| Autor: |
J. M. López Pinto, J. Palma, M. L. González Rodríguez, A. M. Rabasco, FINI, ADAMO |
| Přispěvatelé: |
J.M. López-Pinto, J. Palma, M.L. González-Rodríguez, A. Fini, A.M. Rabasco |
| Jazyk: |
angličtina |
| Rok vydání: |
2004 |
| Předmět: |
|
| Popis: |
Purpose: Lamellarity of liposomes is an important parameter that may influence the entrapment efficacy of vesicles. In order to characterize the number of lamellas of a minoxidil (Mx) liposome system, a new application of Confocal Laser Scanning Microscopy (CLSM) was developped. Methods: Different minoxidil liposomes systems were prepared by mechanical dispersion. MLV (Multilamellar vesicles) dipalmitoylphosphatidylcholine - cholesterol (DPPC – CHOL) liposomes containing Mx or fluorescent probe b-carotene (bC) were obtained. All systems investigated were characterize with regard to its entrapment efficacy, by dynamic dialysis and assayed by HPLC (Mx) or spectrofotometrically (bC). Lamellarity was analized by means of a Confocal Laser Scanning Microscope using both, fluorescence and transmitted light channels. Results: Dynamic dialysis assays revealed high entrapment efficacies both for liposomes containing Mx or bC when a certain amount of cholesterol is present in the formulation. It existed a good correlation between entrapment efficacies of Mx or bC, as not significant differences were observed for both kinds of systems. Lamellarity studies of the vesicles showed a major distribution of multilamellar vesicles for all systems studied, with a number of concentric bilayers ranged between 3 and 6. Sonicated vesicles showed a clear tendency to diminish their lamellarity, finding out a representative number of unilamellar vesicles in the formulation. Conclusion: A new technique is presented for characterization of liposomes lamellarity. CLSM constitutes a new procedure that allows to visualize number and morphology of lamellas in liposomes. CLSM provide a great imaging quality of the formulation in its aqueous medium. Non sonicated liposomes showed a multillamelar distribution, while sonication of MLV introduce a number of unilamellar vesicles in the formulation. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
