The invention relates to a process for preparing a chitosan-containing microcapsules and emulsions of an oil including the steps of (a) forming an oil-in-water emulsion by homogenizing said oil into an aqueous solution containing an anionic emulsifier; and (b) adding to the emulsion obtained in (a) an aqueous chitosan solution while continuously homogenizing the mixture to give a stable emulsion, which is converted into microcapsules by using the proper electrolyte and pH changes. Also encompassed are preparations including as active ingredient a lice repelling agent, vitamin E or a UV radiation photoprotectant. The preparations may be sustained-release or long acting preparations.