Related Experiment Videos
Liposomes dispersed within a thermosensitive gel: a new dosage form for ocular delivery of oligonucleotides
1Laboratoire de Physico-Chimie, Pharmacotechnie, Biopharmacie, URA CNRS 1218, Faculté de Pharmacie, Châtenay-Malabry, France.
Purpose:
The main goal of this study was to develop an ocular controlled release formulation of a model oligonucleotide (pdT16), contained within liposomes dispersed within a thermosensitive gel composed by poloxamer 407.
Methods:
The influence of the poloxamer concentration 2% or 27% on the stability of the liposomes (PC: CHOL and PC: CHOL: PEG-DSPE) was investigated. The in vitro release profiles of pdT16 from various poloxamer formulations (free pdT16 dispersed within 20% and 27% poloxamer gels, pdT16 encapsulated within liposomes dispersed within 20% and 27% poloxamer gels) were realized using a membrane-free release model.
Results:
The dispersion of liposomes within a dilute 2% poloxamer solution resulted in a great leakage of pdT16 from liposomes. However, the destabilization effect of poloxamer was reduced when higher concentration (27%) was used. Poloxamer dissolution was found to control the release process of pdT16, whereas the dispersion of liposomes within 27% poloxamer gel was shown to slow down the diffusion of pdT16 out from the gel.
Conclusions:
The dispersion of liposomes within a 27% poloxamer gel presented an interesting system to control the release of a model oligonucleotide compare to a simple gel.