Paraben Exposure Related To Purine Metabolism and Other Pathways Revealed by Mass Spectrometry-Based Metabolomics

Parabens are widely used as common preservatives in the pharmaceutical and cosmetic industries. Exposure to parabens has been found to be associated with metabolic alterations of human and an increased risk of metabolic disease, such as diabetes. However, limited information is available about metabolic pathways related to paraben exposure. In this study, three parabens were determined in the urine samples of 88 pregnant women by using ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ MS). The samples were divided into different groups based on tertile distribution of urinary paraben concentrations. Metabolic profiling of the 88 urine samples was performed by using UHPLC coupled with Orbitrap high-resolution MS. Differential metabolites were screened by comparing the profiles of urine samples from different paraben-exposure groups. The identified metabolites included purines, acylcarnitines, etc., revealing that metabolic pathways such as purine metabolism, fatty acid β-oxidation, and other pathways were disturbed by parabens. Eighteen and three metabolites were correlated (Spearman correlation analysis, p < 0.05) with the exposure levels of methyparaben and propylparaben, respectively. This is the first MS-based nontargeted metabolomics study on pregnant women with paraben exposure. The findings reveal the potential health risk of exposure to parabens and might help one to understand the link between paraben exposure and some metabolic diseases.

Parabens in breast milk and possible sources of exposure among lactating women in Korea

Parabens, broad-spectrum antimicrobial preservatives widely used in various consumer products and food, are suspected to be linked with several adverse health effects in humans, especially newborn babies, infants, and young children. While human exposure to parabens has been frequently reported by measuring the concentration of parabens in urine, similar measurements in breast milk have rarely been made. To determine paraben concentrations in breast milk and possible sources of exposure, four major parabens, including methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) were measured in breast milk samples collected from 260 lactating women in South Korea. Demographic, socioeconomic, and behavioral factors associated with the presence of parabens in breast milk were determined. EP concentrations were detected at the highest levels in breast milk samples, followed by MP, PP, and BP. Pre-pregnancy BMI, parity, use of basic skin care products, use of cosmetics, canned beverage, and type of milk consumption were associated with higher frequencies of paraben detection. In addition, type of milk, parity, and drinking status were significantly associated with the concentration of EP. Multiple regression analyses showed that colostrum and transitional milk samples had higher levels of EP than mature milk samples. The estimated daily intake of parabens in infants via breastfeeding appears to be negligible when compared to the acceptable daily intake values set forth by the European Food Safety Authority (EFSA); however, considering the vulnerability of breastfed infants and ubiquitous sources of exposure from daily use of household and personal toiletries, efforts to identify sources and mitigate exposure are warranted.

Basics: Excipients Used in Nonsterile Compounding, Part 3: Preservatives

Preservative selection is a critical step in the preparation of a formulation to ensure its microbiological effectiveness and stability. A number of physicochemical factors must be considered when selecting a preservative, including concentration, solubility, and pH. A preservative must also be nontoxic, stable, compatible, inexpensive, and have an acceptable taste, odor, and color. It should also be effective against a wide variety of bacteria, fungi, and yeasts, and be free from incompatibilities. This article discusses some of the factors involved in selecting an appropriate preservative.

Basics: Excipients Used in Nonsterile Compounding, Part 2

The July-August 2019 issue of the International Journal of Pharmaceutical Compounding includes part 1 of a 3-part article on the topic of excipients used in nonsterile compounding. This article, which discusses dosage form design and excipients related to appearance, palatability, flavoring, sweetening, and coloring, represents part 2 of this 3-part series. Part 3 will discuss preservatives used in nonsterile preparations. The topics presented in part 2 are very important for patient compliance. The colors, flavors, sweetening, appearance, and other dosage form characteristics can often be modified to enhance compliance by the patient, which can aid in therapeutic effectiveness.

