Sustained-​release captopril tablets and capsules were prepd. by using the principle of gastric floating approach in order to retain the drug in the stomach for an extended period of time, thus increasing the residence time in the proximal region of the GI tract.  Hydroxypropyl Me cellulose (HPMC) 4,​000 and 15,​000 at a drug-​polymer ratios of 1:1 and 2:3 were used for the prepn. of the tablets and the capsules by the wet granulation method employing Eudragit RS100 and RSPM as granulating agents in a 10 and 25​% wt.​/wt. ratio of the drug.  Sodium bicarbonate at a 3​% wt.​/wt. ratio of the tablet or capsule formulation was used as a CO₂ generating agent.  A single station tablet press was used for making the tablets.  The tablets and capsules were evaluated with regard to their floating as well as their phys. and in-​vitro release properties.  The capsules have an immediate floating, while the onset time for the tablets to float was about 20 min in simulated gastric fluid (SGF)​.  The tablets and the capsules maintained their floating characteristics during the release study (8 h) in the SGF.  The tablets had good phys. characteristics.  An increase in the polymer ratio resulted in a prolongation in the release time.  The release profile from the different batches followed Higuchi model with a correlation coeff. >0.990.