Prednisolone Concentrations Research Articles

Evaluation of the Skin Blanching of Topically Applied Steroids Using a Chroma Meter in Animals

We evaluated the utility of animal skins for determining the skin blanching of steroids. A Chroma Meter was used to determine the skin blanching of steroids. Hydrophilic creams containing clobetasol propionate (CP) or prednisolone (PS) were selected as model steroid formulations. Skin blanching, a*, was determined using a Chroma Meter after the application of 0.005, 0.01, 0.1, or 1.0% CP or PS hydrophilic cream to the back skin of guinea pigs and hairless rats for 24 h. The relationships between Δa*(6h) and the skin concentrations of the steroids were determined at 6 h after removal of the cream. Δa*(6h) was markedly decreased after the application of CP hydrophilic cream to guinea pigs, and a good linear relationship was observed between Δa*(6h) and skin concentration (r=0.98). In contrast, no relationship was observed between these parameters after the application of CP cream to the hairless rats. Although skin blanching was observed after PS cream application in guinea pigs, no relationship was observed between Δa*(6h) and skin concentration of PS in each animal. These results suggest that the skin blanching effect of CP in guinea pigs is greater than that of PS and that its blanching effect in guinea pigs was stronger than that in hairless rats. Guinea pigs were found to be a good animal model for determining the skin blanching produced by steroid creams. In addition, Chroma Meters can be effectively used in skin vasoconstrictive tests in guinea pigs.

Association of β-2 adrenergic agonist and corticosteroid injection in the treatment of lipomas

The aim of this study was to evaluate the efficacy of isoproterenol and prednisolone in the treatment of subcutaneous lipomas. The first experiment evaluated in vitro lipolysis induced by isoproterenol 10(-6) M alone and across a range of prednisolone concentrations to determine the optimal dose to maximize lipolysis. The second experiment evaluated lipolysis in a lipoma and subcutaneous fat by in vivo microdialysis in five subjects to isoproterenol 10(-6) M with and without prednisolone 10(-6) M. These five subjects and five additional subjects had a lipoma treated five times a week for 4 weeks in a 4-cm grid with 0.2 ml injections of 10(-6) M isoproterenol and 10(-6) M prednisolone. Lipoma size was followed monthly for 1 year or until surgical removal. Prednisolone increased in vitro lipolysis to isoproterenol and 10(-6) M was the optimal concentration of both drugs. Lipomas responded with less lipolysis to isoproterenol than subcutaneous fat during microdialysis, and prednisolone treatment increased lipolysis in both lipomas and subcutaneous fat. Injection treatment of the lipomas decreased their volume 50%. All but one lipoma grew after treatment. Eight of the 10 subjects elected for surgical treatment, and the histology of the lipomas was normal fat tissue. Prednisolone and isoproterenol in combination increased lipolysis, and injections of the combination into lipomas decreased their volume 50% over 4 weeks. Eight of the 10 subjects elected for surgical removal.

The stabilization-lysis action of anti-inflammatory steroids on lysosomes

Abstract The effect of anti-inflammatory steroids on lysosomal enzyme release has been investigated. Most of the steroids stabilized lysosomes at pharmacological concentrations (10−4–10−6M) but lysed them at higher concentrations. Etiocholanolone, a steroid pyrogenic in man, had no stabilizing effect. The concentration of steroid would therefore seem critical in determining its subcellular action. Experiments with albumin suggest that anti-inflammatory steroids (at 5 × 10−4M) have little effect in aiding its thermal denaturation whereas other steroids greatly increase denaturation. Increasing concentrations of cortisol and prednisolone however caused greater denaturation of albumin. Although the correlation between albumin solutions and lysosomal membrane proteins is tenuous it is suggested that the lytic effect of anti-inflammatory steroids could be due to protein denaturation. Their stabilizing effect, however, probably involves steroidlipid interactions.

