Intraliposomal conversion of lipophilic cis-bis-carboxylato-trans-R,R-1,2-diaminocyclohexane- platinum(II) complexes into cis-bis-dichloro-trans-R,R-1,2-diaminocyclohexane- platinum(II)

Insook Han, Abdul R. Khokhar, Roman Perez-Soler

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Cis-bis-neodecanoato-trans-R,R-1,2-diaminocyclohexane platinum(II) (NDDP) is a lipophilic platinum complex (Pt complex) developed in a liposomal carrier. Prior studies have suggested that NDDP is a prodrug that exerts its biological activity through activation within the liposome bilayers containing dimyristoyl phosphatidylglycerol (DMPG) before in vivo administration. In order to understand the kinetics of the intraliposomal degradation/activation of different liposomal Pt complexes, we studied the effects of their structure, lipid composition, content of acidic phospholipids and size, and the effects of pH, temperature and the presence of residual chloroform on their stability, in vitro cytotoxicity, and in vivo antitumor activity. The following factors were found to enhance the intraliposomal degradation/activation of Pt complexes: (1) the size and spatial configuration of the Pt complex, (2) an acidic pH, (3) a high temperature, (4) the presence and amount of acidic phospholipids, and (5) the presence of residual chloroform. Liposome size did not affect the intraliposomal stability of different Pt complexes. Good inverse relationships between the extent of drug degradation and in vitro cytotoxicity and between the extent of drug degradation and in vivo antitumor potency were observed, thus confirming that the biological activity of these complexes is exerted through the intraliposomal formation of certain active intermediate(s). The only active intermediate that could be identified was cis-bis-dichloro-trans-R,R-1,2-diaminocyclohexane platinum(II) whose structure was confirmed by 1H, 13C, and 195Pt nuclear magnetic resonance (NMR) spectroscopy.

Original languageEnglish (US)
Pages (from-to)17-24
Number of pages8
JournalCancer Chemotherapy and Pharmacology
Volume39
Issue number1-2
DOIs
StatePublished - 1996
Externally publishedYes

Fingerprint

Chloroform
Platinum
Liposomes
Phospholipids
Degradation
Temperature
Chemical activation
Prodrugs
Cytotoxicity
Bioactivity
Pharmaceutical Preparations
Magnetic Resonance Spectroscopy
Lipids
Nuclear magnetic resonance spectroscopy
Kinetics
((1R,2R)-1,2-diaminocyclohexane)platinum(II)
In Vitro Techniques
Chemical analysis
dimyristoylphosphatidylglycerol

Keywords

  • Drug stability
  • Lipophilic platinum complex
  • Liposome

ASJC Scopus subject areas

  • Cancer Research
  • Pharmacology
  • Oncology

Cite this

@article{9264b0b150a046bd82655f505651a5ee,
title = "Intraliposomal conversion of lipophilic cis-bis-carboxylato-trans-R,R-1,2-diaminocyclohexane- platinum(II) complexes into cis-bis-dichloro-trans-R,R-1,2-diaminocyclohexane- platinum(II)",
abstract = "Cis-bis-neodecanoato-trans-R,R-1,2-diaminocyclohexane platinum(II) (NDDP) is a lipophilic platinum complex (Pt complex) developed in a liposomal carrier. Prior studies have suggested that NDDP is a prodrug that exerts its biological activity through activation within the liposome bilayers containing dimyristoyl phosphatidylglycerol (DMPG) before in vivo administration. In order to understand the kinetics of the intraliposomal degradation/activation of different liposomal Pt complexes, we studied the effects of their structure, lipid composition, content of acidic phospholipids and size, and the effects of pH, temperature and the presence of residual chloroform on their stability, in vitro cytotoxicity, and in vivo antitumor activity. The following factors were found to enhance the intraliposomal degradation/activation of Pt complexes: (1) the size and spatial configuration of the Pt complex, (2) an acidic pH, (3) a high temperature, (4) the presence and amount of acidic phospholipids, and (5) the presence of residual chloroform. Liposome size did not affect the intraliposomal stability of different Pt complexes. Good inverse relationships between the extent of drug degradation and in vitro cytotoxicity and between the extent of drug degradation and in vivo antitumor potency were observed, thus confirming that the biological activity of these complexes is exerted through the intraliposomal formation of certain active intermediate(s). The only active intermediate that could be identified was cis-bis-dichloro-trans-R,R-1,2-diaminocyclohexane platinum(II) whose structure was confirmed by 1H, 13C, and 195Pt nuclear magnetic resonance (NMR) spectroscopy.",
keywords = "Drug stability, Lipophilic platinum complex, Liposome",
author = "Insook Han and Khokhar, {Abdul R.} and Roman Perez-Soler",
year = "1996",
doi = "10.1007/s002800050533",
language = "English (US)",
volume = "39",
pages = "17--24",
journal = "Cancer Chemotherapy and Pharmacology",
issn = "0344-5704",
publisher = "Springer Verlag",
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TY - JOUR

