Interactions of 6-O-Stearoylascorbic Acid and Vitamin K₁ in Mixed Langmuir Films at the Gas/Water Interface

Abstract

6-O-Stearoylascorbic acid (ASC) and vitamin K1 (2-methyl-3-phytylnaphthoquinone) behave as surfactant molecules and form stable monomolecular spreading films at the gas/water interface. This paper reports an investigation on the miscibility of these two amphiphiles in monolayers as a function of temperature and composition of the mixture. A thermodynamic theory is applied to the experimental results in order to obtain information on the intermolecular interactions occurring at the gas/water interface between the two components. Experiments show that the two components are fully miscible in all ratios and at all temperatures, with repulsive interactions that are probably due to the presence of branched methyl groups in the phytyl chains of vitamin K 1 and to the presence of a negative charge on the hydrophilic head group of ASC.

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

“…The addition of ASC 12 to ocular topical preparation improves the permeation of the hydrophobic drug acetazolamide, more efficiently than ASC 16 [5]. The same picture was observed for permeation of ibuprofen through the mouse skin [6].…”

“…It has been shown that ASC n conserve part of the radical scavenging activity in aggregates such as micelles. For example, ASC 10 micelles retain about half of the antioxidant performance for oxygen uptake [1], whilst ASC 12 and ASC 14 only retain $40 and $34% of the antioxidant activity [7,9] compared to unmodified L-ascorbic acid. It is well known that L-ascorbic acid is stable in solid form, but it is susceptible to oxidation when in solution.…”

“…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].…”

Amino Acids, Lactic Acid and Ascorbic Acid as Raw Materials for Biocompatible Surfactants

“…Cappuzzi et al [129] studied the mixtures of stearoyl ascorbic acid and vitamin K 1 . These two compounds form stable Langmuir films at the air/water interface for temperatures ranging from 20 to 35 • C and are completely miscible in the monolayer in all ratios.…”

Pharmacological in vivo test to evaluate the bioavailability of some St. John's wort innovative oral preparations

“…In the literature, many papers demonstrate the synergic effects between different constituents of Hypericum perforatum L. (Butterweck et al, 1998;Noldner and Schotz, 2002;solubility of the constituents of the extract within the formulations was evaluated to better elucidate the results obtained from the pharmacological tests. (Capuzzi et al, 1996); water content and purity were checked by elemental analysis (theoretical C 55.62%, H 7.33%; found C 53.80%, H 7.45%). Ethanol was analytical reagent grade from Riedelde Haen (Seelze, Germany).…”