Compatibility of epirubicin-loaded DC bead™ with different non-ionic contrast media

Purpose

The aim of this study was to determine the compatibility of epirubicin-loaded DC bead™ with different non-ionic contrast media over a period of seven days when stored light protected under refrigerated conditions.

Methods

DC bead™ (2 ml) (Biocompatibles UK Ltd) of the bead size 70–150 µm ( = DC bead M1) or bead size 100–300 µm were loaded with 75 mg epirubicin powder formulation (Farmorubicin® dissolved in 3 ml water for injection to a concentration of 25 mg/ml) or 76 mg epirubicin injection solution (Epimedac® 2 mg/ml) within 2 h or 6 h, respectively. After removal of the excess solution, the epirubicin-loaded beads were mixed in polypropylene syringes with an equal volume (∼1.5 ml) of contrast media, i.e. Accupaque™ 300 (Nycomed Inc.), Imeron® 300 (Bracco S.p.A), Ultravist® 300 (Bayer Pharma AG), Visipaque™ 320 (GE Healthcare) and agitated in a controlled manner to get a homogenous suspension. Syringes with loaded beads in contrast media were stored protected from light under refrigeration (2–8℃). Compatibility was determined by measuring epirubicin concentrations in the suspensions in triplicate on day 0, 1, and 7. A reversed phase high-performance liquid chromatography assay with ultraviolet detection was utilized to analyze the concentration and purity of epirubicin.

Results

Mixing of epirubicin-loaded beads with different non-ionic contrast media released 0.1–0.5% of epirubicin over a period of 24 h, irrespectively, of the DC bead™ size or type of contrast media. No further elution or degradation was observed after seven days when the admixtures were stored protected from light under refrigeration.

Conclusion

Compatibility of epirubicin-loaded DC bead™ with an equal volume of different contrast media in polypropylene syringes is given over a period of seven days. Due to a maximum elution of 0.1–0.5% of epirubicin from loaded DC bead™, admixtures with contrast media can be prepared in advance in centralized cytotoxic preparation units. Microbiological aspects have to be considered when determining the expiration date of the product.

Stability of topotecan infusion solutions in polyvinylchloride bags and elastomeric portable infusion devices

Purpose. The purpose of this study was to determine the physicochemical stability of topotecan after reconstitution and after further dilution in two commonly used infusion fluids (0.9% sodium chloride, 5% dextrose) in both polyvinylchloride (PVC) bags and elastomeric portable infusion devices.

Methods. Each vial of topotecan (Hycamtin®) was reconstituted with sterile water for injection, yielding a nominal concentration of 1 mg/mL. Topotecan infusion solutions were aseptically prepared by further dilution of reconstituted topotecan solutions with either 0.9% sodium chloride or 5% dextrose in both PVC bags and portable elastomeric infusion devices, in amounts yielding topotecan concentrations of 10 µg/mL, 25 µg/mL, or 50 µg/mL. Test solutions were stored light-protected at room temperature (25°C) or under refrigeration (2-8°C) in parallel. One test solution of the nominal concentration of 10 µg/mL topotecan in a 0.9% sodium chloride PVC infusion bag was stored under ambient light conditions (mixed daylight and normal laboratory fluorescent light) at room temperature. Topotecan concentrations were obtained periodically throughout a 4-week storage period via a stability-indicating high performance liquid chromatography assay with ultra-violet detection. In addition, measurements of pH values were performed regularly, and test solutions were visually examined for colour change and precipitation.

Results. The stability tests revealed that the currently available topotecan formulation is stable (at a level of ≥90% topotecan) after reconstitution and dilution, independent of temperature (refrigerated, room temperature), the vehicle (0.9% sodium chlo-ride, 5% dextrose), the concentration (10 µg/mL, 25 µg/mL, or 50 µg/mL), or the container material (PVC bags, elastomeric portable infusion devices). The results were obtained over a test period of ≥4 weeks. Topotecan infusion solutions exposed to daylight were stable for only 17 days.

Conclusions. Reconstituted and diluted topotecan infusion solutions are shown to be physicochemically stable for 4 weeks. Light protection during administration is not necessary.

Viability of microorganisms in novel antineoplastic and antiviral drug solutions

Introduction. In determining the expiration-dates of ready-to-use antineoplastic and antiviral drug solu tions, microbiological aspects must be considered. This is especially true because many antineoplastic drugs introduced into the market are already known to lack antimicrobial activity. The purpose of this study is to evaluate the growth of four different microorganisms in ready-to-use solutions of 14 differ ent novel antineoplastic and antiviral drugs.

