Aims: To evaluate a standard aerosolization method for uniformly depositing threat-representative spores onto surfaces.Methods and Results: Lyophilized Bacillus anthracis Delta Sterne spores, coated in silica, were aerosolized into a containment chamber and deposited onto nine surface types by two independent laboratories. Laboratory A produced a mean loading concentration of 1.78 x 10(5) CFU cm(-2); coefficient of variation (CV) was <40% for 96% of samples. Laboratory B produced a mean loading concentration of 7.82 x 10(6) CFU cm(-2); 68% of samples demonstrated CV <40%.Conclusions: This method has been shown to meet the goal of loading threat-representative spores onto surfaces with low variability at concentrations relevant to the Department of Defense.Significance and Impact of the Study: As demonstrated in 2001, a biological attack using anthrax disseminated as a dry powder is a credible threat. This method will provide a means to load spores onto surfaces that mimic a 'real-world' scenario of an aerosolized anthrax attack. The method has utility for evaluating sporicidal technologies and for nondecontamination studies, for example fate and transport or reaerosolization.

Background:This pharmacokinetic (PK) study was designed to investigate the maximum intranasal insulin dose that could be achieved by repeated doses in a single nostril of a nasal spray of recombinant regular human insulin 1% in combination with cyclopentadecalactone (CPE-215) 2%, a compound that enhances absorption of molecules across mucous membranes (Nasulin™, CPEX Pharmaceuticals, Inc.). Method:A nine-period crossover study of 8 healthy, nonsmoking subjects (ages 18–50, body mass index <33 kg/m2, weight >70 kg) were studied. In a fasted state, subjects were randomly given 25, 50, and 75 U in a single nostril on the first day and randomly given 50, 75, and 100 U doses utilizing both nostrils on two subsequent days. After a 45-minute PK assessment, subjects were given a meal. To determine the mechanism of enhanced absorption in a single nostril, a second study utilizing 24 subjects under similar conditions received 25 U, placebo (P) that included CPE-215 plus 25 U, and 50 U in a single nostril. Results:Single nostril administration revealed enhanced absorption with maximum concentrations (Cmax) of 13, 65, and 96 μU/ml for the 25, 50, and 75 U doses, respectively. Dual nostril administration in two cohorts resulted in Cmax of 31/42, 65/52, and 88/79 μU/ml for the 50, 75, and 100 U, respectively. In the second cohort, Cmax was 23, 19, 56 μU/ml for the 25, P + 25, and 50 U doses, respectively. Conclusions:Repeated dosing in a single nostril resulted in enhanced absorption; this was not due to the increased CPE-215 but to the increased insulin administered.

Background: This pharmacokinetic (PK) study was designed to characterize the dose response of two concentrations (0.7% and 1%) of a nasal spray of recombinant regular human insulin in combination with cyclopentadecalactone (CPE-215), a compound that enhances absorption of molecules across mucous membranes (Nasulin™, CPEX Pharmaceuticals). Nasulin has been effective in lowering blood glucose in both normal subjects and diabetes patients, and additional dosing options would allow greater titration flexibility. Method: A five-period crossover study of 24 healthy, nonsmoking subjects (ages 18–50, basal metabolic index <33 kg/m2, weight >70 kg) were studied. Subjects were in a fasted state for 5 h before and 45 min after administration for PK assessment and were then given a meal. Each spray contained 100 μl. Doses tested were 25, 35, 50, 70, and 100 U. Maximum concentration (Cmax) and area under the curve (AUC) were estimated for each dose group. Glucose measurements were also performed. Results: A dose response (slope of the natural log response versus dose) was demonstrated by baseline-adjusted Cmax of 22, 27, 56, 62, and 84 μU/ml for the 25, 35, 50, 70, and 100 U doses (p < .0001), respectively, and by baseline-adjusted AUC(0–45 min) values of 491, 592, 1231, 1310, and 1894 μU/ml/min (p < .0001). Glucose AUC(0–45 min) determinations also demonstrated a pharmacodynamic (PD) dose response. Conclusions: Proportional and linear dose responses for both PK and PD parameters were demonstrated for the two concentrations, making multiple doses available for clinical development.

