Influence of hydrogel structure on the processes of water penetration and drug release from mixed hydroxypropylmethyl cellulose/thermally pregelatinized waxy maize starch hydrophilic matrices
| Autor: | Rumiana Kotsilkova, E Minkov, E. Krusteva, V. Michailova, St Titeva |
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| Rok vydání: | 2001 |
| Předmět: |
Chromatography
technology industry and agriculture Pharmaceutical Science Hydrogels Starch Penetration (firestop) Methylcellulose Maize starch Dosage form chemistry.chemical_compound Kinetics Hypromellose Derivatives chemistry Chemical engineering Amylopectin Self-healing hydrogels medicine Technology Pharmaceutical Cellulose Swelling medicine.symptom Drug carrier Rheology |
| Zdroj: | International journal of pharmaceutics. 222(1) |
| ISSN: | 0378-5173 |
| Popis: | The kinetics of water penetration and molsidomine release from both hydroxypropylmethyl cellulose (HPMC) and mixed HPMC/thermally pregelatinized waxy maize starch (SDWMT) hydrophilic matrices has been examined in 0.1 mol dm −3 HCl (pH 1.0) and 0.06 mol dm −3 Na 3 PO 4 /HCl buffer (pH 6.8). The rheological oscillatory test parameters of their gel layers obtained by swelling of the matrices in the two aqueous media have been observed. The kinetic swelling properties of mixed HPMC/SDWMT hydrogels (i.e. degree and velocity of both water penetration and swelling, transport mechanism which controls solvent sorption) directly influence the drug release behaviour and the structural features of the formed gel layer. Both diffusion processes are diffusion-controlled ones, their mechanisms being influenced insignificantly by the relaxation properties of the hydrated macromolecules. It has been established by means of comparative viscoelastic analysis, that mixed HPMC/SDWMT hydrogels demonstrate the typical behaviour of ‘filled’ composite systems having poor adhesion between the surface of the elastic SDWMT ‘filler’ and the continuous HPMC phase. Due to the inter-phase relations between the swollen starch granules and the linear cellulose derivative as well as to the specific structure of amylopectin molecule, the pregelatinized waxy maize starch shows a stronger influence on the velocities of both water penetration and drug release from mixed HPMC/SDWMT matrices. |
| Databáze: | OpenAIRE |
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