Preparation, Characterization and In Vivo Studies of Proliposomes Containing Cyclosporine A

2006 ◽  
Vol 6 (9) ◽  
pp. 2967-2973 ◽  
Author(s):  
Neha M. Shah ◽  
Jolly Parikh ◽  
Alok Namdeo ◽  
N. Subramanian ◽  
Subhash Bhowmick
Keyword(s):  
Electron Microscopy ◽  
Cyclosporine A ◽  
Oral Bioavailability ◽  
Morphological Characteristics ◽  
Volume Of Distribution ◽  
Free Drug ◽  
In Vivo Studies ◽  
Clinical Effects ◽  
Drug Solution

The present study was undertaken to prepare proliposomes of Cyclosporine A (CsA) to increase its oral bioavailability. The proliposomes were prepared by spraying a solution of CsA, egg lecithin and cremophor EL® in methanol-chloroform mixture onto directly compressible lactose (carrier) in a rotary evaporator. A dry free flowing powder of proliposomes was obtained. The dry proliposomal powder was characterized for surface morphology by scanning electron microscopy (SEM). Then the proliposomes were hydrated with distilled water to produce liposomes, which were characterized for particle size distribution, % drug entrapment, and morphological characteristics by transmission electron microscopy (TEM). The liposomes exhibited good entrapment of about 99%. The entrapment of CsA in liposomes was found to be dependent mainly on the drug:lipid ratio. Bioavailability studies were carried out for three different formulations of CsA i.e., free drug suspension; proliposomes derived liposomes and marketed formulation (Pannimun Bioral®, Microemulsion) on male SD rats. The results of bioavailability studies indicated that the difference in the mean drug concentration of the free drug and the liposomes was found to be statistically significant (p < 0 05, p value is 0.032). The absorption constant for liposomal product was much greater (10.26 h−1) than for free drug solution (1.2 h−1) or the marketed sample of microemulsion (2.51 h−1) and the volume of distribution was found to be less for liposomes (7629.88 ml/kg) than that of the free drug solution (10971.92 ml/kg) and marketed microemulsion (9012.07 ml/kg). The results of these studies have shown that a stable proliposomal formulation of CsA for oral administration can be prepared which can be easily hydrated into liposomes from which CsA can exert its clinical effects with a better oral bioavailability.

scholarly journals in vitro- and in vivo Evaluation of Methotrexate-Loaded Hydrogel Nanoparticles Intended to Treat Primary CNS Lymphoma via Intranasal Administration

2018 ◽  
Vol 21 ◽  
pp. 305-317 ◽  
Author(s):  
Leila Pourtalebi Jahromi ◽  
Soliman Mohammadi-Samani ◽  
Reza Heidari ◽  
Amir Azadi
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Zeta Potential ◽  
Intranasal Administration ◽  
Free Drug ◽  
In Vivo Studies ◽  
Nano Formulation ◽  
The Brain ◽  
Drug Solution

Purpose: Although it passes through blood-brain barrier (BBB) very poorly, methotrexate (MTX) is an important therapeutic in the treatment of many central nervous system malignancies. Accordingly, intranasal (IN) administration accompanied with a muco-adhesive chitosan-based nanoformulation is expected to overcome this problem. Methods: Nanogel containing MTX was prepared through an ionic gelation method and then characterized in terms of particle size, morphology, zeta potential, drug loading and drug release behavior. The drug release results were fitted on eight mathematical models to choose the model best describing the phenomenon. Then the nano-formulation and free drug solution in deionized water as control were administered in the nasal cavity for rats and after 15, 30, 60 and 240 minutes their brain and plasma were analyzed for MTX quantity. Results: The nano-formulation demonstrated an average particle size near 100 nm with a zeta potential of 18.65±1.77 mv. Loading efficiency and loading capacity were calculated to be 65.46±7.66 and 3.02±0.34 respectively. The Weibull model was found to be best describing the release phenomenon as a combination of swelling and Fickian diffusion. Moreover in in vivo studies, drug targeting efficiency and direct transport percentage for nanogel (test) and free drug solution (control) were 424.88% and 76.46% and 34842.15% and 99.71% respectively.  Conclusion: According to in vivo studies, nanogel produced significantly higher concentration of MTX in the brain but not in the plasma when compared to the free drug solution. Besides, in comparison to intravenous administration of the same nanogel it was indicated that intranasal administration significantly increases the brain concentration of MTX.

