Physicochemical stability of irinotecan injection concentrate and diluted infusion solutions in PVC bags

Purpose. To determine the physicochemical stability of irinotecan injection concentrate and irinotecan infusion solutions after dilution in two commonly used infusion fluids (0.9% sodium chloride, 5% dextrose) in PVC bags, stored under refrigeration (2-8°C) or at room temperature either light protected or exposed to light.

Methods. Stability of irinotecan injection concentrate was determined in the original amber glass vials. Diluted irinotecan infusion solutions were aseptically prepared by further dilution of irinotecan stock solution with either 0.9% sodium chloride or 5% dextrose in PVC bags, in amounts yielding irinotecan concentrations of 0.4, 1.0, or 2.8 mg/ml. Test solutions were stored under refrigeration (2-8°C) or at room temperature either light protected or exposed to light (mixed daylight and normal laboratory fluorescent light) in parallel. Irinotecan concentrations were determined periodically throughout a 4-week storage period via a stability-indicating HPLC assay with ultraviolet detection. In addition, measurements of pH values were performed regularly and test solutions were visually examined for colour change and precipitation.

Results. Irinotecan injection concentrate and infusion solutions are shown to be physicochemically stable (at a level of >90% irinotecan) for 4 weeks when stored under refrigeration or light protected at room temperature, independent of the vehicle (0.9% sodium chloride, 5% dextrose) or the concentration (0.4, 1.0, or 2.8 mg/ml). Irinotecan infusion solutions exposed to daylight exhibited concentration-dependent instability, solutions were stable for only 7 to 14 days.

Conclusions. Irinotecan injection concentrate and diluted infusion solutions are shown to have adequate physicochemical stability for convenient pharmacy-based centralized preparation.

Loading profile of topotecan into polyvinyl alcohol microspheres (DC Bead™) over a 7-day period

Purpose: DC Bead™ is successfully used for chemoembolization of various liver cancers. The purpose of this study was todetermine the loading capacity of the semi-synthetic topoisomerase-1 inhibitor topotecan into the DC Bead™ microspheres under static or agitated conditions and to assess the physicochemical stability over a period of 7 days.

Methods: Commercially available topotecan hydrochloride powder (Hycamtin®) was reconstituted with water for injection to yield a nominal concentration of 1 mg/mL topotecan. Polyvinyl alcohol (PVA)-based microspheres (DC Bead™, 300–500 µm, 2 mL/vial) were mixed with 4 mL of the reconstituted topotecan solution. Vials were stored light protected at room temperature under static or agitated conditions for 7 days ( n = 3, for each loading condition). At different time intervals, samples were taken from the excess solution and assayed via a stability-indicating HPLC assay. Drug-loading profiles were determined by measuring the remaining topotecan concentration in the excess solution.

Results: Under agitated conditions, topotecan was loaded into the microspheres rapidly after mixing. After 5 min 86.4 ± 0.1% of topotecan was loaded. Under static conditions, drug uptake was slower. Only 65.0 ± 0% were loaded after 5 min; 86.6 ± 0.1% drug uptake was achieved not until 1 h. Over a storage period of 7 days, topotecan remained loaded in the DC Bead™ microspheres at a level of >90%.

Conclusion: Drug uptake of 4 mg topotecan (1 mg/mL solution) into DC Beads™ was faster under agitated loading conditions. Nevertheless, after 1 h, ∼90% of topotecan was loaded into the DC Bead™ microspheres independent from the type of loading condition. The loading rate remained >90% over the observation period of 7 days and light-protected storage at room temperature. Loading and stability of topotecan-loaded DC Beads™ is suitable and convenient for preparation in a pharmacy-based cytotoxic preparation unit.

In-use stability of diluted thiamazole (methimazole) infusion solutions in prefilled 0.9% sodium chloride infusion bags for continuous infusion

OBJECTIVE

In patients with severe hyperthyroidism unable to tolerate oral antithyroid therapy, diluted thiamazole infusion solutions (dose 120-240 mg) are administered by continuous infusion over 24 hours. Information about the type of diluent and compatibility/stability of the ready-to-administer thiamazole preparation is missing in the summary of product characteristics of the injection concentrate marketed in Germany. We studied the in-use stability of diluted infusion solutions over 24 hours.