Essential oils and their bioactive compounds as green preservatives against fungal and mycotoxin contamination of food commodities with special reference to their nanoencapsulation

Fungal and mycotoxin contamination of stored food items is of utmost concern throughout the world due to their hazardous effects on mammalian systems. Most of the synthetic chemicals used as preservatives have often been realised to be toxic to humans and also cause adverse environmental effects. In this respect, use of different plant products especially essential oils (EOs) and their bioactive compounds has been recognized as a green strategy and safer alternatives to grey synthetic chemicals in view of their long traditional use. The current nanoencapsulation technology has strengthened the prospective of EOs and their bioactive compounds in food preservation by enhancing their bioactivity and mitigating other problems regarding their large-scale application. Although, the antimicrobial potential of EOs and their bioactive compounds has been reviewed time to time by different food microbiologists, but very less is known about their mode of action. Based on these backgrounds, the present article provides an account on the antifungal and antimycotoxigenic mode of action of EOs as well as their bioactive compounds. In addition, the article also deals with the application of currently used nanoencapsulation approach to improve the stability and efficacy of EOs and their bioactive compounds against mycotoxigenic fungi causing deterioration of stored food items so as to recommend their large-scale application for safe preservation and enhancement of shelf life of food items during storage.

An insight into toxicity and human-health-related adverse consequences of cosmeceuticals - A review

In recent years, the use of cosmeceutical-based personal care and beauty products has ever increased, around the world. Currently, an increasing number of compounds are being assimilated in the formulation of cosmetic products as preservatives, fragrances, surfactants, etc. to intensify the performance, quality, value, and lifespan of cosmetics. Nevertheless, many of these chemical additives pose toxic effects to the human body, exhibiting health risks from a mild hypersensitivity to life-threatening anaphylaxis or lethal intoxication. Therefore, the indiscriminate application of cosmeceuticals has recently become a mounting issue confronting public health. The present review focuses on exposure to a large variety of toxic substances used in cosmetic formulations such as 1,4-dioxane formaldehyde, paraformaldehyde, benzalkonium chloride, imidazolidinyl urea, diazolidinyl urea, trace heavy metals, parabens derivatives, phthalates, isothiazolinone derivatives (methylchloroiso-thiazolinone, and methylisothiazolinone), methyldibromo glutaronitrile, and phenoxy-ethanol. The biological risks related to these substances that they can pose to human health in terms of cytotoxicity, genotoxicity, mutagenicity, neurotoxicity oestrogenicity or others are also discussed. Researchers from academia, consultancy firms, governmental organizations, and cosmetic companies should carry out further progress to keep updating the consumers regarding the dark-sides, and health-related harmful apprehensions of cosmetics. In addition, the industry-motivated initiatives to abate environmental impact through green, sustainable and eco-friendly product development grasp significant perspective.

Prenatal exposure to parabens and anthropometric birth outcomes: A systematic review

Parabens are ubiquitous substances commonly used as preservatives because of their antibacterial activity. The estrogenic activity of parabens may cause undesirable health effects and adverse birth outcomes. The objective of the present systematic review was to investigate the association between prenatal exposure to parabens and anthropometric birth outcomes. PubMed, Web of Science, Scopus, and Embase databases were systematically searched until April 18, 2018. Of 326 records that remained after removing duplicates, 6 original articles were included in the final analysis after excluding irrelevant articles. The included studies indicated that most of the pregnant mothers were exposed to parabens, especially methyl and propyl parabens. However, no definitive association was found between the prenatal urinary concentration of parabens and birth weight or head circumference. In addition, a positive but non-significant association was detected between birth length and maternal exposure to parabens. The present systematic review revealed that assessment of significant associations in current epidemiological studies is impermissible due to methodological limitations and absence of inter-study consistency. Furthermore, because of the complexity of the effect of environmental factors on health, future large-scale studies with proper study design are required to investigate the effect of parabens exposure on birth outcomes.

Human urine contamination with environmental pollutants: simultaneous determination using UPLC-MS/MS

Paraben derivatives are widely used as an antifungal, antimicrobial preservative in cosmetic products, pharmaceuticals, and food. These molecules are called endocrine disruptors (EDCs). The exposure of the human body to paraben derivatives needs further study and for this purpose 200 urine samples were collected from Tunisian men and women aged between 5 and 90 years to determine three paraben derivatives: methylparaben (MP), ethylparaben (EP) and propylparaben (PP) using ultra performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS). The three major parabens were found in 95 urine samples. The obtained results indicate that MP, EP, and PP were detected in 57%, 46%, and 40% of all samples, respectively. Urinary concentration for the three parabens was in the range of 0.88-84.46 ng/mL, 0.52-29.2 ng/mL, and 0.51-28.17 ng/mL of PP, MP, and EP, respectively. In addition, the concentrations of the paraben derivatives in women were higher than those of men. These findings indicate that the exposure occurs from common products (foods, cosmetics, and pharmaceuticals). The Tunisian authorities should control the composition of packaging of these common products in order to protect humans against EDCs.

