Evaluation of cyclosporine A eye absorption after administration of liposomal or conventional forms in animal model

A lot of researches have investigated the effects of topical cyclosporine A on the eye surface layers' diseases. By now the main limitation in cyclosporine application is the low permeation of the drug into the posterior segments of the eye. The aim of present study was to formulate high permeable dosage form can be beneficial in the topical treatment of the uveitis. To reach higher corneal drug absorption and drug concentration in the posterior segments of the eye, 3 nanoliposomal formulations containing 0.5 mg/ml cyclosporine A were prepared. Liposomal formulations and the commercial product [Restasis] were instilled in the right and left eyes of the rabbits, respectively. The rabbits were killed in the 3, 7, 14 and 28 days of study and the aqueous humor and vitreous were extracted. Mean size of liposomal formulation number 1, number 2 and number 3 were 107.2 +/- 0.7, 129.3 +/- 0.9 and 144.8 +/- 1.8 nm and their zeta potential were -5.0 +/- 1.7, -5.5 +/- 2.3 and 44.6 +/- 6.2 mV, respectively. Results of ocular analysis showed that the liposomal formulations could increase the concentration of the drug in the aqueous and vitreous like Restasis. But, in contrast with what has been expected the findings of this study implicate nanoliposomal formulations prepared could not make a significant difference in concentration of the drug in aqueous and vitreous humor compared to Restasis [anionic microemulsion]. In conclusion, we can state that liposomes with the same composition as our formulations are not more efficient than microemulsion for cyclosporine as ophthalmic drug delivery

Preparation and characterization of liposomes containing methanol extract of aerial parts of Platycladus orientalis [L.] Franco

Platycladus orientalis or Thuja orientalis is a native plant of Iran different parts of which are used in the treatment of various diseases such as: gout, rheumatoid arthritis, common cold, cough, bronchitis, asthma, high blood pressure and hormonal disorders like hirsutism and baldness. Also, various organs of this species have been used as appetizer. The purpose of this study was to prepare and characterize liposomal formulations that contain methanol extract of aerial parts of P. orientalis for hirsutism treatment. Plant's leaves were dried in room temperature, and powdered by grinding. Then, methanol extract was prepared by maceration method. Liposomes containing mathanol extract were produced by two methods of fusion and solvent evaporation. To evaluate mathanol extract and encapsulation efficiency of liposomes, quercetin was chosen as standard. The amount of quercetin in samples was determined by high pressure liquid chromatography [HPLC] method. Mean size of liposomes prepared by solvent evaporation and fusion methods was 373 and 320 nm, respectively. According to the quercetin concentration, encapsulation efficiency of liposomes containing menthanol extract was 69.3 +/- 3.1% for solvent evaporation and 62.2 +/- 4.9% for fusion method. In the current study, a suitable liposomal formulation was prepared. The pharmacological activity of these carriers should be evaluated in the future study

effect of linear PEI on characteristics and transfection efficiency of PEI-based cationic nanoliposomes

The development of efficient and safe carrier system to transfer DNA into cells is essential in non-viral gene therapy. The aim of the present study was to evaluate the effect of linear polyetheneimine [lPEI] [2500 Da] on the physicochemical and biological properties of lipopolyplexes constructed from liposomes and lPEI. Different lipopolymers were synthesized from lPEI and acrylate derivatives. Nanocarriers were composed of the lipids [DOPE, DPPE and DOTAP] and the synthesized lipopolymers. After characterization of the prepared vectors by determination of size and zeta potential, transfection activity was tested in Neuro2A cells. Ethidium bromide and MTT test were used to evaluate the DNA condensation ability and cytotoxicity of vectors, respectively. Vector's size ranged from 95 to 337 nm and they had positive charge. The differences in DNA binding properties of lipopolyplexes were not significant. Among lipids, DOTAP showed better impact on transfection efficiency. The highest transfection activity was achieved by liposomal formulation consist of DOTAP and lipopolymer composed of lPEI and hexyl acrylate. The lipopolyplexes showed minimum cytotoxicity to the cultured cells in vitro. The results of study confirmed that it is possible to improve gene expression using lipopolyplexes

Preparation, characterization and mucoadhesive evaluation of chitosan coated liposomes containing cyclosporine A

The aim of this study was to prepare and characterize chitosan coated liposomes containing cyclosporine A [CyA]. For this purpose, negatively charged liposomes containing CyA were prepared by solvent evaporation method. Liposomes were then added dropwise to chitosan solution [0.25% w/w] for coating. Morphology, mean size and encapsulation efficiency of chitosan coated liposomes were evaluated. To assess the mucoadhesive properties of this drug delivery system, percent of mucin adsorption onto the surface of coated liposomes was determined. The in vitro immunosuppressive effects of CyA encapsulated in the formulated liposomes were also determined on human T-cells by MTT [3- [4, 5- dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide] test. Liposomes were multilamellar vesicles [MLVs]. Mean diameter of chitosan coated liposomes was 2.76 micro m and zeta potential of them was positive [45.3 mV]. Encapsulation efficiency of coated liposomes was 86.11% +/- 2.36 and they were stable during two months. The average of IC50 or the half maximal inhibitory concentration for MLV liposomes was 3.08 2-10 M. According to the mucin adsorption results, this particulate system showed suitable mucoadhesive properties. From these results, it was concluded that the surface modification of liposomes by chitosan coating could increase the prospects of their usefulness as oral drug delivery systems for CyA