Fig. 3. Release of virus from the film matrix is tunable.

(A) Virus release rate from films prepared by stepwise addition of excipients. Films containing 1.25 × 10¹² vp were placed in warmed (37°C) PBS with gentle agitation, and samples were collected over a period of 2 hours. The concentration of infectious virus was determined by a standard infectious titer assay. (B) Cumulative release profiles of films containing base, binder, and surfactant combinations. Data collected during the dissolution of each film was normalized with that generated from virus placed in the correlating liquid formulation and collected over 20-min intervals to account for any loss attributable to agitation and extended exposure to heat. In each panel, data represent the average ± SD of a minimum of three films per condition. *P < 0.05, two-tailed Student’s t test. Formulations are summarized in the figure according to the numbers assigned in table S1.