Background: The pharmacokinetics and pharmacodynamics of a Bentley Pharmaceuticals proprietary intranasal (IN) insulin formulation (Nasulin™) were studied in healthy volunteers. Methods: Thirteen fasting healthy male volunteers received five doses of medication (one dose of 4 international units [IU] subcutaneous (SC) regular insulin and four doses of 25 IU IN insulin) at least 48 h apart. Serum insulin, serum C-peptide, and plasma glucose were measured in the 4 h after dosing. Profiles were compared for IN insulin spray following administration into the dominant nostril (more open at time of dosing) and into the nondominant nostril (less open at time of dosing). Results: The formulation was generally well tolerated. A rise in serum insulin levels accompanied by a decrease in plasma glucose was seen following all doses. For IN doses, peak insulin levels were generally attained in 10–20 min and remained elevated for approximately 40–50 min; the resultant effect on glucose peaked at 40 min and waned approximately 2 h postdosing. As reported in other studies, the interindividual response to insulin was variable. The comparative absorption of IN insulin relative to SC insulin was 12.0% (dominant nostril) or 15.4% (nondominant nostril) over 2 h. This increased somewhat if sneezers and volunteers with moderately blocked nostrils were removed from the analysis. Conclusions: This IN formulation was generally well tolerated and relatively well absorbed. While both insulin data (maximal plasma concentration and area under the plasma concentration time curve) and glucose data (% fall) support a trend toward better absorption from the nondominant nostril, this did not reach statistical significance. Nasulin can be administered without reference to the nasal cycle.

BACKGROUNDThe pharmacokinetics and pharmacodynamics of a Bentley Pharmaceuticals (Exeter, NH) proprietary insulin formulation designed for intranasal administration were studied in patients with type 1 diabetes, using subcutaneous insulin or placebo as comparator.METHODSSeven fasting volunteer patients with type 1 diabetes (five men, two women; body mass index 23.54+/-1.32 kg/m2) received up to four doses of medication (placebo, subcutaneous insulin, or intranasal insulin) at least 3 days apart. Serum insulin and plasma glucose were measured in the 5-h period after dosing.RESULTSThe relative bioavailability of intranasal insulin compared with subcutaneous insulin was 16.6-19.8% over 2 h and 14.0-19.8% over 5 h. The formulation was generally well tolerated. At doses of 25 IU and above, a rise in serum insulin levels accompanied by a decrease in plasma glucose was seen. Peak insulin levels were generally attained in 15-20 min and remained elevated for approximately 1 h; the resultant effect upon glucose peaked at 40 min and waned 1.5-2 h post-dosing. The effect was dose related. Mean peak insulin levels increased with dose escalation. As reported in other insulin studies, the inter-individual responsiveness to insulin was variable.CONCLUSIONSThis intranasal formulation was generally well tolerated, and relatively well absorbed as demonstrated by a rapid rise in serum insulin level and concomitant reduction of plasma glucose levels.

BACKGROUND:This exploratory study examined the pharmacokinetics and pharmacodynamics of a Bentley Pharmaceuticals, Inc. (North Hampton, NH) proprietary insulin formulation utilizing CPE-215 technology designed for intranasal administration.METHODS:Eight fasting healthy volunteers (four men, four women; body mass index, 23.6 +/- 1.7 kg/m2) received up to four doses of intranasal insulin at least 1 week apart. Serum insulin, C-peptide, and plasma glucose were measured in the 4-h period following administration.RESULTS:At doses of 18.75 IU and above, a rise in serum insulin levels accompanied by a decrease in plasma glucose and serum C-peptide levels was seen. Insulin levels peaked in 10-20 min and remained elevated for approximately 1 h, and the resultant hypoglycaemic effect peaked at 40 min and returned to normal 1.5-2 h post-dosing. At 25 IU (n = 11 doses; eight subjects with three replicates), there was a mean fall in plasma glucose of 20.49%; a greater fall in plasma glucose was seen with higher insulin doses. In addition, mean peak insulin levels increased with dose escalation. For the 25 IU dose (a single 90-microL spray), the maximum measured insulin concentration was 19.52 +/- 9.28 mIU/L, and the area under the concentration-time curve from 0 to 4 h was 19.06 +/- 5.56 mIU/L/h. Three subjects with repeated 25 IU doses demonstrated similarly reproducible peaks for maximum measured insulin concentration and for plasma glucose reductions. As seen with other insulin studies, the inter-individual responsiveness to insulin was variable.CONCLUSIONS:This intranasal formulation was generally well tolerated and demonstrated rapid onset of action and appropriate duration of action for the potential use in controlling postprandial hyperglycaemia.

