Boonyanupap N.Puttipipatkhachorn S.Charoenthai N.Sungthongjeen S.Mahidol University2023-06-182023-06-182022-01-01Science, Engineering and Health Studies Vol.16 (2022)https://repository.li.mahidol.ac.th/handle/123456789/86630The purpose of this work was to create double coated floating capsules using gas formation. Theophylline was used as a model drug. Theophylline and hydroxypropyl methylcellulose (HPMC) were physically blended and filled in hard capsules. Then, they were coated with a layer of a gas producing agent (NaHCO3) and a gas-entrapped membrane (i.e., EuRL30D, EuRS30D). The impact of types of gel-forming polymers, and gas-entrapped membrane's coating types and levels on floating characteristics and drug release from the floating capsules was investigated. Optimum formulations could float immediately and maintain buoyancy longer than 8 h. The increased viscosity of the high molecular weight HPMC in the floating capsules resulted in a delayed drug release, compared to the low molecular weight HPMC-containing capsules. The floating capsules coated with EuRS30D released the drug more slowly than those coated with EuRL30D. Due to EuRS30D demonstrated relatively low drug release, EuRL30D appeared to be a promising option for gas-entrapped membranes. Drug release was decreased as the gas-entrapped membrane's coating level was increased, resulting from a thicker film. The floating capsules with good floating abilities and sustained drug release were obtained in this investigation.MultidisciplinaryArticleSCOPUS10.14456/sehs.2022.582-s2.0-8514829477226300087