Biochronomer technology

Expert Opin Drug Deliv. 2005 Jan;2(1):169-83. doi: 10.1517/17425247.2.1.169.


Biochronomer (AP Pharma) is a fourth-generation poly(ortho ester) prepared by the condensation of diols and a diketene acetal. The polymer contains a copolymerised latent acid whose concentration controls erosion rate. The polymer has been shown to undergo a surface erosion process and a number of applications have been explored. Among these, the delivery of plasmid DNA for vaccines is currently of most interest. This application takes advantage of the acid-labile nature of the polymer, which leads to rapid polymer hydrolysis and hence rapid release of plasmid DNA once internalised in the acidic environment within the endosomes, and the non-acidic environment within the polymer that conserves plasmid DNA conformation. A low molecular semisolid polymer is now in Phase II clinical trials for the delivery of mepivacaine to control postoperative pain, and in Phase I clinical trials for the systemic delivery of granisetron to control nausea.

MeSH terms

  • Anesthetics, Local / administration & dosage*
  • Anesthetics, Local / therapeutic use
  • Chemistry, Pharmaceutical
  • Clinical Trials as Topic
  • Delayed-Action Preparations
  • Drug Delivery Systems*
  • Gels
  • Granisetron / administration & dosage*
  • Granisetron / therapeutic use
  • Humans
  • Hydrolysis
  • Mepivacaine / administration & dosage*
  • Mepivacaine / therapeutic use
  • Nausea / prevention & control
  • Pain, Postoperative / prevention & control
  • Polyanhydrides / chemistry
  • Polyesters / chemistry
  • Polymers / chemistry*
  • Serotonin Antagonists / therapeutic use
  • Solubility
  • Surface Properties
  • Time Factors
  • Vaccines, DNA / administration & dosage*


  • Anesthetics, Local
  • Delayed-Action Preparations
  • Gels
  • Polyanhydrides
  • Polyesters
  • Polymers
  • Serotonin Antagonists
  • Vaccines, DNA
  • Mepivacaine
  • Granisetron