In addition to solubilization, CAM nanoparticle formation was observed when a 2:1 ground mixture of CAM and ASC-G was dispersed into an aqueous media. This molar ratio-specific nanoparticle formation might be attributable to a grinding-induced interaction in the solid state via the ketone group in the lactone ring of CAM. It is concluded that cogrinding with ASC-G is a promising method for modifying the Inhibitors,research,lifescience,medical dissolution properties of CAM. Further study focusing on the application of ASC-G in other poorly water-soluble drugs is required. Figure 2 Comparison of solubilization

and nanoparticle formation characteristics between the CAM-ascorbic acid (ASA) and CAM-ASC-G systems.

(A) Particle fractions of the drug in the CAM:ASC-G systems. (B) Changes in the mean particle Inhibitors,research,lifescience,medical size of … 1.2. Ascorbyl n-Alkyl Fatty Acid Derivative: Structure and Oxidation Process Ascorbyl monoalkylate has both lipophilic and hydrophilic moiety and exhibits properties of typical surfactant. The structures and physicochemical properties have been well described by Palma et al. [12]. The self-assembly properties depend on the length of the n-alkyl fatty chain. Ascorbyl monoalkylate starts to aggregate at the Krafft point, at which the solubility reaches the critical micellar concentration (CMC). Above this temperature, ascorbyl monoalkylate can Inhibitors,research,lifescience,medical aggregate in micelles or the gel phase, depending Inhibitors,research,lifescience,medical on the alkyl side chain. Upon cooling, liquid-crystal structures (coagels) are obtained for less soluble derivatives (ascorbyl laurate, ascorbyl

myristate, and ascorbyl palmitate). These structures can solubilize drugs, improve their stability, and promote their permeation through the skin. Their rheological properties are also suitable for topical administration of pharmaceuticals. Reducing activity (RA) measurement of some antioxidant chemicals indicated that hydrophobic Inhibitors,research,lifescience,medical KPT-330 supplier vitamin C derivatives (from ascorbyl octanoate to ascorbyl stearate) keep the same antioxidant activity of vitamin C but have the advantage of being soluble in both aqueous and hydrophobic media [1]. These derivatives possess the same RA of several natural products; therefore, they can be used as radical Phosphoprotein phosphatase scavengers in the protection of such natural compounds. The enediol functionality of ascorbyl palmitate is prone to oxidation in the presence of oxygen, a process that usually leads to formation of dehydroascorbyl palmitate (Figure 3) in which the OH functionality is oxidized into keto moiety [13–15]. Figure 3 Tautomerization of ascorbyl palmitate. Structure of dehydroascorbyl palmitate is shown in parentheses. 1.3. Ascorbyl Octanoate (ASC-8) The self-assembling and antioxidant activities of ASC-8 were reported by LoNostro et al. [1].