Of 13 chronic hemodialysis end-stage renal disease (ESRD) patients undergoing open-heart surgery, 7 received intraoperative hemodialysis (IHD) during cardiopulmonary bypass and 6 received hemodialysis on a routine basis (RHD). Within the groups, IHD patients had significantly lower post-operative mean serum potassium and mean plasma creatinine concentrations compared to mean preoperative values. Postoperative mean BUN tended to decrease and mean serum bicarbonate concentration was unchanged as compared to mean preoperative values. In the RHD group, however, post-operative mean serum potassium concentration tended to increase, mean serum bicarbonate concentration significantly declined and mean BUN was unchanged as compared to mean preoperative values. An average of 2.1 +/- 0.5 liters of fluid was removed from the IHD patients during cardiopulmonary bypass. Post-operatively, 0 of 7 IHD patients versus 4 of 6 RHD patients required parenteral sodium bicarbonate therapy (chi-2, p < 0.01). On average, RHD patients required hemodialysis 1 day after surgery, whereas IHD patients were hemodialyzed 2 days after surgery (p = 0.009). We conclude that IHD lessened postoperative hyperkalemia and metabolic acidosis and delayed postoperative hemodialysis by an additional day. IHD should be considered as an adjunct to RHD therapy in the management of ESRD patients undergoing open-heart surgery.

Cyclosporine causes renal vasoconstriction and reduced renal blood flow that may contribute to chronic nephrotoxicity. This effect has not been consistently reversed by available pharmacologic agents. The efficacy of orally administered fenoldopam, a dopamine-1 (DA-1) agonist with renal vasodilator properties, was evaluated in six patients whose condition was stable 3 to 6 months following renal transplantation. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured by inulin and p-aminohippurate (PAH) clearances, respectively, at baseline, after the acute oral administration of 100 mg of fenoldopam, and following 3 weeks of chronic oral fenoldopam therapy (100 mg thrice daily). Mean ERPF increased from 3.15 ± 0.17 mL/s/1.73 m2 (189 ± 10 mL/min/1.73 m2) at baseline to 3.48 ± 0.17 mL/s/1.73 m2 (209 ± 10 mL/min/1.73 m2) 4 hours after acute administration of fenoldopam (P = 0.04). Urine flow rate and fractional excretion of sodium also increased after acute administration, but not significantly. Mean systolic (SBP) and diastolic blood pressure (DBP) decreased maximally by 18 and 6 mm Hg, respectively, and mean pulse rate increased maximally by 8 bpm between 75 and 90 minutes after both acute and chronic administration. GFR was unchanged following both acute and chronic administration. The increase in ERPF was not maintained to the end of the dosing interval during chronic administration, probably due to the short half-life of fenoldopam, However, the renal vasodilatory response was still observed 3 to 4 hours after readministration of the drug following 3 weeks of oral dosing. Thus, fenoldopam significantly reverses the renal vasoconstriction caused by cyclosporine in renal transplant recipients. Further evaluation of fenoldopam in preventing cyclosporine-induced nephrotoxicity appears warranted.

Growth hormone-releasing peptide (GHRP, SK&F 110679) is a hexapeptide (His-DTrp-Ala-Trp-DPhe-LysNH2) that selectively stimulates the release of growth hormone (GH) but not other pituitary hormones in vitro and in vivo in a variety of animal species. GHRP was administered to 17 normal men at doses of from 0.05 to 2.5 micrograms/kg as a 30 min intravenous infusion. Eight of the men were infused with saline as a control. Serum GH increased consistently at doses of 0.25 microgram/kg and above during the infusion of the peptide, peaked at 45 min and then decreased to baseline values by 210 min. The mean peak serum GH concentrations (+/- SE) in response to GHRP infusion were 17.8 +/- 6.1 micrograms/L at a dose of 0.25 microgram/kg (n = 4, p = .03 vs saline), 38.3 +/- 9.2 micrograms/L at 0.5 microgram/kg (n = 4, p = .04 vs saline) and 63.0 +/- 5.4 micrograms/L at 1.0 microgram/kg (n = 4, p = .002 vs saline). Serum LH, FSH, TSH and ACTH were unaffected by GHRP administration. GHRP was safe and well-tolerated in all men. GHRP infusion resulted in a dramatic, selective and dose-dependent increase in serum GH concentrations.