title: Penciclovir solubility in Eudragit films: a comparison of X-ray, thermal, microscopic and release rate techniques.
abstract: The solubility of penciclovir (C(10)N(5)O(3)H(17)) in a novel film formulation designed for the treatment of cold sores was determined using X-ray, thermal, microscopic and release rate techniques. Solubilities of 0.15-0.23, 0.44, 0.53 and 0.42% (w/w) resulted for each procedure. Linear calibration lines were achieved for experimentally and theoretically determined differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) data. Intra- and inter-batch data precision values were determined; intra values were more precise. Microscopy was additionally useful for examining crystal shape, size distribution and homogeneity of drug distribution within the film. Whereas DSC also determined melting point, XRPD identified polymorphs and release data provided relevant kinetics.
authors.affiliation: Drug Delivery Group, School of Pharmacy, University of Bradford, Bradford, West Yorkshire BD7 1DP, UK.
authors.forename: A
authors.initials: A
authors.lastname: Ahmed
authors.forename: B W
authors.initials: BW
authors.lastname: Barry
authors.forename: A C
authors.initials: AC
authors.lastname: Williams
authors.forename: A F
authors.initials: AF
authors.lastname: Davis
mesh_terms: D000212:Acyclovir / Q000031:analogs & derivatives / Q000032:analysis* / Q000737:chemistry / Q000493:pharmacokinetics*; D002152:Calorimetry, Differential Scanning / Q000379:methods; D006147:Guanine; D018613:Microscopy, Confocal / Q000379:methods; D011109:Polymethacrylic Acids / Q000032:analysis* / Q000737:chemistry / Q000493:pharmacokinetics*; D012995:Solubility; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer; C053539:penciclovir; D006147:Guanine; D000212:Acyclovir