Solubilization and Stability of Mitomycin C Solutions Prepared for Intravesical Administration

Theoretical analysis, synthesis and biological activity against normal and cancer cells of a complex formed by a novel sugar cryptand and anticancer drug mitomycin C

This work presents the theoretical, spectroscopic, and biological characterization of cryptand 1,10-N,N'-bis-(β-d-ureidocellobiosyl)-4,7,13,16-tetraoxa-1,10-diazacyclooctadecane (TN) as a drug carrier for the anticancer agent mitomycin C. Spectroscopic analysis confirms the successful formation of a stable 1:1 complex in water, with the preferred configuration involving interactions between mitomycin C and all functional moieties of TN. These findings are further supported and elaborated upon through theoretical modeling. Using the density functional theory (DFT) method, the complexation energy was estimated at -25.8 kcal/mol (-107.95 kJ/mol). This value is compared with the literature data, accompanied by a detailed discussion. The biological assessment conducted for TN, mitomycin C, and their complex demonstrates that binding mitomycin C in a complex effectively reduces its cytotoxicity toward all analyzed cell lines.

Bladder-sparing Therapy for Bacillus Calmette-Guérin-unresponsive Non-muscle-invasive Bladder Cancer: International Bladder Cancer Group Recommendations for Optimal Sequencing and Patient Selection

BACKGROUND AND OBJECTIVE

There has been a recent surge in the development of agents for bacillus Calmette-Guérin-unresponsive (BCG-U) non-muscle-invasive bladder cancer (NMIBC). Critical assessment of these agents and practical recommendations for optimal selection of patients and therapies are urgently needed, especially in the absence of randomized trials on bladder-sparing treatment (BST) options.

METHODS

A global committee of bladder cancer experts was assembled to develop recommendations on BST for BCG-U NMIBC. Working groups reviewed the literature and developed draft recommendations, which were then voted on by International Bladder Cancer Group (IBCG) members using a modified Delphi process. During a live meeting in August 2023, voting results and supporting evidence were presented, and recommendations were refined on the basis of meeting discussions. Final recommendations achieved >75% agreement during the meeting, and some were further refined via web conferences and e-mail discussions.

KEY FINDINGS AND LIMITATIONS

There is currently no single optimal agent for patients with BCG-U disease who seek to avoid radical cystectomy (RC). BST selection should be personalized, taking into account individual patient characteristics and preferences, tumor attributes, and efficacy/toxicity data for the agents available. For patients with BCG-U carcinoma in situ (CIS), gemcitabine/docetaxel (GEM/DOCE), nadofaragene firadenovec (NFF), and nogapendekin alfa inbakicept-pmln (NAI) + BCG are recommended; because of its systemic toxicity, pembrolizumab should only be offered after other options are exhausted. For patients with BCG-U papillary-only tumors, GEM/DOCE, NFF, NAI + BCG, single-agent chemotherapy, hyperthermic mitomycin C, and pembrolizumab are recommended. Given the modest efficacy of available options, clinical trial participation is encouraged. For unapproved agents with reported data, IBCG recommendations await the final results of pivotal trials.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The IBCG consensus recommendations provide practical guidance on BST for BCG-U NMIBC.

Physicochemical stability of ready-to-administer mitomycin C solutions for intravesical instillation

OBJECTIVE

The aim of the study was to investigate the physicochemical stability of mitomycin-containing medicinal products for bladder instillation, formulated with urea as excipient (mito-medac®, Mitomycin medac). For comparison, the stability of reconstituted Urocin® and Mitem® bladder instillation was studied.

METHODS

Mitomycin-containing medicinal products were either reconstituted with the prepackaged 0.9% NaCl solution, nominal volume 20 mL (mito-medac®, Mitem®, Urocin®) or with 20 mL water for injection (Mitomycin medac, Mitem®, Urocin®) to a nominal concentration of 1 mg/mL and stored at room temperature (20-25°C). Samples were taken immediately after reconstitution and after 24 hours. Physicochemical stability was determined by reverse-phase high performance liquid chromatography with photodiode array detection, measurement of pH and osmolarity, and inspection for visible particles or colour changes.

