Liposomal l-asparaginase

in vitro evaluation

M. E M Cruz, M. M. Gaspar, F. Lopes, J. S. Jorge, Roman Perez-Soler

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

The purpose of this work was the development of liposomal formulations of l-asparaginase (l-ASNase) with the following characteristics: preservation of active enzyme, high entrapment efficiency, prolonged serum half-life and reduced toxicity compared with the free enzyme. Several liposome formulations were developed using simplified dehydration-rehydration vesicles (sDRV) or extruded vesicles (VET). The effect of lipid composition, vesicle size, ionic strength and osmolarity on enzyme encapsulation was investigated. Using a simplified dehydration-rehydration method (sDRV) we were able to achieve encapsulation efficiencies of up to 100% with full preservation (99%) of the specific activity of the encapsulated enzyme. The protein to lipid ratios of the liposomal formulations ranged from 5 to 27 μg/μmol, depending on the lipid composition. Extruded vesicles ranging from 85 to 250 nm in diameter were also tested. The encapsulation efficiency of extruded vesicles was lower than that of large vesicles and the range of preservation of specific activity was dependent on the lipid composition. Lipid combinations of phosphatidylcholine and cholesterol and either stearylamine, phosphatidylinositol or monosialoganglioside resulted in a high encapsulation efficiency (40 and 98% in VET and sDRV, respectively), high stability in saline and human serum (65-90% after 48 h) and considerable preservation of enzymatic activity (74-98%). The liposomal formulations were significantly less toxic than the free enzyme against normal CHO cells. In vivo toxicity, pharmacokinetics, biodistribution and antitumour activity studies are planned with the best formulations described in this paper.

Original languageEnglish (US)
Pages (from-to)67-77
Number of pages11
JournalInternational Journal of Pharmaceutics
Volume96
Issue number1-3
DOIs
StatePublished - Jul 31 1993
Externally publishedYes

Fingerprint

Asparaginase
Fluid Therapy
Dehydration
Lipids
Enzymes
Osmolar Concentration
CHO Cells
Poisons
Phosphatidylinositols
Serum
Phosphatidylcholines
Liposomes
Half-Life
Pharmacokinetics
Cholesterol
In Vitro Techniques
Proteins

Keywords

  • Encapsulation
  • Extruded vesicle
  • l-Asparaginase
  • Leukemia
  • Liposome
  • Therapeutic system

ASJC Scopus subject areas

  • Pharmaceutical Science

Cite this

Liposomal l-asparaginase : in vitro evaluation. / Cruz, M. E M; Gaspar, M. M.; Lopes, F.; Jorge, J. S.; Perez-Soler, Roman.

In: International Journal of Pharmaceutics, Vol. 96, No. 1-3, 31.07.1993, p. 67-77.

Research output: Contribution to journalArticle

Cruz, M. E M ; Gaspar, M. M. ; Lopes, F. ; Jorge, J. S. ; Perez-Soler, Roman. / Liposomal l-asparaginase : in vitro evaluation. In: International Journal of Pharmaceutics. 1993 ; Vol. 96, No. 1-3. pp. 67-77.
@article{e0b0640f825148b3b0ebf6e1703f1725,
title = "Liposomal l-asparaginase: in vitro evaluation",
abstract = "The purpose of this work was the development of liposomal formulations of l-asparaginase (l-ASNase) with the following characteristics: preservation of active enzyme, high entrapment efficiency, prolonged serum half-life and reduced toxicity compared with the free enzyme. Several liposome formulations were developed using simplified dehydration-rehydration vesicles (sDRV) or extruded vesicles (VET). The effect of lipid composition, vesicle size, ionic strength and osmolarity on enzyme encapsulation was investigated. Using a simplified dehydration-rehydration method (sDRV) we were able to achieve encapsulation efficiencies of up to 100{\%} with full preservation (99{\%}) of the specific activity of the encapsulated enzyme. The protein to lipid ratios of the liposomal formulations ranged from 5 to 27 μg/μmol, depending on the lipid composition. Extruded vesicles ranging from 85 to 250 nm in diameter were also tested. The encapsulation efficiency of extruded vesicles was lower than that of large vesicles and the range of preservation of specific activity was dependent on the lipid composition. Lipid combinations of phosphatidylcholine and cholesterol and either stearylamine, phosphatidylinositol or monosialoganglioside resulted in a high encapsulation efficiency (40 and 98{\%} in VET and sDRV, respectively), high stability in saline and human serum (65-90{\%} after 48 h) and considerable preservation of enzymatic activity (74-98{\%}). The liposomal formulations were significantly less toxic than the free enzyme against normal CHO cells. In vivo toxicity, pharmacokinetics, biodistribution and antitumour activity studies are planned with the best formulations described in this paper.",
keywords = "Encapsulation, Extruded vesicle, l-Asparaginase, Leukemia, Liposome, Therapeutic system",
author = "Cruz, {M. E M} and Gaspar, {M. M.} and F. Lopes and Jorge, {J. S.} and Roman Perez-Soler",
year = "1993",
month = "7",
day = "31",
doi = "10.1016/0378-5173(93)90213-Y",
language = "English (US)",
volume = "96",
pages = "67--77",
journal = "International Journal of Pharmaceutics",
issn = "0378-5173",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Liposomal l-asparaginase