Methods. The lowest concentrations of 14 dif ferent antineoplastic and antiviral drugs prescribed in our hospital were prepared in polyvinyl chloride bags or a polyethylene container (paclitaxel) containing 0.9% sodium chloride or 5% dextrose solution. Inoc ulations were performed by adding 9 mL of a freshly prepared drug solution to a 1 mL suspension of bacteria or fungi (Staphylococcus aureus, Enterococ cus faecium, Pseudomonas aeruginosa, Candida albicans). Resulting concentrations were about 104 microorganisms per milliliter. Pure 0.9% sodium chlo ride and 5% dextrose solutions served as positive controls. Inoculated solutions were stored at elevated temperatures (22°C or 37°C). Samples of each test solution were withdrawn at 0, 15, 30, and 60 minutes and at 2, 3, 4, 24, 48, and 120 hours after inoculation, transferred to tryptic soy agar, and incubated at 37°C. After 24 hours, colony-forming units were counted.

Results. In the concentrations tested, no antimi crobial activity was registered with most of the drugs tested. There were only two cases of significant antibacterial activity, involving treosulfan and oxali platin against P. aeruginosa, respectively. Moderate antifungal activity was seen with foscarnet, ganciclo vir, pentostatin, and treosulfan.

Conclusions. The lack of antimicrobial proper ties should be considered when assigning extended expiration dates to ready-to-use antineoplastic and antiviral drug solutions. Solutions should be kept under refrigeration whenever possible to minimize the growth of any contaminating microorganism. With the exception of treosulfan, end-product steril ity testing may be performed without further dilution or inactivation.

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.

Prospective, systematically recorded mycophenolate safety data in Graves' orbitopathy

CONTEXT

The antiproliferative mechanism of mycophenolate acid (MPA) suggests a beneficial effect in patients with Graves' orbitopathy (GO).

OBJECTIVE

To systematically analyze for the first time adverse events (AEs) during MPA treatment in GO.

DESIGN

Prospective longitudinal study.

SETTING

Academic tertiary referral center with a joint thyroid-eye clinic.

PATIENTS

Fifty-three consecutive, unselected patients with clinically active and moderate-to-severe GO.

METHODS

MPA 0.720 g was given once daily for 24-weeks in GO patients. AEs were documented and coded according to the standardized medical dictionary for regulatory activities (MedDRA). AE were followed up and seriousness as defined by ICH-guideline E6 was documented. All AEs were analyzed regarding a possible underlying cause and if not, graded as side effect (SE).

RESULTS

Fifty GO patients (93 %) had Graves' disease, 37 (70 %) and 29 (54.7 %) were female and smoker, respectively. Thirty-six patients (68 %) reported at least one AE. A total of 88 AEs were documented, most frequent AEs were insomnia (N = 6), fatigue (N = 5) and optic neuropathy (N = 5), while other AEs occurred in up to three patients (5.6 %), only. In 12 (23 %) patients, at least one SE occurred. All 17 reported SE, i.e. mild infections and gastrointestinal intolerance were within the known safety profile of MPA. No patient dropped MPA medication because of drug-induced SE. Most AEs showed a recovered (76 %) or recovering (16 %) outcome. Seven (13 %) patients were hospitalized, five (62 %) due to optic neuropathy, none of these events was graded as SE.

CONCLUSIONS

MedDRA-coded data documented the good tolerance of a moderate MPA dose in GO patients.

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

Viability of Selected Microorganisms in Non-Cytotoxic Aseptic Preparations

: Numerous ready-to-use parenteral solutions are aseptically prepared in pharmacy-based aseptic preparation units. Microbiological stability of the preparations is influenced by the cleanroom environment, the complexity of the aseptic process, conditions during administration and the microbiological vulnerability of the products.

: The aim of the study was to evaluate the ability of four different pathogens related to hospital infections to grow in ready-to-use, non-cytotoxic parenteral products aseptically prepared in hospital pharmacies.

