Interactions between liposomes and chitosan II: Effect of selected parameters on aggregation and leakage

Henriksen, Ingrid; Våagen, Sissel R.; Sande, Sverre Arne; Smistad, Gro; Karlsen, Jan

doi:10.1016/s0378-5173(96)04801-6

Cited by 72 publications

(54 citation statements)

References 15 publications

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“…169,[175][176][177][178][179][180][181][182][183][184][185][186] Briey, chitosan adsorbs at onto the surface of negatively, neutrally and positively charged vesicles 183,185 and the adsorption does not seem to be inuenced by the vesicle size.…”

Section: Interactions With Phospholipid Vesiclesmentioning

confidence: 99%

Complexes of oppositely charged polyelectrolytes and surfactants – recent developments in the field of biologically derived polyelectrolytes

2013

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We review the work done on complexes between biopolyelectrolytes such as ionically modified cellulose or chitosan and oppositely charged surfactants. Around equimolarity of the charges one typically observes precipitation but for other mixing ratios one may form long-time stable complexes, where structure and rheology depend on the mixing ratio, total concentration and the molecular constitution of the components. In addition, it may be the case that the structures are formed under non-equilibrium situations and therefore depend on the preparation path. The binding is shown to occur cooperatively and the micelles present often retain their shape irrespective of the complexation. However, the rather stiff biopolyelectrolytes may lead to an interconnection between different aggregates thereby forming a network with the corresponding rheological properties. In general, the structure and the properties of the aggregates are rather versatile and correspondingly one can create a wide range of different surfactant-biopolyelectrolyte systems by appropriately choosing the composition. This is very interesting as it allows for formulations with a large range of tuneable properties with ecologically friendly polyelectrolytes for many relevant applications.

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Section: Interactions With Phospholipid Vesiclesmentioning

confidence: 99%

Complexes of oppositely charged polyelectrolytes and surfactants – recent developments in the field of biologically derived polyelectrolytes

2013

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“…Accordingly, the development of stable liposomes is a prerequisite for their exploitation in the delivery of therapeutic drugs [10,11] . For many years, attempts have been made to improve the stability of liposomes by several methods, including preparing more stable bilayers [12] , coating their surface with protecting polymers [13][14][15][16] , and modifying charge [17][18][19] .…”

Section: Introductionmentioning

confidence: 99%

Proliposomes for oral delivery of dehydrosilymarin: preparation and evaluation in vitro and in vivo

Chu

Tong

et al. 2011

Acta Pharmacol Sin

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Aim: To formulate proliposomes with a polyphase dispersed system composed of soybean phospholipids, cholesterol, isopropyl myristate and sodium cholate to improve the oral bioavailability of dehydrosilymarin, an oxidized form of herbal drug silymarin. Methods: Dehydrosilymarin was synthesized from air oxidation of silymarin in the presence of pyridine, and proliposomes were prepared by a film dispersion-freeze drying method. Morphological characterization of proliposomes was observed using a transmission electron microscope. Particle size and encapsulation efficiency of proliposomes were measured. The in vitro release of dehydrosilymarin from suspension and proliposomes was evaluated. The oral bioavailability of dehydrosilymarin suspension and proliposomes was investigated in rabbits. Results: The proliposomes prepared under the optimum conditions were spherical and smooth with a mean particle size in the range of 7 to 50 nm. Encapsulation efficiency was 81.59%±0.24%. The in vitro accumulative release percent of dehydrosilymarinloaded proliposomes was stable, which was slow in pH 1.2, and increased continuously in pH 6.8, and finally reached 86.41% at 12 h. After oral administration in rabbits, the relative bioavailability of proliposomes versus suspension in rabbits was 228.85%. Conclusion: Proliposomes may be a useful vehicle for oral delivery of dehydrosilymarin, a drug poorly soluble in water.

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“…Chitosan is an abundant and natural polysaccharide which presents some interesting and useful properties such as biocompatibility, biodegradability, non-toxicity, adsorption and adhesion properties and the ability to interact with different substances (like hydrophilic and hydrophobic drugs) [13,22,23]. These characteristics are extremely important for medical and pharmaceutical applications, namely for the development controlled drug release devices [13,24,25]. For ocular applications, it is also recognized that chitosan-based formulations present a prolonged precorneal residence time, an ability to increase solution viscosity and excellent mucoadhesive properties [26,27].…”

Section: Introductionmentioning

confidence: 99%

Supercritical solvent impregnation of ophthalmic drugs on chitosan derivatives

Braga

Pato

Silva

et al. 2008

The Journal of Supercritical Fluids

107

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In this work, three chitosan derivatives (N-carboxymethyl chitosan (CMC), N-carboxybutyl chitosan (CBC) and N-succinyl chitosan (SCC)) were impregnated with flurbiprofen (an anti-inflammatory drug) and timolol maleate (an anti-glaucoma drug), using a supercritical solvent impregnation (SSI) technique (and employing high pressure CO 2 and CO 2 + EtOH mixtures) in order to develop hydrogel-type ophthalmic drug delivery applications. Impregnation experiments were carried out from 9.0 up to 14.0 MPa, and at 303.0, 313.0 and 323.0 K. The resulting polymeric drug delivery systems, as well as other polymeric samples processed in CO 2 , were characterized by FTIR spectroscopy and scanning electron microscopy (SEM). Drug release kinetics studies were performed for all prepared systems. The effects of impregnation pressure and temperature on the release kinetics results were studied and compared to the traditional soaking impregnation method. For the same operational conditions, results confirmed that the three different (chemically and physically) polymeric structures conditioned the impregnation and the drug release processes. Despite the final released drug mass is always the result of the employed operational impregnation conditions and of the very complex relative specific interactions that may occur between all species present in the system (drugs, polymers, CO 2 and ethanol), results showed that, for N-carboxymethyl chitosan, the predominant effects in the impregnation process seemed to be the solubility of drugs in CO 2 and in CO 2 + EtOH mixtures, as well as the swelling and plasticizing effect of CO 2 and ethanol on the polymer. Finally, the SSI method proved to be a more efficient and "tunable" impregnation process than the traditional impregnation of drugs by a soaking method. Therefore, and using this "tunable" SSI method, these N-chitosan derivatives-based ophthalmic drug delivery systems can be easily and efficiently prepared taking in consideration the desired drug levels according to patients needs.

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Interactions between liposomes and chitosan II: Effect of selected parameters on aggregation and leakage

Cited by 72 publications

References 15 publications

Complexes of oppositely charged polyelectrolytes and surfactants – recent developments in the field of biologically derived polyelectrolytes

Complexes of oppositely charged polyelectrolytes and surfactants – recent developments in the field of biologically derived polyelectrolytes

Proliposomes for oral delivery of dehydrosilymarin: preparation and evaluation in vitro and in vivo

Supercritical solvent impregnation of ophthalmic drugs on chitosan derivatives

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