Cationic Diclofenac Lipid Nanoemulsion for Improved Oral Bioavailability: Preparation, Characterization and In Vivo Evaluation

2015 ◽  
Vol 8 (2) ◽  
pp. 2874-2880
Author(s):  
Kishan Veerabrahma ◽  
Swapna Madishetty ◽  
Muzammil Afzal Syed ◽  
Prabhakar Kandadi
Keyword(s):  
Oral Bioavailability ◽  
Physical Stability ◽  
Cationic Lipid ◽  
Entrapment Efficiency ◽  
In Vivo Studies ◽  
Pharmacokinetic Parameters ◽  
In Vivo Evaluation ◽  
Drug Content ◽  
Lipid Nanoemulsion

Cationic nanoemulsions were reported to have increased bioavailability. The aim of present study was to prepare a cationic lipid nanoemulsion of diclofenac acid (LNEs) for improved oral bioavailability to treat arthritic conditions. The LNEs of diclofenac acid were prepared by using soya bean oil, egg lecithin, cholesterol and stearylamine. Stearylamine was used as positive charge inducer. The LNEs were processed by homogenization and ultrasonication. The formulation composition was selected based on earlier reports. The LNEs were characterized for size and zeta potential. The physical stability of LNEs was studied using autoclaving, centrifugal, desorption (dilution effect) stresses and on storage. The total drug content and entrapment efficiency were determined using HPLC. During in vivo studies in Wistar rats, the pharmacokinetic parameters of LNEs were compared with a prepared diclofenac suspension in sodium CMC mucilage. The selected formulations, F1, F2 and F3, were relatively stable during centrifugal stress, dilution stress and on storage. The drug content was found to be 2.38 ± 1.70 mg/ml for F1, 2.30 ± 0.82 mg/ml for F2, and 2.45 ± 0.66 mg/ml for F3. The entrapment efficiencies were 97.83 ± 0.53%, 97.87 ± 1.22% and 98.25 ± 0.21% for F1, F2 and F3 respectively. The cumulative percentage drug release from F1, F2 and F3 showed more release in pH 6.8 phosphate buffer than in pH 1.2 HCl. During oral bioavailability studies, the LNEs showed higher serum concentrations than a suspension. The relative bioavailability of the LNE formulations F1, F2 and F3 were found to be 2.35, 2.94 and 6.28 times that of F4 suspension and were statistically significant. Of all, the cationic lipid nanoemulsion (F3) was superior in improving bioavailability, when compared with plain emulsion (F1) and cholesterol containing LNE (F2). The study helps in designing the cationic oral nanoemulsions to improve the oral bioavailability of diclofenac.

Reepithelialization of Orthotopic Tracheal Allografts Prevents Rejection after Withdrawal of Immunosuppression

2005 ◽  
Vol 114 (4) ◽  
pp. 279-288 ◽  
Author(s):  
Satish Govindaraj ◽  
Elena Fedorova ◽  
Eric M. Genden ◽  
Houtan Chaboki ◽  
Jonathan S. Bromberg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cyclosporine A ◽  
Allograft Rejection ◽  
Lymphocyte Subpopulation ◽  
Ciliated Epithelium ◽  
Prior Work ◽  
Cellular Infiltrate ◽  
Tracheal Transplantation

