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1.  Lipid-based supramolecular systems for topical application: A preformulatory study 
AAPS PharmSci  2003;5(4):62-76.
This article describes the production and characterization of monoglyceride-based supramolecular systems by a simple processing technique, avoiding time-consuming procedures, high energy input, and the use of organic solvents. A preformulatory study was performed to study the influence of the experimental parameters on the production of monoglyceride-based disperse systems. In particular the effects of (1) stirring speed, (2) type and concentration of monoglyceride mixture, and (3) type and concentration of surfactant were investigated on the recovery, fraction of larger particles, mean diameter, and shape of smaller particles (so called nanosomes). Dispersions were first characterized by optical microscopy and freeze-fracture electron microscopy. The mean diameter of standard nanosomes, analyzed by photon correlation spectroscopy (PCS) after elimination of larger particles by filtration, was 193.5 nm. Cryotransmission electron microscopy studies, conducted in order to investigate the structure of dispersions, showed the coexistence of vesicles and particles characterized by a cubic organization. X-ray diffraction data revealed the coexistence of 2 different cubic phases, the first being a bicontinuous cubic phase of spatial symmetry Im3m (Q229) and the second belonging to the Pn3m spatial symmetry. A study on the stability of monoglyceride-based dispersions based on macroscopical analysis of organoleptic properties and dimensional analysis by time was performed after elimination of larger particles by filtration. Organoleptic and morphological features do not change by time, appearing free from phase-separation phenomena for almost 1 year from production. PCS studies showed that nanosomes undergo an initial increase in mean diameter within the first month following production; afterwards they generally maintain their dimensions for the next 4 months.
PMCID: PMC2750992  PMID: 15198518
monoglycerides; nanosome dispersions; photon correlation spectroscopy
2.  Formulations for natural and peptide nucleic acids based on cationic polymeric submicron particles 
AAPS PharmSci  2003;6(1):10-21.
This article describes the production and characterization of cationic submicron particles constituted with Eudragit RS 100, plus different cationic surfactants, such as dioctadecyl-dimethyl-ammonium bromide (DDAB18) and diisobutyphenoxyethyl-dimethylbenzyl ammonium chloride (DEBDA), as a transport and delivery system for DNA/DNA and DNA/peptide nucleic acid (PNA) hybrids and PNA-DNA chimeras. Submicron particles could offer advantages over other delivery systems because they maintain unaltered physicochemical properties for long time periods, allowing long-term storage, and are suitable for industrial production. Submicron particles were characterized in terms of size, size distribution, morphology, and zeta potential. Moreover, the in vitro activity and ability of submicron particles to complex different types of nucleic acids were described. Finally, the ability of submicron particles to deliver functional genes to cells cultured in vitro was determined by a luciferase activity assay, demonstrating that submicron particles possess superior transfection efficiency with respect to commercially available, liposome-based transfection kits.
PMCID: PMC2750937  PMID: 18465254
peptide nucleic acids; delivery; submicron particles

Results 1-2 (2)