Changes in ocular signs and symptoms in patients switching from bimatoprost-timolol to tafluprost-timolol eye drops: an open-label phase IV study

OBJECTIVES

Bimatoprost-timolol (bimatoprost 0.03%-timolol 0.5% fixed-dose combination [FDC]) and tafluprost-timolol (tafluprost 0.0015%-timolol 0.5% FDC) eye drops are currently the only topical intraocular pressure (IOP)-reducing therapies available as preservative-free (PF) prostaglandin and timolol FDC. The aim of this study was to investigate changes to ocular signs and symptoms when patients with ocular hypertension (OH) or open-angle glaucoma (OAG) switched from PF or benzalkonium chloride (BAK)-preserved bimatoprost-timolol to PF tafluprost-timolol eye drops.

DESIGN

This was a 12-week, open-label, phase IV study.

SETTING

Sixteen centres in Finland, Germany, Italy and the UK.

PARTICIPANTS

Patients with OH or OAG (IOP on medication ≤21 mm Hg), treated with PF or BAK-preserved bimatoprost-timolol for ≥4 weeks before screening, and presenting with conjunctival hyperaemia and ≥1 ocular symptom.

INTERVENTIONS

Patients were switched to PF tafluprost-timolol once daily in the treated eye(s).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary endpoints were change from screening to week 12 in conjunctival hyperaemia and worst ocular symptom. The secondary outcome measures were changes from screening in ocular signs (other than conjunctival hyperaemia) and symptoms at week 12.

RESULTS

Of 123 enrolled patients, 121 were included in the intention-to-treat dataset, of which all were Caucasian and 54.5% were female; 76 patients used BAK-preserved bimatoprost-timolol and 45 used PF drops. Conjunctival hyperaemia and severity of worst ocular symptom following switch to PF tafluprost-timolol significantly reduced from screening to week 12 in all patients (p<0.001). The percentage of patients with ocular signs and symptoms was significantly reduced at week 12 compared with screening (p<0.001). IOP was not affected by the change of treatment.

CONCLUSIONS

Switching from BAK-preserved or PF bimatoprost-timolol to tafluprost-timolol reduced both signs and symptoms of ocular surface disease with no clinically relevant effect on IOP.

TRIAL REGISTRATION NUMBER

EudraCT2014-005273-37; Results.

Impact of Brush Cytology Analysis for the Diagnosis of Esophageal Squamous Cell Carcinoma: The Quality of Liquid-Based Preparation of Cytological Slides

OBJECTIVES

The diagnostic performance of cytology in esophageal squamous cell carcinoma (ESCC) is meticulously described.

METHODS

Cytological and biopsy specimens were prospectively taken during esophagogastroduodenoscopy of 123 individuals in 2013 and 2014. Cytology samples were maintained in preservative fluid until processing and biopsies were formalin-fixed and paraffin-embedded.

RESULTS

Based on endoscopic biopsy results, 70 cases were positive for ESCC whilst 53 were negative for cancer. In addition, brush cytology showed high sensitivity and specificity (98.57 and 96.23%, respectively) in detecting the disease, and high accuracy (97.5%) comparable to that provided by histopathology which is the accepted gold standard.

CONCLUSION

Brush cytology specimens preserved in liquid medium may be a good alternative for ESCC diagnosis.

[Influence of treatment adherence on the progression of primary open-angle glaucoma in clinical setting]

According to various studies, treatment adherence of patients with primary open-angle glaucoma ranges from 5% to 80% and significantly influences the effectiveness of the therapy. Some authors report higher levels of adherence in patients receiving preservative-free medications.

PURPOSE

To study the influence of treatment adherence in patients receiving preservative-free and preserved medications on the progression of primary open-angle glaucoma (POAG).

MATERIAL AND METHODS

This prospective multicenter non-interventional study was conducted in clinical setting and included 504 patients with primary open-angle glaucoma receiving drug therapy; 51 ophthalmologist was involved in the management of patients' diaries.

