A quantitative assay of cortisol in human plasma by high performance liquid chromatography using a selective chemically bonded stationary phase

Budesonide versus prednisolone for the treatment of active Crohn's disease in children: a randomized, double-blind, controlled, multicentre trial

OBJECTIVES

Budesonide is a corticosteroid with low systemic bioavailability because of its high first-pass metabolism in the liver. In this paediatric, randomized, double-blind, double-dummy, controlled, multicentre trial, the safety and efficacy of budesonide versus prednisolone were evaluated in children with active Crohn's disease.

METHODS

Forty-eight children, aged 6-16 years, with active Crohn's disease (Crohn's Disease Activity Index > 200) involving ileum and/or ascending colon were randomized to receive budesonide (9 mg/day for 8 weeks, 6 mg/day for 4 weeks) or prednisolone (1 mg/kg/day for 4 weeks, tapering for 8 weeks).

RESULTS

The groups were comparable for age, sex, pubertal stage, disease activity and disease duration. Mean morning plasma cortisol concentration was significantly higher in the budesonide group (200 nmol/l) than in the prednisolone group (98 nmol/l) after 8 weeks, reflecting less adrenal suppression by budesonide (difference -102 nmol/l; 95% CI -226, -52; P = 0.0028). Glucocorticosteroid side effects such as moon face and acne occurred significantly less frequently in the budesonide group. Remission (Crohn's Disease Activity Index < or = 150) was seen at 8 weeks in 12/22 (55%) patients treated with budesonide and in 17/24 (71%) patients receiving prednisolone (difference -16%; 95% CI -45,13; P = 0.25).

CONCLUSIONS

Significantly fewer side effects and less adrenal suppression were observed in the children receiving budesonide. Remission rates were not significantly different in the two groups. However, there was a trend for prednisolone to be more effective for inducing remission.

Effects of budesonide inhalation suspension on hypothalamic-pituitary-adrenal-axis function in infants and young children with persistent asthma

BACKGROUND

The initial 12-week, double-blind phases of three studies demonstrated that budesonide inhalation suspension (BIS) is effective and well tolerated in infants and young children (6 months to 8 years of age) with persistent asthma.

OBJECTIVE

Open-label, 52-week extensions to these studies were conducted to evaluate long-term safety of BIS, including effects of treatment with the lowest effective dose of BIS on hypothalamic-pituitary-adrenal (HPA)-axis function, as compared with conventional asthma therapy (CAT). Complete results of the earlier phases of the studies and of long-term safety are reported elsewhere; only results pertaining to HPA-axis function are summarized here.

METHODS

Patients eligible for the open-label phases of the three trials were randomized to treatment with nebulized BIS (n = 447) or CAT (n = 223). CAT included short-acting oral or inhaled beta2-agonists, methylxanthines, or cromolyn sodium; in two of the studies, CAT could have included other inhaled corticosteroids. HPA-axis function, which had been evaluated during the 12-week double-blind studies, was again evaluated at the beginning and end of the 52-week study period using basal plasma cortisol concentrations and response to stimulation with a 250-microg dose of adrenocorticotropic hormone.

RESULTS

There was no evidence of altered HPA-axis function attributable to BIS treatment. No clinically or statistically significant differences in basal or adrenocorticotropic hormone-stimulated plasma cortisol concentrations were observed between BIS and CAT in either the 12-week, double-blind or 52-week, open-label phases of the three studies.

CONCLUSIONS

The results indicate that treatment with BIS does not result in clinically significant suppression of HPA-axis function in infants and young children.

Determination of celecoxib in human plasma by normal-phase high-performance liquid chromatography with column switching and ultraviolet absorbance detection

A method is described for the determination of celecoxib in human plasma. Samples were extracted using 3M Empore membrane extraction cartridges and separated under normal-phase HPLC conditions using a Nucleosil-NO2 (150x4.6 mm, 5 microm) column. Detection was accomplished using UV absorbance at 260 nm. The HPLC method included a column switching procedure, in which late eluting compounds were diverted to waste, to reduce run-time to 12 min. The assay was linear in the concentration range of 25-2000 ng/ml when 1-ml aliquots of plasma were extracted. Recoveries of celecoxib were greater than 91% over the calibration curve range. Intraday precision and accuracy for this assay were 5.7% C.V. or better and within 2.3% of nominal, respectively. The assay was used to analyze samples collected during human clinical studies.

Rapid onset of control with budesonide Turbuhaler in patients with mild-to-moderate asthma

BACKGROUND

Budesonide (Pulmicort) is an inhaled corticosteroid with high topical potency but low systemic activity. Turbuhaler is a novel breath-actuated, multi-dose, dry-powder inhaler.

OBJECTIVES

This study was conducted to determine the efficacy and safety of two different dose regimens of budesonide Turbuhaler, compared with placebo, in adult patients with mild-to-moderate asthma not well-controlled with bronchodilator therapy.

