OBJECTIVE To establish a dissolution test method for vitamin E soft capsules and to investigate the differences in dissolution behavior among samples from different manufacturing sites.

METHODS A systematic investigation was conducted on the effects of critical parameters, including dissolution apparatus(flow-through cell method, paddle apparatus with sinker), dissolution medium(types and concentrations of surfactants), and rotation speed on the dissolution behavior of vitamin E soft capsules. HPLC method was adopted to determine the dissolution quantification at each sampling point.

RESULTS Under the flow-through cell method, the dissolution of vitamin E was slow, with significant differences in dissolution rate across different time points. In the surfactant screening test, Triton X-100 significantly enhanced the solubility of vitamin E in aqueous solution compared to sodium dodecyl sulfate(SDS). Parameter optimization revealed that a rotation speed of 100 r·min^–1 and a Triton X-100 concentration of 10% could effectively promote the transfer of vitamin E from the oil phase to the aqueous phase. Finally, it was determined that the dissolution behavior of vitamin E soft capsules should be investigated by using the paddle apparatus with sinker, 10% Triton X-100, and a rotation speed of 100 r·min^–1.

CONCLUSION The established dissolution method is suitable for quality control of vitamin E soft capsules and provides a methodological reference for the consistency evaluation of vitamin E soft capsules and the development of dissolution methods for lipid-based soft capsules.