We have investigated the influence of charg and lipid concentration on the in-vivo percutaneous absorption of a model compound, methyl nicotinate 8MN), from liposomal vesicles. MN-loaded liposomes were produced by the reverse-phase evaporation method (REV) using different concentrations of phosphatidylcholine (PC) and dicetyl phosphate (DCP), which impart a positive or negative charge to the systems, respectively. The liposomal suspensions were then processed to hydrogels and used to study in-vivo the MN permeation profile. MN was chosen as the model compound since it was capable of causing cutaneous erythema, the intensity and duration of which was proportional to the amount of entering the living epidermis over time. The extent of the erythema was monitored by reflectance spectrophotometry, a non-invasive technique. In-vivo findings showed an interesting MN delayed release, which was proportional to the amount of phospholipids in each liposomal formulation. Furthermore, it could be noted that the erythematous efect was more prolonged when MN was delivered from neutral or negatively-charged liposomal forms.
Effect of charge and lipid concentration on in-vivo percutaneous absorption of methyl nicotinate from liposomal vesicles
ESPOSITO, Elisabetta;MENEGATTI, Enea;NASTRUZZI, Claudio;CORTESI, Rita;
2005
Abstract
We have investigated the influence of charg and lipid concentration on the in-vivo percutaneous absorption of a model compound, methyl nicotinate 8MN), from liposomal vesicles. MN-loaded liposomes were produced by the reverse-phase evaporation method (REV) using different concentrations of phosphatidylcholine (PC) and dicetyl phosphate (DCP), which impart a positive or negative charge to the systems, respectively. The liposomal suspensions were then processed to hydrogels and used to study in-vivo the MN permeation profile. MN was chosen as the model compound since it was capable of causing cutaneous erythema, the intensity and duration of which was proportional to the amount of entering the living epidermis over time. The extent of the erythema was monitored by reflectance spectrophotometry, a non-invasive technique. In-vivo findings showed an interesting MN delayed release, which was proportional to the amount of phospholipids in each liposomal formulation. Furthermore, it could be noted that the erythematous efect was more prolonged when MN was delivered from neutral or negatively-charged liposomal forms.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