METHODS

This double-blind, randomized, placebo-controlled, parallel-group, multicenter study compared the efficacy and safety of 200 microg and 400 microg of budesonide, administered twice daily via Turbuhaler, with placebo, in 273 adult patients (aged 19 to 70 years) with mild-to-moderate asthma (FEV1 67% of predicted normal), not well-controlled with bronchodilator therapy. Efficacy was assessed by pulmonary function tests and patient assessments of asthma symptom control. Safety was assessed in terms of adverse events, laboratory evaluations, and physical examinations.

RESULTS

Two hundred and 400 microg of budesonide bid were significantly more effective than placebo at improving morning PEF (mean differences from placebo of 43.63 L/min and 40.10 L/min, respectively; P < .001) and FEV1 (mean differences from placebo of 0.44 L, and 0.50 L, respectively; P < .001) over the 12-week treatment period. Onset of action as assessed by morning PEF was within two days. Basal and stimulated plasma cortisol concentrations were not significantly affected by budesonide treatment compared with placebo.

CONCLUSIONS

Treatment of adults suffering from mild-to-moderate asthma with budesonide Turbuhaler is well tolerated and results in a rapid onset of asthma control which is maintained over time.

Oral glucocorticosteroid-sparing effect of budesonide administered by Turbuhaler: a double-blind, placebo-controlled study in adults with moderate-to-severe chronic asthma. Pulmicort Turbuhaler Study Group

OBJECTIVE

To determine the ability of budesonide via an inhaler (Pulmicort Turbuhaler; Astra Draco AB) to replace oral glucocorticosteroids (GCSs) in adult subjects with moderate-to-severe asthma.

DESIGN

Double-blind, randomized, and placebo-controlled study, with parallel groups.

SETTING

Multicenter study in outpatient setting.

PARTICIPANTS

Eighty men and 79 women, aged 20 to 69 years, with moderate-to-severe asthma and a mean FEV1 of 58.3% predicted normal. All subjects were receiving oral GCS treatment and 79% of subjects were also receiving inhaled beclomethasone dipropionate (BDP). The mean daily doses of prednisone at baseline, including converted dose of BDP, for the placebo, budesonide 400 microg, and budesonide 800 microg, respectively, were 19.7 mg, 19.5 mg, and 18.7 mg.

MEASUREMENTS AND INTERVENTIONS

After a 2-week baseline period, subjects entered a 20-week treatment period, during which the oral dose of prednisone was reduced by forced down-titration at 2-weekly intervals.

RESULTS

Subjects receiving 400 microg or 800 microg bid of budesonide achieved a significantly greater reduction (82.9% and 79.0% respectively) in oral GCS dose compared with placebo-treated subjects (27%; p<0.001). Two thirds of the subjects receiving budesonide were able to achieve sustained oral corticosteroid cessation, compared with 8% in the placebo group. Additionally, both doses of budesonide resulted in significant improvement in results of pulmonary function tests and asthma symptoms scores, and a significant decrease in the use of bronchodilator therapy. The mean plasma cortisol levels before and after adrenocorticotropic hormone stimulation increased most toward the normal range in the budesonide-treated groups compared with placebo-treated subjects.

CONCLUSION

Budesonide administered via Turbuhaler has a significant oral GCS-sparing capacity with maintained or improved asthma control in adult subjects with moderate-to-severe asthma.

Systemic effects of two nasally administered glucocorticosteroids

Two topical corticosteroids, budesonide (BUD) and beclomethasone dipropionate (BDP), both administered as suspensions in water, were investigated in healthy volunteers regarding influence on cortisol in plasma and urine (U-cortisol) after nasal application. In the first study, single doses of 200, 400, and 800 micrograms of BDP and BUD were given at 10:00 pm. In the second study, 100, 200, and 400 micrograms were given mornings and evenings for 4 days. In the single-dose study, none of the drugs or doses showed any significant influence on cortisol in plasma. However, U-cortisol decreased significantly after BUD 400 and 800 micrograms. In the multidose study, U-cortisol values were significantly reduced after all doses of BUD and the highest dose of BDP. The compounds tested showed different ability to cause measurable systemic effects after nasal application. The clinical implication is that the prescriber, when choosing a compound, should take the application site into consideration and should also be encouraged to find the lowest effective dose.

Budesonide prolongs time to relapse in ileal and ileocaecal Crohn's disease. A placebo controlled one year study

BACKGROUND AND AIMS

To evaluate the efficacy and safety of the topical corticosteroid budesonide, given in an oral controlled release formulation for maintenance of remission in patients with ileal and ileocaecal Crohn's disease (CD).

PATIENTS AND METHODS

Out of 176 patients with active CD who had achieved remission (CD activity index score < or = 150) after 10 weeks' treatment with either budesonide or prednisolone, 90 were randomised to continue with once daily treatment of 6 mg budesonide, or 3 mg budesonide or placebo for up to 12 months in a double blind, multicentre trial. Time to symptomatic relapse was calculated using Kaplan-Meier estimates. Morning plasma cortisol was measured at clinic visits and a corticotropin stimulation test was performed after three months of treatment.

