Mitomycin C reused: an in vitro cost-effectiveness study

The Degradation of Mitomycin C Under Various Storage Methods

PURPOSE

To compare the effects of common pharmacy preparation and storage conditions on the stability of mitomycin C (MMC) in solution.

METHODS

We used C18 reversed-phase high-performance liquid chromatography to determine the stability of 0.4 mg/mL MMC solutions, and liquid chromatography-electrospray ionization-mass spectrometry to identify degradation products. Conditions compared were: compounding and storage by refrigeration (1 and 2 wk), freezing (23 d), shipment "on-ice" (1 mo frozen followed by 1-wk refrigeration), and immediately compounding dry powder (Mitosol; Mobius Therapeutics LLC). We tested 3 samples for each storage method when samples reached room temperature (time 0), and then 1, 4, and 24 hours later. We used MMC peak area as a percentage of total (MMC plus degradants) area detected with high-performance liquid chromatography as a measure of stability.

RESULTS

We assessed MMC stability for 5 preparation and storage methods at 4 timepoints (with n=3 per timepoint). At time 0, we found similar stabilities for MMC (F=0.72, P=0.599) between all 5 storage methods: 1-week refrigerated (97.9±0.2%), dry powder (97.5±0.3%), 2-week refrigerated (96.9±0.2%), 23-day frozen (96.7±3.1%), and shipment on-ice (96.0±1.2%). However, MMC demonstrated significant degradation over a 24-hour period with 2-week refrigeration (95.7±0.3%, β=-0.1%/h, P<0.001) and shipment on-ice (93.1±1.8%, β=-0.1%/h, P=0.013). We identified small amounts (<3.2%) of 2 degradants, cis-hydroxymitosene and trans-hydroxymitosene, across all samples.

CONCLUSIONS

The different preparation and storage methods of MMC showed similar stability when used immediately upon reaching room temperature. However, degradation of MMC occurred with further storage at room temperature. The clinical implication of small amounts of MMC degradants is unclear.

The health economics of bladder cancer: a comprehensive review of the published literature

The aim of this paper was to conduct a critical systematic review of the available literature on the clinical and economic burden of bladder cancer in developed countries, with a focus on the cost effectiveness of interventions aimed at reducing that burden.Forty-four economic studies were included in the review. Because of long- term survival and the need for lifelong routine monitoring and treatment, the cost per patient of bladder cancer from diagnosis to death is the highest of all cancers, ranging from 96000-187000 US dollars (2001 values) in the US. Overall, bladder cancer is the fifth most expensive cancer in terms of total medical care expenditures, accounting for almost 3.7 billion US dollars (2001 values) in direct costs in the US. Screening for bladder cancer in the general population is currently not recommended. The economic value of relatively new and less expensive urine assays and molecular urinary tumour markers has not been assessed. However, the literature suggests that screening patients suspected of having bladder cancer and using less invasive diagnostic procedures is cost effective. Very few cost-effectiveness studies have evaluated intravesical therapies such as bacillus Calmette-Guérin and mitomycin in the management of superficial disease and no robust recommendations can be drawn. Economic analyses suggest that non-surgical treatment strategies for the management of invasive disease aiming at bladder preservation may not be cost effective, because they have not consistently demonstrated survival benefits and do not eliminate the need for subsequent radical cystectomy. The literature suggests that the current conventional frequent follow-up and monitoring of patients can be cost effectively replaced by less frequent and less invasive monitoring, and should rely more heavily on intravesical chemotherapy to reduce the need for cystoscopies. Bladder cancer is a fairly common and costly malignancy. Nevertheless, the existing literature only contributes marginally to our knowledge concerning the burden of bladder cancer and the economic value of various interventions. The limited value of the literature in this area may be attributed to (i) being published as abstracts rather than full peer-reviewed evaluations; (ii) employing questionable methodologies; and (iii) being in many cases nearly obsolete, rendering them less relevant to, if not in conflict with, current clinical practice. Consequently, opportunities exist to conduct meaningful economic research in all areas of the management of bladder cancer, including screening, diagnosis, follow-up and treatment, especially with respect to new and innovative pharmaceutical and other technologies.

Activity of dissolved mitomycin C after different methods of long-term storage

PURPOSE

The cytostatic substance mitomycin C (MMC) is used in trabeculectomy to enhance the success rate in problematic cases and is usually dissolved immediately before application, but only approximately 1% of the substance is needed for treatment. The authors evaluated different methods of long-time storage of MMC for a period of 6 months.

METHODS

MMC in concentrations of 0.02, 0.05, 0.1, 0.2, and 0.4 mg/mL was prepared at the local pharmaceutical department and stored at +22 degrees C (room temperature), +4 degrees C (refrigerator), -20 degrees C (freezer compartment), and -196 degrees C (liquid N2). The activity of MMC was evaluated with a microagar diffusion method (bioassay) after 30 minutes, and 1, 3, 7, 14, 30, 90, and 180 days for the different concentrations and storage methods.

RESULTS

There was no difference in the long-term stability of the investigated MMC concentrations. Ninety percent of the initial activity was preserved after storage at +22 degrees C for 1 week, -20 degrees C for 1 month, or +4 degrees C for 3 months. At 6 months the activities were 16%, 48%, and 78% of the initial values, respectively. The activity of MMC stored at -196 degrees C is not reduced after storage for 6 months.

CONCLUSIONS

Dissolved MMC can be stored in the refrigerator for up to 3 months without significant loss of activity. Storage at room temperature is not recommended. Costs of trabeculectomy can be reduced by storage of reconstituted solutions rather than dissolving MMC before each glaucoma surgery.

A cost-minimization study of cancer patients requiring a narcotic infusion in hospital and at home

We conducted a retrospective, non-randomized, cost-minimization study, from the perspective of the Ministry of Health, to compare the cost of managing cancer patients who required narcotic infusions, in hospital and at home. Our medical costs averaged $369.72 per inpatient day and $150.24 per outpatient day (saving $219.48 per diem, 1988 Canadian dollars), while narcotic costs were the same for any given patient in both settings. Sensitivity analysis showed that no reasonable changes in the quantity and cost of services reduced our savings by more than 50%. During incremental analysis, savings increased as more outpatient days were managed by our centre, from $0.00 for 318 days, to more than $500,000 for over 2000 days per annum. As this program has been extremely cost effective and preferred by our patients, other hospitals and central funding agencies might consider establishing a regional outpatient narcotic infusion program to reduce their costs.

Mitomycin antitumour agents: A review of their physico-chemical and analytical properties and stability

The review enumerates the physico-chemical and analytical properties of mitomycin antitumour antibiotics, of which mitomycin C is the most important representative. After a short overview of the position of the compounds in oncology the following subjects will be discussed: structural features, prototropic properties, spectroscopy (UV-VIS, ORD, CD, IR, NMR, MS), chromatography and electrochemistry. The chemical stability and aspects of the mechanism of action of the compounds are also discussed. The last part of the review surveys the analysis of mitomycin C in biological fluids.