Improving the topical delivery of zinc phthalocyanine using oleic acid as a penetration enhancer: in vitro permeation and retention.

Abstract

Topical photodynamic therapy with zinc phthalocyanine (ZnPc), second-generation photosensitizer, can be an alternative method for the treatment of skin cancer. However, ZnPc has poor penetration in the skin. This study was aimed at investigating whether the presence of oleic acid (chemical enhancer) in propylene glycol can improve the topical delivery of ZnPc. The topical (to the skin) and transdermal (across the skin) delivery of ZnPc were evaluated in vitro using suine ear skin mounted in Franz diffusion cell. Photosensitizer was quantified by fluorescence emission, which is a sensitive and selective method. At 5 and 10%, oleic acid increased the topical and transdermal delivery significantly. When the concentration of oleic acid was further increased (20-60% w/w), the topical delivery of ZnPc was still elevated, but its transdermal delivery was substantially reduced. It was concluded that oleic acid (in propylene glycol formulations) can promote the topical delivery of ZnPc, with reduced transdermal delivery. This approach can be effective for the treatment of skin cancer by topical photodynamic therapy.

• Authors: Eduardo Rodrigues da Silva, Zaida Maria Faria de Freitas, Lycia de Brito Gitirana, Eduardo Ricci-Júnior
• Journal: Drug development and industrial pharmacy (Drug Dev Ind Pharm) Vol. 37 Issue 5 Pg. 569-75 (May 2011) ISSN: 1520-5762 [Electronic] England
• PMID: 21128702 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Indoles
• Isoindoles
• Organometallic Compounds
• Photosensitizing Agents
• Zinc Compounds
• Zn(II)-phthalocyanine
• Oleic Acid
• Propylene Glycol

Topics

• Administration, Cutaneous
• Administration, Topical
• Animals
• Chemistry, Pharmaceutical (methods)
• Drug Delivery Systems (methods)
• Drug Stability
• Ear, External (metabolism)
• Indoles (administration & dosage, chemistry, pharmacokinetics)
• Isoindoles
• Oleic Acid (administration & dosage, chemistry, pharmacokinetics)
• Organometallic Compounds (administration & dosage, chemistry, pharmacokinetics)
• Permeability
• Photochemotherapy (methods)
• Photosensitizing Agents (administration & dosage, chemistry, pharmacokinetics)
• Propylene Glycol (chemistry)
• Skin (drug effects, metabolism)
• Skin Neoplasms (drug therapy, metabolism)
• Swine
• Zinc Compounds