: In four consecutive series the antimicrobial activity of the following products was tested: caspofungin 35 mg or 70 mg in 250 mL 0.9 % NaCl solution (NS), micafungin 0.5 mg/mL in NS, vancomycin 5 mg/mL in G5/G10, heparin-sodium 1 IE/mL in NS, epinephrine 0.02 mg/mL in G5, norepinephrine 0.01 mg/mL in G5, phenylephrine 0.1 mg/mL, KCl solution 0.8 mmol/mL, trace elements 1:1 in G5/G10, midazolam 1 mg/mL injection solution, tranexamic acid 100 mg/mL injection solution, 50 % glucose solution, SMOFlipid 20 % lipid emulsion, 1 % propofol injection.

Nine milliliter aliquots of each test solution were inoculated with 1 mL suspension of selected strains, i. e.

: Most of the tested preparations induced no growth inhibition of the tested organisms. The selected strains lost viability in preparations containing vancomycin, phenylephrine or midazolam after a period of a few hours or days. Glucose 50 % w/v solution generated antimicrobial activity against

: The lack of antimicrobial properties of ready-to-use, non-cytotoxic solutions should be considered while determining the shelf-life of the products. Ready-to-use preparations should be kept refrigerated whenever possible to inhibit the multiplication of any contaminating organism.

Compatibility of irinotecan-loaded DC Bead with different volumes and types of non-ionic contrast media

Objectives

Irinotecan-loaded microspheres are used for simultaneous embolisation and chemotherapy of liver metastases of colorectal carcinoma. The aim of the study was to evaluate the compatibility of recently introduced DC BeadM1 (bead size 70-150 µm) loaded with irinotecan after admixture with different types and volumes of non-ionic contrast media over a maximum period of 24 h and storage at room temperature.

Methods

Test suspensions were prepared by loading 2 mL DC BeadM1 with 100 mg irinotecan within 2 h. The loading efficiency was determined by measuring the concentrations of irinotecan in the excess solutions via a reversed phase high pressure liquid chromatography (RP-HPLC) assay with ultraviolet detection. The compatibility of irinotecan-loaded DC BeadM1 with different types and volumes of contrast media was studied by mixing 2 mL loaded bead slurry each with up to four different volumes (5, 10, 20, 30 mL) of seven different contrast media. Samples were withdrawn after 30 min, 1, 2, 4, 8 and 24 h. Admixtures were stored light protected at room temperature over the observation period. The concentrations of eluted irinotecan were measured in triplicate samples using the RP-HPLC assay.

Results

Mixing of irinotecan loaded beads with non-ionic contrast media decreased the irinotecan loading efficiency between minimum 2.5% and maximum 17% over the observation period of 24 h. The rate and amount of irinotecan eluted from the beads varied relying on the type and volume of contrast medium admixed. However, no further elution or degradation was observed after the rapid release during the first 8 h.

Conclusions

Because of the rapid and extensive release of irinotecan, it is not recommendable to prepare admixtures of irinotecan-loaded DC BeadM1 with contrast media in centralised cytotoxic preparation units in advance. Admixture should be performed with the smallest possible amount by the radiologists immediately prior to the delivery procedure.

The influence of rituximab, high-dose therapy followed by autologous stem cell transplantation, and age in patients with primary CNS lymphoma

For patients with diffuse large B cell lymphoma without the involvement of the CNS, the addition of rituximab to standard chemotherapy has significantly improved survival. In this single-center, retrospective analysis, a total of 81 primary CNS lymphoma (PCNSL) patients treated in our institution between 2000 and 2011 were included. Beside first-line chemotherapy with or without rituximab, we evaluated the impact of age (≤/>60 years), autologous stem cell transplantation (ASCT +/-), and other factors upon overall survival (OS) and progression-free survival (PFS). In patients treated with rituximab (n = 27), 3-year OS was 77.8 % (95 % confidence interval (CI) 62-93 %). In contrast, in patients treated without rituximab (n = 52), 3-year OS was only 39.9 % (CI 27-53 %, Fig. 1). The difference in OS was significant in the univariate (p = 0.002) as well as in the multivariate analysis (p = 0.049, hazard ratio (HR) = 0.248). Patients ≤60 years of age (n = 28) had a 3-year OS of 78.2 % (CI 63-94 %); in patients >60 years (n = 51), 3-year OS was 38.7 % (CI 25-52 %). Patients who received high-dose therapy and ASCT had a 3-year OS of 85.2 % (CI 72-99 %), and 65.1 % were alive up to the time of analysis (range 9-131 months). Without ASCT, median OS was only 16 months (CI 11-21) and 3-year OS was 35.2 % (CI 22-48 %). Age and ASCT were significantly associated with better OS in univariate (p = 0.002 and p < 0.001) as well in multivariate analysis (p = 0.004, HR = 0.023 and p = 0.001, HR = 0.014). Rituximab treatment, ASCT, and age are independent prognostic factors for OS in the first-line treatment of PCNSL.

