A sustained release drug delivery system comprising spores from sporogenous probiotic bacteria and drug, wherein said spores from sporogenous probiotic bacteria act as carrier for sustained release of said drug and a process of preparation of the same. The present invention further provides a sustained release dosage form having a core comprising spores from sporogenous probiotic bacteria, drug and mucoadhesive substance, preferably exopolysaccharides wherein said spores from sporogenous probiotic bacteria act as carrier for sustained release of said drug and a further coating on the core comprising mucoadhesive substance, preferably exopolysaccharides, binder, lubricant, diluent and disintegrating agent and a process for preparation of the sustained release dosage form.