RESULTS

The initial pH values of the test solutions reconstituted with prepackaged 0.9% NaCl (5.2-5.6) were significantly lower than those reconstituted with water for injection (6.6-7.4). Solutions reconstituted with 0.9% NaCl solutions rapidly degraded and concentrations fell below the 90% limit after 24 hours of storage. When reconstituted with water for injection, degradation was less rapid. Concentrations of Mitomycin medac and Urocin remained above the 90% limit after 24 hours.

CONCLUSIONS

The physicochemical stability of mitomycin 1 mg/mL bladder instillation prepared with prepackaged 0.9% NaCl in prefilled PVC bags is less than 24 hours at room temperature. Unfavourable pH values of the solvents cause rapid degradation of mitomycin. Mitomycin solutions reconstituted at the point of care should be administered immediately to avoid degradation and loss of efficacy. Urea added as excipient did not accelerate degradation.

Development and investigation of a novel device with gemcitabine for hyperthermic intravesical chemotherapy

PURPOSE

To evaluate the safety and efficacy of a novel hyperthermic intravesical chemotherapy (HIVEC) device in combination with gemcitabine.

MATERIALS AND METHODS

A pilot clinical trial was performed on patients with high-risk non-muscle invasive bladder cancer (NMIBC), who received HIVEC via the novel device (BR-PRG). Treatment regimen included eight weekly instillations of intravesical GEM (3 g in 150 mL normal saline [NS]) at a temperature of 45 °C for 60 min. Assessment of adverse events (AEs) was the primary objective of the trial. Disease recurrence and the thermal stability of GEM were also analyzed.

RESULTS

A total of 116 HIVEC treatments were delivered. Fifteen and eighteen patients were included in the effectiveness and safety analysis, respectively. Median follow-up was 12 months; five patients experienced a disease recurrence. One-year cumulative incidence of recurrence was 23.8% in EORTC intermediate risk group and 37.5% in high-risk group. Ten patients experienced at least one AE, with the most common being acute urinary tract infection, followed by urinary tract pain, and hematuria. Two patients experienced acute cystitis (grade 3 AE) and instillations were postponed until full recovery. Other AEs were minor, and no systemic toxicity was observed. The contents of GEM in solution of 0.9% NS or NS mixed with artificial urine were stable at 25 °C, 37 °C, 43 °C, 45 °C, 47 °C and 50 °C for 2 h.

CONCLUSION

GEM can be an ideal drug for use in HIVEC due to its good thermal stability. BR-PRG, combined with GEM was safe and effective in administering HIVEC.

Rational Mitomycin Nanocarriers Based on Hydrophobically Functionalized Polyelectrolytes and Poly(lactide-co-glycolide)

Encapsulation of hydrophilic and amphiphilic drugs in appropriate colloidal carrier systems for sustained release is an emerging problem. In general, hydrophobic bioactive substances tend to accumulate in water-immiscible polymeric domains, and the release process is controlled by their low aqueous solubility and limited diffusion from the nanocarrier matrix. Conversely, hydrophilic/amphiphilic drugs are typically water-soluble and insoluble in numerous polymers. Therefore, a core-shell approach─nanocarriers comprising an internal core and external shell microenvironments of different properties─can be exploited for hydrophilic/amphiphilic drugs. To produce colloidally stable poly(lactic-co-glycolic) (PLGA) nanoparticles for mitomycin C (MMC) delivery and controlled release, a unique class of amphiphilic polymers─hydrophobically functionalized polyelectrolytes─were utilized as shell-forming materials, comprising both stabilization via electrostatic repulsive forces and anchoring to the core via hydrophobic interactions. Undoubtedly, the use of these polymeric building blocks for the core-shell approach contributes to the enhancement of the payload chemical stability and sustained release profiles. The studied nanoparticles were prepared via nanoprecipitation of the PLGA polymer and were dissolved in acetone as a good solvent and in an aqueous solution containing hydrophobically functionalized poly(4-styrenesulfonic-co-maleic acid) and poly(acrylic acid) of differing hydrophilic-lipophilic balance values. The type of the hydrophobically functionalized polyelectrolyte (HF-PE) was crucial for the chemical stability of the payload─derivatives of poly(acrylic acid) were found to cause very rapid degradation (hydrolysis) of MMC, in contrast to poly(4-styrenesulfonic-co-maleic acid). The present contribution allowed us to gain crucial information about novel colloidal nanocarrier systems for MMC delivery, especially in the fields of optimal HF-PE concentrations, appropriate core and shell building materials, and the colloidal and chemical stability of the system.

