Submicron lipid emulsion as a drug delivery system for nalbuphine and its prodrugs

Jhi Joung Wang, K. C. Sung, Oliver Yoa Pu Hu, Chih Hui Yeh, Jia You Fang

Research output: Contribution to journalArticlepeer-review

105 Citations (Scopus)


This study investigates the submicron lipid emulsion as a potential parenteral drug delivery system for nalbuphine and its ester prodrugs. Submicron emulsions were prepared using egg phospholipid as the main emulsifier, various co-emulsifiers were also incorporated, including Brij 30, Brij 98, and stearylamine. Squalene as the oil phase formed stable emulsions with small particles. Drug release was affected by incorporating various co-emulsifiers and drugs with various lipophilicity. The loading of nalbuphine into lipid emulsions resulted in the slower and sustained release of nalbuphine. Lipid emulsions containing Brij 98 could further enhance the release of prodrugs as compared to the aqueous solution (control) especially for nalbuphine enanthate (NAE). Hemolysis caused by the interaction between erythrocytes and lipid emulsions was investigated. Brij 30 and Brij 98 could shield the hemolytic activity of phospholipids in the oil/water interface, decreasing the acute toxicological potential of the emulsions. The in vivo analgesic activity of various emulsions was examined by a cold ethanol tail-flick test. The analgesic duration and potency were significantly increased by incorporating nalbuphine and NAE into Brij 98-containing emulsions. There was no need for nalbuphine benzoate (NAB) to show a controlled delivery manner by encapsulating into emulsions, since NAB itself could prolong the analgesic duration of nalbuphine due to the slow enzyme degradation. The in vivo analgesic activity correlated well to the profiles of in vivo pharmacokinetic profiles. The study demonstrates the feasibility of using submicron lipid emulsion as the parenteral drug delivery system for nalbuphine and its prodrugs.

Original languageEnglish
Pages (from-to)140-149
Number of pages10
JournalJournal of Controlled Release
Issue number2
Publication statusPublished - Oct 10 2006
Externally publishedYes


  • Controlled release
  • Drug delivery
  • Lipid emulsions
  • Nalbuphine
  • Prodrugs

ASJC Scopus subject areas

  • Pharmaceutical Science


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