Positively and negatively charged liposomes as carriers for transdermal delivery of sumatriptan: in vitro characterization.
BACKGROUND
The influence of liposome composition, lamellarity, preparation method, and charge on the encapsulation efficiency, size, polydispersity, and surface charge of sumatriptan liposomes was studied. For this purpose, we studied multilamellar, unilamellar, and frozen and thawed liposomes. Positively or negatively charged liposomes were obtained using both phosphatidylcholine and cholesterol, in combination with stearylamine or dicetylphosphate. Liposomal formulations were characterized by confocal laser scanning microscopy and optical microscopy for vesicle formation, morphology, and lamellarity by dynamic laser light scattering for size distribution and polydispersity, and electrophoretic mobility for zeta potential determination. To obtain more information about the sumatriptan encapsulation, dynamic dialysis technique was employed. The sumatriptan amount was quantified by high-performance liquid chromatography.


RESULTS
Overall obtained results showed that liposomes may be interesting carriers for sumatriptan succinate. Statistical analysis evidenced that the preparation method does not affect the evaluated characterization parameters. However, the presence of charge inducer agents modified these characteristics. Highest loading efficiency of sumatriptan was exhibited for positively charged liposomes containing 6.58:10.34:3.73 mmolar ratio for phosphatidylcholine : cholesterol : stearylamine. The mean size was affected by the charge inducer, being smaller in positively charged liposomes. Logically, surface charge of liposomes varied as a function of the employed charged agent. Also, interesting results were obtained when vesicles were loaded with sumatriptan, showing a statistical significance between all pairs, comparing the formulations with and without drug.


CONCLUSIONS
Results obtained revealed that the presence of sumatriptan into the vesicles has a different behavior in negatively and positively charged liposomes.
Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Seville, Seville, Spain.
Sheila
S
Villasmil-Sánchez
Wijdane
W
Drhimeur
Sirce Cecilia Salas
SC
Ospino
Antonio M
AM
Rabasco Alvarez
M L
ML
González-Rodríguez
D000279:Administration, Cutaneous; D004337:Drug Carriers / Q000008:administration & dosage* / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods; D008081:Liposomes; D010316:Particle Size; D018170:Sumatriptan / Q000008:administration & dosage* / Q000737:chemistry*
D004337:Drug Carriers; D008081:Liposomes; D018170:Sumatriptan