title: Developing gelatin-starch blends for use as capsule materials.
abstract: Blends of gelatin with up to 50% hydroxypropylated high amylose (80%) corn starch were developed as capsule materials. Poly(ethylene glycol) (PEG) was used as both a plasticizer and a compatibilizer in the blends. In order to prepare hard capsules for pharmaceutical applications using the well-established method of dipping stainless steel mold pins into solution, solutions with higher solids concentrations (up to 30%) were developed. The solutions, films and capsules of the different gelatin-starch blends were characterized by viscosity, transparency, tensile testing, water contact angle and SEM. The linear microstructure of the high amylose starch, and the flexible and more hydrophilic hydroxylpropylene groups grafted onto the starch improved the compatibility between the gelatin and starch. SEM revealed a continuous phase of gelatin on the surface of films from all blends. The water contact angle of pure gelatin and the different blends were similar, indicating a continuous phase of gelatin. By optimizing temperature and incubation time to control viscosity, capsules of various blends were successfully developed. PEG increased the transparency and toughness of the various blends.
authors.affiliation: CPFRR, ERCPSP, School of Light Industry and Food Engineering South China University of Technology, Guangzhou 510640, China.
authors.forename: Nuozi
authors.initials: N
authors.lastname: Zhang
authors.forename: Hongsheng
authors.initials: H
authors.lastname: Liu
authors.forename: Long
authors.initials: L
authors.lastname: Yu
authors.forename: Xingxun
authors.initials: X
authors.lastname: Liu
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Robert
authors.initials: R
authors.lastname: Shanks
mesh_terms: D000688:Amylose / Q000737:chemistry; D002214:Capsules / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D011092:Polyethylene Glycols / Q000737:chemistry; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D013718:Tensile Strength; D014783:Viscosity; D014867:Water / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry
chemical_list: D002214:Capsules; D014867:Water; D011092:Polyethylene Glycols; D005780:Gelatin; D013213:Starch; D000688:Amylose