title: Analysis of liquid crystalline nanoparticles by small angle X-ray diffraction: evaluation of drug and pharmaceutical additives influence on the internal structure.
abstract: The goal of this work was to study the liquid crystalline structure of a nanodispersion delivery system intended to be used in photodynamic therapy after loading with photosensitizers (PSs) and additives such as preservatives and thickening polymers. Polarized light microscopy and light scattering were performed on a standard nanodispersion in order to determine the anisotropy of the liquid crystalline structure and the mean diameter of the nanoparticles, respectively. Small angle X-ray diffraction (SAXRD) was used to verify the influence of drug loading and additives on the liquid crystalline structure of the nanodispersions. The samples, before and after the addition of PSs and additives, were stable over 90 days, as verified by dynamic light scattering. SAXRD revealed that despite the alteration observed in some of the samples analyzed in the presence of photosensitizing drugs and additives, the hexagonal phase still remained in the crystalline phase.
authors.affiliation: Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av do Café, s/n, 14040-903, Ribeirão Preto, SP, Brazil.
authors.forename: Fábia Cristina
authors.initials: FC
authors.lastname: Rossetti
authors.forename: Márcia C A
authors.initials: MC
authors.lastname: Fantini
authors.forename: Aline Regina H
authors.initials: AR
authors.lastname: Carollo
authors.forename: Antônio Cláudio
authors.initials: AC
authors.lastname: Tedesco
authors.forename: Maria Vitória Lopes Badra
authors.initials: MV
authors.lastname: Bentley
mesh_terms: D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers; D004339:Drug Compounding; D005079:Excipients / Q000737:chemistry*; D005989:Glycerides / Q000737:chemistry; D007211:Indoles / Q000737:chemistry; D054833:Isoindoles; D050866:Liquid Crystals; D008859:Microscopy, Polarization; D015394:Molecular Structure; D053758:Nanoparticles; D019301:Oleic Acid / Q000737:chemistry; D010316:Particle Size; D017319:Photosensitizing Agents / Q000737:chemistry*; D011524:Protoporphyrins / Q000737:chemistry; D053838:Scattering, Small Angle; D013678:Technology, Pharmaceutical / Q000379:methods*; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D004337:Drug Carriers; D005079:Excipients; D005989:Glycerides; D007211:Indoles; D054833:Isoindoles; D017319:Photosensitizing Agents; D011524:Protoporphyrins; D019301:Oleic Acid; C028025:protoporphyrin IX; C005953:monoolein; C013647:phthalocyanine