Impaired Prednisolone Sensitivities of the Endocrine System and Peripheral-blood Lymphocytes are Closely Related to Clinical Incidence in Renal Transplantation

Endocrine- and immune-responses to prednisolone and their relation to clinical incidence were assessed in 19 renal transplant recipients. All of the patients were treated with prednisolone and cyclosporin. Response of the hypothalamic-pituitary-adrenal (HPA) system to prednisolone was evaluated by measuring serum cortisol concentration. Cortisol concentration before transplantation was 126.7 +/- 38.6 ng mL-1, while it decreased to 4.1 +/- 2.5 ng mL-1 within the period characterized by a cumulative dose of prednisolone from 300 to 700 mg. A statistically significant high incidence (P less than 0.01) of acute rejections was observed in low HPA responders; (mean cortisol concentration during prednisolone treatment exceeded 3.0 ng mL-1), 6 of 12 with a low HPA response to prednisolone showed signs of rejection, while none of the 7 with a high HPA response showed signs of rejection. The concentrations of prednisolone suppressing the in-vitro response of pretransplant lymphocytes to concanavalin A by 50% (ID50) were determined. Lymphocytes from 8 patients were extremely insensitive (ID50 greater than 500 ng mL-1), and 5 of the 8 showed signs of rejection. Lymphocytes from the other 11 patients showed high sensitivity (ID50 less than 500 ng mL-1), and only one of those showed signs of rejection. Thus, a significantly high incidence of rejection was observed in low lymphocyte-responders to prednisolone (P less than 0.05). The results suggest that an insensitive endocrine response to prednisolone correlates with an impaired lymphocyte response to the steroid, and that both of the indices are related to occurrence of rejection. Evaluation of these pharmacodynamic parameters in combination may serve as a guideline for successful immunosuppressive therapy in renal transplantation.

Elucidating the identity of resistance mechanisms to prednisolone exposure in acute lymphoblastic leukemia cells through transcriptomic analysis: A computational approach

BackgroundIt has been shown previously that glucocorticoids exert a dual mechanism of action, entailing cytotoxic, mitogenic as well as cell proliferative and anti-apoptotic responses, in a dose-dependent manner on CCRF-CEM cells at 72 h. Early gene expression response implies a dose-dependent dual mechanism of action of prednisolone too, something reflected on cell state upon 72 h of treatment.MethodsIn this work, a generic, computational microarray data analysis framework is proposed, in order to examine the hypothesis, whether CCRF-CEM cells exhibit an intrinsic or acquired mechanism of resistance and investigate the molecular imprint of this, upon prednisolone treatment. The experimental design enables the examination of both the dose (0 nM, 10 nM, 22 uM, 700 uM) effect of glucocorticoid exposure and the dynamics (early and late, namely 4 h, 72 h) of the molecular response of the cells at the transcriptomic layer.ResultsIn this work, we demonstrated that CCRF-CEM cells may attain a mixed mechanism of response to glucocorticoids, however, with a clear preference towards an intrinsic mechanism of resistance. Specifically, at 4 h, prednisolone appeared to down-regulate apoptotic genes. Also, low and high prednisolone concentrations up-regulates genes related to metabolism and signal-transduction in both time points, thus favoring cell proliferative actions. In addition, regulation of NF-κB-related genes implies an inherent mechanism of resistance through the established link of NF-κB inflammatory role and GC-induced resistance. The analysis framework applied here highlights prednisolone-activated regulatory mechanisms through identification of early responding sets of genes. On the other hand, study of the prolonged exposure to glucocorticoids (72 h exposure) highlights the effect of homeostatic feedback mechanisms of the treated cells.ConclusionsOverall, it appears that CCRF-CEM cells in this study exhibit a diversified, combined pattern of intrinsic and acquired resistance to prednisolone, with a tendency towards inherent resistant characteristics, through activation of different molecular courses of action.

Effects of low-dose dexamethasone and prednisolone long term administration in beef calf: Chemical and morphological investigation

