Sustained release of hydroxycamptothecin after subcutaneous administration using a novel phospholipid complex-DepoFoam technology.

OBJECTIVE

In order to prolong the duration of drug in the circulation, multivesicular liposome (MVL, namely DepoFoam) was utilized as a sustained-release delivery system for hydroxycamptothecin (HCPT).

METHODS

HCPT is insoluble in both water and physiological acceptable organic solvents; therefore, HCPT-phospholipid complex (HCPT-PCC) was prepared by solvent evaporation method to improve its liposolubility. In this study, preparation, characterization, in vitro release, and in vivo pharmacokinetics of HCPT-phospholipid complex-loaded MVLs (HCPT-MVLs) were investigated.

RESULTS

The results showed that the average particle size of HCPT-MVL was 9 mum and the encapsulation efficiency was 90%. In addition, HCPT-MVLs could improve both in vitro release and in vivo pharmacokinetic behaviors of the original drug, with a sustained release of drugs over 5-6 days.

CONCLUSION

These data suggested that by combined use of DepoFoam and phospholipid complex formation technique HCPT could be successfully entrapped into the MVLs, which might provide a paradigm for sustained release of insoluble drugs.