Chitosan-coated liposomes: characterization and interaction with leuprolide

Guo, Jian

doi:10.1016/s0378-5173(03)00254-0

Cited by 185 publications

(97 citation statements)

References 10 publications

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“…The increased encapsulation efficiency of uncoated liposomes may be attributed to the absence of coating since chitosan coating is generally formed by electrostatic interaction between chitosan and phospholipid bilayers of liposome. Such a coating is generally very stable and may prevent drug encapsulation in greater quantities [45]. However as can be seen from the results, there is not a significant difference between the uncoated and chitosan-coated combinatorial liposomes.…”

Section: Discussionmentioning

confidence: 99%

Impediment of selenite-induced cataract in rats by combinatorial drug laden liposomal preparation

Huang

Muhemaitia

2018

Libyan Journal of Medicine

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Cataract is the leading cause of blindness globally with surgery being the only form of treatment. But cataract surgery is accompanied by complications, chiefly intra-ocular infections. Hence, preventive nanoformulations may be extremely beneficial. In the present study, novel chitosan-coated liposomal formulations encapsulating a combination of drugs, lanosterol and hesperetin were prepared and characterized. The combinatorial liposomes were prepared by thin film evaporation active extrusion method. The characterization of liposomes was done by transmission electron microscopy, zeta potential, encapsulation efficiency, stability, cytotoxicity and in vitro release studies. The main difference between the chitosan-coated and uncoated combinatorial liposomes is the release of drugs as indicated by the in vitro release studies. The slow and sustained release of the drugs from chitosan-coated ones as against the burst release from uncoated indicates an increased retention time for combinatorial drugs in cornea. This leads to a delay in progression of cataract as seen from in vivo studies. Cytotoxicity studies indicate no cell toxicity of the coating of chitosan or the combination of drugs. Stability studies indicate that there were almost no changes in size, zeta potential and polydispersity index values of the combinatorial liposomes upon storage at room temperature for 60 days. Another important study is the estimation of antioxidant defense system. The estimated values of glutathione reductase, malondialdehyde and chief antioxidant enzymes point toward an upregulation of antioxidant defense system. From the results, it may be concluded that novel chitosan-coated combinatorial liposomes are effective in delaying or preventing of cataract.

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Section: Discussionmentioning

confidence: 99%

Impediment of selenite-induced cataract in rats by combinatorial drug laden liposomal preparation

Huang

Muhemaitia

2018

Libyan Journal of Medicine

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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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“…Lee et al, 2005) has not been pursued by others (e.g. Guo et al, 2003;Filipović-Grčić et al, 2001). Figure 4 indicated that both the liposomes and the coat were disrupted by the bile salts.…”

Section: Discussionmentioning

confidence: 99%

“…Here we have therefore evaluated a conceptually simple idea of bringing together cationic liposomes and anionic polymer with the intention of creating a pH responsive coat around the liposomes which would protect the vesicles en route through the stomach and the small intestine. This general route to coating has been previously explored when anionic liposomes were coated with the cationic polymer chitosan (Guo et al, 2003;Takeuchi et al, 1996Takeuchi et al, , 2005, but no similar work has been completed using a pH responsive polymer for coating. The polymer Eudragit S100 was chosen as the coating material as it is widely used in both commercially available and experimental formulations for colonic targeting e.g.…”

Section: Discussionmentioning

confidence: 99%

“…This strategy has previously been used in the development of polymer-coated cationic and anionic liposomal formulations, where the point at which the zeta potential plateaus is taken to indicate saturation of the vesicle surface with polymer (Guo et al, 2003;Davidsen et al, 2001;Takeuchi et al, 2005). Results from our other studies (sizing, cryo-EM and drug release)…”

Section: Discussionmentioning

confidence: 99%

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Evaluation of liposomes coated with a pH responsive polymer

Barea

Jenkins

Gaber

et al. 2010

International Journal of Pharmaceutics

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Liposomes have been coated with the pH responsive polymer, Eudragit S100, and the formulation's potential for lower GI targeting following oral administration assessed.Cationic liposomes were coated with the anionic polymer through simple mixing. The evolution of a polymer coat was studied using zeta potential measurements and laser diffraction size analysis. Further evidence of an association between polymer and liposome was obtained using light and cryo electron microscopy. Drug release studies were carried out at pH 1.4, pH 6.3 and pH 7.8, representing the pH conditions of the stomach, small intestine and ileocaecal junction, respectively.The polymer significantly reduced liposomal drug release at pH 1.4 and pH 6.3 but drug release was equivalent to the uncoated control at pH 7.8, indicating that the formulation displayed appropriate pH responsive release characteristics. While the coating layer was not able to withstand the additional challenge of bile salts this reinforces the importance of evaluating these types of formulations in more complex media.

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Chitosan-coated liposomes: characterization and interaction with leuprolide

Cited by 185 publications

References 10 publications

Impediment of selenite-induced cataract in rats by combinatorial drug laden liposomal preparation

Impediment of selenite-induced cataract in rats by combinatorial drug laden liposomal preparation

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

Evaluation of liposomes coated with a pH responsive polymer

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