title: Novel starch-based PVA thermoplastic capsules for hydrophilic lipid-based formulations.
abstract: For decades, gelatin has been used in the rotary die process as a shell-forming material of soft capsules because of its unique physicochemical properties. However, with respect to the encapsulation of comparatively hydrophilic lipid-based formulations, gelatin has one considerable drawback: Immediately after production, the capsule shell contains a large amount of water (up to 35%). There is the potential for water to migrate from the capsule shell into the formulation, which will lead to a decrease in drug solubility and, in turn, the potential for drug crystallization. The present study introduces a novel capsule material that was obtained from extrusion. The starch-based polyvinyl alcohol thermoplastic capsules (S-PVA-C) mainly comprised a blend of starch and PVA. Gelatin and the novel material were used to encapsulate a hydrophilic lipid-based system of fenofibrate. Considerable water migration was observed from the soft gelatin shell to the hydrophilic formulation during drying and drug crystallization resulted in soft gelatin capsules. In contrast, S-PVA-C displayed no substantial water exchange or drug crystallization upon storage. The thermoplastic capsule material further exhibited more surface roughness and higher resistance to mechanical deformation compared with gelatin. In conclusion, S-PVA-C provided a robust drug product following encapsulation of a rather hydrophilic lipid-based formulation.
authors.affiliation: University of Applied Sciences and Arts Northwestern Switzerland, Institute of Pharma Technology, Muttenz, Switzerland.
authors.forename: Zdravka
authors.initials: Z
authors.lastname: Misic
authors.forename: Katharina
authors.initials: K
authors.lastname: Muffler
authors.forename: Georg
authors.initials: G
authors.lastname: Sydow
authors.forename: Martin
authors.initials: M
authors.lastname: Kuentz
mesh_terms: D002214:Capsules / Q000737:chemistry*; D011345:Fenofibrate / Q000008:administration & dosage; D005780:Gelatin / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D000960:Hypolipidemic Agents / Q000008:administration & dosage; D008055:Lipids / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D012995:Solubility; D013213:Starch / Q000737:chemistry*
chemical_list: D002214:Capsules; D000960:Hypolipidemic Agents; D008055:Lipids; D005780:Gelatin; D011142:Polyvinyl Alcohol; D013213:Starch; D011345:Fenofibrate