Freeze Drying of Polymer Nanoparticles and Liposomes Exploiting Different Saccharide-Based Approaches.

Biodegradable nanocarriers represent promising tools for controlled drug delivery. However, one major drawback related to their use is the long-term stability, which is largely influenced by the presence of water in the formulations, so to solve this problem, freeze-drying with cryoprotectants has been proposed. In the present study, the influence of the freeze-drying procedure on the storage stability of poly(lactide-co-glycolide) (PLGA) nanoparticles and liposomes was evaluated. In particular, conventional cryoprotectants were added to PLGA nanoparticle and liposome formulations in various conditions. Additionally, hyaluronic acid (HA), known for its ability to target the CD44 receptor, was assessed as a cryoprotective excipient: it was added to the nanocarriers as either a free molecule or conjugated to a phospholipid to increase the interaction with the polymer or lipid matrix while exposing HA on the nanocarrier surface. The formulations were resuspended and characterized for size, polydispersity index, zeta potential and morphology. It was demonstrated that only the highest percentages of cryoprotectants allowed the resuspension of stable nanocarriers. Moreover, unlike free HA, HA-phospholipid conjugates were able to maintain the particle mean size after the reconstitution of lyophilized nanoparticles and liposomes. This study paves the way for the use of HA-phospholipids to achieve, at the same time, nanocarrier cryoprotection and active targeting.

Clinical Assessment of Continuous Hemodialysis with the Medium Cutoff EMiC®2 Membrane in Patients with Septic Shock.

INTRODUCTION: At the time of renal replacement therapy, approximately 20% of critically ill patients have septic shock. In this study, medium cutoff (MCO) continuous venovenous hemodialysis (CVVHD) was compared to high-flux membrane continuous venovenous hemodiafiltration (CVVHDF) in terms of hemodynamic improvement, efficiency, middle molecule removal, and inflammatory system activation. METHODS: This is a monocenter crossover randomized study. Between December 31, 2017, and December 31, 2019, 20 patients with septic shock and stage 3 acute kidney injury (AKI) admitted to 2 Italian ICUs were enrolled. All patients underwent CVVHD with Ultraflux® EMiC®2 and CVVHDF with AV1000S® without washout. Each treatment lasted 24 h. RESULTS: Compared to AV1000S®-CVVHDF, EMIC®2-CVVHD normalized cardiac index (ß = -0.64; p = 0.02) and heart rate (ß = 5.72; p = 0.01). Interleukin-8 and myeloperoxidase removal were greater with AV1000S®-CVVHDF than with EMiC®2-CVVHD (ß = 0.35; p < 0.001; ß = 0.43; p = 0.03, respectively). Leukocytosis improved over 24 h in EMiC®2-CVVHD-treated patients (ß = 4.13; p = 0.03), whereas procalcitonin levels decreased regardless of the modality (ß = 0.89; p = 0.01) over a 48-h treatment period. Reduction rates, instantaneous plasmatic clearance of urea, creatinine, and ß2-microglobulin were similar across modalities. ß2-Microglobulin removal efficacy was greater in the EMiC®2 group (ß = 0-2.88; p = 0.002), while albumin levels did not differ. Albumin was undetectable in the effluent in both treatments. DISCUSSION: In patients with septic shock and severe AKI, the efficacy of uremic toxin removal was comparable between MCO-CVVHD and CVVHDF. Further, MCO-CVVHD was associated with improved hemodynamics. Fraction of filtration and transmembrane pressure reduction and the maintenance of equal efficacy might be the key features of CVVHD with MCO membranes in critically ill patients.

Nanotechnological approaches for pentamidine delivery.