METHODS

Thiamazol 40 mg inject. Henning was diluted in prefilled polyolefin infusion bags containing 250 mL 0.9% sodium chloride (NaCl) infusion solution and kept for 24 hours at room temperature and diffuse room light. Content of the diluted infusion solutions (0.48 and 0.96 mg/mL) was analysed every 4 hours over the course of 24 hours by reversed-phase high-performance liquid chromatography. pH was measured after 0, 12 and 24 hours. The infusion bags were regularly inspected for visible particles. Subvisible particles were measured by particle counting.

RESULTS

Thiamazole infusion solutions of the nominal concentrations 0.48 and 0.96 mg/mL in 0.9% NaCl diluent, kept at room temperature under diffuse room light, are physicochemically stable over a period of at least 24 hours. No evidence of colour change, particle formation or pH change was observed throughout the observation period.

CONCLUSION

Dilution of 120 or 240 mg doses of licensed thiamazole injection concentrate with 0.9% NaCl infusion solution in prefilled polyolefin containers is recommendable for continuous infusion over 24 hours in the treatment of thyrotoxicosis.

[Quality management within the competence network of paediatric oncology and haematology]

The competence network paediatric oncology and haematology aims at improving the structure of paediatric oncology and haematology as a whole focussing in particular on the quality of clinical trials and study centres. This implicates the following measures: (1) Employment of research and trial assistants in order to improve the quality of documentation and study management in the participating hospitals. (2) Building up of an Internet portal to provide medical information for non-professionals, for patients and their families as well as for health professionals. (3) The project "Study Assistance" supports study centers during the process of writing and examining new treatment protocols so that they are in compliance with the Good Clinical Practice criteria, formal criteria and statutory provisions. It presently works on a structural standardisation of study protocols and case record forms in order to improve their usability. In addition, the working group "Quality Assurance in GPOH Study Centres" is engaged in developing a quality management system for study centers.

Quality management for clinical trials within the German Competence Network Paediatric Oncology and Haematology

The German 'Competence Network Paediatric Oncology and Haematology' aims at improving the structure of paediatric oncology and haematology as a whole, focussing in particular on the quality of clinical trials and study co-ordinating centres. This comprises the following measures: (1) Employment of research and trial assistants in order to improve the quality of documentation and study management in the participating hospitals. (2) Development of an internet portal to provide medical information for non-professionals, for patients and their families as well as for health professionals. (3) The project group 'Central Trial Support' supports study centres during the process of writing and examining new treatment protocols so that they are in compliance with the Good Clinical Practice criteria, formal criteria, legal requirements and statutory provisions. This group currently produces a structural standardisation of study protocols and case record forms in order to improve their usability. The 'Competence Network Malignant Lymphomas' is a project with similar aims and will be outlined for comparison.

Physicochemical stability of carfilzomib (Kyprolis®) containing solutions in glass vials, ready-to-administer plastic syringes and infusion bags over a 28-day storage period

Centralized aseptic preparation of ready-to-administer carfilzomib containing parenteral solutions in plastic syringes and polyolefine (PO) infusion bags needs profound knowledge about the physicochemical stability in order to determine the beyond-use-date of the preparations. Therefore, the purpose of this study was to determine the physicochemical stability of carfilzomib solution marketed as Kyprolis® powder for solution for infusion. Reconstituted solutions and ready-to-administer preparations of Kyprolis® stored under refrigeration (2-8℃) or at room temperature (25℃) were analyzed at predetermined intervals over a maximum storage period of 28 days. Chemical stability of carfilzomib was planned to be determined with a stability-indicating reversed-phase high-performance liquid chromatography assay. Physicochemical stability was planned to be determined by visual inspection of clarity and color as well as pH measurement. The study results show that reconstituted carfilzomib containing parenteral solutions are stable in glass vials as well as diluted solutions in plastic syringes and PO infusion bags over a period of at least 28 days when stored light protected under refrigeration. When stored at room temperature, reconstituted and diluted carfilzomib solutions are physicochemically stable over 14 days and 10 days, respectively. The physicochemical stability of carfilzomib infusion solutions allows cost-saving pharmacy-based centralized preparation of ready-to-administer preparations.

Significant interaction between high-dose methotrexate and high-dose piperacillin-tazobactam causing reversible neurotoxicity and renal failure in an osteosarcoma patient

INTRODUCTION

Pharmacokinetic interaction of high-dose methotrexate (MTX) and other concomitantly administered renally secreted medicinal products may lead to insufficient methotrexate serum level decrease and significant MTX toxicity.

