Deuterium pellets are injected into initially pure hydrogen H-mode plasma in order to control H:D isotope mixture. The pellets are deposited in outer 20% of minor radius, similar to that expected in ITER creating transiently hollow electron density profiles. The isotope mixture of H:D ~ 45:55% is obtained in the core with pellet fuelling throughput of similar to previous pellet fuelling experiments in pure deuterium. Inward deuterium transport is consistent with normalised deuterium diffusivity although the higher value could be inferred at the beginning of pellet train.