scholarly journals Distribution of benzalkonium chloride into the aqueous phases of submicron dispersed systems: emulsions, aqueous lecithin dispersion and nanospheres

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Dorota Watrobska–Swietlikowska
Keyword(s):  
Aqueous Phase ◽  
Benzalkonium Chloride ◽  
Microbial Growth ◽  
Total Concentration ◽  
Active Form ◽  
Polysorbate 80 ◽  
Micellar Phase ◽  
Initial Concentration ◽  
Dispersed Systems ◽  
Submicron Emulsions

AbstractPartitioning of benzalkonium chloride (BAC) into the aqueous phases of submicron dispersed systems such as submicron emulsions, aqueous lecithin dispersion (WLD), and suspension of nanospheres (NLC) was studied. The aqueous phases of the investigated systems were obtained by ultracentrifugation and subsequently were subjected to ultrafiltration, which procedure allowed distinguishing between the fractions of free benzalkonium chloride (w) and those incorporated in the liposomal and micellar region (wlm). The fractions present in the oily phase and in the interphase of submicron emulsions were calculated. Despite the various composition of the investigated formulations and the initial concentration of BAC, w values were very small at 0.2–8.0%. The wlm value in submicron emulsions was increased by increasing the total concentration of preservative from 29.0 to 42.0%. Using polysorbate 80 instead of lecithin resulted in a distribution of BAC to aqueous–liposomal–micellar phase that was twice as high. The very low concentration of antimicrobial active form of benzalkonium chloride was analyzed in the aqueous phase of emulsions stabilized with lecithin as well as in aqueous lecithin dispersion and nanospheres (below 3%). Replacement of lecithin with polysorbate 80 in emulsions with polysorbate significantly increase (up to 8%) the fraction of benzalkonium chloride in the aqueous phase where microbial growth occurs.

Extraction of hafnium(IV) with organophosphorus reagents from solutions of mineral acids mixtures

1979 ◽  
Vol 44 (12) ◽  
pp. 3656-3664
Author(s):  
Oldřich Navrátil ◽  
Jiří Smola ◽  
Rostislav Kolouch
Keyword(s):  
Ionic Strength ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Synergic Effect ◽  
Salting Out ◽  
Initial Concentration ◽  
Mixed Complexes ◽  
Synergic Extraction ◽  
Mineral Acids

Extraction of hafnium(IV) was studied from solutions of mixtures of perchloric and nitric acids and of perchloric and hydrochloric acids for constant ionic strength, I = 2, 4, 6, or 8, and for cHf 4 . 10-4 mol l-1. The organic phase was constituted by solutions of some acidic or neutral organophosphorus reagents or of 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, or N-benzoyl-N-phenylhydroxylamine in benzene, chloroform, or n-octane. A pronounced synergic extraction of hafnium proceeds only on applying organophosphorus reagents from an aqueous phase whose acidity is not lower than 3M-(HClO4 + HNO3) or 5M-(HClO4 + HCl). The synergic effect was not affected markedly by a variation of the initial concentration of hafnium in the range 1 . 10-8 -4 .10-4 mol l-1, it lowered with increasing initial concentration of the organophosphorus reagent and decreasing concentration of the H+ ions. It is suggested that the hafnium passes into the organic phase in the form of mixed complexes, the salting-out effect of perchloric acid playing an appreciable part.

scholarly journals The formation of nitro-aromatic compounds under high NO<sub><i>x</i></sub> and anthropogenic VOC conditions in urban Beijing, China

2019 ◽  
Vol 19 (11) ◽  
pp. 7649-7665 ◽  
Author(s):  
Yujue Wang ◽  
Min Hu ◽  
Yuchen Wang ◽  
Jing Zheng ◽  
Dongjie Shang ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Aromatic Compounds ◽  
Total Concentration ◽  
Fine Particulate Matter ◽  
Oxidation Products ◽  
Urban Atmosphere ◽  
Formation Pathway ◽  
Relative Contribution ◽  
Phase Oxidation ◽  
Nitro Aromatic

