The present invention provides a band seal for hard capsules filled with PEG, particularly a low-molecular-weight PEG, PEG 200 to 600, the band seal being capable of effectively preventing content leakage through the gap between the body and cap of the capsule and a liquid for preparing the band seal. The present invention further provides a hard capsule filled with PEG, particularly a low-molecular-weight PEG, PEG 200 to 600, the filled capsule being prevented content leakage through the gap between the body and cap of the capsule. The band seal can be prepared using a polyvinyl alcohol, a polyvinyl alcohol copolymer, or a mixture thereof as a main component.