Pentamidine (PTM), which is a diamine that is widely known for its antimicrobial activity, is a very interesting drug whose mechanism of action is not fully understood. In recent years, PTM has been proposed as a novel potential drug candidate for the treatment of mental illnesses, myotonic dystrophy, diabetes, and tumors. Nevertheless, the systemic administration of PTM causes severe side effects, especially nephrotoxicity. In order to efficiently deliver PTM and reduce its side effects, several nanosystems that take advantage of the chemical characteristics of PTM, such as the presence of two positively charged amidine groups at physiological pH, have been proposed as useful delivery tools. Polymeric, lipidic, inorganic, and other types of nanocarriers have been reported in the literature for PTM delivery, and they are all in different development phases. The available approaches for the design of PTM nanoparticulate delivery systems are reported in this review, with a particular emphasis on formulation strategies and in vitro/in vivo applications. Furthermore, a critical view of the future developments of nanomedicine for PTM applications, based on recent repurposing studies, is provided. Created with BioRender.com.

L-Carnitine Functionalization to Increase Skeletal Muscle Tropism of PLGA Nanoparticles.

Muscular dystrophies are a group of rare genetic pathologies, encompassing a variety of clinical phenotypes and mechanisms of disease. Several compounds have been proposed to treat compromised muscles, but it is known that pharmacokinetics and pharmacodynamics problems could occur. To solve these issues, it has been suggested that nanocarriers could be used to allow controlled and targeted drug release. Therefore, the aim of this study was to prepare actively targeted poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) for the treatment of muscular pathologies. By taking advantage of the high affinity for carnitine of skeletal muscle cells due to the expression of Na+-coupled carnitine transporter (OCTN), NPs have been actively targeted via association to an amphiphilic derivative of L-carnitine. Furthermore, pentamidine, an old drug repurposed for its positive effects on myotonic dystrophy type I, was incorporated into NPs. We obtained monodispersed targeted NPs, with a mean diameter of about 100 nm and a negative zeta potential. To assess the targeting ability of the NPs, cell uptake studies were performed on C2C12 myoblasts and myotubes using confocal and transmission electron microscopy. The results showed an increased uptake of carnitine-functionalized NPs compared to nontargeted carriers in myotubes, which was probably due to the interaction with OCTN receptors occurring in large amounts in these differentiated muscle cells.

Vancomycin concentrations during cardiopulmonary bypass in pediatric cardiac surgery: a prospective study.

INTRODUCTION: Few data are available regarding intraoperative plasma concentrations of vancomycin administered as prophylaxis in pediatric cardiac surgery. The aims of this study were to investigate during pediatric cardiac surgery with cardiopulmonary bypass(CPB) the attainment of the area-under-the-curve of the vancomycin serum concentrations versus time over surgery to minimum inhibitory concentration ratio(AUCintra/MIC) of 400 (mg × h)/l and/or a target concentration of 15-20 mg/l. METHODS: In a prospective study, 40 patients divided into four subgroups (neonates, infants, children <10 years-old, ⩾10 years-old) undergoing cardiac surgery with cardiopulmonary bypass (CPB) were enrolled. A slow vancomycin bolus of 20 mg/kg, up to a maximum dose of 1000 mg was administered before skin incision and a further dose of 10 mg/kg (up to 500 mg) at CPB start. Vancomycin samples were collected intraoperatively at four time points. RESULTS: The median (interquartile range) age was 241.5 days (47-3898) and the median weight was 7.1 kg (3.1-37). The median AUCintra/MIC was 254.73 (165.89-508.06). In 11 patients the AUCintra/MIC target was not reached. Neonates displayed the lowest AUCintra/MIC values, and these were significantly lower than those of children ⩾10 years old (p = 0.02). Vancomycin concentrations were above the maximal target of 20 mg/l in 82.5% and 80% of patients at surgery and CPB start, respectively. At CPB and surgery end, 42.5% of patients showed vancomycin concentrations above 20 mg/l and 42.5% below 15 mg/l. Patients⩾10 years old showed the highest peak values whereas neonates were those with the lowest troughs. AUCintra/MIC correlated with age(r:0.36, p = 0.02), weight(r:0.35, p = 0.03), intraoperative protein value(r:0.40, p = 0.01), CPB priming volume/kg(r:-0.33, p = 0.04), CPB duration(r:0.36, p = 0.02) and vancomycin troughs(r:0.35, p = 0.04). CONCLUSIONS: An AUCintra/MIC ⩾400 target was not reached in one-quarter of children undergoing heart surgery. Vancomycin peaked before the start of surgery and neonates were those with the lowest troughs. Vancomycin concentrations are affected by CPB hemodilution and by patients' age and weight.

