Evaluation of a water-soluble bioadhesive patch for photodynamic therapy of vulval lesions.
An innovative bioadhesive patch intended primarily as a vulval drug delivery system and, specifically, as a means to deliver photosensitisers, or their prodrugs, for photodynamic purposes is described. The patch was formulated with a copolymer of methyl vinyl ether and maleic anhydride (PMVE/MA) as a bioadhesive matrix and poly(vinyl chloride) as a drug-impervious backing layer. Adhesive strength to neonate porcine skin, as a model substrate, was evaluated using peel and tensile testing measurements. Acceptabilities of non-drug loaded patches were appraised using human volunteers and visual-analogue scoring devices. An optimal formulation, with water uptake and peel strengths appropriate for vulval drug delivery, was cast from a 20% (w/w) PMVE/MA solution and adhered with a strength of approximately 1.7 Ncm(-2). Patient evaluation demonstrated comfort and firm attachment for up to 4h in mobile patients. Aminolevulinic acid, a commonly used photosensitiser, was formulated into the candidate formulation and applied to vulval intraepithelial neoplastic lesions. Fluorescence under ultraviolet illumination revealed protoporphyrin synthesis. The patch achieves the extended application times obligatory in topical photodynamic therapy of vulval lesions, thereby contributing to potential methods for the eradication of neoplastic lesions in the lower female reproductive tract.
McCarron
Paul A
PA
School of Pharmacy, Queens University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK. p.mccarron@qub.ac.uk
Donnelly
Ryan F
RF
Zawislak
Agnieszka
A
Woolfson
A David
AD
Price
John H
JH
McClelland
Raymond
R
D000818:Animals; D002278:Carcinoma in Situ / Q000188:drug therapy*; D004341:Drug Evaluation / Q000379:methods; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D010778:Photochemotherapy / Q000379:methods*; D012995:Solubility; D013552:Swine; D014014:Tissue Adhesives / Q000008:administration & dosage*; D014846:Vulvar Neoplasms / Q000188:drug therapy*; D014867:Water
D014014:Tissue Adhesives; D014867:Water