On the plasticizing properties of divalproex sodium: physicochemical and spectroscopic characterization studies.

The objective of the research was to demonstrate the plasticization properties of divalproex sodium, due to its component-valproic acid, on ethyl cellulose, which could prove beneficial for film fabrications or hot melt extrusion based formulations. Films containing 10-50% w/w (DVS/EC) as dry weight were prepared using solvent evaporation method and characterized using texture analyzer, hybrid rheometer, differential scanning calorimetry, thermogravimetry, X-ray diffractometry, polarized microscopy, FTIR, and Raman spectroscopy. It was found that there was a decrease in average peak load, melt viscosity, and glass transition temperature (Tg) while increase in elongation, with increase in concentration of DVS in the films. These results demonstrate the plasticization tendency of DVS on EC, which was attributed to the presence of valproic acid (fatty acid) in DVS. XRD studies showed amorphous nature of the films; however, polarized microscopy revealed the presence of scattered undissolved sodium valproate crystals. The presence of a single Tg established complete miscibility between valproic acid and EC. Films showed reasonable physical stability (similar Tg) at 45 °C/75% RH for 2 weeks (open condition), attributable to the similar solubility parameters of DVS and EC. FTIR and Raman spectroscopy results proved the presence of hydrogen bonding between DVS and EC.

Recent Advances in Lipid-Based Vesicles and Particulate Carriers for Topical and Transdermal Application.

In the recent decade, skin delivery (topical and transdermal) has gained an unprecedented popularity, especially due to increased incidences of chronic skin diseases, demand for targeted and patient compliant delivery, and interest in life cycle management strategies among pharmaceutical companies. Literature review of recent publications indicates that among various skin delivery systems, lipid-based delivery systems (vesicular carriers and lipid particulate systems) have been the most successful. Vesicular carriers consist of liposomes, ultradeformable liposomes, and ethosomes, while lipid particulate systems consist of lipospheres, solid lipid nanoparticles, and nanostructured lipid carriers. These systems can increase the skin drug transport by improving drug solubilization in the formulation, drug partitioning into the skin, and fluidizing skin lipids. Considering that lipid-based delivery systems are regarded as safe and efficient, they are proving to be an attractive delivery strategy for the pharmaceutical as well as cosmeceutical drug substances. However, development of these delivery systems requires comprehensive understanding of physicochemical characteristics of drug and delivery carriers, formulation and process variables, mechanism of skin delivery, recent technological advancements, specific limitations, and regulatory considerations. Therefore, this review article encompasses recent research advances addressing the aforementioned issues.