RESULTS

Thirty two patients were allocated to the 6 mg budesonide group, 31 to the 3 mg group, and 27 to the placebo group. After three months, 19 per cent of the patients in the 6 mg group had relapsed, compared with 45 per cent in the 3 mg group and 44 per cent in the placebo group (p = 0.047). The corresponding results after 12 months was 59 per cent in the 6 mg budesonide group, 74 per cent in the 3 mg group, and 63 per cent in the placebo group (p = 0.44). The median time to relapse or discontinuation was 258 days in the 6 mg group, 139 days in the 3 mg group, and 92 days in the placebo group (p = 0.021). Mean morning plasma cortisol values increased from entry in all three groups with no statistically significant differences at 12 months. All 13 patients remaining in the placebo group after three months had a normal corticotropin stimulation response, compared with 18 of 23 patients in the 6 mg, and 19 of 21 in the 3 mg budesonide groups (p = 0.14). Acne and moon face were slightly more common in the budesonide groups.

CONCLUSION

6 mg budesonide once daily is significantly more efficacious than placebo in prolonging time to relapse in CD, and causes only minor systemic side effects.

Simultaneous determination of cortisol and cortisone in urine by reversed-phase high-performance liquid chromatography. Clinical and doping control applications

A reversed-phase high-performance liquid chromatography (HPLC) method for the simultaneous determination of cortisol and cortisone in human urine samples using methylprednisolone as the internal standard is described. The method involves the systematic use of isocratic mobile phases of water and methanol, acetonitrile or tetrahydrofuran and a reversed-phase Hypersil C18 column. A water-acetonitrile mixture used as the mobile phase proved to be the most adequate one for analyzing urine samples purified by solvent extraction. The proposed method is sensitive, reproducible and selective. It was applied to the determination of cortisol and cortisone in several human urine samples: healthy subjects, sportsmen before and/or after stress for doping control purposes, and patients with Cushing's syndrome.

Biocompatible sample pretreatment for immunochemical techniques using micellar liquid chromatography for separation of corticosteroids

Micellar liquid chromatography (MLC) using Tween 20 as surfactant was evaluated as a biocompatible sample pretreatment preceding immunoassay in order to obtain an increased selectivity of the assay and a simplification of the sample pretreatment procedure. Different stationary phases and chromatographic conditions were studied for the separation of budesonide and cortisol and some steroids known to interfere in immunoassay of these compounds. The separation was dependent on several parameters, for example, temperature, the concentration of Tween 20, pH and ionic strength of the mobile phase, and nature of the stationary phase. A precolumn venting system was used, which allowed for 140 direct injections of 25 microliters of human blood plasma, without loss of chromatographic performance. Results obtained from the coupling of MLC to an immunoassay for cortisol illustrates the selectivity which can be obtained, and that simplification of the sample pretreatment is possible using this technique.

Budesonide versus prednisolone retention enemas in active distal ulcerative colitis

METHODS

Efficacy and safety of the topically acting glucocorticosteroid budesonide retention enema (2.3 mg/115 mL) were compared with prednisolone disodium phosphate enema (31.25 mg/125 mL) in patients with active distal ulcerative colitis. The study was a randomized, multicentre trial, with two parallel groups and single-blind to the investigator. One hundred patients with active ulcerative colitis, not reaching beyond the splenic flexure as determined by endoscopy, were treated for up to 8 weeks.

RESULTS

Forty-five patients were randomized to receive budesonide and 55 to prednisolone. Both treatment groups improved significantly in terms of endoscopic and histological scoring during the study, but there were no statistically significant differences between the two groups. Clinical remission, defined as no more than three daily bowel movements without blood and endoscopically non-inflamed mucosa, was achieved in 16% of the patients in the budesonide group after four weeks and in 24% in the prednisolone group (N.S.). After 8 weeks treatment the clinical remission rate in the groups had increased to 36% for budesonide and 47% for prednisolone (N.S.). Mean morning plasma cortisol levels were unchanged in the budesonide group, whereas they were significantly suppressed in the prednisolone group after 2, 4 and 8 weeks (P < 0.0001). Side effects were mild and rare in both groups.

CONCLUSIONS

Treatment with budesonide enema in active distal ulcerative colitis was comparable, regarding efficacy, to treatment with conventional prednisolone enema. A prolongation of the treatment time from 4 to 8 weeks doubled the clinical remission rate in both groups. However, budesonide may be preferable to prednisolone since it causes less systemic effects as reflected by a lack of plasma cortisol suppression.

Budesonide enema in active haemorrhagic proctitis--a controlled trial against hydrocortisone foam enema

BACKGROUND

The aim was to compare budesonide enema, 2 mg/100 mL (Entocort) and hydrocortisone acetate foam enema, 125 mg (Colifoam) in patients with active haemorrhagic proctitis.

METHODS

The trial was a controlled, randomized, investigator-blind study with two parallel groups. Endoscopy, histology and diary cards were used to assess the response to therapy. Safety was assessed by laboratory tests and adverse event recording.

