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Vincent Jannin - One of the best experts on this subject based on the ideXlab platform.
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in vitro gastrointestinal lipolysis of four formulations of piroxicam and cinnarizine with the self emulsifying excipients labrasol and gelucire 44 14
Pharmaceutical Research, 2009Co-Authors: Sylvie Fernandez, Nicolas Ritter, Bruno Mahler, Frederic Demarne, Frederic Carriere, Stephanie Chevrier, Vincent JanninAbstract:Purpose Labrasol® and Gelucire® 44/14 are defined admixtures of Acylglycerols and PEG esters which are substrates for digestive lipases.
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lipolysis of the semi solid self emulsifying excipient gelucire 44 14 by digestive lipases
Biochimica et Biophysica Acta, 2008Co-Authors: Sylvie Fernandez, Jeandavid Rodier, Nicolas Ritter, Bruno Mahler, Frederic Demarne, Frederic Carriere, Vincent JanninAbstract:Abstract Gelucire® 44/14 is a semi-solid self-emulsifying excipient used for the oral delivery of poorly water-soluble drugs. It is composed of C8-C18 Acylglycerols and PEG-32 esters, all of which are potential substrates for digestive lipases. Here we studied the lipolysis of Gelucire® 44/14 by porcine pancreatic extracts, human pancreatic juice and several purified digestive lipases. Human pancreatic lipase (HPL), the main lipase involved in the digestion of triAcylglycerols, did not show any significant activity on Gelucire® 44/14 or on either of its individual compounds, C8-C18 Acylglycerols and PEG-32 esters. Other pancreatic lipases such as human pancreatic lipase-related protein 2 (HPLRP2) showed low activity on Gelucire® 44/14 although the highest activity of HPLRP2 was that observed on the C8-C18 Acylglycerol fraction, which accounts for 20% (w/w) of Gelucire® 44/14. In addition, HPLRP2 showed low activities on the PEG-32 esters, whether these were tested individually or mixed together. Carboxyl ester hydrolase (CEH) showed high activity on Gelucire® 44/14, and the highest activities of CEH were those recorded on the total PEG-32 ester fraction and on each individual PEG-32 ester, except for PEG-32 monostearate. The highest activity of all the enzymes tested was that of dog gastric lipase (DGL) on Gelucire® 44/14, although DGL showed low activity on the PEG-32 ester fraction and on each individual PEG-32 ester. We compared the lipolysis of Gelucire® 44/14 with that of Labrasol®, another self-emulsifying excipient, which is liquid at room temperature. Human pancreatic juice showed similar rates of activity on both Gelucire® 44/14 and Labrasol®. This finding means that these excipients are hydrolyzed in vivo during pancreatic digestion, mainly by CEH in the case of Gelucire® 44/14 and by both HPLRP2 and CEH in that of Labrasol®, whereas HPL showed very low activities on each of these two excipients. This is the first time the effects of PEG and acyl chain length on the lipolytic activity of digestive lipases on PEG esters have been investigated.
Sylvie Fernandez - One of the best experts on this subject based on the ideXlab platform.
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in vitro gastrointestinal lipolysis of four formulations of piroxicam and cinnarizine with the self emulsifying excipients labrasol and gelucire 44 14
Pharmaceutical Research, 2009Co-Authors: Sylvie Fernandez, Nicolas Ritter, Bruno Mahler, Frederic Demarne, Frederic Carriere, Stephanie Chevrier, Vincent JanninAbstract:Purpose Labrasol® and Gelucire® 44/14 are defined admixtures of Acylglycerols and PEG esters which are substrates for digestive lipases.
