Water soluble derivatives of cellulose are widely used in various biomedical and biotechnological applications. Sodium carboxymethyl cellulose was insolubilized in the form of microspheres using aluminium chloride as the crosslinking agent. It was observed that, depending on the preparation medium pH, the spherical product could either be a microsphere with an ionotropic interior or a microcapsule. Various microspheres with different crosslinker, biopolymer, and drug (2',7'-dichlorofluorescein and aldicarb) contents were prepared and their structures, properties, swelling behaviour and release kinetics investigated. The release kinetics could not be described by typical Fickian or non-Fickian approaches.