RESULTS

Seventy-two patients were included. Investigations were made before treatment and after 2 and 4 weeks. Both treatment groups showed statistically significant improvement in endoscopic scores but significant differences between the groups were not found. In the hydrocortisone group, plasma cortisol was significantly lowered after 4 weeks compared with budesonide. Bowel habits and quality of life variables did not differ between the treatments. The recorded adverse events were mild or moderate and may have been due to the proctitis.

CONCLUSIONS

These results suggest that budesonide enema is as effective as hydrocortisone foam enema, but without the potential for side-effects associated with suppression of plasma cortisol.

A comparison of budesonide with prednisolone for active Crohn's disease

BACKGROUND

Patients with active Crohn's disease are often treated with corticosteroids, but the treatment has many side effects. Budesonide is a potent, well-absorbed corticosteroid, but because of a high rate of first-pass metabolism in the liver, its systemic bioavailability is low.

METHODS

We conducted a randomized, double-blind, 10-week trial comparing the efficacy and safety of an oral controlled-release form of budesonide with the efficacy and safety of prednisolone in 176 patients with active ileal or ileocecal Crohn's disease (88 patients in each treatment group). The dose of budesonide was 9 mg per day for eight weeks and then 6 mg per day for two weeks. The dose of prednisolone was 40 mg per day for two weeks, after which it was gradually reduced to 5 mg per day during the last week.

RESULTS

At 10 weeks, 53 percent of the patients treated with budesonide were in remission (defined as a score < or = 150 on the Crohn's disease activity index), as compared with 66 percent of those treated with prednisolone (P = 0.12). The mean score on the Crohn's disease activity index decreased from 275 to 175 in the budesonide group and from 279 to 136 in the prednisolone group (P = 0.001). Corticosteroid-associated side effects were significantly less common in the budesonide group (29 vs. 48 patients, P = 0.003). Two patients in the prednisolone group had serious complications (one had intestinal perforation and one an abdominal-wall fistula). The mean morning plasma cortisol concentration was significantly lower in the prednisolone group than in the budesonide group after 4 weeks (P < 0.001) and 8 weeks (P = 0.02) of therapy, but not after 10 weeks.

CONCLUSIONS

Among patients with active Crohn's disease, both controlled-release budesonide and prednisolone are effective in inducing remission. In this trial, prednisolone reduced scores on the Crohn's disease activity index more, whereas with budesonide there were fewer glucocorticoid-associated side effects and less suppression of pituitary-adrenal function.

Solvent and solid-phase extraction of natural and synthetic corticoids in human urine

Optimization of the main variables that affect solvent and solid-phase extraction processes, using disposable C18 cartridges and the non-ionic polymeric resin Serdolit AD-2, of human urine containing natural and synthetic corticoids is described. The data were obtained from different HPLC separations of these compounds using calibration graphs obtained before and after extraction of these compounds. The procedures, including sample preconcentration, showed efficiencies over 90%. NaCl was used to avoid emulsion formation in solvent extraction. The results achieved using solvent and solid-phase extraction are discussed.

Pharmacokinetics of budesonide enema in patients with distal ulcerative colitis or proctitis

Pharmacokinetic data obtained after one dose of a 2-mg budesonide enema were compared with data obtained after the last dose of four weeks of daily treatment in 24 patients with active distal ulcerative colitis or proctitis. This open multicentre study involved 28 eligible patients. Sigmoidoscopy and biopsy scores improved significantly (P < 0.002) during the four-week treatment period. Maximal plasma concentration (Cmax) of budesonide was 2.1 nmol/L 1.3 h after the first dose and 2.5 nmol/L 1.2 h after the last dose; the difference was not significant. The area under the curve (AUC) of plasma concentration vs. time was after the first dose 9.7 nmol h/L and after the last dose 11.6 nmol h/L (P < 0.03). The small increase in AUC may be attributed to improved absorption. During the last dose interval, minimal plasma concentration was below the limit of quantitation in most subjects. The Cmax and AUC of budesonide increased slightly after four weeks of treatment, but budesonide did not accumulate. Mean morning plasma cortisol values did not change significantly during treatment (P = 0.083), although a small change in cortisol levels between the first visit (pre-treatment) and last visit was positively correlated to the Cmax of budesonide measured at the last visit (P = 0.012).

A steroid enema, budesonide, lacking systemic effects for the treatment of distal ulcerative colitis or proctitis

The aim of this study was to evaluate whether budesonide enema (2 mg/100 ml) had a significantly better effect than placebo in the treatment of distal ulcerative colitis or proctitis. The trial was of controlled, randomized, double-blind design and included 41 treated patients. The treatment time was 4 weeks, with revisits after 2 and 4 weeks. If no improvement was seen, the patient could be switched over to open-label therapy with budesonide enema. Sigmoidoscopy, histology, blood chemistry, and diary cards were used for estimating the effect of treatment. The results showed that budesonide was superior to placebo. Sigmoidoscopy and biopsy scores improved significantly (p less than 0.01) in budesonide-treated patients compared with placebo. Significantly more patients switched over to open budesonide treatment in the placebo group owing to lack of efficacy compared with budesonide (p less than 0.001). No drug-related adverse experiences occurred, and there was no decrease in endogenous morning plasma cortisol levels. It is concluded that budesonide enema appears to be an effective and safe treatment for distal ulcerative colitis and proctitis.

