Combination of (M)DSC and Surface Analysis to Study the Phase Behaviour and Drug Distribution of Ternary Solid Dispersions

Meeus, Joke; Scurr, David J.; Chen, Xinyong; Amssoms, Katie; Davies, Martyn C.; Roberts, Clive J.; Mooter, Guy Van den

doi:10.1007/s11095-014-1543-8

Cited by 12 publications

(7 citation statements)

References 26 publications

(25 reference statements)

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“…73, 24 74 This may indicate the non-intercalated lactose consists of a large number of local environments with slightly different dynamic properties. 73,74 There are two contributions to the heterogeneity of the amorphous non-intercalated lactose.…”

Section: The Decrease Of the Cpmentioning

confidence: 99%

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Structure and Mobility of Lactose in Lactose/Sodium Montmorillonite Nanocomposites

et al. 2016

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This study aims at investigating the molecular level organization and molecular mobility in montmorillonite nanocomposites with the uncharged organic low-molecular-weight compound lactose commonly used in pharmaceutical drug delivery, food technology, and flavoring. Nanocomposites were prepared under slow and fast drying conditions, attained by drying at ambient conditions and by spray-drying, respectively. A detailed structural investigation was performed with modulated differential scanning calorimetry, powder X-ray diffraction, solidstate nuclear magnetic resonance, scanning electron microscopy, microcalorimetry, and molecular dynamic simulations. The lactose was intercalated in the sodium montmorillonite interlayer space regardless of the clay content, drying rate, or humidity exposure. Although, the spray-drying resulted in higher proportion of intercalated lactose compared with the drying under 2 ambient conditions, non-intercalated lactose was present at 20 wt% lactose content. This indicates limitations in maximum load capacity of nonionic organic substances into the montmorillonite interlayer space. Furthermore, a fraction of the intercalated lactose in the cospray-dried nanocomposites diffused out from the clay interlayer space upon humidity exposure.Also, the lactose in the nanocomposites demonstrated higher molecular mobility than that of neat amorphous lactose. This study provides a foundation for understanding functional properties of nanocomposites, such as loading capacity and physical stability.

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Section: The Decrease Of the Cpmentioning

confidence: 99%

“…73,74 There are two contributions to the heterogeneity of the amorphous non-intercalated lactose. The g is a bulk phase property reflecting the molecular mobility of the amorphous phase, but molecules near surfaces may show significantly different mobility, 75 either increased 76 or decreased.…”

Section: The Decrease Of the Cpmentioning

confidence: 99%

Structure and Mobility of Lactose in Lactose/Sodium Montmorillonite Nanocomposites

et al. 2016

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“…The synthetic development of the tailor-made copolyesters we describe herein includes detailed kinetic studies to elucidate the microstructure and is complemented by an extensive characterization of the thermal and mechanical properties of the materials. Dynamic scanning calorimetry and polarized light microscopy were applied as integrating methods to bulk samples. Atomic force microscopy , was applied to correlate the bulk properties with the mechanical properties of nanoparticles prepared from the materials.…”

Section: Introductionmentioning

confidence: 99%

Maintaining the Hydrophilic–Hydrophobic Balance of Polyesters with Adjustable Crystallinity for Tailor-Made Nanoparticles

et al. 2018

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To explore the relationship between thermal properties of a polymer and the biological performance of the resulting nanoparticle, all other parameters, including the hydrophobicity, should be kept constant. For this purpose, a gradient and a block copolyester were tailor-made via the triazabicyclodecene catalyzed ring-opening copolymerization of δ-valerolactone (δVL) and δ-decalactone (δDL) to match the hydrophobicity of poly(ε-caprolactone) (PεCL). The degree of crystallinity of the semicrystalline materials was significantly reduced due to the incorporation of amorphous PδDL segments, as confirmed by dynamic scanning calorimetry. Atomic force microscopy revealed short and randomly oriented crystals in the gradient copolymer but longer and parallel aligned crystals for the block copolymer and PεCL. The stiffness of nanoparticles (D h ≈ 170 nm) prepared from the polyesters correlated to the bulk crystallinity. The set of nanoparticles with constant hydrophobicity and size will facilitate direct access to the influence of the nanoparticle crystallinity on biological processes such as enzymatic degradation, drug release, and cellular uptake.