Abstract. Nitro-aromatic compounds (NACs), as important contributors to the light absorption by brown carbon, have been widely observed in various ambient atmospheres; however, their formation in the urban atmosphere was little studied. In this work, we report an intensive field study of NACs in summer 2016 at an urban Beijing site, characterized by both high-NOx and anthropogenic VOC dominated conditions. We investigated the factors that influence NAC formation (e.g., NO2, VOC precursors, RH and photolysis) through quantification of eight NACs, along with major components in fine particulate matter, selected volatile organic compounds, and gases. The average total concentration of the quantified NACs was 6.63 ng m−3, higher than those reported in other summertime studies (0.14–6.44 ng m−3). 4-Nitrophenol (4NP, 32.4 %) and 4-nitrocatechol (4NC, 28.5 %) were the top two most abundant NACs, followed by methyl-nitrocatechol (MNC), methyl-nitrophenol (MNP), and dimethyl-nitrophenol (DMNP). The oxidation of toluene and benzene in the presence of NOx was found to be a more dominant source of NACs than primary biomass burning emissions. The NO2 concentration level was found to be an important factor influencing the secondary formation of NACs. A transition from low- to high-NOx regimes coincided with a shift from organic- to inorganic-dominated oxidation products. The transition thresholds were NO2 ∼ 20 ppb for daytime and NO2∼25 ppb for nighttime conditions. Under low-NOx conditions, NACs increased with NO2, while the NO3- concentrations and (NO3-)/NACs ratios were lower, implying organic-dominated products. Under high-NOx conditions, NAC concentrations did not further increase with NO2, while the NO3- concentrations and (NO3-)/NACs ratios showed increasing trends, signaling a shift from organic- to inorganic-dominated products. Nighttime enhancements were observed for 3M4NC and 4M5NC, while daytime enhancements were noted for 4NP, 2M4NP, and DMNP, indicating different formation pathways for these two groups of NACs. Our analysis suggested that the aqueous-phase oxidation was likely the major formation pathway of 4M5NC and 3M5NC, while photo-oxidation of toluene and benzene in the presence of NO2 could be more important for the formation of nitrophenol and its derivatives. Using the (3M4NC+4M5NC) ∕ 4NP ratios as an indicator of the relative contribution of aqueous-phase and gas-phase oxidation pathways to NAC formation, we observed that the relative contribution of aqueous-phase pathways increased at elevated ambient RH and remained constant at RH > 30 %. We also found that the concentrations of VOC precursors (e.g., toluene and benzene) and aerosol surface area acted as important factors in promoting NAC formation, and photolysis as an important loss pathway for nitrophenols.

Anaphylactic Shock following Povidone

1996 ◽  
Vol 30 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Ma Angeles Gonzalo Garijo ◽  
José A Durán Quintana ◽  
Pedro Bobadilla González ◽  
Pilar Máiquez Asuero
Keyword(s):  
Anaphylactic Reaction ◽  
Benzalkonium Chloride ◽  
Reticuloendothelial System ◽  
Pharmaceutical Products ◽  
In Vitro Tests ◽  
Polysorbate 80 ◽  
Provocation Tests ◽  
Release Histamine ◽  
Intraarticular Administration

OBJECTIVE: To report a patient with an anaphylactic reaction related to povidone administration. CASE SUMMARY: A 37-year-old man with a history of allergic rhinitis presented with urticaria, dyspnea, wheezing, rhinorrhea, and dysphonia 20 minutes after the intraarticular administration of mepivacaine hydrochloride and paramethasone acetate in his right knee. Two months after this episode, he was admitted for controlled provocation tests. Tests on mepivacaine were negative. The preparation of paramethasone contained the excipients benzalkonium chloride, polysorbate 80, and povidone. In vitro tests and provocation were negative with polysorbate 80 and benzalkonium chloride, but positive with povidone. DISCUSSION: Povidone, a mixture of synthetic polymers, is commonly used as an excipient in pharmaceutical products, an additive in food products, and a dispersant and stabilizer in hairsprays. Although it is well tolerated when used topically or parenterally, local and systemic effects have been reported. Furthermore, multiorgan involvement resulting from accumulation of the drug in the reticuloendothelial system has been described. The immunologic properties of povidone have not been explored in humans, but have been in animals. In fact, the capacity of povidone to release histamine and its immunogenicity are proportional to its molecular weight. An immunoglobulin (Ig) E-mediated hypersensitivity reaction in asthma has been reported. In our case, povidone was responsible for the syndrome. However, we cannot determine the exact mechanism. An unspecific histamine release and/or an IgE-mediated hypersensitivity could be involved. CONCLUSIONS: Povidone was responsible for a severe anaphylactic reaction in our patient. The possibility of an iatrogenic adverse effect caused by the excipient but not by the active ingredient should be considered in patients exhibiting similar symptoms. We believe that the excipients used in the preparation of all medicines should be disclosed.