T1 - Intraliposomal conversion of lipophilic cis-bis-carboxylato-trans-R,R-1,2-diaminocyclohexane- platinum(II) complexes into cis-bis-dichloro-trans-R,R-1,2-diaminocyclohexane- platinum(II)

AU - Han, Insook

AU - Khokhar, Abdul R.

AU - Perez-Soler, Roman

PY - 1996

Y1 - 1996

N2 - Cis-bis-neodecanoato-trans-R,R-1,2-diaminocyclohexane platinum(II) (NDDP) is a lipophilic platinum complex (Pt complex) developed in a liposomal carrier. Prior studies have suggested that NDDP is a prodrug that exerts its biological activity through activation within the liposome bilayers containing dimyristoyl phosphatidylglycerol (DMPG) before in vivo administration. In order to understand the kinetics of the intraliposomal degradation/activation of different liposomal Pt complexes, we studied the effects of their structure, lipid composition, content of acidic phospholipids and size, and the effects of pH, temperature and the presence of residual chloroform on their stability, in vitro cytotoxicity, and in vivo antitumor activity. The following factors were found to enhance the intraliposomal degradation/activation of Pt complexes: (1) the size and spatial configuration of the Pt complex, (2) an acidic pH, (3) a high temperature, (4) the presence and amount of acidic phospholipids, and (5) the presence of residual chloroform. Liposome size did not affect the intraliposomal stability of different Pt complexes. Good inverse relationships between the extent of drug degradation and in vitro cytotoxicity and between the extent of drug degradation and in vivo antitumor potency were observed, thus confirming that the biological activity of these complexes is exerted through the intraliposomal formation of certain active intermediate(s). The only active intermediate that could be identified was cis-bis-dichloro-trans-R,R-1,2-diaminocyclohexane platinum(II) whose structure was confirmed by 1H, 13C, and 195Pt nuclear magnetic resonance (NMR) spectroscopy.

AB - Cis-bis-neodecanoato-trans-R,R-1,2-diaminocyclohexane platinum(II) (NDDP) is a lipophilic platinum complex (Pt complex) developed in a liposomal carrier. Prior studies have suggested that NDDP is a prodrug that exerts its biological activity through activation within the liposome bilayers containing dimyristoyl phosphatidylglycerol (DMPG) before in vivo administration. In order to understand the kinetics of the intraliposomal degradation/activation of different liposomal Pt complexes, we studied the effects of their structure, lipid composition, content of acidic phospholipids and size, and the effects of pH, temperature and the presence of residual chloroform on their stability, in vitro cytotoxicity, and in vivo antitumor activity. The following factors were found to enhance the intraliposomal degradation/activation of Pt complexes: (1) the size and spatial configuration of the Pt complex, (2) an acidic pH, (3) a high temperature, (4) the presence and amount of acidic phospholipids, and (5) the presence of residual chloroform. Liposome size did not affect the intraliposomal stability of different Pt complexes. Good inverse relationships between the extent of drug degradation and in vitro cytotoxicity and between the extent of drug degradation and in vivo antitumor potency were observed, thus confirming that the biological activity of these complexes is exerted through the intraliposomal formation of certain active intermediate(s). The only active intermediate that could be identified was cis-bis-dichloro-trans-R,R-1,2-diaminocyclohexane platinum(II) whose structure was confirmed by 1H, 13C, and 195Pt nuclear magnetic resonance (NMR) spectroscopy.

KW - Drug stability

KW - Lipophilic platinum complex

KW - Liposome

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