Chemical Degradation of Intravenous Chemotherapy Agents and Opioids by a Novel Instrument

Purpose: To assess chemical degradation of various liquid chemotherapy and opioid drugs in the novel RxDestruct™ instrument. Methods: Intravenous (IV) drug solutions for chemotherapy and pain management were prepared using 0.9% normal saline in Excel^® bags to a final volume of 500 mL. We investigated duplicate IV solutions of methotrexate (0.1 mg/mL), etoposide (0.4 mg/mL), doxorubicin (0.25 mg/mL), cladribine (12.4 µg/mL), fentanyl (1.0 µg/mL), and hydromorphone (12.0 µg/mL) in this study. Solutions were poured into an automated instrument to undergo pulsatile chemical treatment (Fenton reactions) for 20 minutes, and then discharged from the instrument through a waste outlet. Extent of intact drug degradation was determined by measuring concentrations of drugs before entry into the instrument and after chemical treatment in the filtrate using high-performance liquid-chromatography with ultraviolet detection (HPLC-UV). Results: Following chemical reactions (Fenton processes) in the automated instrument, infusion solutions containing methotrexate, etoposide, doxorubicin, and cladribine had levels below the HPLC-UV limit of quantification (LOQ), indicating <50 ppb of each. This equated to >99.5%, 99.99%, 99.9%, and 99.8% intact drug loss, respectively. Likewise, processed samples of fentanyl and hydromorphone contained levels below the LOQ (78 and 98 ng/mL, respectively), indicating extensive degradation (>92.2% and 99.2% intact drug loss, respectively). Conclusion: The novel instrument was capable of degrading intact chemotherapy and opioid drugs prepared in infusion solutions to undetectable quantities by HPLC-UV. RxDestruct™ is a possible alternative for disposal of aqueous medication waste.

History, presence, and future of mitomycin C in glaucoma filtration surgery

PURPOSE OF REVIEW

Mitomycin C (MMC) is an alkylating agent with extraordinary ability to crosslink DNA, preventing DNA synthesis. By this virtue, MMC is an important antitumor drug. In addition, MMC has become the gold standard medication for glaucoma filtration surgery (GFS). This eye surgery creates a passage for drainage of aqueous humor (AqH) out of the eye into the sub-Tenon's space with the aim of lowering the intraocular pressure. A major cause of failure of this operation is fibrosis and scarring in the sub-Tenon's space, which will restrict AqH outflow. Intraoperative application of MMC during GFS has increased GFS success rate, presumably mainly by reducing fibrosis after GFS. However, still 10% of glaucoma surgeries fail within the first year.

RECENT FINDINGS

In this review, we evaluate risks and benefits of MMC as an adjuvant for GFS. In addition, we discuss possible improvements of its use by adjusting dose and method of administration.

SUMMARY

One way of improving GFS outcome is to prolong MMC delivery by using a drug delivery system.

Hyperthermia Improves Solubility of Intravesical Chemotherapeutic Agents

BACKGROUND: Nearly 70% of all new cases of bladder cancer are non-muscle invasive disease, the treatment for which includes transurethral resection followed by intravesical therapy. Unfortunately, recurrence rates approach 50% in part due to poor intravesical drug delivery. Hyperthermia is frequently used as an adjunct to intravesical chemotherapy to improve drug delivery and response to treatment. OBJECTIVE: To assess the solubility profile of intravesical chemotherapies under varying conditions of pH and temperature. METHODS: Using microplate laser nephelometry we measured the solubility of three intravesical chemotherapy agents (mitomycin C, gemcitabine, and cisplatin) at varying physical conditions. Drugs were assessed at room temperature (23°C), body temperature (37°C), and 43°C, the temperature used for hyperthermic intravesical treatments. To account for variations in urine pH, solubility was also investigated at pH 4.00, 6.00, and 8.00. RESULTS: Heat incrementally increased the solubility of all three drugs studied. Conversely, pH largely did not impact solubility aside for gemcitabine which showed slightly reduced solubility at pH 8.00 versus 6.00 or 4.00. Mitomycin C at the commonly used 2.0 mg/mL was insoluble at room temperature, but soluble at both 37 and 43°C. CONCLUSIONS: Hyperthermia as an adjunct to intravesical treatment would improve drug solubility, and likely drug delivery as some current regimens are insoluble without heat. Improvements in solubility also allow for testing of alternative administration regimens to improve drug delivery or tolerability. Further studies are needed to confirm that improvements in solubility result in increased drug delivery.