RESULTS

The percentage of patients who did not reach target IOP was three times lower in the group with high adherence, in comparison to patients with medium and low adherence (7% against 22%, respectively). Development of side effects was one of the factors influencing treatment adherence, their rates and expressiveness were much lower in the preservative-free group compared with the group receiving preserved medication (13.9% against 35.4%). The rate of patients who did not reach target IOP was two times lower in the group of preservative-free medication (10% against 21%).

CONCLUSION

The study confirms that preservative-free glaucoma medication promotes higher adherence to treatment in clinical setting predominantly due to the reduction of quantity and severity of side effects leading to treatment gaps, which results in increased effectiveness and better stabilization of glaucoma.

Temporal Trends of Parabens and Their Metabolites in Mollusks from the Chinese Bohai Sea during 2006-2015: Species-Specific Accumulation and Implications for Human Exposure

Parabens are used as preservatives in many consumer products, and human exposure to these chemicals has been a public concern. In this study, mollusks ( n = 186), collected from the Chinese Bohai Sea during 2006-2015, were analyzed for six parabens and their five metabolites. The total concentration of parabens was in the range of 2.66-299 ng/g dw (geometric mean: 24.1). Methyl paraben and 4-hydroxybenzoic acid were the predominant parent and metabolic parabens, respectively found in mollusks. Mollusk species, Mactra veneriformis, Mytilus edulis, and Cyclina sinensis contained elevated concentrations of both parent and metabolic parabens. A gradual increase in paraben concentrations was found in mollusks collected between 2006 and 2012. Principal component analysis suggested the existence of a common source for these chemicals in mollusks. Consumption of mollusks can contribute to human exposures and we estimated daily intakes of parabens through the consumption of mollusks. This is the first study to report temporal trends and accumulation of parabens and their metabolites in a variety of invertebrate species from coastal marine environments.

ASSESSMENT OF FUNCTIONAL CHANGES TEAR PRODUCTION UNDER THE ACTION OF THE EYE DROPS ON THE BASE OF NATURAL MOLECULE OF ECTOINE AND ARTIFICIAL TEARS IN PATIENTS WITH DRY EYE SYNDROME ON THE BACKGROUND OF ENDOCRINE OPHTHALMOPATHY

Conducted a comparative analysis of functional changes in tear production in patients with dry eye syndrome and endocrine ophthalmopathy in the conditions of the long-term acting of preservative free medications based on natural substances. A total of 30 people, aged 35 to 53 years old with clinical manifestations of DES on the background of EO were divided on two groups. In I group eye drops of ectoine and in II - artificial tears were administered. The examination included general and specific methods. The term of follow up - 30 days. It was found that long-term use of preservative free eye drops based on ectoine leads to more expressive positive changes in the condition of the anterior surface of the eye and the secretion and quality of the tear.

Paraben degradation using catalytic ozonation over volcanic rocks

Parabens are widely used as antimicrobial and preservatives in pharmaceutical and personal care products and are continuously reaching the water streams. Conventional wastewater treatments are proven inefficient on the removal of this kind of contaminants from wastewater. Therefore, catalytic ozonation appears as a suitable option, due to the oxidant power of ozone and its high capacity of hydroxyl radical generation in the presence of a suitable catalyst. The main drawback of catalytic ozonation is related with the choice of stable and active catalysts at low cost. On this way, two volcanic rocks were tested to enhance the removal of a mixture of parabens by ozonation, improving their degradation. Indeed, catalytic ozonation with volcanic rock allowed total paraben degradation using a transferred ozone dose (TOD) of 55 mg/L which corresponds to a reduction of about threefold the amount of TOD comparatively with single ozonation (170 mg/L of TOD). Due to the presence of semiconductors on volcanic rock composition, the effect of UVA irradiation on paraben degradation was analyzed. The neutral and basic conditions enhanced catalytic ozonation comparatively to acid conditions. Higher pH values allowed a total methylparaben degradation with 35 mg O₃/L, whereas for low pH values, 55 mg O₃/L was required. The use of a radical scavenger proven that hydroxyl radicals are the main responsible for paraben degradation with catalytic ozonation. This was confirmed through the analysis of the by-products, where 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid (3,4-diHBA), 2,4-dihydroxybenzoic acid, and hydroquinone were quantified.

