ABSTRACT
BACKGROUND: The use of retinaldehyde or glycolic acid was found to be effective in topical acne treatments. OBJECTIVE: The aim of this study was thus to take advantage of the possible synergistic effect between retinaldehyde and glycolic acid and to combine the latter in a single formulation, in other words, in an oil-in-water emulsion. METHODS: A certain number of critical parameters were taken into account when designing the formulation, i.e. solubility of retinaldehyde and glycolic acid, pH of the finished product and insufficient stability of retinaldehyde notably in the presence of water. Consequently, the oil components, which form the oily phase of the emulsion, were carefully selected according to the solubility of retinaldehyde. Moreover, we aimed at obtaining adequate emulsion stability so that a large amount of water could be used to make the hydroxy acid soluble. RESULTS AND CONCLUSION: The best retinaldehyde-glycolic acid (RALGA) formulation developed had a low pH (around 3.5) and, when stored at 40 degrees C, revealed a good stability. Finally, the antibacterial activity of this formulation was also tested in vitro against Propionibacterium acnes and showed antibacterial results after only 5 min of contact.
Subject(s)
Dermatologic Agents/chemistry , Glycolates/chemistry , Keratolytic Agents/chemistry , Retinaldehyde/chemistry , Chemistry, Pharmaceutical , Drug Combinations , Drug Design , Drug Synergism , Emulsions , Glycolates/pharmacology , Humans , Hydrogen-Ion Concentration , Propionibacterium acnes/drug effects , Retinaldehyde/pharmacology , SolubilitySubject(s)
DNA/chemistry , Phospholipids/chemistry , Polyethylene Glycols/chemistry , Animals , Chemical Phenomena , Chemistry, Physical , DNA/pharmacokinetics , Electrochemistry , Emulsions , Excipients , Freeze Fracturing , Iodine Radioisotopes , Mice , Particle Size , Phosphatidylcholines/chemistry , Tissue Distribution , Transfection/methods , X-Ray DiffractionABSTRACT
Owing to the rapid development of in vivo applications for nonviral gene delivery vectors, it is necessary to have a better understanding of how the structure-activity relationships of these lipid-DNA complexes are affected by their environment. Indeed, research in gene therapy first focused on in vitro cell culture studies to determine the mechanisms involved in the delivery of DNA into the cell. New biophysical techniques such as electron microscopy and X-ray diffraction have been developed to discern the structure of the lipid-DNA complex. However, further studies have revealed discrepancies between optimal lipid-DNA formulations for in vitro transfection and for in vivo administration of these vectors. Furthermore, some immune stimulatory effects have been associated with in vivo lipid-DNA administration. This review summarizes the current state of knowledge on in vitro and in vivo lipid-DNA complex transfections. New prospects of vectors for in vivo gene transfer are also discussed.
Subject(s)
DNA/metabolism , Gene Transfer Techniques , Lipid Metabolism , Animals , DNA/chemistry , Genetic Therapy/methods , Humans , Lipids/chemistry , Liposomes/metabolism , Microscopy, Electron , Models, Biological , Plasmids/metabolism , Structure-Activity Relationship , Transfection , X-Ray DiffractionABSTRACT
The purpose of this work was to study the effect of iontophoretic transport of Propranolol hydrochloride on the lipidic organization of the stratum corneum pretreated under passive or iontophoretic conditions by two model penetration enhancers, sodium lauryl sulfate and hexadecyl trimethylammonium bromide. Characterization of human stratum corneum was performed by X-ray diffraction, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and differential scanning calorimetry (DSC). The structural properties were compared with the iontophoretic permeability of propranolol hydrochloride on human stratum corneum. The iontophoretic fluxes of propranolol hydrochloride were effectively increased by two-fold in stratum corneum pretreated with sodium lauryl sulfate. In contrast, they were halved in stratum corneum pretreated with hexadecyl trimethylammonium bromide. These results could be related to changes in the electrical and structural properties of the stratum corneum after incorporation of these enhancers.