Targeted delivery of mitomycin C-loaded and LDL-conjugated mesoporous silica nanoparticles for inhibiting the proliferation of pterygium subconjunctival fibroblasts

Pterygium is a degenerative disease that characterized by excessive fibrovascular proliferation. To reduce the recurrence rate, surgery is the main strategy, in combination with adjacent procedures or adjunctive therapy. One of the most common adjunctive agents, mitomycin C (MMC), is known as an alkylating agent that inhibits fibroblast proliferation but is limitedly applied in pterygium due to various complications. A previous study demonstrated that activated pterygium subconjunctival fibroblasts overexpressed low-density lipoprotein (LDL) receptors. In this study, we designed and synthesized MMC-loaded mesoporous silica nanoparticles conjugated with LDL (MMC@MSNs-LDL) to deliver MMC into activated pterygium fibroblasts in a targeted manner. The MMC loading efficiency was approximately 6%. The cell viability test (CCK-8 assay) revealed no cytotoxicity for the empty carrier MSNs at a concentration of ≤1 mg/ml after administration for 48 h in subconjunctival fibroblasts. Primary pterygium and normal human subconjunctival fibroblasts with or without stimulation by vascular endothelial growth factor (VEGF) were treated as follows: 1) 10 μg/ml MMC@MSNs-LDL for 24 h (MMC concentration: 0.6 μg/ml); 2) 0.2 mg/ml MMC for 5 min then cultured for 24 h after MMC removal; and 3) normal culture without any drug treatment. At 24 h, the anti-proliferative effect of MMC@MSNs-LDL in activated pterygium fibroblasts was similar to that of MMC (cell viability: 46.2 ± 5.5% vs 40.5 ± 1.1%, respectively, P = 0.349). Furthermore, the cytotoxicity of MMC@MSNs-LDL to normal fibroblasts with or without VEGF stimulation was significantly lower than that of traditional MMC (cell viability: 75.6 ± 4.4% vs 36.0 ± 1.5%, respectively, P < 0.001; 84.7 ± 5.5% vs 35.7 ± 1.3%, P < 0.001). The binding of fluorescently labeled MMC@MSNs-LDL in fibroblasts was assessed using confocal fluorescence microscopy. The uptake of targeted nanoparticles in fibroblasts was time dependent and saturated at 6 h. VEGF-activated pterygium fibroblasts showed more uptake of MMC@MSNs-LDL than normal fibroblasts with or without VEGF activation (both P < 0.001). Our data strongly suggest that MMC@MSNs-LDL had an effective antiproliferative role in activated pterygium fibroblasts, with reduced toxicity to normal fibroblasts compared to traditional application of MMC. LDL-mediated drug delivery might have great potential in the management of pterygium recurrence.

Dextrose-Containing Carrier Solution for Hyperthermic Intraperitoneal Chemotherapy: Increased Intraoperative Hyperglycemia and Postoperative Complications

PURPOSE

Intraoperative hyperglycemia is associated with infectious complications in general surgery patients. This study aimed to determine if the use of lactated Ringer's (LR) carrier solution during hyperthermic intraperitoneal chemotherapy (HIPEC) would lower the incidence of intraoperative hyperglycemia and improve postoperative outcomes when compared with a standard 1.5% dextrose peritoneal dialysate carrier solution.