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lipolysis of the semi solid self emulsifying excipient gelucire 44 14 by digestive lipases
Biochimica et Biophysica Acta, 2008Co-Authors: Sylvie Fernandez, Jeandavid Rodier, Nicolas Ritter, Bruno Mahler, Frederic Demarne, Frederic Carriere, Vincent JanninAbstract:Abstract Gelucire® 44/14 is a semi-solid self-emulsifying excipient used for the oral delivery of poorly water-soluble drugs. It is composed of C8-C18 Acylglycerols and PEG-32 esters, all of which are potential substrates for digestive lipases. Here we studied the lipolysis of Gelucire® 44/14 by porcine pancreatic extracts, human pancreatic juice and several purified digestive lipases. Human pancreatic lipase (HPL), the main lipase involved in the digestion of triAcylglycerols, did not show any significant activity on Gelucire® 44/14 or on either of its individual compounds, C8-C18 Acylglycerols and PEG-32 esters. Other pancreatic lipases such as human pancreatic lipase-related protein 2 (HPLRP2) showed low activity on Gelucire® 44/14 although the highest activity of HPLRP2 was that observed on the C8-C18 Acylglycerol fraction, which accounts for 20% (w/w) of Gelucire® 44/14. In addition, HPLRP2 showed low activities on the PEG-32 esters, whether these were tested individually or mixed together. Carboxyl ester hydrolase (CEH) showed high activity on Gelucire® 44/14, and the highest activities of CEH were those recorded on the total PEG-32 ester fraction and on each individual PEG-32 ester, except for PEG-32 monostearate. The highest activity of all the enzymes tested was that of dog gastric lipase (DGL) on Gelucire® 44/14, although DGL showed low activity on the PEG-32 ester fraction and on each individual PEG-32 ester. We compared the lipolysis of Gelucire® 44/14 with that of Labrasol®, another self-emulsifying excipient, which is liquid at room temperature. Human pancreatic juice showed similar rates of activity on both Gelucire® 44/14 and Labrasol®. This finding means that these excipients are hydrolyzed in vivo during pancreatic digestion, mainly by CEH in the case of Gelucire® 44/14 and by both HPLRP2 and CEH in that of Labrasol®, whereas HPL showed very low activities on each of these two excipients. This is the first time the effects of PEG and acyl chain length on the lipolytic activity of digestive lipases on PEG esters have been investigated.
Margrit Frentzen - One of the best experts on this subject based on the ideXlab platform.
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cdna clones from limnanthes douglasii encoding an erucoyl coa specific 1 Acylglycerol 3 phosphate acyltransferase
1995Co-Authors: Christiane Hanke, Gabriele Peterek, Frank P Wolter, Margrit FrentzenAbstract:Rapeseed oil represents a renewable resource suitable for different technical purposes. Its industrial applicability can be improved by a homogenous fatty acid composition consisting of 90 % of one technically attractive fatty acid, such as erucic acid [1]. The content of erucic acid in the oil of current rapeseed varieties is limited to about 60 % since erucic acid is esterified in the sn-1 and sn-3 position of the glycerol backbone only, whereas the sn-2 position carries unsaturated C18 acyl groups [2]. This fatty acid pattern of rapeseed oil is established by the microsomal acyltransferases involved in triAcylglycerol biosynthesis [3]. Due to the pronounced specificity and selectivity of the l-Acylglycerol-3-phosphate acyltransferase for unsaturated C18 acyl groups, erucic acid is excluded from the sn-2 position of the glycerol backbone and, thus, the formation of trierucin is prevented [3, 4]. In contrast to the acyltransferase of rapeseed, the respective seed-specific enzyme from Limnanthes douglasii effectively utilizes erucoyl-CoA as substrate [5]. To achieve trierucin biosynthesis in rapeseed by genetic engineering, we have isolated cDNAs from Limnanthes douglasii encoding an erucoyl-CoA specific 1-Acylglycerol-3-phosphate acyltransferase.