An analytical, pharmacokinetic and histopathologic investigation was conducted by two experimental trials on beef cattle in order to determine fate and effects of dexamethasone and prednisolone, administered to distinct cattle groups at low dosage for long periods of time. In trial 1, eighteen Charolaise beef cattle, male, 17–22-months-old, were divided in three groups: to group A ( n = 6) dexamethasone-21-sodium-phosphate 0.7 mg day −1 per os for 40 days was administered; group B ( n = 6) was orally treated with prednisolone 15 mg day −1 for 30 days, while group C ( n = 6) served as negative control. Urine was collected at days 0, 7, 15, 25 and 47 from groups A and C, and at days 0, 8, 18 and 42 from group B. In trial 2, sixteen Friesian cattle, male, 10–17-months-old, were randomly divided into two groups: group D ( n = 8) was administered prednisolone 30 mg day −1 per os for 35 days, while group K ( n = 8) served as control. In both trials, the animals were slaughtered after a 6-days drug withdrawal and thymus and livers were collected and properly stored until the analysis was performed. Quantitative determinations of dexamethasone, prednisolone and its main metabolite, prednisone, in urine and liver samples were conducted by HPLC–MS/MS, after the analytical procedure was optimized and fully validated. The method validation included the assessment of specificity, linearity, precision, trueness, robustness, CC α and CC β values. By a morphological point of view, severe atrophy of thymus parenchyma was observed in group A, together with a significant ( P < 0.005) reduction of the mean thymus weight (217 ± 94 g), while group B (646 ± 215 g) presented normal thymus features and weights (group C, 415 ± 116 g). Accordingly, no differences were found in trial 2 for groups D (727 ± 275 g) and K (642 ± 173 g). Average dexamethasone concentrations in group A urine samples ranged from 1.4 to 3.0 μg L −1 during the treatment, while no residue was detected in the urine samples collected 6–7 days after the end of the treatment. Low amounts of dexamethasone (<1 μg L −1) were detected in liver samples of group A. All average prednisolone concentrations in group B urine samples (sum of conjugate and free form) turned out to be below 1.0 μg L −1 during the treatment, despite the much higher concentration administered (15–30 mg day −1) with respect to dexamethasone in group A (0.7 mg day −1). No prednisolone residues were found in the urine and liver samples taken at the slaughterhouse. The absence of any prednisolone residue in the urine samples of control group animals supports the theory that the origin of this molecule is fundamentally exogenous, at least for this cattle category maintained under unstressing conditions. Remarkable findings are represented by the absence of thymus atrophy in the prednisolone treated animals and the extremely low residue concentrations found in urine during the treatment. Both findings reveal that the detection of illegal growth-promoting treatments with this drug is difficult.

Apoptotic Effects of Corticosteroids on Pure CD34+ Hematopoietic Stem Cells and Modulation of This Effect with Cytokines

AbstractAbstract 4770Hematopoietic stem cells which can self-renew, are very important for regeneration of hematopoietic system. Because, in chemotherapy applications, malign cells are killed but on the other hand normal cells are also damaged. It is known that corticosteroids, which is essential drug for all chemotherapy protocols, efficiently induce apoptosis not only in malign cells also in normal hematopoietic cells. But, there are no comprehensive studies about the apoptotic effects of glucocorticoids on pure CD34+ hematopoietic cell population. In several studies, it has been showed that hematopoietic cytokines can prevent apoptosis caused by chemotherapy and decrease toxic effects of this drugs. In this study, for the first time, we investigated apoptotic effects of corticosteroids on CD34+ hematopoietic stem cell population collected from human peripheral blood buffy coats by using immunomagnetic positive selection method and protective effects of hematopoietic cytokines. Buffy coats were obtained from standard blood collection bags of voluntary blood donors. Two control groups are composed that is not including cytokines in serum free medium (SFC) and induced with cytokine coctail that including interleukin 3, thrombopoietin, stem cell factor and flt3/flk2 ligand (CC). Test groups are dexamethasone group (D), prednisolone group (P) and groups induced with cytokines before drug application (CD, CP). High concentrations of dexamethasone (10-3 M) and prednisolone (10-3 M) were used in vitro in concordance with clinical treatment doses. To determine apoptotic mechanisms, immunohistochemical staining was carried out by using monoclonal antibodies against fas, caspase 3, sitocrom c, bax and bcl2. Then cells were counting and determining degree of peroxidase reactions were quantified using H-score. For statistical analysis paired t-test and one sample t-test were used. As a result, both dexamethasone and prednisolon induce apoptosis in pure CD34+ cells. When compared with control groups, corticosteroids caused significant increase for apoptotic fas, caspase 3, sitocrom c and bax (p<0,05), and a significant decrease for antiapoptotic bcl2 (p<0,05). In control that is not including cytokines (SFC) apoptosis induced and same results were determined. When cytokines were added before, it was observed a significant decrease for all apoptotic markers (p<0,05) and a significant increase for antiapoptotic bcl2 (p<0,05) (Figure 1). So that, corticosteroids induce apoptosis in human pure CD34+ hematopoietic stem cells and cytokines decrease apoptotic effects of this drugs and prevent apoptosis in vitro. As a results, our findings demonstrated that may be useful cytokine treatment in order to minimize hematopoietic toxicity and to protect CD34+ cells from high-dose corticosteroid damage. [Display omitted] Disclosures:Cetin:Istanbul University Research Fund: Employment, Research Funding. Kuruca:Istanbul University Research Fund: Research Funding.

