title: Polymorphism and kinetic behavior of binary mixtures of triglycerides.
abstract: The work is aimed at investigating the polymorphism and the phase transition kinetics of binary lipid mixtures with potential application in controlled drug delivery. The lipid systems, constituted of glyceryl tristearate (GTS) added with different amounts (1.0-7.5% w/w) of a medium-chain liquid triglyceride (C10-C12 acyl derivative - MCT), were studied by differential scanning calorimetry, by X-ray diffraction and hot-stage microscopy. The liquid lipid, although present in small amount, modified the thermal profile and the diffraction pattern of the systems, indicating that it promoted the formation of the GTS stable polymorph, β, during the re-solidification of the melted mixture. This promotion effect of MCT was concentration-dependent and evident for systems containing MCT>2.5%. Also the kinetics of transformation of GTS polymorphs was affected by the percentage of the liquid component. The α → β-transition was a biphasic process which for GTS-MCT mixture (99:1) superimposed that of pure GTS, while followed a different trend for systems containing percentages of MCT higher than 2.5.
authors: Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale "A. Avogadro", Largo Donegani, 2/3, 28100 Novara, Italy. Electronic address: franco.pattarino@unipmn.it.
authors: Franco
authors: F
authors: Pattarino
authors: Dipartimento di Farmacia, Università degli Studi di Parma, Parco Area delle Scienze, 27/A, 43124 Parma, Italy.
authors: Ruggero
authors: R
authors: Bettini
authors: Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale "A. Avogadro", Largo Donegani, 2/3, 28100 Novara, Italy.
authors: Andrea
authors: A
authors: Foglio Bonda
authors: Dipartimento di Farmacia, Università degli Studi di Parma, Parco Area delle Scienze, 27/A, 43124 Parma, Italy.
authors: Andrea
authors: A
authors: Della Bella
authors: Dipartimento di Scienze del Farmaco, Università degli Studi del Piemonte Orientale "A. Avogadro", Largo Donegani, 2/3, 28100 Novara, Italy.
authors: Lorella
authors: L
authors: Giovannelli
mesh_terms: D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D007700:Kinetics; D008853:Microscopy / Q000379:methods; D044367:Phase Transition; D033362:Powder Diffraction; D014280:Triglycerides / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D014280:Triglycerides; C022618:tristearin
keywords: Kinetics phase behavior; Lipids; Polymorphism; Solid/liquid lipid mixture; Triacyl glycerides