Experimental and clinical studies on the intraperitoneal administration of cis-diamminedichloroplatinum (II) for peritoneal carcinomatosis caused by gastric cancers

Pilot Study of Intraperitoneal Administration of Triamcinolone Acetonide for Cancerous Ascites in Patients With End-Stage Gynecological Cancer

Objective

Patients with end-stage cancer have poorly controlled ascites retention resulting due to cancerous peritonitis. We intraperitoneally administered triamcinolone acetonide (TA) to patients with end-stage gynecological cancer as a pilot study, and our treatment results are reported herein.

Patients and Methods

We enrolled 26 patients with end-stage gynecological cancer requiring frequent abdominal paracentesis for ascites drainage between April 2010 and September 2012. The volume of ascites drainage was 2000 to 3000 mL per drainage session, and TA at 10 mg/kg was intraperitoneally administered after drainage. We compared abdominal paracentesis intervals, performance status (PS), total protein level, albumin level, white blood cell count, changes in C-reactive protein (CRP) level, and adverse events before and after TA use.

Results

Triamcinolone acetonide was administered to 26 patients for a total of 59 times. The abdominal paracentesis intervals, PS, and mean (SD) of C-reactive protein before and after TA use were 13.2 (12.6) days and 21.9 (23.6) days (P = 0.0117), 2.4 (0.7) and 1.6 (1.1) (P < 0.0001), and 7.5 (5.2) mg/dL and 5.5 (5.0) mg/dL (P = 0.007), respectively. With regard to adverse events, abdominal pain of grade 2 was observed once (1.7%), but there were no other acute adverse events. Four subjects (15.4%) had intestinal perforation.

Conclusions

Intraperitoneal administration of TA after drainage was considered to be a useful treatment, as it seems to extend paracentesis intervals and improve PS while maintaining quality of life for end-stage gynecological cancer patients with massive ascites.

Organ distribution of cisplatin after intraperitoneal administration of cisplatin-loaded microspheres

The aim of this study was to clarify the organ distribution of cisplatin (CDDP) after intraperitoneal (i.p.) administration of cisplatin-loaded microspheres (CDDP-MS). The distribution of CDDP to normal organs lying in the peritoneal cavity after i.p. administration of CDDP-MS was assessed by comparing with subcutaneous administration to non-cancerous mice. The organ distribution of CDDP after i.p. administration of CDDP-MS shows that CDDP released from microspheres was distributed to the organs lying in the peritoneal cavity and in the retroperitoneum. These are mainly from the systemic circulation, but are not directly from the organ surface. The distribution of CDDP to tumors was evaluated in sarcoma180 tumor-bearing mice by comparing with a bolus injection. The CDDP-MS delivered CDDP to tumors more effectively than did bolus injection. The distribution of CDDP-MS in the peritoneal cavity was in accord with the tumor distribution. This concordance and sustained exposure of CDDP to the tumors might play a critical role in enhancing the CDDP accumulation in tumors. It is concluded that CDDP-MS have a distinct regional pharmacokinetic advantage for peritoneal carcinomatosis, and that i.p. administration of CDDP-MS is an effective treatment for peritoneal carcinomatosis.

Relation between dissolution profiles and toxicity of cisplatin-loaded microspheres

The aim of this study is to evaluate and compare the dissolution profiles of cisplatin-loaded microspheres (CDDP-MS) in vitro and in vivo, and to determine the relationship between the dissolution profiles in vitro and systemic toxicity. For this purpose, three types of CDDP-MS that release the CDDP for 1, 2 and 5 weeks without a large amount of initial release in phosphate buffered saline (pH 7.4) were prepared. The dissolution profiles of these formulations in vivo were well correlated with in vitro studies, and resulted in well-controlled plasma platinum concentration. The systemic toxicity of the CDDP-MS and CDDP dissolved in saline (CDDP-SOL) were assessed by intraperitoneal administration in mice. The maximal tolerable dose (MTD) of CDDP-SOL was 13.4 mg/kg, whereas the CDDP-MS of 1, 2 and 5-week types were 34.6, 44.2, 62.6 mg/kg, respectively. The MTD of CDDP increased proportionally when 50% of CDDP had been released from MS in vitro (MTD (mg/kg)=5.22 x T(50(day)) + 13.2, R(2)=0.9935). We demonstrate that the systemic toxicity of CDDP-MS can be predicted by evaluation of the dissolution rate in vitro since in vivo dissolution was correlated with the in vitro.

