Amount Of Cyclosporine Research Articles

Cyclosporine-loaded micelles for ocular delivery: Investigating the penetration mechanisms

Cyclosporine is an immunomodulatory drug commonly used for the treatment of mild-to-severe dry eye syndrome as well as intermediate and posterior segment diseases as uveitis. The ocular administration is however hampered by its relatively high molecular weight and poor permeability across biological barriers. The aim of this work was to identify a micellar formulation with the ability to solubilize a considerable amount of cyclosporine and promote its transport across ocular barriers. Non-ionic amphiphilic polymers used for micelles preparation were tocopherol polyethylene glycol 1000 succinate (TPGS) and Solutol® HS15. Furthermore, the addition of alpha-linolenic acid was assessed. A second aim was to evaluate micelles fate in the ocular tissues (cornea and sclera) to shed light on penetration mechanisms. This was possible by extracting and quantifying both drug and polymer in the tissues, by studying TPGS hydrolysis in a bio-relevant environment and by following micelles penetration with two-photon microscopy. Furthermore, TPGS role as permeation enhancer on the cornea, with possible irreversible modifications of tissue permeability, was analyzed. Results showed that TPGS micelles (approx. 13nm in size), loaded with 5mg/ml of cyclosporine, promoted drug retention in both the cornea and the sclera. Data demonstrated that micelles behavior strictly depends on the tissue: micelles disruption occurs in contact with the cornea, while intact micelles diffuse in the interfibrillar pores of the sclera and form a reservoir that can sustain over time drug delivery to the deeper tissues. Finally, cornea quickly restore the barrier properties after TPGS removal from the tissue, demonstrating its potential good tolerability for ocular application.

The cyclosporine transdermal transfer possibility study on model systems

Aim: to develop the emulsion transdermal therapeutic system (TTS) of cyclosporine and the research of its diffusion from TTS.Materials and methods. The quantitative evaluation of cyclosporine in model media was performed on liquid chromatograph Agilent 1100 G1311 with spectrophotometric detector G1315B (Germany). For the production of the emulsion matrix, the Heidolph DIAX900 disperser (Germany) and the ultrasonic homogenizer Hielscher UIS250V (Germany) were used. The cyclosporine diffusion from TTS through Strat-M membrane (25 mm in diameter, Merck Millipore) was studied using Copley diffusion analyser (Great Britain).Results. Using the developed method of micro-HPLC, it was established that the amount of cyclosporine passed through the Strat-M membrane over 24 hours from 10 sm2 TTS, containing 173 mg of the substance, was 5.9 mg. The estimated blood concentration is ~ 50 ng/ml which corresponds to the therapeutic maintenance blood concentration during organ transplantation (50–75 ng/ml).Conclusion. The model studies demonstrate the possibility of the cyclosporine transdermal transfer.

Bioassay for enrich-blood bioactivity of Agelicae Sinensis Radix

Danggui, Agelicae Sinensis Radix, is a widely used Chinese herb to enrich blood, but its quality cannot be effectively assessed by the known chemical markers such as ferulic acid, ligustilide, polysaccharides, etc. A new bioassay was therefore developed to quantify the Enrich-Blood Bioactivity (EBB) for the quality assessment of Danggui raw materials. Danggui sample was first extracted with ethanol and water, respectively. Then the ethanolic extract and water extract were mixed as a test sample to quantify the amount of EBB by mice experiment. The blood deficiency mode in mice was developed by intraperitoneal injecting cyclophospharmide and phenylhdrazine hydrochloride. The quantity of red blood cell was chosen as EBB marker. Cyclosporine A was chosen as a control substance. EBB in analytes was quantified by the amount reaction of parallel line analysis (3, 3') method. The results indicated that the reliability test for quantifying EBB was passed through and the measured value was valid. The analytes showed the significant EBB (P < 0.05). The correlation coefficient was 0.9984 (n=5) between the amount of cyclosporine A (0.035-0.56 g x kg(-1)) and the increased number of red blood cell. The relative standard deviation (RSY) on the amount of EBB was estimated to be 6.15% (n = 6) by six replicated tests, and the confidence limit rate was 26.68% (n = 6). Five Danggui samples, which were collected from different cultivation areas with various morphological characters, showed the variety of EBB in the range of 21.95-44.16 U x g(-1). It is concluded that the developed method is accurate to quantify the EBB of Danggui raw materials, and is therefore suitable to assess its quality.

シクロスポリン単独療法で寛解したネフローゼ症候群の1例

The case was a female in her early 80's. Due to abdominal bloating and lower limb edema, she visited a nearby doctor, was diagnosed to have nephrotic syndrome, and then was referred to our department. Upon initial consultation, TP of 4.1 g/dl, Alb of 1.7 g/dl, UN of 73 mg/dl, and Cr of 1.43 mg/dl, along with pleural effusion were observed by chest X-ray. A renal biopsy was not performed because permission could not be obtained. Despite the fact that management of the edema was performed using diuretic agents and albumin preparations, a reduced renal function and deterioration of the fluid retention were gradually observed. She originally displayed lower back pain and digestive symptoms and, therefore, cyclosporine monotherapy was initiated in order to address concerns of side effects such as osteoporosis and peptic ulcer due to adrenocortical steroid drugs (hereinafter abbreviated as steroid). Subsequently, hemodialysis was temporarily required but reduced urine protein and an improved renal function were gradually observed and she eventually achieved a complete remission. The possibility of a spontaneous remission of membranous nephropathy, etc. was considered, but a relapse occurred when the amount of cyclosporine was reduced. Thereafter, a complete remission was obtained with an increased dosage. As a result, the effectiveness of cyclosporine was thus confirmed. In treating nephrotic syndrome, steroid therapy is commonly performed and it is common for cyclosporine to be limited to steroid-resistant cases and/or steroid-dependent cases. However, it is believed that monotherapy could also be an option in cases in which the use of steroids is difficult, such as in cases of elderly patients.