Long term safety and tolerability of Tafluprost 0.0015% vs Timolol 0.1% preservative-free in ocular hypertensive and in primary open-angle glaucoma patients: a cross sectional study

BACKGROUND

The effects of preservatives of antiglaucoma medications on corneal surface and tear function have been widely shown in literature; it's not the same as regards the active compounds themselves. The purpose of our study was to compare Ocular Surface Disease (OSD) signs and symptoms of Tafluprost 0.0015% versus preservative free (PF) Timolol 0.1% eyedrops in ocular hypertensive (OH) and in primary open-angle glaucoma (POAG) patients.

METHODS

A cross-sectional study included patients in monotherapy for at least 36 months with Tafluprost 0.0015% (27) or PF Timolol 0.1% (24) and 20 healthy age and sex-matched volunteers. All subjects underwent clinical tests (Schirmer I and break-up time), in vivo confocal microscopy (IVCM) and were surveyed using Ocular Surface Disease Index (OSDI) and Glaucoma Symptoms Scale (GSS) questionnaires. The groups were compared with ANOVA, Kruskal-Wallis test, t-test, Mann-Whitney test and Bonferroni's adjustment of p-values.

RESULTS

No significant differences were found in questionnaires scores, clinical tests, IVCM variables between therapy groups. Tafluprost 0.0015% group showed significantly higher OSDI score, basal epithelial cells density, stromal reflectivity, sub-basal nerves tortuosity (p = 0.0000, 0.037, 0.006, 0.0000) and less GSS score, number of sub-basal nerves (p = 0.0000, 0.037) than controls but similar clinical tests results (p > 0.05). PF Timolol group had significantly higher OSDI score, basal epithelial cells density, stromal reflectivity and sub-basal nerve tortuosity (p = 0.000, 0.014, 0.008, 0.002), less GSS score, BUT and number of sub-basal nerves (p = 0.0000, 0.026, 0.003) than controls.

CONCLUSIONS

Compared to PF Timolol 0.1%, Tafluprost 0.0015% showed similar safety with regards to tear function and corneal status and a similar tolerability profile. Both therapy groups show some alterations in corneal microstructure but no side effects on tear function except for an increased tear instability in PF Timolol 0.1% group. Ophtalmologists should be aware that even PF formulations may lead to a mild ocular surface impairment.

Paraben Concentrations in Maternal Urine and Breast Milk and Its Association with Personal Care Product Use

Parabens are broad-spectrum antimicrobial preservatives and fragrances used in a wide range of personal care products, pharmaceuticals, and food providing the opportunity for people to be exposed on a daily basis. In 2009-2010, 80 pregnant women from Ottawa Canada participated in the Plastics and Personal-Care Product Use in Pregnancy (P4) Study. A subset of women (n = 31) who provided multiple spot urine samples (n = 542) collected over two 24-h periods had their samples analyzed for methylparaben (MP), n-propylparaben (PP), ethylparaben (EP), butylparaben (BP), isobutylparaben (IBP), and benzylparaben (BzP). These parabens were also measured in breast milk samples collected at approximately 3 months postpartum (n = 56 women). Women kept a diary of products that they used 24 h prior to and during the collection. All parabens measured in maternal urine had moderate to high reproducibility. Women who used lotions in the past 24 h had significantly higher geometric mean paraben concentrations (80-110%) in their urine than women who reported no use in the past 24 h. Women who used shampoo, conditioner, and cosmetics also showed 70-80% higher BP concentrations in their urine. Breast milk samples had >50% detection for MP, PP, and EP.

24-Hour Efficacy and Ocular Surface Health with Preservative-Free Tafluprost Alone and in Conjunction with Preservative-Free Dorzolamide/Timolol Fixed Combination in Open-Angle Glaucoma Patients Insufficiently Controlled with Preserved Latanoprost Monotherapy

INTRODUCTION

The aim of the present study was to evaluate the 24-h efficacy, tolerability, and ocular surface health with preservative-free (PF) tafluprost and a PF triple drug regimen comprising tafluprost and dorzolamide/timolol fixed combination (DTFC) in open-angle glaucoma patients who were insufficiently controlled with preserved branded or generic latanoprost monotherapy and who exhibited signs or symptoms of ocular surface disease (OSD).

