A hard capsule which is made mainly of a polymer or copolymer obtained by polymerizing or copolymerizing at least one polymerizable vinyl monomer in the presence of polyvinyl alcohol and/or a derivative thereof. Unlike conventional hard capsules, this hard capsule can be filled with a solvent (e.g., polyethylene glycol) for a sparingly soluble drug ingredient.
1. A hard capsule, that is made mainly of a polymer or copolymer obtained by polymerizing or copolymerizing at least one polymerizable vinyl monomer in the presence of polyvinylalcohol and/or a derivative thereof, wherein the polymerizable vinyl monomer is a compound represented by general formula
H 2 C═C(R 1 )—COOR 2 [1].
2. A hard capsule, that is made mainly of a polymer or copolymer obtained by polymerizing or copolymerizing at least one polymerizable vinyl monomer in the presence of polyvinylalcohol and/or a derivative thereof, wherein the polymerizable vinyl monomers are acrylic acid or methacrylic acid and methyl methacrylate, and the acrylic acid or methacrylic acid is 5 to 50 wt % of the total amount of the polymerizable vinyl monomers, and the methyl methacrylate is 50 to 95 wt % of the total amount of the polymerizable vinyl monomers.
3. A hard capsule, that is made mainly of a polymer or copolymer obtained by polymerizing or copolymerizing at least one polymerizable vinyl monomer in the presence of polyvinylalcohol, wherein the polymerizable vinyl monomer is a compound represented by general formula
H 2 C═C(R 1 )—COOR 2 [1].
4. The hard capsule according to claim 1 or 3 , wherein the polyvinylalcohol and/or derivative thereof is 20 to 95 wt %, and the polymerizable vinyl monomer(s) is/are 5 to 80 wt %.
5. The hard capsule according to claim 1 or 3 , further containing a gelating agent.
6. The hard capsule according to claim 1 , wherein the inside of the capsule is filled with polyethylene glycol having a degree of polymerization of 2000 or less or a derivative thereof.
7. The hard capsule according to claim 1 , wherein the inside of the capsule is filled with an ether derivative of diethylene glycol.
8. The hard capsule according to claim 6 , wherein a thickener is further added to the inside of the capsule.
9. A hard capsule, that is made mainly of a polymer or copolymer obtained by polymerizing or copolymerizing at least one polymerizable vinyl monomer in the presence of polyvinylalcohol, wherein the polymerizable vinyl monomers are acrylic acid or methacrylic acid and methyl methacrylate, and the acrylic acid or methacrylic acid is 5 to 50 wt % of the total amount of the polymerizable vinyl monomers, and the methyl methacrylate is 50 to 95 wt % of the total amount of the polymerizable vinyl monomers.