In vivo labeling method of cyclosporin A with [14C-methyl]-S-adenosyl-L-methionine can evaluate a potency of cyclosporin A-producing mutant

Cyclosporin A synthetase activity ofTolypocladium inflatum can be estimated by measuring its N-methyltransferase activity. In vivo N-methyltransferase activity of cyclosporin A synthetase of cells was measured by in vivo [14C-methyl] labeling assay, which was designed for actively growing cells. After the cells were incubated with 0.025 μCi of [14C-methyl]-S-adenosyl-l-methionine, [14C-methyl] labelled cyclosporin A and its analogs inside the cells were extracted with ethylacetate and14C radioactivity of the ethylacetate extract of the cells was counted. When various mutant cells grown on agar plate medium after ultraviolet irradiation or N-methyl-N’-nitroso-guanidine treatment were applied to in vivo [14C-methyl] labeling assay, these mutants showed a broad range of in vivo N-methyltransferase activity. Poor correlation was found between in vivo N-methyltransferase activity of cyclosporin A synthetase of the mutant grown on agar plate and the actual amount of cyclosporin A production in shake-flask culture. However, when the cells grown on the shake-flask culture were applied in the in vivo [14C-methyl] labeling assay, a better correlation was resulted. In vivo N-methyltransferase activity reached the maximum value at about 150 h, and then declined quickly, but cyclosporin A was synthesized for 200 h during fermentation. Specific in vivo N-methyltransferase activity was not greatly influenced by culture age during fermentation. The major product of in vivo [14C-methyl] labeling assay was identified as cyclosporin A, and only trace amounts of other cyclosporin analogues were detected. Therefore, the results suggest that in vivo labeling method with [C14-methyl]-S-adenosyl-l-methionine can easily compare a potency of cyclosporin A-producing mutant during fermentation.

Variable effect of ursodeoxycholic acid on cyclosporin absorption after orthotopic liver transplantation.

The acute effects of administering a single dose of ursodeoxycholic acid (UDCA) on cyclosporin pharmacokinetics were recorded during paired studies in twelve liver transplant recipients, six of whom were cholestatic. Cyclosporin was measured using monoclonal selective antibodies (for parent drug) and non-selective antibodies (for cyclosporin plus metabolites). UDCA resulted in more rapid absorption of cyclosporin in 8 of 12 cases (67%) but had no effect in two patients with and two patients without cholestasis. Median tmax did not change significantly after UDCA (3.0 vs 4.0 h without UDCA) and only 7 of 12 patients (58%) showed a rise in the amount of cyclosporin absorbed over 24 h with the AUC not having changed significantly (median 4527 vs 4979 micrograms.h.l-1 without UDCA). Median Cmax and C24 also increased only marginally following UDCA administration (616 vs 587 micrograms.l-1 and 87 vs 58 micrograms.l-1 without UDCA, respectively). In the cholestatic patients, median AUC was 50% smaller (3223 vs 6439 micrograms.h.l-1) and median t1/2 a was 100% longer (1.58 vs 0.8 h) than in patients without cholestasis. There was no consistent improvement in cyclosporin pharmacokinetics in the cholestatic patients following UDCA, although the significantly elevated ratio of non-selective:selective AUC measurements (median 4.8 vs 2.7) fell markedly in the two most severely affected, possibly as a result of an increased clearance of cyclosporin metabolites by choleresis.

Isoflurane Alters the Kinetics of Oral Cyclosporine

Cyclosporine is an important immunosuppressive agent often given orally preoperatively to patients undergoing organ transplantation. The aim of the present study was to evaluate the effects of anesthesia on the pharmacokinetics of orally administered cyclosporine. Sixty unanesthetized fasting female Lewis rats were given 25 mg/kg cyclosporine by gastric tube and were then randomized to immediately receive an isoflurane anesthetic (n = 30) or to serve as nonanesthetized controls. At 1, 2, 3, 4, and 6 h after the administration of the cyclosporine, six animals from each group (while still anesthetized for those in the anesthesia group) were killed, and arterial blood and the entire bowel from the esophagogastric junction to the ileocecal junction were removed for measurement of cyclosporine concentrations. A subsequent study with six animals in each group was performed to examine more closely the distribution of cyclosporine in the stomach and small intestine 4 h after the oral dose. In these animals the cyclosporine concentration in the stomach and in five 10-cm-long segments of small bowel was assayed. In all studies of gastrointestinal specimens, the cyclosporine extracted is a combination of that contained in the lumen and the wall. At all times except at 6 h, the blood cyclosporine levels were significantly higher in the control group than in the isoflurane group. Conversely, the amount of cyclosporine in the distal small bowel of control rats was increased as compared with the anesthetized animals. In the animals studied at 4 h, the amount of cyclosporine in the stomach of control rats was significantly lower than that in the anesthetized animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption and disposition of colloidal drug delivery systems. I. High-performance liquid chromatographic (HPLC) analysis of a cyclosporin emulsion.

The amount of cyclosporin A in an oil-in-water emulsion drug delivery system was determined by HPLC. The direct extraction and analysis of an intact emulsion were compared to the analysis of a cracked emulsion and an olive oil solution of the drug. The intra- and interday variability for the intact emulsion was less than 10% from 35 to 150 micrograms/ml, with recovery of 94%. Comparison of the assay results obtained with the emulsion and the olive oil solution gave a highly correlated regression line with a small intercept and a slope close to unity. Thus, the direct extraction and HPLC analysis of drugs in emulsions may be a viable approach to evaluate drug content.