Permeation Of Mannitol Research Articles

Impact of Media in Transport Study on Cell Monolayer Integrity and Permeability

Literature review shows that various media have been used for in vitro transport study, but their impact on the monolayer integrity and permeability has been somehow neglected, and there is no systemic study on this subject. This study aims to investigate the impact of 6 commonly used media on Madin-Darby Canine Kidney cell viability and adherence, and the permeation of mannitol and propranolol. Dulbecco's modified Eagle medium (DMEM), cMedium (DMEM with serum), Hanks’ balanced salt solution (HBSS), HBSS− (without Ca2+/Mg2+), Dulbecco's phosphate-buffered saline (DPBS), and DPBS− (without Ca2+/Mg2+) exhibited no cytotoxicity. Cell detachment was observed in 4 media in the order of DPBS− ≈ HBSS− > DPBS > HBSS. HBSS−/DPBS− caused 70% TEER reduction and 4-fold higher apparent permeability (Papp) of mannitol than the other media. The addition of D-glucose in DPBS− decreased the Papp of mannitol. Cations and glucose negligibly influenced the Papp of propranolol. The addition of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) in HBSS increased the Papp of both mannitol and propranolol for 2-3 folds without TEER reduction. In conclusion, the media compositions (Ca2+/Mg2+, glucose, vitamins, amino acids, and HEPES) can affect the monolayer integrity and permeability. DMEM and cMedium without HEPES are hence suggested as the media in transport study to avoid the potential impact on the monolayer integrity and permeability by the media.

Effect of penetration enhancers on the permeation of mannitol, hydrocortisone and progesterone through human skin.

Mannitol, hydrocortisone and progesterone were selected as model penetrants to assess the mode of action of eight potential penetration enhancers in human skin. Their partition coefficients, octanol: water and stratum corneum: water were measured and correlated with their postulated routes of penetration through human skin. The results suggest that mannitol penetrated via a polar route, hydrocortisone by a mainly lipid route and progesterone via a lipid pathway but its penetration rate was probably affected by aqueous layers. From permeation studies through cadaver skin in which an in-vivo mimic method was used, it was concluded that the penetration enhancers fell into three main categories: solvents which enhanced permeation of polar and non-polar compounds e.g. 2-pyrrolidone, N-methylpyrrolidone, N-methylformamide and propylene glycol plus Azone; enhancers which preferentially affected the polar route e.g. propylene glycol plus decylmethylsulphoxide, and accelerants which mainly modified the non-polar route e.g. propylene glycol plus oleic acid, propylene glycol alone and, to a limited extent, water.

Effect of electroporation on the electroosmosis across hairless mouse skin in vitro

The effect of electroporation on the iontophoresis-produced electroosmosis across the skin was evaluated by measuring the permeability of hairless mouse skin, to mannitol, a non-electrolyte, in vitro. Immediately after electroporation by squared pulses (10 times/s) at 100, 150 or 200 V for 1 ms, anodal iontophoretic permeations were determined at 0.4 mA/cm 2 for 4 h. The observed iontophoretic permeability of mannitol was higher with electroporation pretreatment than without pretreatment. The enhanced flux of mannitol induced by electroporation, however, was due to increased passive diffusion. The contribution of convective or osmotic flow caused by anodal iontophoresis on skin permeation of mannitol was decreased by the pretreatment. In addition, osmotic flow was decreased with an increase in the applied voltage for electroporation. In contrast, mannitol flux during cathodal iontophoresis at 0.4 mA/cm 2 after 150 or 200 V electroporation was higher than without electroporation as well as anodal iontophoresis, but cathodal iontophoretic flux after electroporation was lower than without iontophoresis. The neutral high-molecular compound dextran rhodamine B was also used as a second model. Anodal iontophoresis alone did not increase skin permeability of the compound. However, electroporation pretreatment before anodal iontophoresis enhanced the skin permeation of dextran rhodamine B, which was due to increased osmotic flow induced by this combination. These results suggest that electroporation decreases the electroosmosis produced by iontophoresis, and that electroporation increases skin permeability to neutral low and high model compounds (mannitol and dextran rhodamine B) probably due to an enlarged permeation pathway. Thus, electroporation affects osmotic flow from the anode to cathode during iontophoresis. Therefore, one has to pay attention to the change in electroosmosis produced by iontophoresis for the combined use of electroporation and iontophoresis to attain a high skin-penetration enhancing effect.

