A Dual Mechanism to Deter Intravenous Drug Abuse Using Crosslinked Anionic Polymers

Nova Southeastern University, Davie, Florida, USA

Objective: The objective was to evaluate the contribution of binding and swelling of two crosslinked anionic polymers (carboxymethyl starch, CMS; and carboxymethyl cellulose, CMC) in reducing the amount of free drug available for intravenous abuse in different extracting solvents. Background: CMS and CMC polymers can offer both swelling and binding properties in aqueous solutions. Binding to cationic opioid drugs and entrapping portion of the drug solution due to swelling are expected to significantly lower the amount of free drug available for injection. This study evaluated the contribution of the two mechanisms in total drug entrapment from drug solutions. Methods: CMS and CMC were mixed with Dextromethorphan HBr in 10.0 ml of common extracting solvents. Followed by centrifugation, the supernatant was measured for its volume and drug concentration (UV spectroscopy). The results were used to calculate the total drug entrapment, entrapment due to swelling and entrapment due to binding. Results: In most extracting solvents, drug entrapment due to binding with CMS and CMC were ≥ 25% and ≥ 40% higher than that due to swelling, respectively. In solvents containing ions, entrapment due to swelling was greater but not exceeding 15% and 5% for CMS and CMC, respectively. Conclusion: The binding is the primary contributor to total drug entrapment in all extracting solvents, except in those containing salts (sodium) and ionic moieties (carboxyl groups). Grants: This study was supported by NSU Grant 335081