T2 - in vitro evaluation

AU - Cruz, M. E M

AU - Gaspar, M. M.

AU - Lopes, F.

AU - Jorge, J. S.

AU - Perez-Soler, Roman

PY - 1993/7/31

Y1 - 1993/7/31

N2 - The purpose of this work was the development of liposomal formulations of l-asparaginase (l-ASNase) with the following characteristics: preservation of active enzyme, high entrapment efficiency, prolonged serum half-life and reduced toxicity compared with the free enzyme. Several liposome formulations were developed using simplified dehydration-rehydration vesicles (sDRV) or extruded vesicles (VET). The effect of lipid composition, vesicle size, ionic strength and osmolarity on enzyme encapsulation was investigated. Using a simplified dehydration-rehydration method (sDRV) we were able to achieve encapsulation efficiencies of up to 100% with full preservation (99%) of the specific activity of the encapsulated enzyme. The protein to lipid ratios of the liposomal formulations ranged from 5 to 27 μg/μmol, depending on the lipid composition. Extruded vesicles ranging from 85 to 250 nm in diameter were also tested. The encapsulation efficiency of extruded vesicles was lower than that of large vesicles and the range of preservation of specific activity was dependent on the lipid composition. Lipid combinations of phosphatidylcholine and cholesterol and either stearylamine, phosphatidylinositol or monosialoganglioside resulted in a high encapsulation efficiency (40 and 98% in VET and sDRV, respectively), high stability in saline and human serum (65-90% after 48 h) and considerable preservation of enzymatic activity (74-98%). The liposomal formulations were significantly less toxic than the free enzyme against normal CHO cells. In vivo toxicity, pharmacokinetics, biodistribution and antitumour activity studies are planned with the best formulations described in this paper.

AB - The purpose of this work was the development of liposomal formulations of l-asparaginase (l-ASNase) with the following characteristics: preservation of active enzyme, high entrapment efficiency, prolonged serum half-life and reduced toxicity compared with the free enzyme. Several liposome formulations were developed using simplified dehydration-rehydration vesicles (sDRV) or extruded vesicles (VET). The effect of lipid composition, vesicle size, ionic strength and osmolarity on enzyme encapsulation was investigated. Using a simplified dehydration-rehydration method (sDRV) we were able to achieve encapsulation efficiencies of up to 100% with full preservation (99%) of the specific activity of the encapsulated enzyme. The protein to lipid ratios of the liposomal formulations ranged from 5 to 27 μg/μmol, depending on the lipid composition. Extruded vesicles ranging from 85 to 250 nm in diameter were also tested. The encapsulation efficiency of extruded vesicles was lower than that of large vesicles and the range of preservation of specific activity was dependent on the lipid composition. Lipid combinations of phosphatidylcholine and cholesterol and either stearylamine, phosphatidylinositol or monosialoganglioside resulted in a high encapsulation efficiency (40 and 98% in VET and sDRV, respectively), high stability in saline and human serum (65-90% after 48 h) and considerable preservation of enzymatic activity (74-98%). The liposomal formulations were significantly less toxic than the free enzyme against normal CHO cells. In vivo toxicity, pharmacokinetics, biodistribution and antitumour activity studies are planned with the best formulations described in this paper.

KW - Encapsulation

KW - Extruded vesicle

KW - l-Asparaginase

KW - Leukemia

KW - Liposome

KW - Therapeutic system

UR - http://www.scopus.com/inward/record.url?scp=0027222049&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027222049&partnerID=8YFLogxK

U2 - 10.1016/0378-5173(93)90213-Y

DO - 10.1016/0378-5173(93)90213-Y

M3 - Article

VL - 96

SP - 67

EP - 77

JO - International Journal of Pharmaceutics

JF - International Journal of Pharmaceutics

SN - 0378-5173

IS - 1-3

ER -