Temoporfin-loaded liposomes: Physicochemical characterization

Temoporfin (mTHPC) is a potent but highly hydrophobic second-generation photosensitizer and has been approved for the palliative treatment of patients with advanced head and neck cancer by photodynamic therapy. Liposome formulations have been evaluated as carrier system for this drug to overcome som...

Full description

Saved in:

Bibliographic Details
Published in:	European journal of pharmaceutical sciences Vol. 40; no. 4; pp. 305 - 315
Main Authors:	Kuntsche, Judith, Freisleben, Ines, Steiniger, Frank, Fahr, Alfred
Format:	Journal Article
Language:	English
Published:	Kindlington Elsevier B.V 11-07-2010 Elsevier
Subjects:	Biological and medical sciences Calorimetry, Differential Scanning Chemical Phenomena Chemistry, Pharmaceutical Cryoelectron Microscopy Drug Carriers - chemistry Drug Stability Fatty Acids - chemistry Foslip Freeze Drying General pharmacology Liposomes Liposomes - chemistry Liposomes - ultrastructure Lyophilization Medical sciences Mesoporphyrins - chemistry Micelles Pegylation Pharmaceutical technology. Pharmaceutical industry Pharmacology. Drug treatments Phase Transition Photosensitizing Agents - chemistry Physicochemical characterization Polyethylene Glycols - chemistry Temoporfin Transition Temperature Unilamellar Liposomes - chemistry Water - analysis Physicochemical characterization Liposomes Lyophilization Foslip Temoporfin Pegylation Pharmaceutical technology Liposome Pegylated form Photosensitizer Porphyrin derivatives Physicochemical properties
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Temoporfin (mTHPC) is a potent but highly hydrophobic second-generation photosensitizer and has been approved for the palliative treatment of patients with advanced head and neck cancer by photodynamic therapy. Liposome formulations have been evaluated as carrier system for this drug to overcome some problems associated with the commercial formulation Foscan ® where the drug is dissolved in a mixture of water-free ethanol and propylene glycol. The present study focuses on the physicochemical characterization of different liposome formulations with special emphasis on the influence of drug incorporation on the thermal phase behavior of the liposomes. In addition to conventional liposomes, pegylated lipids were used for the preparation of “stealth” liposomes. The dispersions as well as freeze-dried formulations were characterized by photon correlation spectroscopy, differential scanning calorimetry and cryo-electron microscopy. Incorporation of temoporfin resulted in a distinct concentration dependent decrease of the main phase transition of the liposomes. In case of liposomes based on dipalmitoylphosphatidylcholine/-glycerol, phase transition was close or even below body temperature. In contrast, if phospholipids with longer fatty acid chains (distearoylphosphatidylcholine/-glycerol) were used, phase transitions were well above body temperature even at high drug load. Size and thermal behavior were not distinctly influenced by the addition of pegylated lipids but cryo-electron microscopic investigations indicate the presence of micellar structures in addition to vesicles. Lyophilization and reconstitution led to an alteration in the morphology but had overall no distinct influence on the colloidal stability.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0928-0987 1879-0720
DOI:	10.1016/j.ejps.2010.04.005