The Influence of Polyethylene Glycol Solution on the Dissolution Rate of Sustained Release Morphine

J Med Toxicol. 2016 Dec;12(4):391-395. doi: 10.1007/s13181-016-0561-9. Epub 2016 Jun 13.


Introduction: Whole bowel irrigation (WBI) is a management option for overdose of medications poorly adsorbed to activated charcoal, with modified release properties, or for body packers. Polyethylene glycol (PEG) is a mixture of ethylene oxide polymers of varying molecular weight. PEG with an average molecular weight of 3350 g/mol is used for WBI. PEG electrolyte lavage solution has been shown in vitro to hasten the dissolution of acetaminophen. The impact of PEG on the pharmacokinetics of extended release pharmaceuticals is unknown. Lower average molecular weight PEG mixtures are used as solvents and excipients. We sought to investigate the impact of PEG on the release of morphine from several extended release morphine formulations.

Methods: An in vitro gastric model was developed. To test the validity of our model, we first investigated the previously described interaction of ethanol and Avinza®. Once demonstrated, we then investigated the effect of PEG with several extended release morphine formulations.

Results: In the validation portion of our study, we confirmed an ethanol Avinza® interaction. Subsequently, we did not observe accelerated release of morphine from Avinza® or generic extended release morphine in the presence of PEG.

Conclusion: The use of PEG for gastric decontamination following ingestion of these extended release morphine formulations is unlikely to accelerate morphine release and aggravate intoxication.

Keywords: Delayed release preparations; Gastric decontamination; In vitro drug release; Modified release morphine; Morphine/pharmacokinetics; Whole bowel irrigation.

MeSH terms

  • Chromatography, Gas
  • Delayed-Action Preparations
  • Drug Liberation*
  • Drug Overdose / therapy*
  • Humans
  • Hydrogen-Ion Concentration
  • Mass Spectrometry
  • Morphine / administration & dosage
  • Morphine / pharmacokinetics*
  • Morphine Dependence / therapy*
  • Pharmaceutical Solutions / therapeutic use
  • Polyethylene Glycols / therapeutic use*
  • Therapeutic Irrigation


  • Delayed-Action Preparations
  • Pharmaceutical Solutions
  • Polyethylene Glycols
  • Morphine