Nanotechnology Addressing Cutaneous Melanoma: The Italian Landscape.

Cutaneous melanoma is one of the most aggressive solid tumors, with a low survival for the metastatic stage. Currently, clinical melanoma treatments include surgery, chemotherapy, targeted therapy, immunotherapy and radiotherapy. Of note, innovative therapeutic regimens concern the administration of multitarget drugs in tandem, in order to improve therapeutic efficacy. However, also, if this drug combination is clinically relevant, the patient's response is not yet optimal. In this scenario, nanotechnology-based delivery systems can play a crucial role in the clinical treatment of advanced melanoma. In fact, their nano-features enable targeted drug delivery at a cellular level by overcoming biological barriers. Various nanomedicines have been proposed for the treatment of cutaneous melanoma, and a relevant number of them are undergoing clinical trials. In Italy, researchers are focusing on the pharmaceutical development of nanoformulations for malignant melanoma therapy. The present review reports an overview of the main melanoma-addressed nanomedicines currently under study in Italy, alongside the state of the art of melanoma therapy. Moreover, the latest Italian advances concerning the pre-clinical evaluation of nanomedicines for melanoma are described.

Adherence to oral chemotherapy: Evidence from a randomised clinical trial.

OBJECTIVE: To evaluate the efficacy of a reinforcement message (RM) administered by a hospital pharmacist on adherence, through a randomised study involving patients undergoing oral chemotherapy from which an objective outcome measure and patients' subjective opinions were collected. A secondary aim was to detect which psychological or clinical factors influence adherence. METHODS: Forty patients were enrolled and randomised to an experimental group (EG) or a control group (CG). The EG received a 10-minute RM provided by a hospital pharmacist with a doctor and a nurse. The CG received the standard of care. To measure adherence, plasma drug concentration and subjective evaluation were taken during the visits, in addition to a psychological assessment (coping strategies, psychological distress and personality traits). RESULTS: The EG reported higher drug levels and a statistically significant higher mean score on the subjective evaluation. A linear regression model highlighted statistically significant differences in the plasma drug concentration, after considering toxicity and dose reduction and controlling for the Reward Dependence Scale of the Temperament and Character Inventory between the EG and the CG. CONCLUSION: Adequate information and education on the therapy, using an RM strategy provided by a hospital pharmacist, seems to positively influence adherence to the treatment.

Glargine insulin loaded lipid nanoparticles: Oral delivery of liquid and solid oral dosage forms.

BACKGROUND AND AIMS: The oral administration of insulin has so far been precluded by gastro-intestinal enzyme degradation and poor intestinal absorption. Preliminary evidence for peptide uptake by the gut has recently been obtained, by our research group, following the administration of nanostructured lipid-carrier suspensions loaded with glargine insulin in healthy animal models. METHODS AND RESULTS: In this experimental study, glargine insulin-loaded nanostructured lipid carriers have been converted into solid oral dosage forms (tablets, capsules), that are more suitable for administration in humans and have prolonged shelf-life. The liquid and solid oral dosage forms were tested for glargine insulin uptake and glucose responsivity in healthy and streptozotocin-induced diabetic rats (6 animals in each group). A suitable composition gave redispersible solid oral dosage forms from glargine insulin-loaded carriers, using both spray-drying and freeze-drying. It was observed that the liquid and solid formulations had relevant hypoglycaemic effects in healthy rats, while only capsules were efficacious in diabetic rats; probably because of gut alterations in these animal models. Detected glargine insulinaemia was consistent with a glycaemic profile. CONCLUSION: The formulations under study showed their potential as oral glucose-lowering agents, particularly when used as capsules. However, further study is needed to produce a useful orally-active insulin preparation.

Effects of the Molecular Weight of Hyaluronic Acid in a Carbon Nanotube Drug Delivery Conjugate.

