Linear delivery of verapamil via nanofibrous sheet-based system.

To achieve linear delivery of a highly water-soluble oral drug, verapamil, with a nanofibrous sheet-based system. The nanofibrous sheets made of poly (lactic-co-glycolic acid) were used as a diffusion barrier to cap a tablet containing verapamil. For controlled drug delivery, we varied the sheet thickness to 20 μm, 50 μm and 80 μm to give the capped drug tablets, 20CT, 50CT and 80CT, respectively. Drug release was more sustained as the sheet thickness increased. Thus, the periods for almost complete drug release could be extended up to 14 h with the 80 μm-thick sheets. As we assessed the linear least square fits to the in vitro drug release data from the capped tablets, 20CT and 50CT showed a fairly good correlation with linear release. The periods of linear release were 6 h and 8 h for 20CT and 50CT, respectively, both releasing more than 85% drug during this period. We conclude that a drug tablet capped with nanofibrous sheets is a promising system for linear delivery of a highly water-soluble oral drug.