Quaternary polymethacrylate–sodium alginate films: effect of alginate block structures and use for sustained release tablets

Abstract

The objectives in this study were to characterize quaternary polymethacrylate–sodium alginate (QPM–SA) films prepared using high G block or high M block SA (GSA or MSA, respectively), and to investigate the effects of QPM–SA ratios, film-coating levels and SA block structures on propranolol HCl (PPN) released from coated tablets. The results demonstrated that GSA and MSA shared a similar interaction mechanism with QPM. The QPM–GSA films had higher puncture strength than the QPM–MSA films in dry and wet states, whereas the % elongations were not different. The drug permeability of the QPM–GSA films was lower than that of the QPM–MSA films in both acidic and neutral media, but higher water uptake of the QPM–GSA films was found at neutral pH. Moreover, the QPM–MSA-coated tablets had a greater PPN release rate than the QPM–GSA-coated tablets, and drug release was dependent on the film-coating levels. In addition, the QPM–SA films at a ratio of 4:0.5 produced a stronger film and could sustain PPN release. These results indicate that the QPM–GSA films had greater film strength and lower drug permeability than the QPM–MSA films. Additionally, the QPM–SA films have a strong potential for use in sustained-release tablets.

• Block structure
• drug release
• film coating
• quaternary polymethacrylate
• sodium alginate

Declaration of interest

The authors wished to thank the Thailand Research Fund (Bangkok, Thailand) for research funding (Grant no. BRG5580016), and the Faculty of Pharmaceutical Sciences, Khon Kaen University (Khon Kaen, Thailand) for technical support. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.