Hyaluronic acid (HA) is a ubiquitous biopolymer involved in many pathophysiological roles. One HA receptor, the cluster of differentiation CD44 protein, is often overexpressed in tumor cells. As such, HA has attracted considerable interest in the development of drug delivery formulations, given its intrinsic targetability toward CD44 overexpressing cells. The present study is focused on examining the correlation of HA molecular weight with its targetability properties. A library of conjugates obtained by linking the amino group of the phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) to the carboxylic residues of HA of different molecular weight (6.4, 17, 51, 200, and 1,500 kDa) were synthesized and fully characterized. The HA-DMPE conjugates were then used to non-covalently functionalize the highly hydrophobic single-walled carbon nanotubes (CNT), and further encapsulate the anticancer drug doxorubicin (DOX). Our results show that the complexes DOX/CNT/HA-DMPE maintain very good and stable dispersibility. Drug release studies indicated a pH-responsive release of the drug from the nanocarrier. Cell viability tests demonstrated that all HA modified CNTs have good biocompatibility, and specific targeting toward cells overexpressing the CD44 receptor. Among all the molecular weights tested, the 200 kDa HA showed the highest increase in cellular uptake and cytotoxic activity. All these promising attributes make CNT/HA200-DMPE a "smart" platform for tumor-targeted delivery of anticancer agents.

Validation of a simple and economic HPLC-UV method for the simultaneous determination of vancomycin, meropenem, piperacillin and tazobactam in plasma samples.

Critically ill patients are often affected by several pathophysiological conditions requiring antibiotic administration and, frequently, extracorporeal therapy that significantly alter the normal pharmacokinetics of drugs. Therapeutic drug monitoring (TDM) may assist to establish the correct antibiotic dosage, but a TDM service is usually available only for some aminoglycosides and glycopeptides. The aim of this study is the validation of an HPLC-UV method for the simultaneous quantification of meropenem, vancomycin, piperacillin and tazobactam in human plasma samples. The analytes were extracted from 250 µL of human plasma by the addition of acetonitrile for protein precipitation. After evaporation to dryness of the solvent, samples were reconstituted with 250 µL of mobile phase, and 100 µL were injected in HPLC. Chromatographic analysis was performed using a Kinetex C18 column and an UV/Vis detector set at 220 and 298 nm. The mobile phase was a mixture of phosphate buffer 0.1 M pH 3.15 and methanol in gradient, delivered at 1 mL/min. The method was validated over clinical concentration ranges. For all the analytes, the lower limit of quantification was 1 µg/mL, and the calibration curves were linear between 1 and 100 µg/mL, with coefficients of determination ≥ 0.999. Intra-day precision was < 4%, while inter-day precision was < 7% for each analyte. The applicability of the method has been evaluated by analysing plasma samples collected from 4 critically ill patients undergoing continuous renal replacement therapy. Moreover, the analysis of vancomycin with VANC Flex® confirmed a good correlation between the results of HPLC-UV and commercially available kits usually used by TDM service. The method we developed only requires a small volume of plasma and uses the same sample preparation protocol, stationary phase and elution conditions for all analytes. This method offers the additional advantages of simple and rather inexpensive sample preparation and instrumentation, features that make this method an easy implementation for a general TDM laboratory.

Population Pharmacokinetics of Cefoxitin Administered for Pediatric Cardiac Surgery Prophylaxis.