CASE REPORT

We report the case of an 18-year-old male patient treated with high-dose MTX for an osteosarcoma and with high-dose piperacillin-tazobactam at the same time. MTX serum levels were severely elevated 24 hours after the MTX infusion and did not decrease in accordance with the specific calcium folinate rescue protocol. The patient experienced renal failure accompanied by neurological symptoms, most consistent with MTX-related renal and CNS toxicity.Management and outcome: After discontinuation of piperacillin-tazobactam, intensified calcium folinate rescue therapy, and IV hydration, the MTX serum levels decreased appropriately, and toxicity symptoms resolved.

DISCUSSION

Severe MTX-related toxicity, caused by drug-drug interaction, suggests that the concomitant use of high-dose MTX and high-dose piperacillin-tazobactam should be avoided generally.

Physicochemical stability of human insulin 1 I.U./mL infusion solution in 50 mL polypropylene syringes

Objectives

The objective of this study was to investigate the physicochemical stability of human insulin 1 I.U./mL injection solutions (Insuman® Rapid) diluted with 0.9% NaCl solution in 50 mL disposable three-piece polypropylene syringes and stored refrigerated or at room temperature.

Methods

1 I.U./mL test solutions were prepared with Insuman® Rapid and 0.9% sodium chloride infusion solution in 50 mL Original-Perfusor® syringes and BD® Perfusion syringes. Test solutions were stored for 90 days at 2–8 °C/dark or 48 h at 20–25 °C/diffuse room light in order to determine chemical stability. Additional test solutions were stored 28 days at 2–8 °C/dark followed by 24 h at 20–25 °C/diffuse room light to measure pH and particle counts. Human insulin concentrations were analysed by reversed-phase high-performance liquid chromatography at predefined time points. Test solutions were regularly inspected; subvisible particles and pH values were measured.

Results

Insuman® Rapid 1 I.U./mL injection solutions, stored at 2–8 °C/dark for 90 days showed a decrease of insulin content over time, regardless of the syringe type used. When kept at 20–25 °C/diffuse room light for 48 h, a slight decrease of the HI concentration was observed in both syringe types. No evidence of colour change, relevant particle formation or major pH-change was observed throughout the observation period in any test solution.

Conclusions

Insuman® Rapid 1 I.U./mL injection solutions can be prepared by dilution with 0.9% NaCl infusion solution in disposable 50 mL three-piece polypropylene syringes as suitable primary containers. Physicochemical stability has been demonstrated for at least 21 days stored at 2–8 °C/dark followed by 48 h at 20–25 °C/diffuse room light.

Evaluation of a Process Monitoring Method for Compounding Parenteral Nutrition with the Baxter EM2400 in a Hospital Pharmacy Department

Background

A method for process monitoring of the Baxter ACD, Exactamix EM2400, by chemically analyzing the concentrations of the ingredients in parenteral nutrition test preparations was evaluated.

Methods

In the study, three different test preparations were developed consisting of four ingredients varying in volume and concentration, which simulated actual PN products. Each test preparation was produced in triplicate by a trained pharmacy technician using the Exactamix EM2400 from Baxter (Baxter International Inc.). The process was repeated on three consecutive days using the same conditions. The amount of each ingredient in the test preparation was measured in an external contract laboratory using European Pharmacopoeia methods. Based on USP monographies and the Guidelines on the Safe Use of Automated Compounding Devices for the Preparation of Parenteral Nutrition from the ASHP the device was tested to be accurate to deliver within 5 % of the amount programmed.

Results

The study showed that in most cases the ingredient delivery of the automated compounder deviated less than 3 % from the expected concentrations. For certain ingredients out of specification results were detected and analyzed. By resetting the flow factor, it was possible to optimize the performance of the ACD.

Conclusion

The study emphasizes the need for process monitoring of the Exactamix EM2400 during the initial installation and on a regular basis for each ingredient to ensure the accurate delivery of ingredients. Further methods need to be analyzed to determine the most feasible method to regularly conduct process monitoring tests on an ACD in a hospital pharmacy setting.

Implementation and microbiological stability of dose-banded ganciclovir infusion bags prepared in series by a robotic system

OBJECTIVES

The implementation of dose-banding (DB) in centralised, pharmacy-based cytotoxic drug preparation units allows the preparation of standardised doses in series. The aim of this study was to evaluate the feasibility of DB for the prescribing of ganciclovir (GV) infusion solutions and to investigate the microbiological stability of dose-banded, automatically prepared ready-to-administer GV infusion bags by media-fill simulation tests and sterility tests.

