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Heidelberg, Germany

Gautschi N.,University of Applied Sciences and Arts Northwestern Switzerland | Van Hoogevest P.,Phospholipid Research Center | Kuentz M.,University of Applied Sciences and Arts Northwestern Switzerland
International Journal of Pharmaceutics | Year: 2015

There is a growing interest in drug-phospholipid complexes and similar formulations that are mostly solid dispersions with high drug load. This study aims to explore the feasibility of such phospholipid-based solid dispersions as well as to characterize them. A particular aim was to compare monoacyl phosphatidylcholine (PC) with the diacyl excipient. The solid dispersions were manufactured using a solvent evaporation technique and characterized by means of differential scanning calorimetry and X-ray diffractometry. Density functional theory was used to calculate molecular frontier orbitals of the different compounds. Finally, the dissolution properties were analyzed in a flow-through cell by means of UV imaging. It was found that the ability to form solid dispersions with the phospholipids containing amorphous or solubilized drug (at equimolar ratio with the lipid) was dependent on the drug's frontier orbital energy, the enthalpy of fusion, as well as the log P value. In a subsequent dissolution study, UV imaging revealed pronounced surface swelling of the solid dispersions. Only the monoacyl PC was found to substantially enhance in vitro dissolution compared to pure drug. The gained understanding will support a future development of solid drug dispersions using phospholipids as matrix components. © 2015 Elsevier B.V. All rights reserved. Source

Bonechi C.,University of Siena | Martini S.,University of Siena | Ciani L.,University of Florence | Lamponi S.,University of Siena | And 3 more authors.
PLoS ONE | Year: 2012

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a polyphenol found in various plants, especially in the skin of red grapes. The effect of resveratrol on human health is the topic of numerous studies. In fact this molecule has shown anti-cancer, anti-inflammatory, blood-sugar-lowering ability and beneficial cardiovascular effects. However, for many polyphenol compounds of natural origin bioavailability is limited by low solubility in biological fluids, as well as by rapid metabolization in vivo. Therefore, appropriate carriers are required to obtain efficient therapeutics along with low administration doses. Liposomes are excellent candidates for drug delivery purposes, due to their biocompatibility, wide choice of physico-chemical properties and easy preparation. In this paper liposome formulations made by a saturated phosphatidyl-choline (DPPC) and cholesterol (or its positively charged derivative DC-CHOL) were chosen to optimize the loading of a rigid hydrophobic molecule such as resveratrol. Plain and resveratrol loaded liposomes were characterized for size, surface charge and structural details by complementary techniques, i.e. Dynamic Light Scattering (DLS), Zeta potential and Small Angle X-ray Scattering (SAXS). Nuclear and Electron Spin magnetic resonances (NMR and ESR, respectively) were also used to gain information at the molecular scale. The obtained results allowed to give an account of loaded liposomes in which resveratrol interacted with the bilayer, being more deeply inserted in cationic liposomes than in zwitterionic liposomes. Relevant properties such as the mean size and the presence of oligolamellar structures were influenced by the loading of RESV guest molecules. The toxicity of all these systems was tested on stabilized cell lines (mouse fibroblast NIH-3T3 and human astrocytes U373-MG), showing that cell viability was not affected by the administration of liposomial resveratrol. © 2012 Ristori et al. Source

Van Hoogevest P.,Phospholipid Research Center
European Journal of Lipid Science and Technology | Year: 2013

This 2-day event was organized for the third time by the Phospholipid Research Center Heidelberg. The symposium was held at the University of Heidelberg (facilities provided by Prof. Gert Fricker) and visited by 170 scientists from academia, pharmaceutical industry, authorities, etc. from all over the world. Sixty posters and 16 lectures were presented. This year event started with lectures on the physico-chemical properties of phospholipids, followed by a systematic review of the administration route specific use of phospholipid. The second day of the event was devoted to the latest advances in application of phospholipids, followed by a session on the future use of phospholipids comprising oral presentations of selected posters, and a lecture on the appreciation of liposomes as nanotechnology. The symposium was concluded with an award ceremony of the three best posters. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Husch J.,Central Laboratory of German Pharmacists | Gerbeth K.,Central Laboratory of German Pharmacists | Fricker G.,Institute of Pharmacy and Molecular Biotechnology | Setzer C.,Phospholipid Research Center | And 5 more authors.
Journal of Natural Products | Year: 2012

Boswellia serrata gum resin extracts are used widely for the treatment of inflammatory diseases. However, very low concentrations in the plasma and brain were observed for the boswellic acids (1-6, the active constituents of B. serrata). The present study investigated the effect of phospholipids alone and in combination with common co-surfactants (e.g., Tween 80, vitamin E-TPGS, pluronic f127) on the solubility of 1-6 in physiologically relevant media and on the permeability in the Caco-2 cell model. Because of the high lipophilicity of 1-6, the permeability experiments were adapted to physiological conditions using modified fasted state simulated intestinal fluid as apical (donor) medium and 4% bovine serum albumin in the basolateral (receiver) compartment. A formulation composed of extract/phospholipid/pluronic f127 (1:1:1 w/w/w) increased the solubility of 1-6 up to 54 times compared with the nonformulated extract and exhibited the highest mass net flux in the permeability tests. The oral administration of this formulation to rats (240 mg/kg) resulted in 26 and 14 times higher plasma levels for 11-keto-μ-boswellic acid (1) and acetyl-11-keto-μ-boswellic acid (2), respectively. In the brain, five times higher levels for 2 compared to the nonformulated extract were determined 8 h after oral administration. © 2012 The American Chemical Society and American Society of Pharmacognosy. Source

Fricker G.,Phospholipid Research Center | Fricker G.,University of Heidelberg | Fricker G.,Institute of Pharmacy and Molecular Biotechnology | Kromp T.,Phospholipid GmbH | And 16 more authors.
Pharmaceutical Research | Year: 2010

Phospholipids become increasingly important as formulation excipients and as active ingredients per se. The present article summarizes particular features of commonly used phospholipids and their application spectrum within oral drug formulation and elucidates current strategies to improve bioavailability and disposition of orally administered drugs. Advantages of phospholipids formulations not only comprise enhanced bioavailability of drugs with low aqueous solubility or low membrane penetration potential, but also improvement or alteration of uptake and release of drugs, protection of sensitive active agents from degradation in the gastrointestinal tract, reduction of gastrointestinal side effects of non-steroidal anti-inflammatory drugs and even masking of bitter taste of orally applied drugs. Technological strategies to achieve these effects are highly diverse and offer various possibilities of liquid, semi-liquid and solid lipid-based formulations for drug delivery optimization. © 2010 Springer Science+Business Media, LLC. Source

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