BACKGROUND: Available data about pharmacokinetics (PK) of antimicrobials administered as surgical prophylaxis to children undergoing cardiac surgery with cardiopulmonary bypass (CPB) showed that drug concentrations during CPB may be supra or subtherapeutic. The aim of this study was to determine the population PK and pharmacodynamic target attainment (PTA) of cefoxitin during pediatric CPB surgery. METHODS: A prospective interventional study was conducted. Cefoxitin (40 mg/kg, up to max 1000 mg) was administered before skin incision. Blood samples were obtained in the operatory room throughout surgery. Population PK, PTA, and safety of cefoxitin were evaluated in neonates, infants, children <10 and >10 years old. RESULTS: Forty patients were enrolled. Cefoxitin levels correlated with time from bolus administration (r = -0.6, P = 0.0001) and, after 240 minutes from bolus, drug values below the target (8 mg/L) were shown. Cefoxitin concentrations were best described by a one-compartment model with first order elimination. A significant relationship was identified between body weight, age, body mass index, and serum creatinine on drug clearance and age, body weight, and body mass index on cefoxitin volume of distribution. The PTA for free drug concentration being above the minimum inhibitory concentration of 8 mg/L for at least 240 minutes was >90% in all age groups except in patients >10 years of age (PTA = 62%). CONCLUSIONS: Cefoxitin PK appears to be significantly influenced by CPB with generally reduced drug clearance. The PTA was adequately achieved in the majority of patients except in patients >10 years old or longer surgeries.

Lipid nanoparticles as vehicles for oral delivery of insulin and insulin analogs: preliminary ex vivo and in vivo studies.

AIMS: Subcutaneous administration of insulin in patients suffering from diabetes is associated with the distress of daily injections. Among alternative administration routes, the oral route seems to be the most advantageous for long-term administration, also because the peptide undergoes a hepatic first-pass effect, contributing to the inhibition of the hepatic glucose output. Unfortunately, insulin oral administration has so far been hampered by degradation by gastrointestinal enzymes and poor intestinal absorption. Loading in lipid nanoparticles should allow to overcome these limitations. METHODS: Entrapment of peptides into such nanoparticles is not easy, because of their high molecular weight, hydrophilicity and thermo-sensitivity. In this study, this objective was achieved by employing fatty acid coacervation method: solid lipid nanoparticles and newly engineered nanostructured lipid carriers were formulated. Insulin and insulin analog-glargine insulin-were entrapped in the lipid matrix through hydrophobic ion pairing. RESULTS: Bioactivity of lipid entrapped peptides was demonstrated through a suitable in vivo experiment. Ex vivo and in vivo studies were carried out by employing fluorescently labelled peptides. Gut tied up experiments showed the superiority of glargine insulin-loaded nanostructured lipid carriers, which demonstrated significantly higher permeation (till 30% dose/mL) compared to free peptide. Approximately 6% absolute bioavailability in the bloodstream was estimated for the same formulation through in vivo pharmacokinetic studies in rats. Consequently, a discrete blood glucose responsivity was noted in healthy animals. CONCLUSIONS: Given the optimized ex vivo and in vivo intestinal uptake of glargine insulin from nanostructured lipid carriers, further studies will be carried out on healthy and diabetic rat models in order to establish a glargine insulin dose-glucose response relation.

Chemical and microbiological stability, anticoagulant efficacy and toxicity of 35 and 90†mM trisodium citrate solutions stored in plastic syringes.

BACKGROUND: Trisodium citrate is an interesting alternative to heparin for the prevention of circuit clotting during extracorporeal procedures, but some protocols require non-commercially available citrate concentrations. Little published information is available about the stability of diluted citrate solutions. OBJECTIVES: To evaluate the long-term stability, efficacy and toxicity of 35 mM and 90 mM trisodium citrate solutions prepared by diluting a commercially available sterile solution, stored in plastic syringes and used as an anticoagulant during citrate bag changes in the coupled plasma filtration adsorption (CPFA) technique in the COMPACT-2 clinical trial. METHODS: The chemical stability of trisodium citrate solutions was evaluated by high-performance liquid chromatography after 7, 14, 21 and 28 days of storage. Sterility tests were performed both immediately after preparation and after 28 days of storage. RESULTS: After 28 days of storage, the concentration of trisodium citrate had not changed in comparison with day 1, and both solutions passed the sterility test. A preliminary test indicated that a 35 mM solution is insufficient to ensure an effective anticoagulant action on an extracorporeal circuit, but the 90 mM solution was successfully used for 7 CPFA treatments in 2 patients, without clinical signs of toxicity. CONCLUSIONS: Both the 35 mM and 90 mM solutions are chemically and microbiologically stable for 28 days when stored at room temperature in 50 mL syringes protected by light. The 90 mM solution is an effective and safe regional anticoagulant in the CPFA protocol. TRIAL REGISTRATION NUMBER: NCT01639664.

