Thermal and 31P-NMR studies to elucidate sumatriptan succinate entrapment behavior in phosphatidylcholine/cholesterol liposomes. Comparative 31P-NMR analysis on negatively and positively-charged liposomes.

In this paper, two techniques, differential scanning calorimetry (DSC) and phosphorus nuclear magnetic resonance ((31)P-NMR), have been used to characterize sumatriptan succinate-loaded charged liposomes. To complete the results obtained by DSC a hot stage microscopy (HSM) technique was used. Data concerning the drug entrapment efficiency were published in a previous paper.

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.