Budesonide enema in distal ulcerative colitis. A randomized dose-response trial with prednisolone enema as positive control. The Danish Budesonide Study Group

The effect of budesonide, 1, 2, and 4 mg/100 ml in daily enemas, on active distal ulcerative colitis was compared with that of prednisolone disodium phosphate enemas, 25 mg/100 ml, in a multicentre, randomized, group-comparative trial. A total of 146 patients with active disease were treated for 2 weeks. Data from 139 were valid for statistical analyses. Bowel habits, proctoscopy findings, and histologic pictures were evaluated, and plasma cortisol was determined for measurement of influence on the hypothalamic-pituitary-adrenal axis. Clinical symptoms and proctoscopy findings improved within all treatment groups. The improvement of these effect variables tended to be less after treatment with the lowest dose of budesonide, 1 mg/100 ml, than after the other treatments. Plasma cortisol did not change in any of the budesonide groups, whereas a mean reduction of 30% (P = 0.07) was observed after prednisolone. It can be concluded that budesonide enemas of 2 mg/100 ml constitute an attractive alternative to prednisolone enemas for topical treatment of distal ulcerative colitis.

Chemiluminescence high performance liquid chromatography of corticosteroids using lucigenin as post-column reagent

A chemiluminescence high performance liquid chromatographic method for the determination of corticosteroids and tetrahydrocorticosteroids has been developed. Corticosteroids and their metabolites extracted from urine samples were separated using an ODS column and a mixture of methanol + water + 0.01 M sodium acetate solution (70:30:5) as eluent. The eluent from the column was mixed with the chemiluminescent solution containing lucigenin and Triton X-100 and a 0.28 M KOH solution by pumps and monitored by a chemiluminescence detector. No interference was encountered and the method is both precise and reproducible.

Clinical analysis of individual steroids by column liquid chromatography

At present, there are various LC methods available for the determination of estriol, aldosterone, and cortisol in urine, and for cortisol, cortisone, 11-deoxycortisol, corticosterone, 17-hydroxyprogesterone, estriol, vitamin D isomers, and various exogenous glucocorticoids in serum. The LC methods are more specific than the currently available RIAs or homogenous immunoassays. However, whether the data obtained by more specific LC methods are better clinically than the commonly used immunoassays for these steroids must still be proven. In this review, I have critically evaluated various LC methods currently available for the routine determination of clinically important steroids in the clinical laboratories. A complete evaluation and advantages and disadvantages of alternative techniques are beyond the scope of this review. However, the readers are urged to refer to the review articles and chapters listed in the reference section.

High-performance liquid chromatography of steroid hormones

Although a considerable amount of work has been carried out in the last ten years in developing methods for the separation of steroids by HPLC, it is still not widespread for the reasons discussed above. There is however no doubt that further developments in HPLC technology, in increasing sensitivity and/or specificity of detection systems, perhaps with microbore columns, may lead to an increase in the use of this powerful analytical procedure as an additional separation method to improve specificity of assay. Solution of the problem of simple interfacing of HPLC systems with mass spectrometers (discussed in another chapter by Games) should further increase the application of HPLC. HPLC is of particular value in providing a means of separating unstable compounds prior to assay by relatively nonspecific quantitation methods. Most steroids do not fall into this category, but the steroid vitamin D and its metabolites do and HPLC has proved in this area to be invaluable (see chapter by Jones & DeLuca). There are a multiplicity of different HPLC systems for the separation of steroids, varying in column type (and manufacturer), solvent composition and method of elution, temperature of elution, etc., and only a few attempts have been made to rationalise these data. It would therefore seem that a fruitful area of future study would be the investigation of computerised systems for the selection and optimisation of HPLC systems for particular steroid separations.

A controlled randomized trial of budesonide versus prednisolone retention enemas in active distal ulcerative colitis

Sixty-four patients with active distal ulcerative colitis participated in a multicentre, randomized, investigator-blind trial to compare the effect of budesonide enema, 2 mg/100 ml, with prednisolone disodium phosphate enema, 31.25 mg/100 ml. Budesonide is a new potent corticosteroid with a rapid first-pass elimination. The patients were treated for 4 weeks, and the efficacy of the drugs were evaluated by sigmoidoscopy, histology, and subjective symptoms after 2 and 4 weeks. After 4 weeks of treatment 16 of 31 patients (52%) receiving budesonide enema had healed endoscopically, compared with 8 of 33 (24%) (p = 0.045) receiving prednisolone enema. Budesonide was superior to prednisolone in terms of both significantly improved sigmoidoscopic and histologic scores and subjective symptoms evaluated by visual analogue scales. The patients receiving prednisolone had a significant depression of endogenous cortisol levels during the treatment period, but not the patients receiving budesonide. Budesonide enema seems to be a promising therapy for active distal ulcerative colitis and causes no adverse reactions.