Valproic Acid, a Histone Deacetylase Inhibitor, in Combination with Paclitaxel for Anaplastic Thyroid Cancer: Results of a Multicenter Randomized Controlled Phase II/III Trial.

Anaplastic thyroid cancer (ATC) has a median survival less than 5 months and, to date, no effective therapy exists. Taxanes have recently been stated as the main drug treatment for ATC, and the histone deacetylase inhibitor valproic acid efficiently potentiates the effects of paclitaxel in vitro. Based on these data, this trial assessed the efficacy and safety of the combination of paclitaxel and valproic acid for the treatment of ATC. This was a randomized, controlled phase II/III trial, performed on 25 ATC patients across 5 centers in northwest Italy. The experimental arm received the combination of paclitaxel (80 mg/m2/weekly) and valproic acid (1,000 mg/day); the control arm received paclitaxel alone. Overall survival and disease progression, evaluated in terms of progression-free survival, were the primary outcomes. The secondary outcome was the pharmacokinetics of paclitaxel. The coadministration of valproic acid did not influence the pharmacokinetics of paclitaxel. Neither median survival nor median time to progression was statistically different in the two arms. Median survival of operated-on patients was significantly better than that of patients who were not operated on. The present trial demonstrates that the addition of valproic acid to paclitaxel has no effect on overall survival and disease progression of ATC patients. This trial is registered with EudraCT 2008-005221-11.

Dual Constant Domain-Fab: A novel strategy to improve half-life and potency of a Met therapeutic antibody.

The kinase receptor encoded by the Met oncogene is a sensible target for cancer therapy. The chimeric monovalent Fab fragment of the DN30 monoclonal antibody (MvDN30) has an odd mechanism of action, based on cell surface removal of Met via activation of specific plasma membrane proteases. However, the short half-life of the Fab, due to its low molecular weight, is a severe limitation for the deployment in therapy. This issue was addressed by increasing the Fab molecular weight above the glomerular filtration threshold through the duplication of the constant domains, in tandem (DCD-1) or reciprocally swapped (DCD-2). The two newly engineered molecules showed biochemical properties comparable to the original MvDN30 in vitro, acting as full Met antagonists, impairing Met phosphorylation and activation of downstream signaling pathways. As a consequence, Met-mediated biological responses were inhibited, including anchorage-dependent and -independent cell growth. In vivo DCD-1 and DCD-2 showed a pharmacokinetic profile significantly improved over the original MvDN30, doubling the circulating half-life and reducing the clearance. In pre-clinical models of cancer, generated by injection of tumor cells or implant of patient-derived samples, systemic administration of the engineered molecules inhibited the growth of Met-addicted tumors.

Efficacy and safety of a new device for intravesical thermochemotherapy in non-grade 3 BCG recurrent NMIBC: a phase I-II study.

PURPOSE: We report for the first time the activity and safety of Unithermia(®) (Elmedical Ltd, Hod-Hasharon, Israel), a novel device for administration of MMC-C with hyperthermia (HT), that employs conductive heating, in a series of non-grade 3 non-muscle-invasive bladder cancer (NMIBC) that failed Bacillus Calmette-Guerin (BCG). METHODS: Patients with non-grade 3 NMIBC recurring after at least a full induction course of BCG were eligible for this phase I-II prospective single-arm study. Six weekly instillations with Unithermia(®) were scheduled following complete TUR. Primary end points were treatment safety and response rate (RR), and the latter defined as the absence of any unfavourable outcome at 12 months. Any grade 3 and/or muscle-invasive (T > 1) recurrence was considered disease progression. Kaplan-Meier estimation of the time to recurrence and progression, cancer-specific survival and overall survival was taken as secondary end points. RESULTS: Thirty-four eligible patients entered the study between January 2009 and April 2011. RR was documented in 20/34 (59%). Among the 14/34 (41%) non-responders, four developed G3 disease, one developed carcinoma in situ, and one progressed to muscle-invasive bladder cancer, with an overall 18% progression rate at 1 year. At a median follow-up of 41 months, recurrence and progression rates were 35.3 and 23.5%, respectively. Toxicity did not go beyond grade 2 except in five cases. CONCLUSIONS: Initial experience with MMC-HT with Unithermia(®) showed an interesting activity and safety profile in non-grade 3 NMIBC recurring after BCG, suggesting a role as second-line therapy in this selected subgroup of NMIBC.