Loading, release and stability of epirubicin-loaded drug-eluting beads

Purpose

The aim of this study was to determine the loading efficiency, physico-chemical stability and release of epirubicin-loaded DC Bead™ (Biocompatibles UK Ltd, a BTG International group company) (bead size 70–150 µm (=DC Bead M1™) and 100–300 µm) after loading with epirubicin solution (2 mg/ml) or reconstituted powder formulation (25 mg/ml) and controlled storage.

Methods

DC Bead™ were loaded with 76 mg epirubicin solution (Epimedac™, Medac GmbH) or 75 mg epirubicin powder formulation (Farmorubicin™, Pharmacia Pfizer GmbH) per 2 ml of beads. Drug loading efficiency and stability were determined by measuring the epirubicin concentration in the excess solution after predetermined intervals (maximum 24 h) and different agitation conditions. Syringes with loaded beads were stored protected from light at room temperature. At predetermined intervals the beads were transferred into 200 ml phosphate buffered solution (pH 7.2) as elution medium and stirred automatically for 2 h not followed or followed by addition of 200 ml of 20% sodium chloride (=NaCl) solution and stirred for another 2 h to analyse the drug release and integrity of the epirubicin-loaded beads. Elution experiments were performed and samples taken periodically over a four-week period (day 0, 7, 14 and 28). A reversed-phase high-performance liquid chromatography assay with ultraviolet detection was utilized to analyse the concentration and purity of epirubicin.

Results

The loading procedure for DC Bead™ with epirubicin drug solutions resulted in a loading percentage of 95–99% within 6 h dependent on the bead size, epirubicin concentration in the loading solution and loading conditions. Loading levels remained stable and no epirubicin degradation products were observed over the period of 28 days, while the loaded beads were stored light protected at room temperature. Release of epirubicin into 200 ml phosphate buffered solution elution medium and additionally followed by release into the admixture with 200 ml 20% NaCl solution amounted to 5% and about 20% of the loaded epirubicin, respectively. Integrity of loaded epirubicin was proven over 28 days.

Conclusions

Epirubicin can be loaded into DC Bead™ of different sizes using the epirubicin powder formulation (25 mg/ml) or epirubicin injection concentrate (2 mg/ml). Physico-chemical stability is maintained over a period of at least 28 days when stored light protected at room temperature. Elution of epirubicin is dependent on the volume and cation exchange capacity of the elution medium.

Lesser-known or hidden reservoirs of infection and implications for adequate prevention strategies: Where to look and what to look for

In developing hygiene strategies, in recent years, the major focus has been on the hands as the key route of infection transmission. However, there is a multitude of lesser-known and underestimated reservoirs for microorganisms which are the triggering sources and vehicles for outbreaks or sporadic cases of infection. Among those are water reservoirs such as sink drains, fixtures, decorative water fountains and waste-water treatment plants, frequently touched textile surfaces such as private curtains in hospitals and laundry, but also transvaginal ultrasound probes, parenteral drug products, and disinfectant wipe dispensers. The review of outbreak reports also reveals Gram-negative and multiple-drug resistant microorganisms to have become an increasingly frequent and severe threat in medical settings. In some instances, the causative organisms are particularly difficult to identify because they are concealed in biofilms or in a state referred to as viable but nonculturable, which eludes conventional culture media-based detection methods. There is an enormous preventative potential in these insights, which has not been fully tapped. New and emerging pathogens, novel pathogen detection methods, and hidden reservoirs of infection should hence be given special consideration when designing the layout of buildings and medical devices, but also when defining the core competencies for medical staff, establishing programmes for patient empowerment and education of the general public, and when implementing protocols for the prevention and control of infections in medical, community and domestic settings.

Prospectively recorded and MedDRA-coded safety data of intravenous methylprednisolone therapy in Graves' orbitopathy

CONTEXT

Safety of intravenous (IV) steroid pulses in patients with Graves' orbitopathy (GO) is still controversial while steroid dose and treatment application have not been finalized. Frequency, severity and characterization of adverse events (AE) were prospectively analyzed.