Adrenal function of the rat in relation to peroral administration of xylitol: depression of aldosterone

The effect of peroral administration of xylitol (5% or 20% in food) on adrenal function was investigated in thirty-five Long-Evans male rats. The control rats were fed either a non-substituted stock diet or a 20% glucose diet. Glucose elevated and 20% xylitol reduced the growth of the rats (P less than 0.001), but 5% xylitol had no effect on the body weight. The concentrations of serum glucose and lactic acid decreased in rats fed 20% and 5% xylitol, respectively, but those of insulin, glucagon, corticosterone and aldosterone were not affected. In the adrenal glands, 20% xylitol loading was associated with increased epinephrine (P less than 0.05) and norepinephrine (P less than 0.001), but with decreased aldosterone (P less than 0.001) concentrations. The weights and histological picture of adrenal glands were normal. The urinary pH of xylitol-fed rats decreased significantly (P less than 0.01). Although peroral xylitol affected the levels of aldosterone and catecholamines, a normal glucocorticoid metabolism was permitted. The reduced aldosterone levels were regarded as secondary reactions, possibly resulting from alterations in electrolyte and/or acid-base balance. The increased catecholamine synthesis may be associated with the promoting effect of xylitol on intestinal calcium absorption.

Isotope dilution analysis using chromatographic separation of isotopic forms of the compound to be measured

Using progesterone, testosterone, androstenedione, 11-oxoprogesterone and 11 beta-hydroxyprogesterone as models, a new form of isotope dilution assay has been developed. A known mass of deuterium-labelled steroid is added to the serum sample. High-performance liquid chromatography is used to separate endogenous steroid from its deuterium-labelled form. After separation, the two forms of the analyte are quantitated using conventional methods: radioimmunoassay, enzyme-linked immunoassay and, where the concentrations are high enough, ultraviolet light absorption. The ratio of the amounts of the two forms of the analyte is used to calculate the amount of unlabelled material in the original sample. The assay principle is quite general. A variety of high resolution methods are available to separate isotopic analogues of the same compound. A number of detection methods can be used to quantitate the separated isotopic forms. Extension of this principle to other fields of interest in bio-medicine is discussed briefly.

Drug level monitoring of antiasthmatic drugs

In general assays pertaining to drug level monitoring (DLM) of antiasthmatic agents (except theophylline), published during the period 1978-1983, used mostly high-performance liquid chromatographic (HPLC) methodology (approximately 45%) with mass spectrometric (MS) based assays in second place (approximately 30%) followed by immunochemical techniques (approximately 25%). Whenever nanogram or subnanogram antiasthmatic drug concentrations had to be measured such as for the adrenergic stimulants or for the prophylactic agents, then both HPLC-and MS-based methodologies were employed with about equal frequency. The trend in DLM for the phosphodiesterase inhibitor class (theophyllines) seemed to be shifting towards the HPLC methodologies. In part, this was justified by the need for improved selectivity. This criterion appears to have been better satisfied by HPLC, but for all practical purposes the immunochemical methods are and will probably continue to prevail in the clinical laboratory setting until HPLC procedures become truly automated. In the case of DLM of corticosteroids used for the asthmatic, the situation is in our opinion still unclear. This is caused by the presence of endogenous corticosteroids and metabolites, the levels of which in man are known to vary. The current immunochemical procedures offer a facile but less selective option. The future for selective routine corticosteroid assays may well be in HPLC or gas chromatography coupled with MS.

Clinical applications of the rapid high-performance liquid chromatographic determination of serum cortisol

We report a rapid and specific analytical method for the measurement of serum cortisol by reversed-phase high-performance liquid chromatography (HPLC). The method allows the diagnostic measurement of cortisol in emergency clinical circumstances of glucocorticoid deficiency or excess. Results obtained by HPLC are comparable to those by radioimmunoassay. The lower limit of sensitivity is 6 ng cortisol per ml of serum.

A simple and convenient method for quantitation of corticosterone by high-performance liquid chromatography-ultraviolet detection

This paper describes the quantitation of corticosterone in the rat serum and adrenal gland by high-performance liquid chromatography-Ultraviolet detection. The extraction and separation were optimized, resulting in an 80% recovery of corticosterone with a detection limit of 10 ng/ml serum. The separation was achieved in less than 5 min on a micro silica gel column using isocratic elution with hexane: chloroform: methanol (7:1:1, v/v) as the mobile phase. The levels of corticosterone in rat serum in the morning and the afternoon were 105.6 +/- 11.96 ng/ml (10:00 a.m., n = 28) and 174.8 +/- 17.60 ng/ml (17:00 p.m., n = 20), respectively. Because of its simplicity, this method provides a new promising analysis for determining hypothalamus-pituitary-adrenal function.

