Comparative study on digestive lipase activities on the self emulsifying excipient Labrasol, medium chain glycerides and PEG esters.
Labrasol is a lipid-based self-emulsifying excipient used in the preparation of lipophilic drugs intended for oral delivery. It is mainly composed of PEG esters and glycerides with medium acyl chains, which are potential substrates for digestive lipases. The hydrolysis of Labrasol by porcine pancreatic extracts, human pancreatic juice and several purified digestive lipases was investigated in the present study. Classical human pancreatic lipase (HPL) and porcine pancreatic lipase, which are the main lipases involved in the digestion of dietary triglycerides, showed very low levels of activity on the entire Labrasol excipient as well as on separated fractions of glycerides and PEG esters. On the other hand, gastric lipase, pancreatic lipase-related protein 2 (PLRP2) and carboxyl ester hydrolase (CEH) showed high specific activities on Labrasol. These lipases were found to hydrolyze the main components of Labrasol (PEG esters and monoglycerides) used as individual substrates, whereas these esters were found to be poor substrates for HPL. The lipolytic activity of pancreatic extracts and human pancreatic juice on Labrasol(R) is therefore mainly due to the combined action of CEH and PLRP2. These two pancreatic enzymes, together with gastric lipase, are probably the main enzymes involved in the in vivo lipolysis of Labrasol taken orally.
Fernandez
Sylvie
S
Laboratoire d'Enzymologie Interfaciale et de Physiologie de la Lipolyse, CNRS UPR 9025, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
Jannin
Vincent
V
Rodier
Jean-David
JD
Ritter
Nicolas
N
Mahler
Bruno
B
Carrière
Frédéric
F
D000818:Animals; D043182:Carboxylesterase / Q000378:metabolism; D002417:Cattle; D004655:Emulsions; D004952:Esters / Q000378:metabolism; D005989:Glycerides; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D009930:Organic Chemicals / Q000378:metabolism; D010179:Pancreas / Q000201:enzymology*; D011092:Polyethylene Glycols / Q000378:metabolism*; D013379:Substrate Specificity; D013552:Swine; D014280:Triglycerides / Q000378:metabolism*
D004655:Emulsions; D004952:Esters; D005989:Glycerides; D009930:Organic Chemicals; D014280:Triglycerides; C440220:Labrasol; D011092:Polyethylene Glycols; D043182:Carboxylesterase; D008049:Lipase