title: Binding of local anaesthetics to the lipid emulsion Clinoleic™ 20%.
abstract: Lipid emulsions have been used to treat cardiovascular collapse due to local anaesthetic toxicity. However, there are few data available on the comparative efficiency of the partitioning properties of available lipid emulsions in clinical use. This in vitro study compared the buffering properties of the lipid emulsions Clinoleic™ 20% (Baxter, Old Toongabbie, NSW) and Intralipid® 20% (Fresenius Kabi, Pymble, NSW) using both bupivacaine (Marcain® 0.5%, AstraZeneca, North Ryde, NSW) and ropivacaine (Naropin® 1%, AstraZeneca, North Ryde, NSW). The concentration of anaesthetic in buffer before and after mixing with lipid was quantified using chromatographic analysis. Bupivacaine was more effectively bound by the lipid agents, with a 40% reduction in initial concentration. Ropivacaine demonstrated a 20% reduction in concentration with the addition of lipid agents. Importantly, there was no significant difference between Intralipid and Clinoleic in terms of their buffering behaviour, suggesting equivalent binding efficacy.
authors: Department of Anaesthesia and Perioperative Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia. jacquelineevans@gmail.com
authors: J A
authors: JA
authors: Evans
authors: S C
authors: SC
authors: Wallis
authors: J M
authors: JM
authors: Dulhunty
authors: G
authors: G
authors: Pang
mesh_terms: D000577:Amides / Q000737:chemistry; D000779:Anesthetics, Local / Q000737:chemistry*; D002045:Bupivacaine / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry; D005217:Fat Emulsions, Intravenous / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry*; D000077212:Ropivacaine; D013024:Soybean Oil / Q000737:chemistry*
chemical_list: D000577:Amides; D000779:Anesthetics, Local; C568346:ClinOleic; D004655:Emulsions; D005217:Fat Emulsions, Intravenous; D010743:Phospholipids; D010938:Plant Oils; C545823:soybean oil, phospholipid emulsion; D000077212:Ropivacaine; D013024:Soybean Oil; D002045:Bupivacaine
keywords: Clinoleic™; lipid emulsion; local anaesthetics: bupivacaine, ropivacaine; toxicity