The properties of HPMC: PEO extended release hydrophilic matrices and their response to ionic environments

Hu, Anran; Chen, Chen; Mantle, Michael D.; Wolf, Bettina; Gladden, Lynn F.; Rajabi-Siahboomi, Ali; Missaghi, Shahrzad; Mason, Laura; Melia, Colin D.

Abstract

Purpose

Investigate the extended release behaviour of compacts containing mixtures of hydrophilic HPMC and PEO in hydrating media of differing ionic strengths.
Methods

The extended release behaviour of various HPMC:PEO compacts was investigated using dissolution testing, confocal microscopy and magnetic resonance imaging, with respect to polymer ratio and ionic strength of the hydrating media.
Results

Increasing HPMC content gave longer extended release times, but a greater sensitivity to high ionic dissolution environments. Increasing PEO content reduced this sensitivity. The addition of PEO to a predominantly HPMC matrix reduced release rate sensitivity to high ionic environments. Confocal microscopy of early gel layer development showed the two polymers appeared to contribute independently to gel layer structure whilst together forming a coherent and effective diffusion barrier. There was some evidence that poorly swollen HPMC particles added a tortuosity barrier to the gel layer in high ionic strength environments, resulting in prolonged extended release. MRI provides unique, non-invasive spatially resolved information from within the HPMC:PEO compacts that furthers our understanding of USP 1 and USP 4 dissolution data.
Conclusions

Confocal microscopy and MRI data show that combinations of HPMC and PEO have advantageous extended release properties, in comparison with matrices containing a single polymer.

Citation

Hu, A., Chen, C., Mantle, M. D., Wolf, B., Gladden, L. F., Rajabi-Siahboomi, A., …Melia, C. D. (2017). The properties of HPMC: PEO extended release hydrophilic matrices and their response to ionic environments. Pharmaceutical Research, 34(5), 941-956. https://doi.org/10.1007/s11095-016-2031-0

• Journal Article Type: Article
• Acceptance Date: Aug 25, 2016
• Online Publication Date: Sep 15, 2016
• Publication Date: May 1, 2017
• Deposit Date: May 30, 2017
• Publicly Available Date: May 30, 2017
• Journal: Pharmaceutical Research
• Print ISSN: 0724-8741
• Electronic ISSN: 1573-904X
• Publisher: American Association of Pharmaceutical Scientists
• Peer Reviewed: Peer Reviewed
• Volume: 34
• Issue: 5
• Pages: 941-956
• DOI: https://doi.org/10.1007/s11095-016-2031-0
• Keywords: confocal fluorescence microscopy; digital imaging; dissolution; HPMC; hydrophilic matrix; MRI; PEO; polymer mixtures
• Public URL: https://nottingham-repository.worktribe.com/output/969424
• Publisher URL: https://link.springer.com/article/10.1007%2Fs11095-016-2031-0
• Additional Information: The original publication is available at www.springerlink.com.