Long-term delivery of all-trans-retinoic acid using biodegradable PLLA/PEG-PLLA blended microspheres.

Abstract

All-trans-retinoic acid (atRA) has been proved to be effective against several malignancies in human clinical trials. However, in many patients who were treated with atRA, the cancer relapsed after a brief remission. One reason for such relapse is that atRA is metabolized by specific P450s that are induced in the liver during prolonged atRA treatments. In order to overcome such a drawback of atRA, we prepared biodegradable microspheres to provide continuous release of atRA for a long period of time. These biodegradable microspheres were prepared by poly(L-lactide) (PLLA) and polyethylene glycol (PEG)-PLLA diblock copolymers (PLE) in various blending ratios to control the release rate of atRA. As the PLE content in microsphere was increased, the density of the hydrophilic PEG block of PLE on microsphere surfaces increased and the microspheres were dispersed well in PBS without any surfactants. Various release patterns of atRA were obtained according to PLE and atRA contents in the microspheres. Especially, the pseudo-zero-order release profiles were observed for 5 weeks when the contents of PLE and atRA in the microspheres were above 4 wt.%.

• Authors: Y Choi, S Y Kim, S H Kim, K S Lee, C Kim, Y Byun
• Journal: International journal of pharmaceutics (Int J Pharm) Vol. 215 Issue 1-2 Pg. 67-81 (Mar 14 2001) ISSN: 0378-5173 [Print] Netherlands
• PMID: 11250093 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Excipients
• Keratolytic Agents
• Polyesters
• Polyethylene Glycols
• poly(lactide)
• Tretinoin

Topics

• Excipients
• Keratolytic Agents (administration & dosage, chemistry)
• Microspheres
• Polyesters
• Polyethylene Glycols
• Solubility
• Tretinoin (administration & dosage, chemistry)