Effect of synthesis parameters of the sol–gel-processed spray-dried silica gel microparticles on the release rate of dexmedetomidine
| Autor: | Martti Marvola, Pirjo Kortesuo, Minna Kangas, Tiina Leino, Lauri Vuorilehto, Mika Jokinen, Antti Yli-Urpo, Sirpa Laakso, Juha Kiesvaara, Manja Ahola |
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| Rok vydání: | 2002 |
| Předmět: |
Male
Time Factors Materials science Polymers Silicon dioxide Biophysics Silica Gel Bioengineering 02 engineering and technology 010402 general chemistry 01 natural sciences Biomaterials chemistry.chemical_compound Dogs Animals Isoelectric Point Microparticle Sol-gel Chromatography Silica gel Water Analgesics Non-Narcotic Hydrogen-Ion Concentration Silicon Dioxide 021001 nanoscience & nanotechnology 0104 chemical sciences Bioavailability Kinetics Isoelectric point chemistry Mechanics of Materials Area Under Curve Spray drying Alkoxide Ceramics and Composites Female 0210 nano-technology Dexmedetomidine |
| Zdroj: | Biomaterials. 23:2795-2801 |
| ISSN: | 0142-9612 |
| DOI: | 10.1016/s0142-9612(02)00016-9 |
| Popis: | The objective of this study was to evaluate the possibilities to control the release rate of dexmedetomidine (DMED) from different spray-dried silica gel microparticle formulations. Microparticles were prepared by spray drying a silica sol polymer solution containing the drug. Drug release was investigated both in vitro and in vivo. The influence of sol-gel synthesis parameters, like pH and the water/alkoxide ratio (r) of the sol, on the release behaviour of the drug was studied. Silica gel microparticles had a smooth surface. Microparticles prepared from diluted sol, however, were more aggregated and clustered. The drug release conformed to zero order release from microparticles prepared near the isoelectric point of silica (pH 2.3 and pH 3) and to the square root of time kinetics from microparticles prepared at pH 1 and pH 5. The release also showed a dual-phasic profile with an initial burst and after that a slower release period. The dexmedetomidine release conformed to zero order kinetics from microparticles prepared at water/ alkoxide ratios between r = 6 and r = 35 (at pH 2.3). The release rate was the slowest from microparticles prepared with water/ alkoxide ratio 35. The bioavailability of dexmedetomidine in dogs showed that the release was sustained from silica gel microparticles as compared with a subcutaneously administered reference dose of 0.1 mg. |
| Databáze: | OpenAIRE |
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