Quantification of corticosteroids in bovine urine using selective solid phase extraction and reversed-phase liquid chromatography/tandem mass spectrometry

This paper presents the development of a simple liquid chromatography–tandem mass spectrometry (LC–MS/MS) method to determine corticosteroids in bovine urine sample matrices. This method uses a single phase extraction (SPE) for cleaning of the sample with an Oasis MAX cartridge at pH 9.0–9.5 and elution by a neutral organic solvent (acetonitrile/dichloromethane), followed by separation on a GEMINI C18 column in the gradient mode with acetate buffer (pH 4.1)/methanol. A triple quadrupole mass spectrometer equipped with a multimode ion source, set to negative atmospheric pressure chemical ionization (APCI) in the multiple reaction monitoring mode was used for detection. The main advantage of this method over other commonly used methods includes the use of SPE with a low volume cartridge for sample preparation and no ion suppression effects from matrix components of the urine samples in the LC–MS/MS analysis. This allowed a reduction the quantification limits (decision limits, CCα) for the first time to 0.1 μg/L (1 and 0.2 μg/L for triamcinolone and flumethasone, respectively). The developed method was validated in accordance with the European Union Commission Decision 2002/657 EC. The recoveries and within-laboratory reproducibility varied from 77% to 115% and 87% to 107.5%, respectively, at 2, 3, and 4 μg/L levels of corticosteroids. The relative standard deviation (RSD) of the measurements was lower than 30%. The decision limit was calculated by multiplying the signal-to-noise ratio by 3 and the obtained values were in the range of 0.1–1.0 μg/L, confirmed by the analysis of twenty blank samples, which were spiked at the desired concentrations. The detection capability was calculated by the addition of the decision limit and the standard deviation followed by multiplication by 1.64 of the within-laboratory reproducibility at 2 μg/L of corticosteroids. The method was applied to four urine samples, giving concentrations of prednisolone (PRED) residues in the range from 0.3 to 0.9 μg/L.

Effect of plasma lipid on pharmacokinetics of ciclosporin and its relationship with plasma prednisolone level in renal transplant patients

Ciclosporin (cyclosporine A, CyA) is a potent immunosuppressant used after organ transplantation. The pharmacokinetic properties of CyA vary widely and lipoproteins are the major complexing constituents for CyA in the plasma. Therefore, a change in lipoprotein level may influence the pharmacokinetic properties of CyA. Prednisolone (PSL) is concomitantly used with CyA as an immunosuppressant. After organ transplantation, hyperlipidaemia resulting from PSL therapy has been mostly observed and PSL increased the plasma lipoprotein level. Therefore, in this study, to obtain more useful information of the therapeutic drug monitoring (TDM) of CyA, the relationship between the plasma PSL level, plasma lipoprotein level and blood CyA level was investigated in detail. An open-label, non-randomized, retrospective study was performed. Data from 21 male and 11 female patients (age 11-65 years) who received a living-related renal transplantation from 2002 to 2004 were included. On postoperative days (PODs) 7, 14 and 28, the area under the plasma concentration-time curve until 9 h after 40 mg of PSL administration (AUCPSL40(0-9)) correlated well with total cholesterol (T-cho) (r=0.558, 0.768, 0.660, all P<0.05) and high-density lipoprotein (HDL) (r=0.688, P<0.05; 0.835, P<0.01; 0.508, p<0.05), and correlated negatively with very-low-density lipoprotein (VLDL) (r=-0.486, p<0.01; -0.776, p<0.01; -0.967, p<0.01). In addition, AUC until 9 h after CyA administration (AUCCyA0-9) also correlated with T-cho (r=0.797, p<0.01; 0.577, p<0.05; 0.901, p<0.01), HDL (r=0.514, p<0.05; 0.614, p<0.05; 0.893, p<0.01) and low-density lipoprotein (LDL) (r=0.906, p<0.01; 0.573, p<0.05; 0.537, p<0.05), and there was a negative correlation with VLDL (r=-0.480, -0.630, -0.632, all p<0.05). Moreover, AUCCyA0-9 correlated well with AUCPSL40(0-9) (r=0.728, p<0.01; 0.482, p<0.05; 0.688, p<0.05); namely, it was considered that the variety of plasma PSL concentrations influenced the pharmacokinetic properties of CyA through the change in lipoprotein levels. These results suggested that monitoring of the biochemical parameters of the plasma lipid and plasma PSL level might be useful for the TDM of CyA.