Protein extration from an aqueous phase into a reversed micellar phase: Effect of water content and reversed micellar composition

1995 ◽  
Vol 46 (4) ◽  
pp. 375-387 ◽  
Author(s):  
R. Hilhorst ◽  
M. Sergeeva ◽  
D. Heering ◽  
P. Rietveld ◽  
P. Fijneman ◽  
...  
Keyword(s):  
Water Content ◽  
Aqueous Phase ◽  
Phase Effect ◽  
Micellar Phase ◽  
Effect Of Water

Cytotoxicity of Ear Drop Excipients in Human and Mouse Tympanic Membrane Fibroblasts

2019 ◽  
Vol 162 (2) ◽  
pp. 204-210
Author(s):  
Carolyn O. Dirain ◽  
David N. Karnani ◽  
Patrick J. Antonelli
Keyword(s):  
Tympanic Membrane ◽  
Benzyl Alcohol ◽  
Benzalkonium Chloride ◽  
Phase Contrast ◽  
Growth Media ◽  
Polysorbate 80 ◽  
Mouse Fibroblasts ◽  
Dose Dependent ◽  
Ear Drops ◽  
Human And Mouse

Objective Commercial ear drops contain ingredients reported to be inactive. We sought to evaluate such excipients for possible cytotoxicity on human and mouse tympanic membrane (TM) fibroblasts. Study Design Prospective, in vitro. Setting Tertiary academic center. Subjects and Methods Mouse and human TM fibroblasts were treated with 1:10 dilutions of benzalkonium chloride (BKC) 0.0025%, 0.006%, or 0.01%; benzyl alcohol 0.9%; polysorbate 80 (PSB) 2.5%; glycerin 2.4%; povidone 0.2%; or water (control), twice within 24 hours or 4 times within 48 hours, for 2 hours each time. Cells were placed back in growth media after the treatments. Cells were observed with phase-contrast microscopy until the cytotoxicity assay was performed. Results Mouse fibroblasts had lower survival in only the PSB-treated cells compared to the control ( P < .0001) after 24 hours. After 48 hours, PSB killed nearly all mouse fibroblasts ( P < .0001). BKC decreased fibroblast survival in a dose-dependent manner ( P < .001). In human TM fibroblasts, all excipients except povidone and benzyl alcohol after 24 hours and povidone after 48 hours reduced cell survival compared to control ( P = .012 to P < .0001). The cytotoxicity of BKC in human TM fibroblasts was also dose dependent (<.0001). PSB was less cytotoxic to human fibroblasts. Phase-contrast images mirrored the cytotoxicity findings. Conclusion Polysorbate 80 and benzalkonium chloride, at concentrations found in commercial ear drops, may be cytotoxic to human and mouse TM fibroblasts. “Inactive” ingredients may need to be considered when evaluating clinical outcomes with commercial ear drops.

Transport between an aqueous phase and a CTAB/hexanol-octane reversed micellar phase

1998 ◽  
Vol 1 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Lu Qiang ◽  
Chen Hongyan ◽  
Li Kuanhong ◽  
Shi Yajun
Keyword(s):  
Aqueous Phase ◽  
Micellar Phase

scholarly journals Determination of Individual Homologues and Total Content of Benzalkonium Chloride by Reversed-Phase High-Performance Liquid Chromatography Using a Short Butyl Column

2009 ◽  
Vol 92 (6) ◽  
pp. 1644-1651 ◽  
Author(s):  
Fangzhu Liu ◽  
Kang Ping Xiao ◽  
Abu M Rustum
Keyword(s):  
Benzalkonium Chloride ◽  
Mobile Phase ◽  
High Performance ◽  
Total Concentration ◽  
Total Content ◽  
Reversed Phase ◽  
Hplc Method ◽  
Raw Material ◽  
Short Column

Abstract Benzalkonium chloride (a mixture of alkylbenzyldimethylammonium chlorides that usually contains C-10, C-12, C-14, and C-16 homologues), commonly known as BKC, is used as a bacteriostatic agent in many household, food, and drug products. In this paper, we report a simple, rapid, robust, and stability-indicating reversed-phase HPLC method using a short butyl (C4) column for the simultaneous determination of each individual homologue content, as well as the total concentration of individual homologues in commercial bulk raw material batches of BKC samples. The chromatographic separation was performed on a 5 cm ACE C4 column with mobile phase consisting of water, acetonitrile, and potassium chloride. Even though using a short column can potentially cause some challenges to resolving certain critical pairs of peaks, we have successfully separated all of the analyte peaks (including those from stressed, degraded products) on a short column using an optimal mobile phase.

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