Disclosed is a method for making low density particles, comprising the steps of (i) providing a powder mixture comprising a swelling agent； (ii) granulating the powder of step (i) with a granulating solution comprising a lipophilic agent into granules； (iii) drying the granules of step (ii). The process may further include coating the granules, adding in an active ingredient and/or a binder. The swelling agent may be a cellulose derivative, the lipophilic agent may be hydrophobic dusty powders and lipidic excipients, preferably from the group consisting of talc, hydrophobic silica, magnesium stearate, glicerides, fatty acid esters or fatty acid, preferably talc, stearic acid glicerides and mixtures thereof and the granulating solution may be an aqueous solution or dispersion an organic solvent, a hydrophobic liquid or water, preferably water. The particle may be further processed into an oral solid gastro-retentive dosage form, such as a tablet, capsule or a sachet.