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triAcylglycerol biosynthesis in developing seeds of tropaeolum majus l and limnanthes douglasii r br
Planta, 1992Co-Authors: Imma Lohden, Margrit FrentzenAbstract:TriAcylglycerols of both Tropaeolum majus L. and Limnanthes douglasii R. Br. are predominantly esterified with very long-chain acyl groups at each position of the glycerol backbone. In order to elucidate whether these acyl groups are directly chanelled into the triAcylglycerols via the stepwise acylation of glycerol-3-phosphate, seed oil formation has been investigated in developing embryos of both plant species. [1-14C]Acetate labelling experiments using embryos at different stages of development, as well as the determination of the properties of the microsomal acyl-CoA:sn-glycerol-3-phosphate acyltransferase (EC 2.3.1.15) and acyl-CoA:sn-1-Acylglycerol-3-phosphate acyltransferase (EC 2.3.1.51), revealed differences between the two plant species, especially with respect to the incorporation of very longchain acyl groups into the C2 position of the triAcylglycerols. In microsomal fractions of developing embryos of L. douglasii both a glycerol-3-phosphate and a 1-Acylglycerol-3-phosphate acyltransferase were detected which utilize very long-chain acyl-CoA thioesters as substrates. Thus, in seeds of L. douglasii very long-chain acyl groups can enter not only the C1, but also the C2 position of the triAcylglycerols in the course of de-novo biosynthesis. A comparison of the properties of the acyltransferases of developing embryos with those of the corresponding activities of leaves indicates an embryo specific expression of an erucoyl-CoA-dependent microsomal 1-Acylglycerol-3-phosphate acyltransferase in L. douglasii. The microsomal glycerol-3-phosphate acyltransferase of developing embryos of T. majus displayed properties very similar to those of the corresponding activity of L. douglasii. On the other hand, the microsomal 1-Acylglycerol-3-phosphate acyltransferases of the two plant species showed strikingly different substrate specificities. Irrespective of the acyl groups of 1-Acylglycerol-3-phosphate and regardless of whether acyl-CoA thioesters were offered separately or in mixtures, the enzyme of T. majus, in contrast to that of L. douglasii, was inactive with erucoyl-CoA. These results of the enzyme studies correspond well with those of the [1-14C]acetate labelling experiments and thus indicate that T. majus has developed mechanisms different from those of L. douglasii for the incorporation of erucic acid into the C2 position of its triAcylglycerols.
Nicolas Ritter - One of the best experts on this subject based on the ideXlab platform.
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in vitro gastrointestinal lipolysis of four formulations of piroxicam and cinnarizine with the self emulsifying excipients labrasol and gelucire 44 14
Pharmaceutical Research, 2009Co-Authors: Sylvie Fernandez, Nicolas Ritter, Bruno Mahler, Frederic Demarne, Frederic Carriere, Stephanie Chevrier, Vincent JanninAbstract:Purpose Labrasol® and Gelucire® 44/14 are defined admixtures of Acylglycerols and PEG esters which are substrates for digestive lipases.
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lipolysis of the semi solid self emulsifying excipient gelucire 44 14 by digestive lipases
Biochimica et Biophysica Acta, 2008Co-Authors: Sylvie Fernandez, Jeandavid Rodier, Nicolas Ritter, Bruno Mahler, Frederic Demarne, Frederic Carriere, Vincent JanninAbstract:Abstract Gelucire® 44/14 is a semi-solid self-emulsifying excipient used for the oral delivery of poorly water-soluble drugs. It is composed of C8-C18 Acylglycerols and PEG-32 esters, all of which are potential substrates for digestive lipases. Here we studied the lipolysis of Gelucire® 44/14 by porcine pancreatic extracts, human pancreatic juice and several purified digestive lipases. Human pancreatic lipase (HPL), the main lipase involved in the digestion of triAcylglycerols, did not show any significant activity on Gelucire® 44/14 or on either of its individual compounds, C8-C18 Acylglycerols and PEG-32 esters. Other pancreatic lipases such as human pancreatic lipase-related protein 2 (HPLRP2) showed low activity on Gelucire® 44/14 although the highest activity of HPLRP2 was that observed on the C8-C18 Acylglycerol fraction, which accounts for 20% (w/w) of Gelucire® 44/14. In addition, HPLRP2 showed low activities on the PEG-32 esters, whether these were tested individually or mixed together. Carboxyl ester hydrolase (CEH) showed high activity on Gelucire® 44/14, and the highest activities of CEH were those recorded on the total PEG-32 ester fraction and on each individual PEG-32 ester, except for PEG-32 monostearate. The highest activity of all the enzymes tested was that of dog gastric lipase (DGL) on Gelucire® 44/14, although DGL showed low activity on the PEG-32 ester fraction and on each individual PEG-32 ester. We compared the lipolysis of Gelucire® 44/14 with that of Labrasol®, another self-emulsifying excipient, which is liquid at room temperature. Human pancreatic juice showed similar rates of activity on both Gelucire® 44/14 and Labrasol®. This finding means that these excipients are hydrolyzed in vivo during pancreatic digestion, mainly by CEH in the case of Gelucire® 44/14 and by both HPLRP2 and CEH in that of Labrasol®, whereas HPL showed very low activities on each of these two excipients. This is the first time the effects of PEG and acyl chain length on the lipolytic activity of digestive lipases on PEG esters have been investigated.
