title: In vitro evaluation of sol-gel processed spray dried silica gel microspheres as carrier in controlled drug delivery.
abstract: The objective of this study was to evaluate sol-gel-derived spray dried silica gel microspheres as carrier material for dexmedetomidine HCl and toremifene citrate. The drug was dissolved in sol-gel processed silica sol before spray drying with Büchi laboratory scale equipment. Microspheres with a low specific surface area were spherical by shape with a smooth surface without pores on the external surface. The particle size distribution was quite narrow. The in vitro release of toremifene citrate and dexmedetomidine HCl showed a dose-dependent burst followed by a slower release phase, that was proportional to the drug concentration in the concentration range between 3.9 and 15.4 wt.%. The release period for toremifene citrate was approximately 10 days and for dexmedetomidine HCl between 7 and 50 days depending on drug concentration. Spray drying is a promising way to produce spherical silica gel particles with a narrow particle size range for controlled delivery of toremifene citrate and dexmedetomidine HCl.
authors.affiliation: Pharamaceutical Development Department, Orion Corporation, Orion Pharma, PO Box 425, FIN-20101, Turku, Finland. pirjo.kortesuo@orion.fi
authors.forename: P
authors.initials: P
authors.lastname: Kortesuo
authors.forename: M
authors.initials: M
authors.lastname: Ahola
authors.forename: M
authors.initials: M
authors.lastname: Kangas
authors.forename: I
authors.initials: I
authors.lastname: Kangasniemi
authors.forename: A
authors.initials: A
authors.lastname: Yli-Urpo
authors.forename: J
authors.initials: J
authors.lastname: Kiesvaara
mesh_terms: D003692:Delayed-Action Preparations; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D004337:Drug Carriers; D016503:Drug Delivery Systems; D005782:Gels; D008863:Microspheres; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D017312:Toremifene / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005782:Gels; D058428:Silica Gel; D020927:Dexmedetomidine; D012822:Silicon Dioxide; D017312:Toremifene