EFFECT OF NEEDLE SIZE AND SOLVENT ON INJECTABILITY OFPOLYETHYLENE OXIDE (PEO) SOLUTIONS

POSTER PRESENTATIONS

Objective. The objective of this study was to evaluate the effect of solvent, as well as needle length and thickness (gauge) on the injectability of PEO solutions. Background. To abuse drugs such as tablets intravenously, the products are first crushed and then dissolved in a small amounts of liquid. This mixture is then filtered and drawn into a syringe to extract the drug before being injected. High viscosifying agents such as PEO have been incorporated into abusable medications to deter this abuse. It is assumed that the more viscous a solution, the more difficult it would be drawing into and out (injectability) of a syringe. This was tested using solutions of PEO in common extraction solvents ejected through various needle configurations. Methods. Water, normal saline, pH3, and 40% ethanol were solvents used to make 2.5% w/v concentrations of PEO (Polyox™ WSR Coagulant NF). A texture analyzer was used to measure ease of injectability of solutions through a 19G, 22G or 25 gauge needed attached to a 3 mL syringe at a rate of 0.5 mm/sec. Resistance or Dynamic Gliding Force (DGF) was quantified as the average force obtained over the syringe distance using Texture Pro CT Software. Results. As the diameter of the needle decreased, DGF increased in all solvents tested. A two to four fold increase in DGF was seen when changing from a 19 to 25 gauge needle. Conclusion. PEO can deter injectability through small needles (gauge) virtually independent of extracting solvents. Grants. NSU grants # 335357 and 335829