Materials and methods relating to encapsulation

Methods are provided for producing microcapsules based on two oppositely charged polymers, in particular to optimise the permeability and mechanical stability of microcapsules. The capsules are formed by introducing liquid droplets from an aqueous solution of a charged (usually anionic) polyelectrolyte (or a blend) into an aqueous solution of a counter-charged (usually cationic) polyelectrolyte (or a blend). The membrane is formed during the reaction time of the opposite-charged polymers. The capsules are optionally subject to an additional coating step.The methods are characterised by one or more of the following: the use of polyvinylamine (PVAm) of low Mw (