Microemulsion preservation needed or not

The aim of this work was to investigate is there is a need for microemulsions preservation or not. Two oil in water microemulsions with the same water/surfactant/co-surfactant [saturated polyglycolysed C8-C10 glycerides and polyglycerol isostearate], but differing in the oil phase [dipelargonate propylene glycol and isopropyl myristate] were prepared. Three different preservatives [methyl paraban, propyl paraban and sorbic acid] were added in two different concentrations to the prepared microemulsions. Challenge test [according to US Pharmacopoeia] was done for both plain microemulsion and microemulsion containing different preservatives. The results showed that there is no need for microemulsion preservation

Effect of [+] -limonene on the percutaneous absorption of naproxen from pluronic F127 gels in rabbits

In this work, the percutaneous absorption of naproxen in rabbits was investigated and compared with its in vitro release. The effect of incorporation of [+]-limonene [1-3%] as penetration enhancer on in vitro release of drug from gels and percutaneous absorption was studied using pluronic F127 as a gel base model. Percutaneous absorption was evaluated by determining the serum concentration of naproxen in rabbit's blood. The area under the curve and Cmax in plasma were also calculated. It was proved that the in vitro drug release and its percutaneous absorption were functions of the concentration of [+]-limonene. A significant increase in percutaneous absorption was obtained in the presence of enhancer