Dose uniformity of topical corticosteroid preparations: difluprednate ophthalmic emulsion 0.05% versus branded and generic prednisolone acetate ophthalmic suspension 1%

PurposeTo compare the dose uniformity of difluprednate ophthalmic emulsion 0.05% (Durezol®) with both branded and generic prednisolone acetate ophthalmic suspension 1% under different simulated patient usage conditions.MethodsDrug concentrations of difluprednate emulsion, branded prednisolone acetate suspension (Pred Forte®) and generic prednisolone acetate suspension following three storage conditions (upright, then shaken; upright, not shaken; inverted, not shaken) were analyzed by high performance liquid chromatography assay and results were reported as percent of declared concentration. Two drops were dispensed every four hours four times daily.ResultsRegardless of bottle orientation and shaking, all difluprednate emulsion concentrations at each time point analyzed were within 15% of declared concentration. Both branded and generic prednisolone acetate suspension concentrations varied substantially throughout the study. For the bottle stored upright and not shaken, 46% of the branded concentrations were not within 15% of declared concentration; for the bottle stored upright and shaken prior to use, 60% failed to meet this criterion. None of the branded concentrations from the inverted and not shaken bottle was within 15% of declared concentration. Generic prednisolone concentrations demonstrated the poorest dose uniformity, with 96% of the concentrations from the inverted and not shaken bottle not within 15% of declared concentration; 94% of the concentrations from the upright and shaken bottle and 87% from the upright and not shaken bottle similarly failed to meet this criterion.ConclusionsDose uniformity of Durezol emulsion was predictable in all simulated patient usage conditions, whereas the drop concentrations of Pred Forte and generic prednisolone acetate suspensions were highly variable throughout the study. Drop concentrations are more predictable with Durezol emulsion than with either prednisolone acetate suspension.

No impact of age on dose-adjusted pharmacokinetics of tacrolimus, mycophenolic acid and prednisolone 1 month after renal transplantation

The purpose of the study was to assess the impact of age on the pharmacokinetics of immunosuppressive drugs. One hundred and ten renal transplant recipients, including 12 elderly patients over 60 years of age, 57 middle-aged patients between 40 and 59 years and 41 young adult patients 20 to 39 years of age were studied. To evaluate dose-adjusted pharmacokinetics and cytochrome P450 (CYP) 3A5 pharmacogenetics, the concentrations of tacrolimus, mycophenolic acid (MPA), MPA glucuronide (MPAG) and prednisolone were measured at 1 month post-transplantation. There were no differences in dose (D) and body weight (BW)-adjusted pharmacokinetic parameters of tacrolimus among the three groups. D/BW-adjusted C(max), C(0) and AUC(0-12) values of tacrolimus were significantly greater in patients with the CYP3A5*3/*3 genotype than in those with the CYP3A5*1 allele in young and middle-aged patients as previously reported, but not in the elderly. There were no significant differences in the D-adjusted pharmacokinetics of prednisolone and MPA among the three groups. The aging process itself may have a small effect on the pharmacokinetics of tacrolimus, MPA, or prednisolone. However, a larger number of subjects need to be studied to confirm the impact of age on the CYP3A5 pharmacogenetics of tacrolimus in the elderly.

Bax-gene transfer enhances apoptosis by steroid treatment in human nasal fibroblasts

Gene therapy has become a focus not only in the study of cancer but also lifestyle-related diseases. In case of chronic rhinosinusitis with nasal polyps and aspirin-induced asthma, nasal polyps poorly respond to a local administration of steroid. The Bax and Bcl-2 proteins play important roles in the regulation of apoptosis. The treatment of steroid (prednisone) induced apoptosis in the fibroblast. The Bax accelerates apoptosis. Apoptosis is very important in the anti-inflammatory mechanism. In this study, we investigated whether the overexpression of Bax in human fibroblasts influences apoptosis by treatment with a steroid (prednisolone) in vitro. Human nasal fibroblasts were isolated from small pieces of nasal polyp and were transfected with a bax gene-bearing mammalian expression vector. Human nasal fibroblasts were transiently transfected with the expression vector hBaxpcDNA3 (Bax-NF) or native pcDNA3 (Neo-NF). Both transfectants (Bax-NF, Neo-NF) and wild-type-nasal fibroblast (wt-NF) were cultured in conditioning medium and treated with each concentration of prednisolone for 72 h. Prednisolone at a concentration of 10 ng/ml decreased the viability of Bax-NF compared to that of Bax-NF in the absence of prednisolone. The cytotoxicity of prednisolone to Bax-NF was significantly higher than that to Neo-NF or wt-NF (p < 0.01) and the susceptibility of Bax-NF to prednisolone was about 1,000 times that of Neo-NF or wt-NF. We found that the transfer of the exogenous bax gene enhanced the induction of apoptosis by steroid-treatment in human nasal fibroblasts. Therefore, we suggest that exogenous Bax protein expression by gene transfer might be useful for the treatment of nasal polyps. We will further the preclinical study in improving steroids dose and in adopting to transfer bax gene to the nasal polyps by intranasal injection, thus providing a more effective and safer way for the nasal polyps that poorly respond to a local administration of steroids.

