Stability Studies on L-Ascorbic Acid DL-Alpha-Tocopherol Phosphoric Acid Diester Potassium Salt (EPC-K)

The document reports on the stability of L-ascorbic acid dl-alpha-tocopherol phosphoric acid diester potassium salt (EPC-K), a compound with properties of vitamins E and C, used in hair care products to prevent dandruff and itching, which can contribute to hair loss. Stability tests of EPC-K in 75% ethanolic solutions across pH levels 2-10 were conducted by storing at 50 degrees Celsius for 30 days and by exposing to sunlight for 30 days. EPC-K showed significant decomposition only at pH 2 (50% loss) and under sunlight (25% loss). The main decomposition product was identified as tocopheryl phosphate (EP), indicating hydrolysis as the decomposition pathway. EPC-K also decomposed up to 20% in 30 days at 50 degrees Celsius in solutions with 0-30% ethanol concentration. Nuclear magnetic resonance (NMR) studies and micelle formation tests suggested that EPC-K forms micelles in low ethanol concentrations, which may lead to instability. The hydrolytic decomposition of EPC-K was determined to be a pseudo first-order reaction with an activation energy of 16.98 kcal/mol.