In vitro cytotoxic dose-relation of cisplatin and sodium thiosulphate in human tongue and oesophageal squamous carcinoma cell lines

BACKGROUND

Intraarterial chemotherapy of oral and oropharyngeal cancer with cisplatin (cis-diamminedichloroplatinum [II]) has experienced a revival in the last decade. Side-effects of the therapy were very low with concomitant systemic infusion of the neutralizing agent sodium thiosulphate. The requisite dose of the chemotherapeutic agent which safely leads to apoptosis of oral cancer cells has not yet been assessed in vitro, nor has the combination of cisplatin and sodium thiosulphate been examined for the potential reduction of cytotoxicity in oral cancer cells.

STUDY DESIGN

In a panel of two tongue squamous cancer cell lines and an oesophageal cancer cell line as control and comparison, cisplatin (0.2-10 microgram/ml) was combined with sodium thiosulphate (0-0.5 mg/ml).

RESULTS

10 microgram/ml of cisplatin proved to be 100% antiproliferative, while any additional concentration of sodium thiosulphate decreased this effect. At the maximum dose of cisplatin, a sodium thiosulphate/cisplatin concentration relation of less than 6:1 still effected cytotoxic activity of >80%. An increase of cisplatin concentration led to higher cytotoxicity irrespective of sodium thiosulphate concentration. The oesophageal cell line was more sensitive to cisplatin and to sodium thiosulphate than the tongue cell lines.

CONCLUSIONS

In this study, it was found that high concentrations of cisplatin are necessary in oral cancer to reach cytotoxic levels which support high-dose intraarterial chemotherapy by which these levels might be reached. A sodium thiosulphate/cisplatin concentration ratio within the tumour of less than 6:1 may be allowed without compromising the cytotoxic activity of cisplatin.

Pharmacokinetic behaviour of cisplatin in peritoneal fluid after intraperitoneal administration of cisplatin-loaded microspheres

The objective of this study was to establish a pharmacokinetic model for the estimation of unchanged cis-dichlorodiammine-platinum (II) (CDDP) concentration in peritoneal fluid after intraperitoneal administration of cisplatin-loaded microspheres (CDDP-MS) and to elucidate the accuracy of this model by comparisons between actual and simulated values after intraperitoneal administration of CDDP-MS. We developed a method enabling the precise and quick assessment of the drug concentration in the peritoneal cavity. The pharmacokinetic parameters obtained after intravenous bolus injection at a dose of 2 mg kg(-1) were total body clearance (1026 mL h(-1) kg(-1)), elimination rate constant (3.24 h(-1)) and distribution volume of systemic circulation (316.7 mL kg(-1)). After an intraperitoneal bolus injection at a dose of 5 mg kg(-1), the absorption rate constant from the peritoneal cavity (3.64 h(-1)) and the distribution volume of the peritoneal cavity (13.5 mL kg(-1)) were determined. The protein-binding rate constant in ascites was 0.58 h(-1). Using these pharmacokinetic parameters, we established a pharmacokinetic model consisting of two compartments. Administration of CDDP-MS at a dose of 10 mg kg(-1), which released CDDP over 7 days in-vitro, yielded sustained concentrations of unchanged CDDP (1-2 mg mL(-1)) in the peritoneal cavity that persisted for 7 days, and that were predictable by applying the in-vitro dissolution profile to the pharmacokinetic model. The findings obtained from this study are useful for understanding the basic pharmacokinetic characteristics of unchanged CDDP in the peritoneal cavity and may also be important in the development of optimized CDDP-MS formulations.

Human variability and noncancer risk assessment- An analysis of the default uncertainty factor

A 10-fold uncertainty factor is used for noncancer risk assessments to allow for possible interindividual differences between humans in the fate of the chemical in the body (kinetics) and target organ sensitivity (dynamics). Analysis of a database on the variability in each of these aspects is consistent with an even subdivision of the 10-fold factor into 10(0.5) (3.16) for kinetics and 10(0.5) (3.16) for dynamics. Analysis of the number of subjects in a normally and log-normally distributed population which would not be covered by factors of 3.16 supports this subdivision and also the use of a 10-fold factor to allow for both aspects. Analysis of kinetic data for subgroups of the population indicates that the standard default value of 3.16 for kinetics will not be adequate for all routes of elimination and all groups of the population. A scheme is proposed which would allow the selection of appropriate default uncertainty factors based on knowledge of the biological fate and effects of the chemical under review. Copyright 1998 Academic Press.