Swelling, erosion and drug release characteristics of salbutamol sulfate from hydroxypropyl methylcellulose-based matrix tablets

Abstract

Background: Hydrophilic matrix formulations are important and simple technologies that are used to manufacture sustained release dosage forms. Method: Hydroxypropyl methylcellulose-based matrix tablets, with and without additives, were manufactured to investigate the rate of hydration, rate of erosion, and rate and mechanism of drug release. Scanning electron microscopy was used to assess changes in the microstructure of the tablets during drug release testing and whether these changes could be related to the rate of drug release from the formulations. Results: The results revealed that the rate of hydration and erosion was dependent on the polymer combination(s) used, which in turn affected the rate and mechanism of drug release from these formulations. It was also apparent that changes in the microstructure of matrix tablets could be related to the different rates of drug release that were observed from the test formulations. Conclusion: The use of scanning electron microscopy provides useful information to further understand drug release mechanisms from matrix tablets.

Keywords:

• Carbopol®
• drug release
• erosion
• hydrophilic matrix tablets
• hydroxypropyl methylcellulose
• salbutamol sulfate
• sodium carboxymethylcellulose
• swelling

Acknowledgments

The authors acknowledge the Electron Microscopy Unit (Rhodes University) for assistance with SEM; Aspen-Pharmacare for the generous donation of SBS; and the Andrew Mellon Foundation, the National Research Foundation, and the Joint Research Committee of Rhodes University for financial support.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.