Active-elastic instabilities are common phenomena in the biological world, where they may have the aspect of sudden mechanical morphings [1]. Typically, the driving force of the instability mechanisms has a chemo-mechanical nature which makes the instabilities very different from the standard elastic instabilities and also require high skills in computational sciences, due to the multiphysics characteristics of the key phenomenon. An interesting sample of active elastic instability occurs in presence of soft gel-based bodies with small cavities, which can be filled with water or gas or a combination of the two. When the gel body lose its water content, due to a de-hydration process, the content of the cavity is relevant as it can determines the type of observed instability. The aim of the present study is the analysis of the impact of different initial conditions in the mechanical instability. In particular, both chemical and geometrical conditions will be taken into account by considering cavities differently filled and of different size with respect to the capsule size. In particular, the computational analysis will be carried on in successive steps: firstly, symmetrical conditions will be assumed to reduce the dof of the full system and focus on the physics of the problem; secondly, the full three-dimensional problem will be tackled. In both the cases, the computational model is developed by using the weak form formulation in Comsol Multiphysics.