tea.
• Interactions between medications and dietary components can affect drug efficacy.

Purpose of the Study:

• To investigate the precipitation interaction between risperidone and major tea catechins.
• To quantify the amounts of risperidone and catechins involved in precipitate formation.
• To determine which specific catechins are responsible for precipitating risperidone.

Main Methods:

• A mixture of risperidone and eight major tea catechins was prepared in a tartaric acid buffer.
• Precipitates were formed and collected.
• Quantitative 1H-NMR (qNMR) was used to measure the amounts of risperidone and catechins in the precipitates.

Main Results:

• Gallated catechins (ECg, EGCg, Cg, GCg) precipitated risperidone significantly, while non-gallated catechins (EC, EGC, CA, GC) did not.
• 2,3-cis gallated catechins (EGCg, ECg) were more effective in precipitating risperidone than 2,3-trans gallated catechins (Cg, GCg).
• EGCg and ECg were identified as the primary catechins responsible for risperidone precipitation.

Conclusions:

• The efficacy of risperidone may be reduced when co-administered with catechin-rich beverages.
• 2,3-cis gallated catechins, specifically EGCg and ECg, form complexes with risperidone, leading to precipitation.
• This interaction highlights the importance of considering dietary components in medication management.