Improved liquid chromatographic determination of serum cortisol with double internal standardization compared to radioimmunoassay and fluorometry, and evaluated by isotope dilution/mass spectrometry

A sensitive and specific high-performance liquid chromatographic (HPLC) method for the determination of cortisol in only 200 microliters of serum is described. Cortisol and two internal standards, 19-nortestosterone (IS1) and 6 alpha-methylprednisolone (IS2) are extracted with dichloromethane and analyzed on a C18 reversed-phase column eluted with a mobile phase of methanol:water at a flow rate of 0.75 ml/min. Ultraviolet absorption at 254 nm is used for detection and quantitation is performed by peak height ratio measurement. Using 200 microliters of serum, the lower limit of detection for cortisol is 10 ng/ml, the analytical recovery is 104 +/- 3.6% (n = 8), and the day-to-day precision was 1.69% at a level of 90 ng/ml (n = 16). Cortisol values obtained by this method were generally lower than those obtained by radioimmunoassay or by fluorometry. A serum pool was analyzed both by HPLC and by isotope dilution/mass spectrometry (ID/MS). A mean value of 90.1 ng/ml was obtained by HPLC (n = 16, CV = 1.7%), whereas ID/MS yielded a mean of 90.8 ng/ml (n = 28, CV = 0.4%). These results clearly demonstrate the high specificity and the accuracy of the HPLC procedure. The use of two internal standards not only compensates for losses during the sample manipulation but also prevents erroneous results in case of medication by either of these two products.

Analysis of corticosteroids in human adrenal tissue by high pressure liquid chromatography

High pressure liquid chromatography (HPLC) was demonstrated to be a good tool for the separation, identification and quantitation of corticosteroids (CS) extracted from homogenized tissue of adrenal glands and adrenal tumors in patients with hypercorticism. A chromatographic system consisting of Sorbax-SIL and Sorbax-CN columns, organic solvent extraction and a UV detector was used to analyze both more polar and less polar corticosteroids in the adrenal tissue.

Determination of 17-hydroxycorticosteroids in urine by fluorescence high-performance liquid chromatography using Dns-hydrazine as a pre-column labeling reagent

A method is described for the determination of urinary 17-hydroxycorticosteroids using fluorescence high-performance liquid chromatography. After enzymatic hydrolysis, 17-hydroxycorticosteroids were extracted using an Extrelut column and then labeled with Dns-hydrazine in hydrochloric acid-ethanol solution. The labeled steroids were chromatographed on a microparticulate silica gel column, the mobile phase was dichloromethane-ethanol-water (900:60:40). The eluate was monitored on a fluorophotometer at 365 nm (excitation) and 505 nm (emission). Linearity of the fluorescence intensities (peak heights) of various 17-hydroxycorticosteroids were obtained between 60 pg and 20 ng. The assay was sensitive, precise and accurate. Comparison with the results obtained by radioimmunoassay gave correlation coefficients of 0.932 for tetrahydrocortisol and 0.930 for tetrahydrocortisone. The proposed method is clinically useful for the routine analysis of urinary 17-hydroxycorticosteroids.

In vitro biotransformation of glucocorticoids in liver and skin homogenate fraction from man, rat and hairless mouse

The pharmacological effects of glucocorticoids are greatly influenced by their pharmacokinetic properties. In the present report, the in vitro biotransformation of the topical glucocorticoids [3H]-budesonide ([3H]-BUD). [3H]-triamcinolone acetonide ([3H]-TAAc) and [3H]-hydrocortisone ([3H]-HC) was studied in the 9000 g liver and skin supernatant from man, rat and hairless mouse. The rate of disappearance of the compounds was estimated during the initial 30 min of incubation by high performance liquid chromatography. In human liver the half life (t1/2) rank order was [3H]-BUD (7--23 min) less than [3H]-TAAc (13--68 min) less than [3H]-HC (40--67 min), in rat liver [3H]-HC (14--21 min) less than [3H]-BUD (28--38 min) less than [3H]-TAAc (161--196 min) and in hairless mouse liver [3H]-BUD (17--22 min) less than [3H]-TAAc (21--34 min) less than [3H]-HC (82--165 min). Negligible biotransformation of these glucocorticoids occurred in skin. BUD is a one to one mixture of the [22R]- and [22S]-epimers. It was found that the [22R]-epimer was more susceptible to liver biotransformation than the [22S]-epimer of [3H]-BUD. The results are discussed with particular reference to the extent of systemic side effects of these compounds.

