title: Emulsion type new vehicle for soft gelatin capsule available for preclinical and clinical trials: effects of PEG 6000 and PVP K30 on physicochemical stability of new vehicle.
abstract: To prevent temperature-dependent gel-sol transformation of an o/w emulsion type new vehicle system for a soft gelatin capsule, which may be available for both preclinical and clinical trials, the basic new vehicle formulation (PEG 400:purified water:medium chain triglyceride:polyoxyethylene (20) cetylether = 77:10:10:3) was modified by partially (1, 2 or 3%) replacing PEG 400 with PEG 6000 or PVP K30. When 2 or 3% of PEG 400 was replaced with PEG 6000, temperature-dependent gel-sol transformation was prevented at temperatures below 40 degrees C, and the vehicle appeared to be stable during 8 weeks of storage at 4 to 40 degrees C; the particle size distribution remained unchanged. When 1% of PEG 400 was replaced with PEG 6000, gel-sol transformation was not prevented, though phase separation was not observed at sol state, and the particle size distribution was shifted to be in a larger particle size range after 2 weeks of storage. When PEG 400 was partially (1, 2 or 3%) replaced with PVP K30, temperature-dependent gel-sol transformation was not prevented and, after 2 weeks of storage at 40 degrees C, the particle size distributions of the vehicles were shifted to be in a larger particle size range and the vehicles were separated into two layers. These results suggested that a small amount of PEG 6000 plays an important role in preventing temperature-dependent gel-sol transformation of our developed vehicle system.
mesh_terms: D002214:Capsules; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004355:Drug Stability; D004655:Emulsions; D005780:Gelatin / Q000737:chemistry*; D014677:Pharmaceutical Vehicles / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry*; D013696:Temperature; D014783:Viscosity