title: Study of interaction of hypericin and its pharmaceutical preparation by fluorescence techniques.
abstract: We report the detection of interactions between a photosensitizer, hypericin (HY), and its solvent system prepared with a formulation additive, polyvinylpyrrolidone (PVP), a commonly used pharmaceutical excipient. Fluorescence correlation spectroscopy (FCS) and fluorescence lifetime imaging microscopy (FLIM) were used to study aggregation and binding of HY in the presence of PVP. Digitized fluorescence endoscopic imaging (DFEI) was used to study the effect of the pharmaceutical formulation in the in vivo tumor implanted chick chorioallantoic membrane (CAM) model. The results presented reveal the coordination of HY-PVP binding, HY disaggregation in the presence of PVP, and strengthened HY tumor uptake selectivity. PVP is thus suggested as a potential adjuvant to previously investigated N-methyl pyrrolidone (NMP) in the HY delivery system as well as a replacement for the conventionally used albumin in the HY bladder instillation fluids preparation for clinical use.
authors.affiliation: National University of Singapore, Department of Chemistry, 3 Science Drive 3, Singapore 117543, Singapore.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Constance Lay Lay
authors.initials: CL
authors.lastname: Saw
authors.forename: Malini
authors.initials: M
authors.lastname: Olivo
authors.forename: Thankiah
authors.initials: T
authors.lastname: Sudhaharan
authors.forename: Sohail
authors.initials: S
authors.lastname: Ahmed
authors.forename: Paul Wan Sia
authors.initials: PW
authors.lastname: Heng
authors.forename: Thorsten
authors.initials: T
authors.lastname: Wohland
mesh_terms: D000818:Animals; D000873:Anthracenes; D045744:Cell Line, Tumor; D002642:Chick Embryo; D004337:Drug Carriers / Q000737:chemistry*; D006801:Humans; D008856:Microscopy, Fluorescence / Q000379:methods*; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D011205:Povidone / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D001749:Urinary Bladder Neoplasms / Q000378:metabolism*
chemical_list: D000873:Anthracenes; D004337:Drug Carriers; D010569:Perylene; C004965:hypericin; D011205:Povidone