Oral hydrocortisone pharmacokinetics: a comparison of fluorescence and ultraviolet high-pressure liquid chromatographic assays for hydrocortisone in plasma

Three fasted, male subjects received single 10-, 30-, and 50-mg oral doses of hydrocortisone tablets on separate occasions. Endogenous hydrocortisone was suppressed by giving 2 mg of dexamethasone 9 hr prior to dosing. Plasma samples obtained serially for 8 hr after hydrocortisone dosing were assayed by reversed-phase high-pressure liquid chromatography (HPLC) with UV detection and by normal-phase HPLC with fluorescence detection of the dansylhydrazine derivative of hydrocortisone. The two assay methods yielded equivalent plasma hydrocortisone concentrations. Metabolite interference was absent in both assay methods. Drug concentrations in plasma from all three doses of hydrocortisone were described by one-compartment open-model kinetics, with first-order absorption and elimination, and an absorption lag time. Mean Cmax values of 199, 393, and 419 ng/ml were obtained at 1.0, 1.0, and 1.7 hr following the 10-, 30-, and 50-mg doses, respectively. Hydrocortisone was cleared from plasma with an elimination half-life of approximately 1.5 hr. Within the dosage range studied, plasma levels of hydrocortisone were related, but not directly proportional, to dose size. This apparent lack of proportionality may be due to reduced drug availability or altered distribution with increasing dose.

Determination of prednisone and prednisolone in human serum by high-performance liquid chromatography--especially on impaired conversion of corticosteroids in patients with chronic liver disease

A reliable and rapid method is described for the determination of prednisone and prednisolone in human serum by high-performance liquid chromatography, using a Zorbax-SIL column with dichloromethane-ethanol (92.5:7.5) as eluent, with UV detection at 254 nm. Metabolites and endogenous hydrocortisone did not interfere with the determination of prednisone and prednisolone. The alteration of corticosteroid concentrations in serum from patients with chronic liver diseases was studied following a single oral administration of prednisone or prednisolone (30 mg). The proposed method showed good separation of several corticosteroids and was time-saving, suitable and reliable for the routine analysis of corticosteroids in human serum.

Suppression of endogenous hydrocortisone with dexamethasone

A newly developed high-pressure liquid chromatographic method was used to study the optimum dosage regimen needed to suppress endogenous hydrocortisone. Nine volunteers were randomly placed in three groups. Each group received 1 mg of dexamethasone at 11 pm (Treatment A), 2 mg of dexamethasone at 11 pm (Treatment B), or 1 mg at 11 pm and an additional 1 mg at 6 am the following day (Treatment C). Analysis of multiple blood samples obtained the day before and the day after drug administration showed suppression in all three groups. Although the duration and extent of this suppression varied, adequate suppression to permit bioavailability studies was observed for Treatments B and C.

The determination of cortisol in human plasma: evaluation and comparison of seven assays

In a comparative study, seven different methods for the determination of cortisol in human plasma were evaluated, using routine patient samples. Four of these methods used radioactive steroids (125I- or 3H-labelled) and in three no radioactivity was needed. For the statistical evaluation a direct 3H-radioimmunoassay was arbitrarily taken as the independent variable. It was found that all other methods correlated well with this assay. However, the simplest method, the fluorimetric, cannot be recommended mainly because of its non-specific fluorescence and troublesome interference from some widely-used drugs. Of the methods evaluated a radioimmunoassay is recommended. For laboratories having no equipment for measurements of radioactivity, the more elaborate and time-consuming fluorometric method of Clark may represent a good alternative.

High-pressure liquid chromatography of steroids

After a brief discussion of the merits and limitations of high-pressure liquid chromatography (HPLC) relative to other chromatographic methods, special problems in the application to steroids are discussed. Publications on HPLC of steroids are then discussed under the headings of individual classes, arranged generally in the order of increasing polarity.

Determination of cortisol in human plasma by reversed-phase high-performance liquid chromatography

A method is described for the measurement of cortisol in human plasma using 45% aqueous methanol eluent on a 120 mm x 4.5 mm I.D. Hypersil octadecylsilane column with UV detection at 239 nm after a simple dichloromethane extraction and evaporation with a prednisone internal standard. The sample preparation time and chromatography time are each about 15 min and linear correlations have been obtained with plasma samples assayed by the Mattingly fluorimetric technique and a commercial-kit competitive protein binding method. Concentration down to 30 nmol/l may be measured and the method can be used when fluorimetry is invalidated by interference, particularly from spironolactone.

Comparison of different high-performance liquid chromatographic systems for the purification of adrenal and gonadal steroids prior to immunoassay

The high-performance liquid chromatography of nineteen hormonal steroids with special respect to its suitability for routine purification of these steroids from crude, organic extracts of biological fluids prior to final quantitation by immunoassay has been studied. In all systems the gradient elution technique was applied. Separation of steroids has been investigated using different stationary phases chemically coated with non-polar, hydroxyl, NO2 and CN groups. Reproducibility of retention times was studied on a stationary phase coated with hydroxyl groups (DIOL column) using different organic eluents. Coefficients of variation range from 0.76 to 8.16%. Reproducibility was shown to be unequivocally better in the gradient part than in the isocratic part of the chromatographic run. In contrast to the other steroids, 18-hydroxylated steroids were more or less unstable in certain systems studied. As to resolution and reproducibility, the DIOL column run with an n-hexane-dioxane gradient has been shown to be superior to the other systems studied.