Hyaluronic acid conjugates as vectors for the active targeting of drugs, genes and nanocomposites in cancer treatment.

Hyaluronic acid (HA) is a naturally-occurring glycosaminoglycan and a major component of the extracellular matrix. Low levels of the hyaluronic acid receptor CD44 are found on the surface of epithelial, hematopoietic, and neuronal cells; it is overexpressed in many cancer cells, and in particular in tumor-initiating cells. HA has recently attracted considerable interest in the field of developing drug delivery systems, having been used, as such or encapsulated in different types of nanoassembly, as ligand to prepare nano-platforms for actively targeting drugs, genes, and diagnostic agents. This review describes recent progress made with the several chemical strategies adopted to synthesize conjugates and prepare novel delivery systems with improved behaviors.

Intravesical thermo-chemotherapy based on conductive heat: a first pharmacokinetic study with mitomycin C in superficial transitional cell carcinoma patients.

PURPOSE: To evaluate, for the first time, the mitomycin C (MMC) pharmacokinetics during intravesical hyperthermia treatment based on conductive heat and the stability and recovery of the drug at the end of the instillation period. METHODS: Eleven patients with recurrent intermediate-risk superficial transitional cell carcinoma of the bladder were treated weekly for six cycles with intravesical MMC (40 mg MMC in 50 ml) in local hyperthermia (45 °C) with Unithermia(®) system. Each instillation lasted 45 min, with the solution being replaced after the first 22 min. The MMC recovery at the end of the two instillation period and the plasmatic pharmacokinetics of MMC were evaluated by high-pressure liquid chromatography. RESULTS: Nine patients completed all the six planned cycles, whereas two patients missed the last cycle because of allergic reactions. No other systemic toxicity was observed, and the local toxicities were mild. Median MMC concentration in the instillation residual solution decreases from the initial 0.8 to 0.22 mg/ml for the 0-22-min instillation period and to 0.38 mg/ml for the 22-45-min instillation period; the median percentage of MMC recovered after instillation was 66.2 and 99.6, respectively. In all patients, MMC plasmatic C max resulted considerably lower than the toxic threshold (400 ng/ml). CONCLUSIONS: The MMC is stable during the instillation, and its absorption occurs mainly during the first minutes of the treatment. The plasmatic MMC concentration is always well below the threshold level for myelosuppression, as confirmed by the total lack of hematological toxicity evidenced by the patients. In order to evaluate the efficacy of the treatment performed with UniThermia(®) in reducing the disease recurrence rate in short- and long-term follow-up, we are currently carrying out a clinical multicentric study involving a larger number of patients.

Preparation and characterization of novel poly(ethylene glycol) paclitaxel derivatives.

Paclitaxel has been found to be very effective against several human cancers; one of the major problems with its use is its poor solubility, which makes necessary its solubilization with excipients that can determine allergic reactions often severe. The aim of this study is to develop highly water-soluble prodrugs of paclitaxel. For this purpose we prepared a series of new paclitaxel-poly(ethylene glycol) (PEG) conjugates that were characterized and evaluated for their in vitro stability and cytotoxicity. In particular, in order to modulate the release of paclitaxel from prodrugs, we prepared different compounds introducing PEG in the drug C2' and/or C7 positions via ester or carbamate linkage. The conjugates were obtained in high purity and good yield. The carbamate prodrugs were highly stable in different media, while the compounds obtained linking PEG at C2' position through an ester bond showed lower stability. Finally, the cytotoxic activity of the conjugates was evaluated on two cancer cell lines and the results showed that all the derivatives had a reduced cytotoxicity compared to that of paclitaxel.