Prior work has demonstrated that immunosuppressed orthotopic tracheal allografts undergo progressive reepithelialization over a 48-day period with recipient-derived tracheal epithelium. We hypothesized that reepithelialization of tracheal allografts would prevent rejection after withdrawal of immunosuppression. BALB/c murine tracheal grafts were transplanted orthotopically into either syngeneic or allogeneic C57/BL6 recipients. The recipients were either not immunosuppressed, immunosuppressed with cyclosporine A (10 mg/kg per day) continuously, or immunosuppressed for 48 days and then withdrawn from immunosuppression. The grafts were assessed for acute and chronic rejection 10 days and 50 days after immunosuppression withdrawal. The immunosuppressed allograft recipients maintained a ciliated epithelium acutely and chronically after immunosuppression withdrawal. Ten days after immunosuppression withdrawal, there was a mild cellular infiltrate, which resolved 50 days after withdrawal. Electron microscopy, lymphocyte subpopulation assays, and lamina propria analysis demonstrated that immunosuppression withdrawal did not result in tracheal allograft rejection. In vitro and in vivo assessments did not demonstrate evidence of systemic or local immune tolerance. We conclude that reepithelialization of orthotopic tracheal allografts with recipient-derived mucosa prevents rejection of allograft segments. Tracheal transplantation may require only transient immunosuppression, which can be withdrawn after tracheal reepithelialization.

scholarly journals AN ANALYSIS OF COLLAGEN SECRETION BY ESTABLISHED MOUSE FIBROBLAST LINES

1964 ◽  
Vol 22 (1) ◽  
pp. 227-258 ◽  
Author(s):  
Burton Goldberg ◽  
Howard Green
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Mouse Fibroblast ◽  
In Vivo Studies ◽  
In Vitro Synthesis ◽  
Collagen Secretion ◽  
Golgi System ◽  
Alternative Theories

In vitro synthesis of collagen by established mouse fibroblast lines has been examined by electron microscopy. During rapid growth (log phase), when collagen could not be detected in the cultures, the cells lacked a well developed granular ergastoplasm and Golgi system. Upon cessation of growth (stationary phase), collagen accumulated in the cultures and the cells demonstrated highly developed granular and smooth ergastoplasm. Collagen appeared to be synthesized in the rough-surfaced endoplasmic reticulum and to be transported as a soluble protein to the cell surface by vesicular elements of the agranular ergastoplasm. Fusion of the limiting membranes of these vesicles with the cell membrane permitted the discharge of the soluble collagen into the extracellular space, where fibrils of two diameter distributions formed. The secretion of collagen is concluded to be of the merocrine type. Alternative theories of collagen secretion are discussed and the data for established lines compared with the results of other in vitro and in vivo studies of collagen fibrillogenesis.

scholarly journals Research Status of Mesenchymal Stem Cells in Liver Transplantation

2019 ◽  
Vol 28 (12) ◽  
pp. 1490-1506 ◽  
Author(s):  
Yu You ◽  
Di-guang Wen ◽  
Jian-ping Gong ◽  
Zuo-jin Liu
Keyword(s):  
Stem Cells ◽  
Liver Transplantation ◽  
Clinical Trials ◽  
Mesenchymal Stem Cells ◽  
In Vivo Studies ◽  
Cell Contact ◽  
Clinical Effects ◽  
Clinical Safety

Liver transplantation has been deemed the best choice for end-stage liver disease patients but immune rejection after surgery is still a serious problem. Patients have to take immunosuppressive drugs for a long time after liver transplantation, and this often leads to many side effects. Mesenchymal stem cells (MSCs) gradually became of interest to researchers because of their powerful immunomodulatory effects. In the past, a large number of in vitro and in vivo studies have demonstrated the great potential of MSCs for participation in posttransplant immunomodulation. In addition, MSCs also have properties that may potentially benefit patients undergoing liver transplantation. This article aims to provide an overview of the current understanding of the immunomodulation achieved by the application of MSCs in liver transplantation, to discuss the problems that may be encountered when using MSCs in clinical practice, and to describe some of the underlying capabilities of MSCs in liver transplantation. Cell–cell contact, soluble molecules, and exosomes have been suggested to be critical approaches to MSCs’ immunoregulation in vitro; however, the exact mechanism, especially in vivo, is still unclear. In recent years, the clinical safety of MSCs has been proven by a series of clinical trials. The obstacles to the clinical application of MSCs are decreasing, but large sample clinical trials involving MSCs are still needed to further study their clinical effects.