Bruno Mahler - One of the best experts on this subject based on the ideXlab platform.
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in vitro gastrointestinal lipolysis of four formulations of piroxicam and cinnarizine with the self emulsifying excipients labrasol and gelucire 44 14
Pharmaceutical Research, 2009Co-Authors: Sylvie Fernandez, Nicolas Ritter, Bruno Mahler, Frederic Demarne, Frederic Carriere, Stephanie Chevrier, Vincent JanninAbstract:Purpose Labrasol® and Gelucire® 44/14 are defined admixtures of Acylglycerols and PEG esters which are substrates for digestive lipases.
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lipolysis of the semi solid self emulsifying excipient gelucire 44 14 by digestive lipases
Biochimica et Biophysica Acta, 2008Co-Authors: Sylvie Fernandez, Jeandavid Rodier, Nicolas Ritter, Bruno Mahler, Frederic Demarne, Frederic Carriere, Vincent JanninAbstract:Abstract Gelucire® 44/14 is a semi-solid self-emulsifying excipient used for the oral delivery of poorly water-soluble drugs. It is composed of C8-C18 Acylglycerols and PEG-32 esters, all of which are potential substrates for digestive lipases. Here we studied the lipolysis of Gelucire® 44/14 by porcine pancreatic extracts, human pancreatic juice and several purified digestive lipases. Human pancreatic lipase (HPL), the main lipase involved in the digestion of triAcylglycerols, did not show any significant activity on Gelucire® 44/14 or on either of its individual compounds, C8-C18 Acylglycerols and PEG-32 esters. Other pancreatic lipases such as human pancreatic lipase-related protein 2 (HPLRP2) showed low activity on Gelucire® 44/14 although the highest activity of HPLRP2 was that observed on the C8-C18 Acylglycerol fraction, which accounts for 20% (w/w) of Gelucire® 44/14. In addition, HPLRP2 showed low activities on the PEG-32 esters, whether these were tested individually or mixed together. Carboxyl ester hydrolase (CEH) showed high activity on Gelucire® 44/14, and the highest activities of CEH were those recorded on the total PEG-32 ester fraction and on each individual PEG-32 ester, except for PEG-32 monostearate. The highest activity of all the enzymes tested was that of dog gastric lipase (DGL) on Gelucire® 44/14, although DGL showed low activity on the PEG-32 ester fraction and on each individual PEG-32 ester. We compared the lipolysis of Gelucire® 44/14 with that of Labrasol®, another self-emulsifying excipient, which is liquid at room temperature. Human pancreatic juice showed similar rates of activity on both Gelucire® 44/14 and Labrasol®. This finding means that these excipients are hydrolyzed in vivo during pancreatic digestion, mainly by CEH in the case of Gelucire® 44/14 and by both HPLRP2 and CEH in that of Labrasol®, whereas HPL showed very low activities on each of these two excipients. This is the first time the effects of PEG and acyl chain length on the lipolytic activity of digestive lipases on PEG esters have been investigated.