Drastic differences between the release kinetics of two highly related porphyrins in liposomal membranes: mTHPP and pTHPP

•Minor structural differences of hydrophobic porphyrins can distinctly influence their release properties from liposomes.•mTHPP (meta OH) redistributes much slower than pTHPP (para OH) from liposomal membranes.•Reversed-phase HPLC experiments indicate a higher partition coefficient for mTHPP.•In MD simulations, mTHPP has a higher tendency for hydrogen bonding, a larger tilt angle and locates deeper in the membrane.•Both HPLC and MD simulation results support the observed differences in release and redistribution of mTHPP and pTHPP from liposomal membranes.