Effect of cathode and anode positions, frequency of applied pulse, and electrode materials at electroporation on the in vitro skin permeation of mannitol: Comparison with iontophoresis.

Effect of cathode and anode positions, frequency of applied pulse, and electrode materials at electroporation on the in vitro skin permeation of mannitol: Comparison with iontophoresis.

Apoplasmic and Protoplasmic Water Transport through the Parenchyma of the Potato Storage Organ.

Stationary volume fluxes through living and denatured parenchyma slices of the potato (Solanum tuberosum L.) storage organ were studied to estimate the hydraulic conductivity of the cell wall and to evaluate the significance of water transport through protoplasts, cell walls, and intercellular spaces. Slices were placed between liquid compartments, steady-state fluxes induced by pressure or concentration gradients of low- and high-molecular-mass osmotica were measured, and water transport pathways were distinguished on the basis of their difference in limiting pore size. The protoplasts were the dominating route for osmotically driven water transport through living slices, even in the case of a polymer osmoticum that is excluded from cell walls. The specific hydraulic conductivity of the cell wall matrix is too small to allow a significant contribution of the narrow cell wall bypass to water flow through the living tissue. This conclusion is based on (a) ultrafilter coefficients of denatured parenchyma slices, (b) the absence of a significant difference between ultrafilter coefficients of the living tissue slices for osmotica with low and high cell wall reflection coefficients, and (c) the absence of a significant interaction (solvent drag) between apoplasmic permeation of mannitol and the water flux caused by a concentration difference of excluded polyethylene glycol. Liquid-filled intercellular spaces were the dominating pathways for pressure-driven volume fluxes through the parenchyma tissue.

A Method to Quantitatively Compare In Vivo the Effects of Gallstone Solvents on Intestinal Mucosal Function: A Controlled Study Comparing Mono-Octanoin with Methyl tert-Butyl Ether in the Rat

During contact dissolution of gallstones, solvents may escape from the gallbladder and damage the intestinal mucosa. In order to compare the extent of this potential injury, we developed a method to objectively quantify the effects of two commonly used cholesterol solvents, methyl tert-butyl ether and mono-octanoin, on mucosal transport function in the rat intestine. Two intestinal segments in each of 184 anesthetized rats were cannulated. Three milliliters of either solvent were instilled in one segment and left for varying periods of time, while saline was instilled in the other as control. The segments were then washed and perfused for 45 min with an isotonic solution containing [3H]polyethylene glycol 4000 (a nonabsorbable reference marker) and either [14C]alpha-aminoisobutyric acid (a marker for active absorption) or [14C]mannitol (a marker for passive permeability). Methyl tert-butyl ether caused more inhibition of alpha-aminoisobutyric acid absorption (64%) than mono-octanoin (48%) and a greater reduction of dry weight per centimeter of the perfused segment (22%) compared with mono-octanoin (10%). Such effects appeared after only 1 min of solvent exposure and did not appreciably increase with longer exposures. Permeation of mannitol increased by 26% after 1 min of exposure to mono-octanoin and by 54% after a similar period of exposure to methyl tert-butyl ether. Longer exposures to both solvents did not seem to cause progressive increases in mannitol permeation. The results indicate that brief exposure of the rat jejunum to either of the two solvents causes a reduction in active transport ([14C]alpha-aminoisobutyric acid absorption), an increase in passive permeability (mannitol permeation), and a loss of mucosal constituents. We conclude that the intestinal mucosa is susceptible to solvent damage and may be used as a selectively sensitive model that can characterize the biological injury of gallstone solvents. The study also suggests that escape of the currently available solvents into the small intestine in patients undergoing contact dissolution of gallbladder stones may cause injury to the small intestine.

Analysis of in vivo skin penetration enhancement by oleic acid based on a two-layer diffusion model with polar and nonpolar routes in the stratum corneum

