Drug release from hydroxypropylcellulose gels cannot be statistically predicted from their viscometric and initial viscoelastic properties.
This study questioned whether rheological properties can predict drug (metronidazole) release from Hydroxypropylcellulose (HPC) platforms. Viscometric and viscoelastic properties of aqueous, alcohols/diols and mixed solvent HPC solutions and gels were determined using viscometry and oscillatory analysis. Drug release was conducted at pH 7.4 under sink conditions. Relationships between rheological parameters and drug release were modelled using multiple linear stepwise regression. Viscometry identified ethanol and water as good solvents for HPC. Diol solvents were predicted to exhibit greater interactions with HPC (COSMO modelling) but possessed lowest intrinsic viscosities. Pentanediol or ethylene glycol prepared gels exhibited greatest elasticity. No relationships were observed between dilute solution properties and initial gel viscoelasticity. Drug release from HPC gels occurred via gel erosion and diffusion. No relationships were observed between initial gel viscoelasticity and drug release and thus, for gel platforms that undergo erosion in aqueous media, drug release cannot be predicted from initial gel viscoelasticity.
['Jones|David S|DS|', 'Rafferty|Gerard P|GP|', 'Andrews|Gavin P|GP|']
D000438:Alcohols D000890:Anti-Infective Agents D002482:Cellulose D004058:Diffusion D004337:Drug Carriers D065546:Drug Liberation D004548:Elasticity D005782:Gels D007700:Kinetics D008795:Metronidazole D011108:Polymers D012996:Solutions D012997:Solvents D014783:Viscosity D014867:Water
Viscoelasticity Gel erosion Drug diffusion Statistical modelling Viscometric properties