PATIENTS AND METHODS

This is a retrospective cohort study of 134 patients who underwent HIPEC at the University of Colorado. Perioperative glucose levels and outcomes were compared between patients who were perfused with 1.5% dextrose peritoneal dialysate carrier solution (n = 68) versus LR carrier solution (n = 66).

RESULTS

The study population consisted of patients undergoing HIPEC for appendiceal (50%), colorectal (34%), mesothelioma (8%), and ovarian cancer (5%). Intraoperative severe hyperglycemia (glucose ≥ 180 mg/dL) was significantly more common among patients perfused with a dextrose-containing carrier solution versus those perfused with LR (88% vs. 21%; p < 0.001). Patients in the dextrose cohort had significantly more severe complications (39% vs. 12%; p = 0.034), infectious complications (35% vs. 15%; p = 0.011), and organ space infections (18% vs. 5%: p = 0.026) than the LR cohort. On multivariable analysis, dextrose-containing carrier solution was significantly associated with an increased risk of postoperative infectious complications (HR 5.16; p = 0.006).

CONCLUSIONS

Intraoperative hyperglycemia is common when dextrose-containing carrier solution is used during HIPEC, and severe intraoperative hyperglycemia is strongly associated with an increased risk for infectious of complications following HIPEC. LR carrier solution should be routinely used to reduce intraoperative hyperglycemia and its associated risks.

Meta-analysis of efficacy and safety of continuous saline bladder irrigation compared with intravesical chemotherapy after transurethral resection of bladder tumors

PURPOSE

We performed a meta-analysis to confirm the efficacy and safety of continuous saline bladder irrigation compared with intravesical chemotherapy after transurethral resection for the treatment of non-muscle invasive bladder cancer.

METHODS

Randomized controlled trials of continuous saline bladder irrigation compared with intravesical chemotherapy were searched using MEDLINE, EMBASE, and the Cochrane Controlled Trials Register. The data were evaluated and statistically analyzed using RevMan version 5.3.0.

RESULTS

Four studies including 861 participants which compared continuous saline bladder irrigation with intravesical chemotherapy were considered. One-year recurrence-free survival [odds ratio (OR) = 0.76, 95% CI = 0.55-1.05, p = 0.09]; 2-year recurrence-free survival (OR = 0.94, 95% CI = 0.71-1.25, p = 0.68); the median period to first recurrence (OR = - 1.01, 95% CI = - 2.96 to 0.94, p = 0.31); the number of tumor progression (OR = 0.80, 95% CI = 0.54-1.17, p = 0.25); and the number of recurrence during follow-up (OR = 1.12, 95% CI = 0.84-1.50, p = 0.43) suggested that two methods of postoperative perfusion had no significant differences. In terms of safety, including macrohematuria, frequency of urination and bladder irritation symptoms, continuous saline bladder irrigation showed better tolerance than intravesical chemotherapy.

CONCLUSION

Continuous saline bladder irrigation seems to provide a better balance between prevention of recurrence and local toxicities than intravesical chemotherapy after transurethral resection of bladder tumors.

Chitosan/β-glycerophosphate in situ gelling mucoadhesive systems for intravesical delivery of mitomycin-C

The development of mucoadhesive in situ gelling formulations for intravesical application may improve the therapeutic outcomes of bladder cancer patients. In this work, chitosan/β-glycerophosphate (CHIGP) thermosensitive formulations have been prepared using three different chitosan grades (62, 124 and 370 kDa). Their ability to form in situ gelling systems triggered by changes in temperature upon administration to urinary bladder were evaluated using vial inversion and rheological methods. Texture analysis was used to study their mucoadhesive properties as well as syringeability through the urethral catheter. The retention of CHIGP formulations, with fluorescein sodium as the model drug, was studied on porcine urinary bladder mucosa ex vivo using the flow-through technique and fluorescent microscopy. CHIGP formulations containing mitomycin-C were prepared and drug release was studied using in vitro dialysis method. It was established that the molecular weight of chitosan influenced the thermogelling, mucoadhesive and drug release behaviour of the in situ gelling delivery systems. Formulations prepared from chitosan with greatest molecular weight (370 kDa) were found to be the most promising for intravesical application due to their superior gelling properties and in vitro retention in the bladder.