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“…ToF-SIMS has been used as a surface analysis technique in a wide array of research fields; from biological samples (cells, tissues, proteins, lipids…) [13][14][15][16][17] , over material science 18 to pharmaceutical formulations [19][20][21][22][23][24] . ToF-SIMS is based upon the bombardment of a sample surface with a primary ion beam (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Time of flight secondary ion mass spectrometry (ToF-SIMS) has been used as a surface analysis technique in a wide array of research fields from biological samples (cells, tissues, proteins, lipids) − over material science to pharmaceutical formulations. − ToF-SIMS is based upon the bombardment of a sample surface with a primary ion beam (e.g., Ar + , Cs + , Bi 3 + ) under ultrahigh vacuum conditions. The impact of the kinetic energy of these primary ions upon the sample surface will result in desorption of electrons, atoms, molecular fragments, and whole molecules.…”

Section: Introductionmentioning

confidence: 99%

Controlling the Release of Indomethacin from Glass Solutions Layered with a Rate Controlling Membrane Using Fluid-Bed Processing. Part 1: Surface and Cross-Sectional Chemical Analysis

et al. 2017

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den Mooter, Guy (2017) Controlling the release of indomethacin from glass solutions layered with a rate controlling membrane using fluid-bed processing. A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. AbstractFluid bed coating has been shown to be an adequate manufacturing technique to formulate poorly soluble drugs in glass solutions. Layering inert carriers with a drug-polymer mixture enables these beads to be immediately filled into capsules, thus avoiding additional, potentially destabilizing, downstream processing. In this study fluid bed coating is proposed for the production of controlled release dosage forms of glass solutions by applying a second, rate controlling membrane on top of the glass solution. Adding a second coating layer adds to the physical and chemical complexity of the drug delivery system so a thorough understanding of the physical structure and phase behavior of the different coating layers is needed. This study aimed to investigate the surface and cross-sectional characteristics (employing SEM and ToF-SIMS) of an indomethacin-polyvinylpyrrolidone (PVP) glass solution, top-coated with a release rate controlling membrane consisting of either ethyl cellulose or Eudragit RL. The implications on the addition of a pore former (PVP) and the coating medium (ethanol or water) were also considered. In addition, polymer miscibility and the phase analysis of the underlying glass solution were investigated.Significant differences in surface and cross sectional topography of the different rate controlling membranes or the way they are applied (solution vs. dispersion) were observed. These observations can be linked to the polymer miscibility differences. The presence of PVP was observed in all rate controlling membranes, even if it is not part of the coating solution. This could be attributed to residual powder presence in the coating chamber. The distribution of PVP among the sample surfaces depends on the concentration and the rate controlling polymer used.Differences can again be linked to polymer miscibility. Finally, it was shown that the underlying glass solution layer remains amorphous after coating of the rate controlling membrane, whether formed from an ethanol solution or an aqueous dispersion.4

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Combination of (M)DSC and Surface Analysis to Study the Phase Behaviour and Drug Distribution of Ternary Solid Dispersions

Cited by 12 publications

References 26 publications

Structure and Mobility of Lactose in Lactose/Sodium Montmorillonite Nanocomposites

Structure and Mobility of Lactose in Lactose/Sodium Montmorillonite Nanocomposites

Maintaining the Hydrophilic–Hydrophobic Balance of Polyesters with Adjustable Crystallinity for Tailor-Made Nanoparticles

Controlling the Release of Indomethacin from Glass Solutions Layered with a Rate Controlling Membrane Using Fluid-Bed Processing. Part 1: Surface and Cross-Sectional Chemical Analysis

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