title: The application of novel nano-thermal and imaging techniques for monitoring drug microstructure and distribution within PLGA microspheres.
abstract: Poly (d,l-lactic-co-glycolic) acid (PLGA) based microspheres have been extensively used as controlled drug release systems. However, the burst effect has been a persistent issue associated with such systems, especially for those prepared by the double emulsion technique. An effective approach to preventing the burst effect and achieving a more ideal drug release profile is to improve the drug distribution within the polymeric matrix. Therefore, it is of great importance to establish a rapid and robust tool for screening and optimizing the drug distribution during pre-formulation. Transition Temperature Microscopy (TTM), a novel nano-thermal and imaging technique, is an extension of nano-thermal analysis (nano-TA) whereby a transition temperature is detected at a localized region of a sample and then designated a color based on a particular temperature/color palette, finally resulting in a coded map based on transition temperatures detected by carrying out a series of nanoTA measurements across the surface of the sample. In this study, we investigate the feasibility of applying the aforementioned technique combined with other thermal, imaging and structural techniques for monitoring the drug microstructure and spatial distribution within bovine serum albumin (BSA) loaded and nimodipine loaded PLGA microspheres, with a view to better predicting the in vitro drug release performance.
authors.affiliation: Department of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
authors.forename: De
authors.lastname: Chen
authors.affiliation: Department of Pharmacy, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510000, China.
authors.forename: Zhe-Fei
authors.initials: ZF
authors.lastname: Guo
authors.affiliation: Department of Pharmacy, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510000, China.
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: UCL School of Pharmacy,29-39 Brunswick Square, London, WC1N 1AX, UK.
authors.forename: Sean
authors.initials: S
authors.lastname: Askin
authors.affiliation: UCL School of Pharmacy,29-39 Brunswick Square, London, WC1N 1AX, UK.
authors.forename: Duncan Q M
authors.initials: DQ
authors.lastname: Craig
authors.affiliation: UCL School of Pharmacy,29-39 Brunswick Square, London, WC1N 1AX, UK; Queen's University Belfast School of Pharmacy,97 Lisburn Road, Belfast, BT9 7BL, UK. Electronic address: m.zhao@qub.ac.uk.
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
mesh_terms: D003116:Color; D004339:Drug Compounding; D019344:Lactic Acid / Q000737:chemistry*; D008863:Microspheres; D009553:Nimodipine / Q000008:administration & dosage / Q000737:chemistry; D061848:Optical Imaging; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012710:Serum Albumin, Bovine / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D044366:Transition Temperature; D014961:X-Ray Diffraction
chemical_list: D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D012710:Serum Albumin, Bovine; D019344:Lactic Acid; D009553:Nimodipine
keywords: Bovine serum albumin; Controlled drug release; Microsphere; Nimodipine; Poly (d,l-lactic-co-glycolic) acid; Transition temperature microscopy