SETTING

Academic referral orbital center with a joint thyroid-eye clinic.

PATIENTS

Eighty consecutive and unselected patients with active and severe GO.

METHODS

During an established treatment with IV methylprednisolone (cumulative dose 4.5 g) occurring AE were prospectively coded according to the standardized and recognized medical dictionary for regulatory activities (MedDRA). Outcome and severity of AE were documented. AEs judged as at least possibly related to drug treatment were graded as side effect (SE). AEs matching a seriousness criteria as defined by the ICH guideline E6 (good clinical practice) were graded as serious.

RESULTS

A total of 38.75% (31/80) of the treated GO patients reported at least one AE while 18 patients (22.5%) reported at least one SE. All SE were within the safety profile of IV methylprednisolone; 31/32 SE (96.87%) were mild-moderate and reversible and only 1/80 patient (1.25%) stopped steroid treatment due to exacerbation of her depression. Most AE were accessory symptoms of the underlying disease and a few only were directly related to IV steroids. Most AEs (90.6%) were graded as mild. Only six patients (7.5%) were hospitalized, three of them due to a dysthyroid optic neuropathy.

CONCLUSIONS

Prospective and standardized evaluation with MedDRA and the ICH guideline demonstrated the good pharmacological tolerance and low morbidity of this moderate steroid regimen.

Media-fill simulation tests in manual and robotic aseptic preparation of injection solutions in syringes

OBJECTIVE

The purpose of this study was to evaluate the contamination rate of media-fill products either prepared automated with a robotic system (APOTECAchemo™) or prepared manually at cytotoxic workbenches in the same cleanroom environment and by experienced operators. Media fills were completed by microbiological environmental control in the critical zones and used to validate the cleaning and disinfection procedures of the robotic system.

METHODS

The aseptic preparation of patient individual ready-to-use injection solutions was simulated by using double concentrated tryptic soy broth as growth medium, water for injection and plastic syringes as primary packaging materials. Media fills were either prepared automated (500 units) in the robot or manually (500 units) in cytotoxic workbenches in the same cleanroom over a period of 18 working days. The test solutions were incubated at room temperature (22℃) over 4 weeks. Products were visually inspected for turbidity after a 2-week and 4-week period. Following incubation, growth promotion tests were performed with Staphylococcus epidermidis. During the media-fill procedures, passive air monitoring was performed with settle plates and surface monitoring with contact plates on predefined locations as well as fingerprints. The plates got incubated for 5-7 days at room temperature, followed by 2-3 days at 30-35℃ and the colony forming units (cfu) counted after both periods. The robot was cleaned and disinfected according to the established standard operating procedure on two working days prior to the media-fill session, while on six other working days only six critical components were sanitized at the end of the media-fill sessions. Every day UV irradiation was operated for 4 h after finishing work.

RESULTS

None of the 1000 media-fill products prepared in the two different settings showed turbidity after the incubation period thereby indicating no contamination with microorganisms. All products remained uniform, clear, and light-amber solutions. In addition, the reliability of the nutrient medium and the process was demonstrated by positive growth promotion tests with S. epidermidis. During automated preparation the recommended limits < 1 cfu per settle/contact plate set for cleanroom Grade A zones were not succeeded in the carousel and working area, but in the loading area of the robot. During manual preparation, the number of cfus detected on settle/contact plates inside the workbenches lay far below the limits. The number of cfus detected on fingertips succeeded several times the limit during manual preparation but not during automated preparation. There was no difference in the microbial contamination rate depending on the extent of cleaning and disinfection of the robot.

CONCLUSION

Extensive media-fill tests simulating manual and automated preparation of ready-to-use cytotoxic injection solutions revealed the same level of sterility for both procedures. The results of supplemental environmental controls confirmed that the aseptic procedures are well controlled. As there was no difference in the microbial contamination rates of the media preparations depending on the extent of cleaning and disinfection of the robot, the results were used to adapt the respective standard operating procedures.

