  We examine the phase dependent Helfrich energy and show an Euler-Lagrange
equation on the phase seperation line. This result has already been observed by
e.g. J\"ulicher-Lipowski and later Elliot-Stinner. Here we are able to lower
the regularity assumption for this result down to $C^{1,1}$ for the seperation
line. In the proof we employ a carefully choosen test function utilising the
signed distance function.
