Example 2
Dosage forms B and C were prepared as follows. 20 wt % acetaminophen drug particles were first mixed with the excipient, 80 wt % HPMC of molecular weight 120 kg/mol. The mixture was then combined with a solvent, either DMSO (for preparing dosage form B) or water (for dosage form C). The volume of solvent per mass of excipient was 5.5 ml/g and 3.33 ml/g, respectively, for preparing dosage forms B and C. The drug-excipient-solvent mixture was then extruded through a laboratory extruder to form a uniform viscous paste. The viscous paste was put in a syringe equipped with a hypodermic needle of inner radius, Rn=130 μm (for preparing dosage form B) or Rn 500 μm (for preparing dosage form C). The paste was then extruded through the needle and patterned as a fibrous dosage form with cross-ply arrangement of fibers. The nominal inter-fiber distance in a ply was uniform and equal to 730 μm (for preparing dosage form B) or 2800 μm (for preparing dosage form C). During and after patterning, warm air at a temperature of 60° C. and a velocity of about 2.3 m/s was blown over the fibrous dosage forms for a time, tdry˜40 minutes, to evaporate the solvent and freeze the structure. The process parameters to prepare the dosage forms are summarized in Table 1. After drying, the structure was trimmed to a square disk shaped dosage form of side length, L0˜8 mm. The thickness, H0, of the dosage forms B and C was about 3 mm.
Single fibers B and C were prepared as dosage forms B and C, but without structuring the fibrous extrudate to a dosage form.