Physicochemical compatibility and stability of nebulizable drug admixtures containing Dornase alfa and tobramycin

The objective of this in-vitro study was to determine whether admixtures of the inhalation solutions Pulmozyme(®) (Dornase alfa) and either Bramitob(®) or Tobi(®) (both containing Tobramycin) are physicochemically compatible and to analyze the aerodynamic parameters of these admixtures. After mixing, test solutions were stored at room temperature and under ambient light conditions over a period of 24 h. Tobramycin concentrations were determined by using a fluorescence immunoassay. Stability of dornase alfa was determined by size-exclusion high performance liquid chromatography, ultraviolet spectroscopy, sodium dodecyl sulfate polyacrylamide gel electrophoresis and tentacle strong cation-exchange chromatography. In addition, pH values and osmolality of the admixtures were measured and test solutions were visually examined for any changes up to 24 h. Aerosols of Pulmozyme(®)/Bramitob(®) or Pulmozyme(®)/TOBI(®) admixtures were generated with the PARI eFlow(®) rapid and aerodynamic particle sizing was performed via cascade impaction with the Next Generation Pharmaceutical Impactor. The stability tests revealed that neither the stability of tobramycin nor the stability of dornase alfa was affected by mixing the inhalation products. Cascade impaction showed no relevant changes in particle size distribution, Mass Median Aerodynamic Diameter, Geometric Standard Deviation and Fine Particle Fraction in comparison to aerodynamic parameters of the unmixed solutions. Thus, admixtures of Pulmozyme(®) and either Bramitob(®) or TOBI(®) can be designated as compatible for a 24 h period and simultaneous inhalation is feasible.

Physicochemical compatibility of nebulizable drug admixtures containing colistimethate and tobramycin

Inhalation therapy with nebulizable antibiotic drugs is a mainstay in treating Pseudomonas aeruginosa infections in cystic fibrosis patients. The combination of tobramycin and colistin was found to be superior to monotherapy in killing P. aeruginosa in biofilms. The simultaneous inhalation of tobramycin and colistin might be an option to increase the compliance of patients. The objective of this in-vitro study was to determine whether admixtures of inhalation solutions containing colistin methanesulfonate (CMS) and tobramycin are physicochemically compatible. Physical compatibility was determined by measuring pH and osmolality. Chemical compatibility was determined by testing the antibiotic activity of the mixtures by the pharmacopoeial microbiological assay and comparing the results to those of standard solutions. Samples were analyzed immediately after mixing and after 24 h. Values of pH and osmolality remained unchanged and in physiologically acceptable ranges. Neither for colistin methanesulfonate (CMS) nor for tobramycin losses of antibiotic potency were registered at any time. Admixtures of nebulizer solutions containing CMS and tobramycin were shown to be physicochemically compatible. Further investigations are needed to determine whether drug delivery is affected by mixing the nebulizer solutions to ensure that simultaneous inhalation is recommendable.

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.

Increased medication compliance of liver transplant patients switched from a twice-daily to a once-daily tacrolimus-based immunosuppressive regimen

BACKGROUND

Compliance with immunosuppressive therapy plays a major role in the long-term success of liver transplantation. Thus, the development of strategies to promote compliance of liver transplant patients and its evaluation over time are of particular interest.

OBJECTIVE

The main objective of this study was to compare medication compliance rates among liver transplant patients over time after transplantation where switched from a twice- to once-daily tacrolimus-based regimen.

METHODS

Sixty-five liver transplant patients being administered tacrolimus-based therapy were classified into three subgroups with regard to time posttransplantation. Medication compliance with tacrolimus-based therapy was measured using an electronic medication event monitoring system over a 12-month period: for 6 months tacrolimus was administered twice-daily and for 6 months, once-daily. Dosing, taking, and timing compliance as well as drug holidays were compared intra-individually between twice- and once-daily intake and among the three subgroups. In addition, patient compliance and quality of life were evaluated using questionnaires.

RESULTS

A per protocol analysis of electronically obtained data showed 63 patients to be eligible. The resulting dosing, taking, and timing compliance rates of the patients were higher during the once-daily dosing period. No significant differences in compliance rates with tacrolimus therapy were observed among three subgroups independent of the dosing regimen. More patients failed the correct timing of the evening compared to the morning dose. Missing doses occurred particularly during weekends. Compliance variables measured by questionnaires (Morisky score, self-report, Medication Experience Scale for Immunosuppressants (MESI) score) and the Hospital Anxiety and Depression Scale score were similar in the two dosing periods. The short-form health survey (SF-36) score was higher with once-daily intake.

CONCLUSION

The high measured compliance rates did not vary significantly dependent upon the time after transplantation. Nevertheless, compliance rates were greater using once-daily tacrolimus dosing.