Hyperglycemia Promotes in Vitro All Blast Resistance to Steroid Induced Blast Lysis

Clinical patient observations led to the hypothesis of increased ALL blast resistance in hyperglycemia (HG) states in pediatric ALL patients, either with preexisting diabetes mellitus (DM) or with steroid induced diabetes (SID). To evaluate the above, the chromometric MTT (methyl thiazole tetrazolium) assay was used Kaspers GJ et al, Leuk Res 1995; 19:175–81.Ficoll separated nucleated bone marrow cells from newly diagnosed pediatric ALL patients were cultured in usual conditions (NL) and in higher glucose levels (233–295 mg/dl), with the addition of titrated prednisolone (PDN) concentrations. The PDN concentration that lyses 50 % of the cultured blast cells (LD50) is the measure of PDN drug sensitivity. PDN concentrations of 0.02–2.0, 2.1–150, above 150 μg/uL indicate high, intermediate and low blast sensitivity to PDN, respectively. Hence, patient blasts with LD50 at >150 μg/uL are resistant to PDN. The MTT assay results have been related to patient outcome (remission induction and event free survival, Pieters R et al Pediatr Oncol 1994; 22:299–308). Twelve newly diagnosed pediatric patients, with median age 6.4 years (range, 1.7 to 16.5 years) with common/CD10+ (N=8), pre-B (N=2), early pro-B (N=1) and maturing B (N=1) ALL were studied. All patients exhibited >80% ALL blast BM infiltration. Sensitivity (LD50 < 150 μg/uL) in both NL and HG conditions was evident for 2 patients, while resistance to both conditions was seen in 3 patients. Patients resistant at NL conditions were resistant in HG, too. In contrast, 7 of 12 patients sensitive to PDN in NL conditions proved resistant in HG conditions (glucose 233–295 mg/dL). All 9 sensitive in NL conditions patients (in HG conditions 2 sensitive and 7 resistant) exhibited a median ×800 fold increase of the MTT LD50 measured (range 6–29.000 fold). For all patients (N=12) median MTT LD50 under NL conditions was 0.15 μg/uL and in HG conditions 167.5 μg/uL (× 116.6 fold increase). This change was statistically significant (Mc Nemar's test, p=0,016) and this change was not simply related to the change in glucose concentration. These findings of greatly increased ALL blast resistance in hyperglycemia environment, can support the notions given earlier (Weiser MA et al, Cancer 2004; 100:1179–85, Pieter's R EHA 2008) that hyperglycemia by itself can promote PDN resistance. Given that steroids is a mainstay in ALL treatment and that steroid induced hyperglycemia is a common occurrence, blood glucose monitoring and hyperglycemia correction appears to be of paramount significance in delivering an effective ALL treatment.

Influence of Antiretroviral Drugs on the Pharmacokinetics of Prednisolone in HIV-Infected Individuals

Corticosteroids are cytochrome P450 3A4 substrates, which have been associated with toxicities in patients receiving cytochrome P450 3A4 inhibitors such as human immunodeficiency virus protease inhibitors. In a study in healthy volunteers, ritonavir significantly increased prednisolone exposure. We investigated the influence of antiretroviral (ARV) medications on prednisolone pharmacokinetics in 3 groups of 10 human immunodeficiency virus-infected subjects. One group received lopinavir/ritonavir, and another efavirenz, as part of their ARV regimen; a third group did not receive ARV medications. Each subject received a single 20-mg prednisone dose followed by serial blood sampling for prednisolone. Prednisolone pharmacokinetics were compared among the groups. Area under the concentration-time curve was significantly lower in efavirenz recipients versus subjects receiving lopinavir/ritonavir (geometric mean ratio = 0.60, P = 0.01). Average prednisolone area under the concentration-time curve was higher in subjects taking lopinavir/ritonavir versus subjects not on ARVs; however, this difference was not significant (P > 0.05). These data indicate that prednisolone concentrations may fluctuate widely when human immunodeficiency virus-positive individuals established on efavirenz therapy change to lopinavir/ritonavir or vice versa.

