New insights on the influence of manufacturing conditions and molecular weight on phase-separated films intended for controlled release

作者：Moore Helene Andersson; Marucci Mariagrazia; Hardelin Linda; Hjartstam Johan; Stading Mats; von Corswant Christian; Larsson Anette^*

来源：International Journal of Pharmaceutics, 2018, 536(1): 261-271.

DOI：10.1016/j.ijpharm.2017.10.012

• Manufacturing conditions
• Polymer blend
• Film coating
• Phase separation
• Hydroxypropyl cellulose
• Ethyl cellulose
• Controlled release
• Molecular weight

The aim of this work was to investigate how manufacturing conditions influence phase-separated films of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) with different molecular weights of HPC. Two HPC grades, SSL and M, with weight average molecular weights (M-w) of 30x10(3) g/mol and 365 x10(3) g/mol, respectively, were combined with EC 10 cps (70:30 w/w EC/HPC) and spray-coated from ethanol solutions onto a rotating drum under well-controlled process conditions. Generally, a low spray rate resulted in a more rapid film drying process and, consequently, in smaller HPC-rich domains in the phase-separated film structure. For EC/HPC films with the low M-w HPC (SSL) the most rapid drying process resulted in a shift from a HPC-discontinuous to a partly bicontinuous structure and an increase in the permeability for water. In contrast, films containing the high M-w HPC (M) all showed bicontinuous structures, which resulted in overall higher water permeabilities and polymer release compared to the low M-w films. Interestingly, a maximum in permeability was observed for the high M-w films at intermediate spray rates. Below this spray rate the permeability decreased due to a lower amount of polymer released and at higher spray rates, the permeability decreased due to a loss of pore connectivity (or increased tortuosity). To conclude, this study shows that different M-w systems of EC/HPC can respond differently to variations in manufacturing conditions.

• 出版日期2018-1-30