In this paper, the authors consider the use of inter-packet encoding at the source node to improve the delay performance of data block transmissions in a multipath communication scenario. First they propose a formal derivation to obtain the coding ratio and the per-path packet allocation that minimizes the data block delay. Then, they validate this model through an experimental campaign carried out in a testbed in close-to-real conditions. The proposed encoding scheme is also compared with fixed multiplexing criteria previously proposed in the literature for multipath communications scenarios. Their evaluation shows the benefits of the inter-packet encoding specially when packets travelling through the paths experience unbalanced service rates and heavy tail delays.