Point of use production of liposomal solubilised products

With the progression towards personalised and age-appropriate medicines, the production of drug loaded liposomes at the point of care would be highly desirable. In particular, liposomal solubilisation agents that can be produced rapidly and easily would provide a new option in personalised medicines. Such a process could also be used as a rapid tool for the formulation and pre-clinical screening of low soluble drugs. Within this paper, we outline a novel easy-to-use production method for point of use production of liposome solubilised drugs. Our results demonstrate that pre-formed multilamellar liposomes, stored in a fresh or frozen format, can be bilayer loaded with low solubility drugs using a simple bath sonication process. Sonication is undertaken in a sealed vial allowing the contents to remain sterile. Liposomes around 100 nm were prepared and these liposomes were able to increase the amount of drug dissolved by up to 10 fold. These liposomal solubilisation agents were stable in terms of size and drug solubilisation for up to 8 days when stored in the fridge making them an easy to use and robust small-scale tool for drug solubilisation

Curcumin loaded pH-sensitive hybrid lipid/block copolymer nanosized drug delivery systems

Curcumin is a perspective drug candidate with pleiotropic antineoplastic activity, whose exceptionally low aqueous solubility and poor pharmacokinetic properties have hampered its development beyond the preclinical level. A possible approach to overcome these limitations is the encapsulation of curcumin into nano-carriers, incl. liposomes. The present contribution is focused on feasibility of using hybrid pH-sensitive liposomes, whereby curcumin is entrapped as a free drug and as a water soluble inclusion complex with PEGylated tert-butylcalix[4]arene, which allows the drug to occupy both the phospholipid membranes and the aqueous core of liposomes. The inclusion complexes were encapsulated in dipalmithoylphosphathydilcholine:cholesterol liposomes, whose membranes were grafted with a poly(isoprene-b-acrylic acid) diblock copolymer to confer pH-sensitivity. The liposomes were characterized by DLS, ζ-potential measurements, cryo-TEM, curcumin encapsulation efficacy, loading capacity, and in vitro release as a function of pH. Free and formulated curcumin were further investigated for cytotoxicity, apoptosis-induction and caspase-8, and 9 activation in chemosensitive HL-60 and its resistant sublines HL-60/Dox and HL-60/CDDP. Formulated curcumin was superior cytotoxic and apoptogenic agent vs. the free drug. The mechanistic assay demonstrated that the potent proapoptotic effects of pH-sensitive liposomal curcumin presumably mediated via recruitment of both extrinsic and intrinsic apoptotic pathways in both HL-60 and HL-60/CDDP cells

Curcumin loaded pH-sensitive hybrid lipid/block copolymer nanosized drug delivery systems

Curcumin is a perspective drug candidate with pleiotropic antineoplastic activity, whose exceptionally low aqueous solubility and poor pharmacokinetic properties have hampered its development beyond the preclinical level. A possible approach to overcome these limitations is the encapsulation of curcumin into nano-carriers, incl. liposomes. The present contribution is focused on feasibility of using hybrid pH-sensitive liposomes, whereby curcumin is entrapped as a free drug and as a water soluble inclusion complex with PEGylated tert-butylcalix[4]arene, which allows the drug to occupy both the phospholipid membranes and the aqueous core of liposomes. The inclusion complexes were encapsulated in dipalmithoylphosphathydilcholine:cholesterol liposomes, whose membranes were grafted with a poly(isoprene-b-acrylic acid) diblock copolymer to confer pH-sensitivity. The liposomes were characterized by DLS, ζ-potential measurements, cryo-TEM, curcumin encapsulation efficacy, loading capacity, and in vitro release as a function of pH. Free and formulated curcumin were further investigated for cytotoxicity, apoptosis-induction and caspase-8, and 9 activation in chemosensitive HL-60 and its resistant sublines HL-60/Dox and HL-60/CDDP. Formulated curcumin was superior cytotoxic and apoptogenic agent vs. the free drug. The mechanistic assay demonstrated that the potent proapoptotic effects of pH-sensitive liposomal curcumin presumably mediated via recruitment of both extrinsic and intrinsic apoptotic pathways in both HL-60 and HL-60/CDDP cells