METHODS

The frequency of prescription of GV doses was retrospectively analysed before and after implementing the DB scheme. Four dose-ranges or 'bands' and the corresponding standard doses (250, 300, 350, 400 mg) were identified. The maximum variance was set at ±10% of the individually prescribed dose. The aseptic preparation of a series of GV infusion bags was simulated with double strength tryptic soy broth as growth medium and prefilled 0.9% NaCl polyolefin infusion bags as primary packaging materials. The simulation process was performed with the APOTECAchemo robot on five consecutive days. In total, 50 infusion bags were filled, incubated and stored for 12 weeks at room temperature. The media-filled bags were visually inspected for turbidity after 2, 4, 8, 10 and 12 weeks. Following incubation, growth promotion tests were performed. During the simulation tests, airborne contamination was monitored with settle plates and microbial surface contamination with contact plates. Pooled sterility tests were performed for a series of 10 standard GV infusion bags after a 12-week storage period under refrigeration (2 °C-8 °C).

RESULTS

After implementation of the DB scheme, about 60% of the prescribed GV doses were prepared as standard preparations by the robotic system. The number of different GV doses was reduced by 61.8% (76 vs 29). None of the 50 media-filled bags showed turbidity after a storage period of 12 weeks, indicating the absence of microorganisms. The environmental monitoring with settle/contact plates matched the recommended limits set for cleanroom Grade A zones, except in the loading area of the robot. Media fills used for the sterility tests remained clear during the incubation period, thereby revealing sterility. Positive growth promotion tests proved the process's reliability.

CONCLUSIONS

A DB scheme for prescribing and preparation of standard GV infusion bags was successfully implemented. Microbiological tests of aseptic preparation of infusion bags in series by the APOTECAchemo robot revealed an adequate level of sterility and a well-controlled aseptic procedure. The sterility was maintained over extended storage periods, thereby encouraging extended beyond-use dating.

Physico-chemical stability of eribulin mesylate containing concentrate and ready-to-administer solutions

OBJECTIVES

The aim of this study was to determine the stability of commercially available eribulin mesylate containing injection solution as well as diluted ready-to-administer solutions stored under refrigeration or at room temperature.

METHODS

Stability was studied by a novel developed stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay with ultraviolet detection (detection wavelength 200 nm). Triplicate test solutions of eribulin mesylate containing injection concentrate (0.5 mg/mL) and with 0.9% sodium chloride solution diluted ready-to-administer preparations (0.205 mg/mL eribulin mesylate in polypropylene (PP) syringes, 0.020 mg/mL eribulin mesylate in polypropylene/polyethylene (PE) bags) were stored protected from light either at room temperature (25) or under refrigeration (2-8). Samples were withdrawn on day 0 (initial), 1, 3, 5, 7, 14, 21 and 28 of storage and assayed. Physical stability was determined by measuring the pH value once a week and checking for visible precipitations or colour changes.

RESULTS

The stability tests revealed that concentrations of eribulin mesylate remained unchanged over a period of 28 days irrespective of concentration, container material or storage temperature. Neither colour changes nor visible particles have been observed. The pH value varied slightly over time but remained in the stability favourable range of 5-9.

CONCLUSION

Eribulin mesylate injection (0.5 mg/mL) is physico-chemically stable over a period of 28 days after first puncture of the vial. After dilution with 0.9% NaCl vehicle solution, ready-to-administer eribulin mesylate injection solutions (0.205 mg/mL in PP syringe) and infusion solutions (0.02 mg/mL in prefilled PP/PE bags) are physico-chemically stable for a period of at least four weeks either refrigerated or stored at room temperature. For microbiological reasons storage under refrigeration is recommended.

Physicochemical Stability of Reconstituted Decitabine (Dacogen®) Solutions and Ready-to-Administer Infusion Bags when Stored Refrigerated or Frozen

Background

Profound knowledge about the physicochemical stability is necessary in order to determine the “beyond-use-dates” of ready-to-administer preparations after reconstitution and dilution. This is especially true for unstable azanucleoside drugs like decitabine. The aim of this study was to determine the physicochemical stability of decitabine after reconstitution and dilution of Dacogen

Methods

To determine the stability of frozen Dacogen

To determine the stability of reconstituted Dacogen

Diluted Dacogen

Decitabine concentrations were determined at 0, 5, 8, 12, 24 and 48 hours after preparation. The pH-values were determined at 0, 8, 24 and 48 hours. Each sample was assayed by a validated stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay with photodiode array detection.

