title: ToF-SIMS analysis of chemical heterogenities in inkjet micro-array printed drug/polymer formulations.
abstract: Three different formulations comprising two drugs, felodipine and hydrochlorothiazide (HCT) and two polymers, poly(vinyl pyrolidone) (PVP) and poly(lactic-co-glycolic acid) (PLGA) were inkjet printed as micro-dot arrays and analysed on an individual micro-spot basis by time-of-flight secondary ion mass spectrometry (ToF-SIMS). For the HCT/PLGA formulation, the spots showed heterogeneity of the drug and other chemical constituents. To further investigate these heterogeneities, multivariate curve resolution was applied to the ToF-SIMS hyperspectral image datasets. This approach successfully identified distinct chemical components elucidating the HCT, PLGA, substrate material, and contaminants based on sulphur, phosphorous and sodium chloride. Spots printed using either of the drugs with PVP exhibited full substrate coverage and a uniform distribution of the active ingredient along with all other constituents within the printed spot area. This represents the preferred situation in terms of stability and controlling the release of a drug from a polymer matrix.
authors.affiliation: Laboratory of Biophysics and Surface Analysis, School of Pharmacy, The University of Nottingham, Nottingham, UK.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Scoutaris
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Hook
authors.forename: Paul R
authors.initials: PR
authors.lastname: Gellert
authors.forename: Clive J
authors.initials: CJ
authors.lastname: Roberts
authors.forename: Morgan R
authors.initials: MR
authors.lastname: Alexander
authors.forename: David J
authors.initials: DJ
authors.lastname: Scurr
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D016503:Drug Delivery Systems; D015195:Drug Design; D015736:Felodipine / Q000737:chemistry; D006852:Hydrochlorothiazide / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D046228:Microarray Analysis; D008956:Models, Chemical; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry; D011327:Printing; D011760:Pyrrolidinones / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods; D013499:Surface Properties
chemical_list: D007477:Ions; D011108:Polymers; D011145:Polyvinyls; D011760:Pyrrolidinones; D006852:Hydrochlorothiazide; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D012965:Sodium Chloride; D015736:Felodipine
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