Preparation and characterization of lyophilised EGG PC liposomes incorporating curcumin and evaluation of its activity against colorectal cancer cell lines

Curcumin has been associated with the treatment of various diseases in traditional medicine, among them cancer. The major problems that prevent its approval as therapeutic agent are its low water solubility and its relatively low in vivo bioavailability. Liposomes are considered as effective drug carriers because of their ability to solubilize hydrophobic compounds and to alter their pharmacokinetic properties. The purpose of this study was the development of lyophilised liposomal curcumin fully characterized in terms of its physical properties [(ζ-potential, size, size distribution and Polydispercity index (PI)], and to evaluate its in vitro cytotoxic against colorectal cancer cell lines in a short term and in a long term (clonogenic) assay. Curcumin was incorporated in egg-phosphatidylcholine (EPC) liposomes at a drug to lipid molar ratio 1:14 achieving high incorporation efficiency close to 85%. The liposomal curcumin was lyophilized preserving thus its stability. The reconstitution of the formulation resulted in the original liposomal suspension. The release in FBS showed a plateau near 14% at 96 hours of incubation. The in vitro studies against colorectal cancer cell lines have shown that liposomes improve the activity of curcumin especially in the long term assay and the liposomal formulation found to be more potent against HCT116 and HCT15, cell lines which express the MDR phenotype. EPC liposomal curcumin in a molar ratio of curcumin/EPC 1:14 has shown improved cytotoxic activity versus free curcumin against colorectal cancer cell lines. In vivo studies based on the recent findings are in progress in our laboratory. Copyright © 2011 American Scientific Publishers All rights reserved

Reduction (%) of MN frequency induced by MMC (0.05 and 0.50 µg/ml) in presence of CMW (1, 2 and 5% v/v).

<p>Reduction (%) of MN frequency induced by MMC (0.05 and 0.50 µg/ml) in presence of CMW (1, 2 and 5% v/v).</p

Frequencies of BNMN and MN as well as CBPI values in cultured human lymphocytes treated with CMW, MMC (0.05 and 0.50 µg/ml) and their mixture.

<p>BN: binucleated cells; BNMN: micronucleated binucleated cells; MN: micronuclei; CBPI: Cytokinesis Block Proliferation Index; CMW: Chios Mastic Water; MMC: Mitomycin-C; MF (‰) ± se, mean frequencies (‰) ± standard error; MN were scored in 2000 binucleated lymphocytes per experimental point;</p>1,2,3<p>significant difference in relation to control at <i>p</i><0.05, <i>p</i><0.01 and <i>p</i><0.001 respectively;</p>a,b,c<p>significant difference in relation to MMC at <i>p</i><0.05, <i>p</i><0.01 and <i>p</i><0.001 respectively [G-test for BNMN and MN; <i>χ2</i> for CBPI].</p

Comparative distribution of MN frequency (‰) induced by CMW, MMC and their combination.

<p>The dotted line is read on the left hand Y-axis and the solid line on the right hand Y-axis.</p

Summary of the results obtained in the Somatic Mutation And Recombination Test (SMART) on <i>Drosophila melanogaster,</i> after larvae treatment with CMW, MMC (1.00, 2.50 and 5.00 µg/ml) and their mixture.

<p>Symbols next to values signify the following: +, positive mutagenic effect; −, no mutagenic effect; w, weakly positive effect; i, inconclusive effect; <i>m</i> is the multiplication factor¹ (<i>p = </i>0.05); ^{a, b, c} is significant difference in relation to MMC at <i>p</i><0.05, <i>p</i><0.01 and <i>p</i><0.001, respectively (U-test).</p>1<p>The number of mutant spots is given in parenthesis. Statistical diagnosis according to Frei and Würgler <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069494#pone.0069494-Frei1" target="_blank">[53]</a>.</p

Wing spot frequency (%) induced by MMC (1.00, 2.50 and 5.00 µg/ml) in presence of CMW (50 and 100% v/v).

<p>[*<i>p</i><0.05, **<i>p</i><0.01, ***<i>p</i><0.001, U-test].</p