Results

When test solutions of reconstituted Dacogen

In reconstituted test solutions in glass vials and in diluted test solutions in infusion bags stored under refrigeration decitabine concentrations remained above 90 % of the initial concentration for 12 hours and 24 hours, respectively. Several peaks of degradation products were observed which explicitly increased over time.

In all test solutions the pH-values amounted to pH 7 and remained unchanged. No particulate matter and no colour changes were observed over the test period.

Conclusions

Reconstituted decitabine solution (Dacogen

Physicochemical Stability of Generic Thiotepa Concentrate and Ready-to-Administer Infusion Solutions for Conditioning Treatment

The objective of this study was to determine the physicochemical in-use stability of recently approved Thiotepa Riemser concentrate in the original vial and diluted ready-to-administer (RTA) infusion solutions in prefilled glucose 5% and 0.9% NaCl polyolefin bags. Thiotepa Riemser 10 mg/mL concentrates and infusion solutions (1 mg/mL, 2 mg/mL, 3 mg/mL) were prepared in triplicate and stored at 2-8 °C or 25 °C for 14 days. Thiotepa concentrations were determined using a stability-indicating RP-HPLC assay. In parallel, pH and osmolality were measured. Sub-visible particles were counted on day 0 and 14. Thiotepa Riemser concentrate was revealed to be stable for 14 days when stored at 2-8 °C, or for 24 h when stored at 25 °C. Thiotepa concentrations in infusion solutions stored at 2-8 °C remained above 95% of the initial concentrations for at least 14 days, regardless of the type of vehicle solution. When stored at 25 °C, thiotepa infusion solutions in glucose 5% proved to be physicochemically stable for 3 days (1 mg/mL), 5 days (2 mg/mL) or 7 days (3 mg/mL). Thiotepa infusion solutions in 0.9% NaCl remained physicochemically stable for 5 days (1 mg/mL) or 7 days (2 mg/mL, 3 mg/mL). At these points in time, the specification limit of ≤0.6% monochloro-adduct was fulfilled. In parallel, an elevation of the pH values was registered. Thiotepa concentrates and infusion solutions should be stored at 2-8 °C due to temperature-dependent physicochemical stability, and for microbiological reasons. Glucose 5% infusion solution is recommended as a diluent, and stability-improving nominal 2 mg/mL to 3 mg/mL thiotepa concentrations should be obtained.

A NOVEL MONOCLONAL ANTIBODY DEGRADES THE THYROTROPIN RECEPTOR AUTOANTIBODIES IN GRAVES' DISEASE

OBJECTIVE

Autoantibodies (Ab) against the thyrotropin receptor (TSH-R-Ab) are key mediators for the pathogenesis of Graves' disease (GD). TSH-R-Ab degradation was evaluated using several immunoassays within an exploratory, controlled trial in patients with GD receiving a monoclonal antibody (mAb) targeting the neonatal crystallizable fragment receptor (FcRn).

METHODS

Serial measurements of TSH-R-Ab serum levels were performed using three different binding and cell-based assays in GD patients either on medication or on placebo.

RESULTS

In contrast to placebo where no changes were observed, a 12-week mAb therapy led to an early and significant decrease (> 60%) of the serum TSH-R-Ab serum levels in patients with thyroidal and extra-thyroidal GD, as unanimously shown in all three assays. These marked changes were noted already at week seven post baseline (P<0.0001 for the binding immunoassay and for the luciferase (readout) bioassay. The three TSH-R-Ab binding and bioassays highly correlated in the samples of both study groups (binding immunoassay versus luciferase bioassay r = 0.91, P < 0.001, binding vs. cyclic adenosine monophosphate (cAMP) bioassay, r = 0.86, P < 0.001, luciferase versus cAMP bioassay, r = 0.71, P = 0.006). The serological results correlated with the course of the extra-thyroidal clinical parameters of GD, i.e. clinical activity score and proptosis.

CONCLUSIONS

Targeting the FcRn markedly reduces the disease-specific TSH-R-Ab in patients with GD. The novel and rapid TSH-R-Ab bioassay improves diagnosis and management of GD patients.

[Synthesis and H2-antagonistic action of N3, N5-substituted 1,2, 4-oxadiazole-3, 5-diamine. 26. H2-antihistaminics]

N5-(3-[3-(1-Piperidinylmethyl)phenoxy) phenoxy]propyl)-1,2, 4-oxadiazole-3, 5-diamines and N5(2-[(5-dimethylaminomethyl-2-furanyl) methylthio] ethyl)-1,2,4-oxadiazole-3,5-diamines with different N3-substituents were prepared and tested for their H2-antihistaminic activity on the isolated guinea-pig atrium. They were synthesized by nucleophilic substitution of the appropriate 5-trichloromethyloxadiazoles with the amines 3 and 11. Of the prepared substances 10a,c in particular showed high H2-antagonistic activity.

