The present disclosure relates to a method including exposing a composition comprising a wax-microsphere matrix to a first melt-condition, wherein said wax-microsphere matrix comprises a wax component and a plurality of lyophilised microspheres, wherein said plurality of lyophilised microspheres comprise one or more reagent, whereby exposing said composition comprising said wax-microsphere matrix to said first melt-condition melts the wax component; exposing said composition to a first release-condition to rehydrate at least one lyophilised microsphere; and exposing said at least one rehydrated lyophilised microsphere to a separation-condition to separate said wax component from said at least one rehydrated lyophilised microsphere. Also disclosed are methods of preparing a wax-microsphere matrix and releasing one or more reagent from a wax-microsphere matrix as well as compositions. Also disclosed are cartridges with a reagent reservoir including the compositions described herein. Also disclosed are systems for controlling release of one or more reagent including the compositions described herein.