Assessment of the Impact of Dosing Time on the Pharmacokinetics/Pharmacodynamics of Prednisolone

Prednisolone is widely used for the treatment of inflammation and auto-immune diseases. It exhibits nonlinear pharmacokinetics (PK); and its induced systemic effects (pharmacodynamics (PD)) are commonly evaluated with two biomarkers, cortisol and blood lymphocytes in plasma. Circadian patterns are observed in both biomarkers. Furthermore, the disease itself may show a circadian pattern. For example, in rheumatoid arthritis patients, better therapeutic outcomes have been reported when prednisolone was administered in the very early morning. The aim of this study is to evaluate the impact of dosing time on the PK/PD of prednisolone with a simulation approach using an interactive algorithm. A series of simulations were performed with either intravenous or oral administration of prednisolone or prednisone. The results showed that the initial or maximum concentration and trough concentration of total prednisolone were lower when the drug was administered in the early morning around 6 AM: . Oscillation patterns were observed in cumulative cortisol suppression (CCS) and alteration of total lymphocyte trafficking in blood. When the drug was given in the morning within the therapeutic dose range, or around 6 PM: for a small dose amount (<1 mg), the minimum CCS and maximum effect on lymphocytes were observed. These results indicated that the PK/PD of prednisolone are time- and dose-dependent, and suggested that it is necessary to consider the application of chronotherapy to achieve better clinical outcomes with fewer side effects of prednisolone, and a PK/PD simulation approach could provide a valuable tool to evaluate and predict time-dependency in the system.

Influence of CYP3A5, ABCB1 and NR1I2 polymorphisms on prednisolone pharmacokinetics in renal transplant recipients

The objective of this study was to evaluate whether genetic polymorphisms of CYP3A5 (A6986G, CYP3A5*3), ABCB1 (C1236T, G2677T/A, C3435T) and NR1I2 (A7635G) significantly impact the pharmacokinetics of prednisolone in renal transplant recipients. Ninety-five recipients were given repeated doses of triple therapy immunosuppression consisting of prednisolone, tacrolimus and mycophenolate mofetil. Twenty-eight days after renal transplantation, plasma prednisolone concentrations were measured by high-performance liquid chromatography. Comparisons of the CYP3A5 and ABCB1 genotypes revealed no significant differences in the prednisolone pharmacokinetics. The mean prednisolone C max for recipients ( n = 14) having both the ABCB1 3435CC genotype and the CYP3A5*3/*3 genotype was significantly higher than those ( n = 11) having both ABCB1 3435TT and CYP3A5*3/*3 genotypes (180 ng/mL versus 129 ng/mL, P = 0.0392). The plasma concentrations of prednisolone in recipients having both ABCB1 3435CC and CYP3A5*3/*3 genotypes tended to be higher than those having both ABCB1 3435TT and CYP3A5*3/*3 genotypes. The mean AUC 0–24 and C max values for prednisolone in recipients having the NR1I2 7635G allele (AG: n = 45, GG: n = 32) were significantly lower than in patients having the 7635AA allele ( n = 18) (7635GG versus 7635AA, P = 0.0308 for AUC 0–24, P = 0.0382 for C max of prednisolone). In conclusion, NR1I2 (A7635G) rather than CYP3A5 or ABCB1 allelic variants affected patient variability of plasma prednisolone concentration. Recipients carrying the NR1I2 7635G allele seemed to possess higher metabolic activity for prednisolone in the intestine, greatly reducing its maximal plasma concentration.