Physicochemical Stability of Mozobil® (Plerixafor) Solution for Injection in Glass Vials and Plastic Syringes over a Three-Month Storage Period

: The stability of ready-to-administer parenteral preparations is an important issue of drug safety. Profound knowledge about the physicochemical stability is necessary in order to determine the “beyond-use-dates” of solutions in injection vials after first opening and ready-to-administer preparations in syringes.

: The aim of this study was to determine the physicochemical stability of plerixafor solution marketed as Mozobil

: The stability of Mozobil

: No plerixafor degradation products were detected in the HPLC chromatograms over the period of 84 days, independent of the storage temperature. In vials and syringes plerixafor concentrations declined less than 5 % over the entire test period of 84 days. The pH values remained unchanged; the mean values varied between 6.79 and 6.60 for Mozobil

: Plerixafor injection solution (Mozobil

[Bevacizumab. Progress in cancer therapy by antiangiogenesis]

Bevacizumab represents the first humanized monoclonal antibody with antiangiogenic properties which has been introduced in clinical oncology. The VEGF antagonist is used for the treatment of advanced colorectal cancer based on significant survivial benefits. Besides hypertension, proteinuria, wound healing disorders, bleeding and thromboembolic events appear to be related to bevacizumab. Optimization of combination therapy, new potential indications as well as pharmacoeconomic considerations represent the topics of current discussion regarding the novel monoclonal antibody.

Long-term stability of ready-to-use epinephrine 0.02 mg/mL injection solution in 50 mL glass vials

Objectives

In adult intensive care patients, epinephrine is mostly administered by continuous injection with syringe pumps. The objective of this study was to investigate the physicochemical stability of pharmacy prepared ready-to-use epinephrine (E) 0.02 mg/mL injection solutions (total volume 50 mL) for assigning shelf-life.

Methods

E 0.02 mg/mL injection solution in 50 mL amber type l glass vials was produced batch-wise in the pharmacy department. Stability of the refrigerated (2–8 °C) product was investigated in real time over a period of 36 months by analyzing E concentrations, osmolality, pH, and sub-visible particles at predefined time-points. For E concentration measurements a stability-indicating, validated reversed-phase HPLC-PDA assay was used.

Results

The autoclaving process of E 0.02 mg/mL injection solution in 50 mL amber type I glass vials caused 5% loss of the active substance. The finished product remained stable over the study period of 36 months when stored refrigerated.

Conclusions

Batch-wise production of ready-to-use E injection solution 0.02 mg/mL in 50 mL amber glass vials was successfully implemented in our pharmacy department. According to the stability tests, a shelf-life of 36 months can be assigned to the finished product stored refrigerated. Studies concerning stability at room temperature would be useful.

Physicochemical compatibility of fluticasone-17- propionate nebulizer suspension with ipratropium and albuterol nebulizer solutions

The objective of this in-vitro study was to determine whether mixtures of three nebulizable drugs are physicochemically compatible. Drug combinations were prepared by mixing the content of one respule Flutide forte "ready to use" (fluticasone propionate) with 2 milliliter Atrovent LS (ipratropium bromide) and 0.5 milliliter Sultanol inhalation solution (albuterol sulfate). Test suspensions were stored at room temperature and exposed to normal laboratory light for 5 hours. Concentrations of fluticasone- 17-propionate, ipratropium bromide, and albuterol sulfate were determined by using stability-indicating high-performance liquid chromatography assays with ultraviolet detection. Physical compatibility was determined by measuring pH and osmolality. Main outcome measures were the drug concentrations of the active components of the mixtures. All drug concentrations retained nearly 100% of the initial drug concentrations after mixing and storage in glass containers at room temperature. Osmolality and pH of the mixtures exhibited no significant changes and no visible changes of the mixtures were detectable over the inspection period. Mixtures of fluticasone propionate, ipratropium bromide, and albuterol sulfate inhalation drug products were shown to be physicochemically compatible over a period of 5 hrs. In order to avoid contamination and microbiological instability, mixing should only take place immediately before administration. Further investigations are needed to determine whether or not drug delivery is affected by mixing the nebulizer suspensions and to ensure that simultaneous nebulization is recommendable.