We present a technique to extend a Kripke structure (for intuitionistic logic) into an elementary extension satisfying some property (cardinality, saturation, etc.) which can be ''axiomatized'' by a family of sets of sentences, where, most often, many constant symbols occur. To that end, we prove extended theorems of completeness and compactness. Also, a section of the paper is devoted to the back-and-forth construction of isomorphisms between Kripke structures.
Dzierzgowski, D. (1995). Constants in Kripke Models for Intuitionistic Logic. Mathematical Logic Quarterly, 41(4), 431-441. https://doi.org/10.1002/malq.19950410402 (Original work published 1995)