Simultaneous determination of prednisolone, prednisone, cortisol, and cortisone in plasma by GC–MS: Estimating unbound prednisolone concentration in patients with nephrotic syndrome during oral prednisolone therapy

Individual variability of the pharmacokinetics of prednisolone based on the unbound concentration in plasma is of significant clinical consideration. The unbound concentrations of prednisolone were measured in 10 patients with nephrotic syndrome, two patients with systemic lupus erythematosus, and one patient with dermatomyositis by examining protein bindings of prednisolone on one or more occasions during prednisolone treatment. In this study, plasma concentrations of prednisolone, prednisone, cortisol, and cortisone were simultaneously analyzed by GC–MS by using stable isotope-labeled internal standards. Equilibrium dialysis was employed to accurately estimate the unbound fractions of prednisolone in plasma. The unbound fraction of prednisolone changed depending on plasma total prednisolone concentration and plasma albumin concentration. The unbound fraction of prednisolone ( Y) is calculated: Y = (−0.0101 x′ + 0.0736) x + 10.23, where x′ is the plasma albumin concentration and x is the total prednisolone concentration. The estimated concentrations of unbound prednisolone by using the above equation were in good agreement with the measured concentrations of unbound prednisolone. Since the protein binding of prednisolone did not change in the presence of prednisone (114.0 ng/ml), it appeared that prednisone produced from the therapeutic dose of prednisolone did not affect the unbound fraction of prednisolone.

Study on the Colon Specific Delivery of Prednisolone Using Chitosan Capsules

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Gastrointestinal distribution and absorption behavior of Eudragit-coated chitosan–prednisolone conjugate microspheres in rats with TNBS-induced colitis

Conjugate of chitosan and succinyl-prednisolone, termed Ch–SP, was synthesized, and Ch–SP microspheres (Ch–SP-MS) and Eudragit L100-coated Ch–SP-MS (Ch–SP-MS/EuL) were prepared using Ch–SP. Ch–SP-MS and Ch–SP-MS/EuL had a mean size of 1.5 and 26.6 μm, respectively, and a drug content of 4.6 and 3% (w/w), respectively. Prednisolone (PD) was released very slow in JP 14 first fluid (pH 1.2), and gradually in JP 14 second fluid (pH 6.8). The addition of cecal or colonic content did not accelerate the release. Rats with 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis were used in animal studies. Gastrointestinal distribution and plasma concentration were investigated by oral administration of PD alone and Ch–SP-MS/EuL. For PD alone, PD was distributed at the stomach and small intestine, and disappeared from the gastrointestinal tracts within 8 h. When administering Ch–SP-MS/EuL, the drug was distributed mainly in the lower intestine between 3 and 24 h. Plasma concentration was much lower in Ch–SP-MS/EuL than in PD alone, suggesting lower toxic side effects of Ch–SP-MS/EuL. Thus, Ch–SP-MS/EuL delivered PD specifically near the diseased site and PD was released gradually, with much less plasma concentration of PD. Ch–SP-MS/EuL are suggested as a useful delivery system to the site of inflammatory bowel disease.

Occurrence of Natural and Synthetic Glucocorticoids in Sewage Treatment Plants and Receiving River Waters

This paper first reports the occurrence of sixglucocorticoids (prednisone, prednisolone, cortisone, cortisol, dexamethasone, and 6alpha-methylprednisolone) in sewage treatment plants (STPs) and receiving rivers by establishing a method for analyzing glucocorticoids in complex environmental waters. For the various types of aqueous matrices considered, the absolute recoveries were from 73 to 99%, and limits of quantification were below 0.2 ng/L. Among the seven STPs studied, the average concentrations of prednisone, prednisolone, cortisone, cortisol, dexamethasone, and 6alpha-methylprednisolone in influents were, respectively, 2.6 +/- 2.1, 3.0 +/- 1.6, 30 +/- 21, 39 +/- 26, 1.2 +/- 0.70, and 0.62 +/- 0.65 ng/L, and their percent removals were 99 +/- 3.1, 78 +/- 8.8, 99 +/- 1.2, 98 +/- 2.5, 99 +/- 1.8, and 100 +/- 0%, respectively. The lower removal of prednisolone was found to be due to its relatively low efficiency of biodegradation, especially in anoxic and aerobic units. The frequently detected glucocorticoids in effluents were prednisolone, cortisol, and cortisone with average concentrations 0.56 +/- 0.06, 0.50 +/- 0.33, and 0.26 +/- 0.10 ng/ L. In the receiving waters, the Tonghui and Qing Rivers, the concentrations of these compounds in some samples were much higher than those in their corresponding STP effluents; these differences depended on the sampling date, suggesting that there was random discharging of untreated wastewaters into these rivers. In addition, the ratio between the combined concentrations of two natural glucocorticoids (cortisol and cortisone) and the concentration of one synthetic glucocorticoid, prednisolone, was found to be a potential index to reflect the wastewater discharging.