The enhancement effect of oleic acid on the in vivo percutaneous absorption of mannitol, 6-mercaptopurine, and butylparaben was evaluated in rats. A deconvolution method was applied to estimate skin permeation from urinary excretion profiles of drugs. Oleic acid markedly increased skin permeation of mannitol and 6-mercaptopurine, while it slightly increased the permeation of butylparaben at the low dose but decreased it at the high dose. To elucidate the mechanism of enhancement of skin permeation by oleic acid, the estimated in vivo penetration profiles were analyzed based on a two-layer skin diffusion model with polar and nonpolar routes in the stratum corneum. With respect to the polar route, oleic acid did not change the diffusion parameter but increased the partition parameter, suggesting that it increased hydration of the stratum corneum and enlarged the aqueous pore pathway. On the other hand, oleic acid increased both the diffusion and partition parameters of 6-mercaptopurine in the nonpolar route. The mechanism of action of oleic acid was compared to those determined in a previous in vitro study using guinea pig skin. It was revealed that the basic mechanism of oleic acid for enhancing drug permeation was comparable between the present and previous studies, and that the difference in the apparent enhancement effect of oleic acid was due to the in vitro-in vivo difference in the degree of hydration of the stratum corneum and the diffusion length of the dermis layer.

Enhanced permeation of polar compounds through human epidermis. I. Permeability and membrane structural changes in the presence of short chain alcohols

The influence of alcohol chain length on polar compound permeation in human skin was investigated to further understand alcohol-enhanced permeation mechanisms. Both thermodynamic and kinetic variables associated with the enhanced permeation of mannitol were ascertained in the presence of high concentrations of short chain alcohols. Permeation of mannitol through human epidermis in the presence of 75% (v/v) alcohol-saline mixtures was determined in symmetric, side-by-side diffusion cells at 32°C. Permeability coefficients increased with increasing alcohol chain length ( iso-propanol > ethanol > methanol ). Uptake of mannitol into the epidermal tissue increased in the presence of the short chain alcohols, but was independent of alcohol chain length. In addition, mannitol solubility decreased in the presence of the short chain alcohols, but again was independent of alcohol chain length. Therefore, increased mannitol permeability with increasing alcohol chain length could not be attributed to thermodynamic variables. Changes in the amount and conformation of stratum corneum lipids and proteins were determined by Fourier transform infrared (FTIR) spectroscopy. Stratum corneum lipid conformation and mobility was not significantly altered in the presence of the short chain alcohols. However, decreased absorbance of the alkyl chain suggested lipid extraction, which increased with increasing alcohol chain length. Stratum corneum protein conformation was altered in the presence of the short chain alcohols. Decreased infrared absorbance of the Amide I band maximum suggested extraction of stratum corneum proteins, which increased with increased alcohol chain length. These results suggest a correlation between enhanced permeation and extraction of lipids as well as proteins from human skin in the presence of 75% (v/v) aqueous alcohol solutions.

Differential effects of osmotic pressure on mitochondrial respiratory chain and indices of oxidative phosphorylation

Oxidative phosphorylation was critically evaluated in terms of activities which are sensitive and insensitive to variations in external osmotic pressure in mitochondria. Integrity of mitochondria was determined in terms of a variety of parameters, including the latency of the occluded enzymes, by careful titrations as a function of external osmotic pressure as well as detergent concentrations. The evidence indicated that the rate-limiting step in respiratory states 2 and 4 would be osmotically insensitive, as opposed to the osmotically sensitive respiration of states 1 and 3 and uncoupler-stimulated respiration with glutamate + malate and succinate. Cytochrome oxidase activity in mitochondria as well as in purified reconstituted systems exhibited osmotic insensitivity but marked sensitivity to ionic strength, offering an interesting model to study the osmotically insensitive respiration. Cytochrome oxidase activity led to permeation of mannitol across the mitochondrial inner membrane. Stimulation of cytochrome oxidase activity by uncouplers did not require an intact membrane.

An automated diffusion apparatus for studying skin penetration

An automated diffusion apparatus was developed, holding 24 stainless steel diffusion cells with flow-through receptor solution. The apparatus can be used for pseudo-steady-state or in vivo mimic procedures, and requires only small samples of skin. To validate the apparatus, the absorption was determined of water, methanol, ethanol, butanol and hexanol from aqueous solution under pseudo-steady-state conditions: the permeability coefficients increased with carbon number. We measured the permeation of mannitol from dimeihylisosorbide-water (DS : water) vehicle and deposited drug films, and the effects of N-methyl-2-pyrrolidone (NP) and 2-pyrrolidone (2P), using pseudo-steady-state and in vivo mimic conditions. Although penetration from the deposited mannitol film was low, penetration from DS: water and from NP and 2P was similar, indicating that NP and 2P had not accelerated mannitol permeation. Both investigations provided information which correlated favourably with the literature, thus confirming the validity and usefuless of the automated apparatus.