TLC characterization of liposomes containing D-myo-inositol derivatives.
The thin-layer chromatographic (TLC) behaviour of liposomes containing inositol phosphates (IPs) was studied. The liposomes contained different concentrations of D-myo-inositol 1,4,5k-trisphosphate (IP3), D-myo-inositol 1,2,6-trisphosphate (alpha-trinositol, PP 56, a novel Perstorp Pharma derivative), D-myo-inositol 1,3,4,5-tetrakisphosphate (IP4), D-myo-inositol 1,3,4,5,6-pentakisphosphate (IP5) and D-myo-inositol 1,2,3,4,5,6-hexakisphosphate (IP6). Migration of all liposome batches was compared to that of control liposomes (containing only triple distilled water), and to that of free phosphatidylcholine (PC); the same amount of lipid was used in all situations. Thin-layer chromatography was performed on silica gel as adsorbent. As solvent we used an n-buthanol:ethanol:water mixture in a 4:3:3 volume ratio. Significant differences were found between PC and all liposome batches, as well as between control liposomes and the ones containing IP3, alpha-trinositol, IP4, or IP5, in various concentrations. Liposomes containing IP6 migrate completely differently compared not only to phosphatidylcholine and control liposomes, but also to the ones containing other IPs ( < 10(-3) M). Unlike the other IPs studied, liposome-entrapped IP6 elicits dose-dependent contractions of the isolated rat aorta. This suggests that liposomes loaded with IP6 undergo, during or after their preparation, physico-chemical alterations that eventually change their drug-delivery capacity.
Department of Physiology, University of Medicine and Pharmacy Gr. T. Popa, Iasi, Romania.
E
E
Brailoiu
G
G
Huhurez
S
S
Slatineanu
C M
CM
Filipeanu
M
M
Costuleanu
D D
DD
Branisteanu
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D002855:Chromatography, Thin Layer; D004337:Drug Carriers; D015544:Inositol 1,4,5-Trisphosphate / Q000032:analysis / Q000737:chemistry; D007295:Inositol Phosphates / Q000032:analysis / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008297:Male; D010713:Phosphatidylcholines / Q000737:chemistry; D010833:Phytic Acid / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D051381:Rats
D004337:Drug Carriers; D007295:Inositol Phosphates; D008081:Liposomes; D010713:Phosphatidylcholines; C081655:inositol-1,3,4,5-tetrakisphosphate; C013571:inositol pentaphosphate; D010833:Phytic Acid; D015544:Inositol 1,4,5-Trisphosphate; C059368:atrinositol