The ascorbyl palmitate-water system: Phase diagram and state of water

A liquid crystal of ascorbyl palmitate, used as vaccine platform, provides sustained release of antigen and has intrinsic pro-inflammatory and adjuvant activities which are dependent on MyD88 adaptor protein

“…The first hydration layer is composed of about 11 water molecules per ASC16 molecule, which are strongly attached to the oxygen and the hydrogen of the -OH groups of the polar headgroups by hydrogen bonds, included in a 3 Å thick layer; the second hydration layer is formed by about 50-60 water molecules per ASC16 one and is extended up to 9 Å from the polar group. Water not included in these two categories behaves as bulk water that surrounds the plate like "islands" and dissolves the few monomers in equilibrium with the coagel phase [3]. Their applications are numerous and we have previously reported that these systems are able to improve the apparent solubility and permeation of certain molecules [4][5][6], and/or generating in vitro a controlled release [7].…”

Alkyl esters of l-ascorbic acid: Stability, surface behaviour and interaction with phospholipid monolayers

“…The physicochemical behaviour of ASC n has been extensively studied in drug/water systems [2,3,11], but only a few studies have investigated the surface behaviour of these amphiphiles comprising early studies on ascorbyl stearate [12][13][14] and more recently about ascorbyl palmitate (ASC 16 ) [15,16]. Whilst Langmuir monolayers at the air/water interface composed of ascorbyl stearate shows a completely condensed behaviour in the whole surface pressure range, the commercial product ASC 16 forms monolayers which undergo phase transition from a liquid-expanded (LE) to a liquid-condensed (LC) or crystalline phase (C), depending on the electrostatic properties of the film conferred by ionic strength and subphase pH [16,17].…”

Phase Behavior of Ascorbyl Palmitate Coagels Loaded with Oligonucleotides as a New Carrier for Vaccine Adjuvants

“…The phase Gabriela behavior of Asc n (c n being the length of the alkyl chain) is probably one of the most reliable physicochemical evidence of the complex series of intermolecular interactions (hydrophobic, electrostatic and hydrogen bonding interactions), which control the thermal behavior of aqueous dispersions of these surfactants. Ascorbyl palmitate (Asc 16 ) belongs to this family of molecules and its physicochemical behavior has been widely studied [1][2][3][4]. Ambrosi et al [5] and later Benedini et al [3] have reported that Asc 16water system forms clear dispersions at temperatures higher than the critical micelle temperature (CMT) and at higher concentration than the critical micelle concentration (CMC).…”