Fig. 1.
The Simulator of IntraMuscular Injection (SIMI) in vitro modelling tool.
(A) A polystyrene float (1) suspended a 5 mL hydrogel contained within a semi-porous cuvette (2), suspended in interstitial fluid-mimicking buffer (37 °C, pH 7.4) (3). The whole system was stirred (4) on a heated stirring plate (5). (B) Materials were directly injected (vertically) into the hydrogel at a 90o angle to form a bolus. (C) Over time, injected material distributes through the hydrogel matrix, before releasing through the non-specific membranes into the buffer system. The buffer can then be sampled for quantifying drug at discreet time points.