In Vivo and In Vitro Characterization of Mesothelial Lipid Inclusions

1991 ◽  
Vol 11 (3) ◽  
pp. 207-212 ◽  
Author(s):  
J. Thomas Hjelle ◽  
Barbara T. Golinska ◽  
Diane C. Waters ◽  
Kevin R. Steidley ◽  
David R. McCarroll ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Culture Media ◽  
Morphological Characteristics ◽  
Mesothelial Cells ◽  
Lipid Bodies ◽  
Lamellar Bodies ◽  
Peritoneal Mesothelial Cells ◽  
Lipid Inclusions

The nature of intracytoplasmic lipid inclusions found in cultured rabbit and rat peritoneal mesothelial cells was examined by ultrastructural and biochemical techniques. Transmission electron microscopy also demonstrated extracellular release of these lipid bodies. Differential fixation with tannic acid revealed 2 types of inclusions, lamellated (lamellar bodies) and nonlamellated (homogeneous). The lamellar bodies were found near or in the Golgi apparatus and on the cell surface where occasionally they were observed in exocytotic pouches. The homogeneous inclusions were the predominant species being found primarily intracellularly. Lipid bodies obtained from the culture media over the cells displayed on electron microscopy the same morphological characteristics as those seen intracellularly. Exposure of confluent cultures of mesothelial cells to the vital lipid stain Nile Red caused the appearance of intensely fluorescent droplets in or on the cells at wave lengths consistent with staining for phosphatidylcholine-rich vesicles. Incubation of the cells with r4C)-choline an d subsequent analysis of phospholipid formation revealed high rates of r4C)-phosphatidylcholine addition to both intra and extracellular lipid pools. Taken together, mesothelial cells exhibit lipid bodies similar in ultrastructure to the surfactant containing organelles of Type II pneumocytes.

Lipid nanoparticles enhance the absorption of cyclosporine A through the gastrointestinal barrier: In vitro and in vivo studies

2016 ◽  
Vol 500 (1-2) ◽  
pp. 154-161 ◽  
Author(s):  
Melissa Guada ◽  
Beatriz Lasa-Saracíbar ◽  
Hugo Lana ◽  
Maria del Carmen Dios-Viéitez ◽  
Maria J. Blanco-Prieto
Keyword(s):  
Cyclosporine A ◽  
Lipid Nanoparticles ◽  
In Vivo Studies ◽  
Gastrointestinal Barrier

scholarly journals Mitochondrial damage: a possible mechanism of the “topical” phase of NSAID induced injury to the rat intestine

Gut ◽  
1997 ◽  
Vol 41 (3) ◽  
pp. 344-353 ◽  
Author(s):  
S Somasundaram ◽  
S Rafi ◽  
J Hayllar ◽  
G Sigthorsson ◽  
M Jacob ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
In Vivo Studies ◽  
Tolerability Profile ◽  
Marker Enzyme ◽  
Subcellular Organelle

Background—The “topical” effect of non-steroidal anti-inflammatory drugs (NSAIDs) seems to be an important cause of NSAID induced gastrointestinal damage.Aim—To examine the possible mechanism of the “topical” phase of damage in the small intestine.Methods—Electron microscopy and subcellular organelle marker enzyme studies were done in rat small intestine after oral administration of indomethacin (doses varied between 5 and 30 mg/kg). The effect of conventional and non-acidic NSAIDs on rat liver mitochondrial respiration was measured in vitro in a Clarke-type oxygen electrode.Results—The subcellular organelle marker enzymes showed mitochondrial and brush border involvement within an hour of indomethacin administration. Electron microscopy showed dose dependent mitochondrial changes following indomethacin administration consistent with uncoupling of oxidative phosphorylation (or inhibition of electron transport) which were indistinguishable from those seen with the uncoupler dinitrophenol. Parenteral indomethacin caused similar changes, but not in rats with ligated bile ducts. A range of NSAIDs, but not paracetamol or non-acidic NSAIDs which have a favourable gastrointestinal tolerability profile, uncoupled oxidative phosphorylation in vitro at micromolar concentrations and inhibited respiration at higher concentrations. In vivo studies with nabumetone and aspirin further suggested that uncoupling or inhibition of electron transport underlies the “topical” phase of NSAID induced damage.Conclusion—Collectively, these studies suggest that NSAID induced changes in mitochondrial energy production may be an important component of the “topical” phase of damage induction.

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