Butterfly pea flower was collected from the
botanical garden at Faculty of Pharmaceutical Sciences,
Chulalongkorn University. Fifteen grams of fresh butterfly
pea petals were blended (Moulinex, France) with
600 ml of vehicle solution (1.0% MP, 0.1% PP in
Deionized (DI) water) to a uniform consistency and filtered
twice through 4-layers of cheesecloth. Filtrate was
collected and the pH of the solution was measured
and adjusted to 4, 7, and 10 using 1 N sodium hydroxide
or 10% citric acid solution. The extract solution was
further used in the stability studies.