Abstract: A container (70) for constituting a formulation in liquid form, comprises an elongate outer body (71) split into a first section (72) and a second section (73), along the longitudinal axis thereof, The container (70) has an inner chamber (77) divided into a first compartment (78) and a second compartment (79) by a seal (80). Seal (80) is movable in use between a closed position, wherein the first compartment 78 and the second compartment are sealed thereby, to an open position, wherein the first compartment (78) and the second compartment (79) are unsealed and any contents therein are free to mix together in the inner chamber (77) to form the formulation. The seal (80) is movable from the closed position to the open position by rotation of the first section (72) relative to the second section (73), and the volume of the inner chamber (77) remains unchanged following unsealing. Once the seal (80) has been moved to the open position it is retained in that position.