METHODS

Prospective, observer-masked, crossover, comparison. Eligible consecutive open-angle glaucoma patients were randomized to either PF tafluprost or the triple PF regimen for 3 months. They were then crossed over to the opposite therapy for another 3 months. At the end of the latanoprost run-in period and after each PF treatment period, patients underwent habitual 24-h intraocular pressure (IOP) monitoring with Goldmann tonometry in the sitting position (at 10:00, 14:00, 18:00, and 22:00) and Perkins tonometry in the supine position (at 02:00 and 06:00). Tolerability and selected ocular surface parameters were evaluated at baseline and the end of each treatment period.

RESULTS

Forty-three open-angle glaucoma patients completed the trial. Mean 24-h IOP on preserved latanoprost was 22.2 ± 3.9 mmHg. Compared with latanoprost monotherapy, PF tafluprost obtained a greater reduction in mean, peak, and fluctuation of 24-h IOP including the 02:00 and 06:00 time points (P < 0.05). With the exception of 24-h fluctuation, the triple PF regimen provided significantly lower IOP parameters than latanoprost or PF tafluprost (P < 0.001). Finally, PF tafluprost therapy displayed significantly improved tear film break-up times (6.7 vs 6.0 s), corneal staining (1.3 vs 2.2), and Schirmer I test results (9.1 vs 8.2 mm) compared with the preserved latanoprost baseline (all P < 0.01). The triple PF regimen demonstrated similar tear film break-up times (6.1 vs 6.0 s) and Schirmer I test results (8.2 vs 8.2 mm) to latanoprost, but revealed a significant improvement in the corneal stain test (1.7 vs 2.2; P < 0.001).

CONCLUSIONS

In this trial PF tafluprost therapy provided statistically greater 24-h efficacy and improved tolerability compared with preserved latanoprost. The combination of PF tafluprost and PF dorzolamide/timolol fixed combination was statistically and clinically more efficacious than both monotherapies and demonstrated similar ocular surface characteristics to preserved latanoprost monotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02802137).

FUNDING

Santen.

Presumed Sterile Endophthalmitis Afer Intravitreal Triamcinolone (Kenalog)-More Common and Less Benign Than We Thought?

PURPOSE

This study aimed to review the incidence and clinical outcome of presumed sterile endophthalmitis after the off-label use of intravitreal Kenalog injections (triamcinolone acetonide with 1.5% benzyl alcohol) and to compare it with the presumed sterile endophthalmitis incidence after intravitreal Kenacort-A (0.99% benzyl alcohol) at our center.

DESIGN

This was a single-center, retrospective, consecutive, interventional case series of all patients who underwent intravitreal Kenalog injections at Hong Kong Eye Hospital from November 1, 2009, to July 31, 2012.

METHODS

This was a retrospective medical records review.

RESULTS

A total of 81 intravitreal Kenalog injections were performed. Ten eyes (12.3%) developed presumed sterile endophthalmitis, presenting clinically with dense anterior chamber cells, fibrin, hypopyon, and vitritis. All cases were treated with topical steroids and antibiotics. Although the inflammation resolved eventually in all cases, 2 eyes developed complications, resulting in eventual loss of best corrected visual acuity: one developed rhegmatogenous retinal detachment with choroidal detachment, and another developed vitreous hemorrhage.

CONCLUSIONS

The rate of presumed sterile endophthalmitis after Kenalog injection is much higher than our previous experience with Kenacort-A. To the best of our knowledge, this is the first study reporting the incidence of presumed sterile endophthalmitis using intravitreal Kenalog and Kenacort in the same center using the same injection technique. We believe that it may be due to a difference in the concentration of the preservative. Although sterile endophthalmitis is generally thought to run a benign course, this study has shown that serious complications may occur.

pH modulation ameliorates the red blood cell storage lesion in a murine model of transfusion

BACKGROUND

Prolonged storage of packed red blood cells (pRBCs) induces a series of harmful biochemical and metabolic changes known as the RBC storage lesion. RBCs are currently stored in an acidic storage solution, but the effect of pH on the RBC storage lesion is unknown. We investigated the effect of modulation of storage pH on the RBC storage lesion and on erythrocyte survival after transfusion.

METHODS

Murine pRBCs were stored in Additive Solution-3 (AS3) under standard conditions (pH, 5.8), acidic AS3 (pH, 4.5), or alkalinized AS3 (pH, 8.5). pRBC units were analyzed at the end of the storage period. Several components of the storage lesion were measured, including cell-free hemoglobin, microparticle production, phosphatidylserine externalization, lactate accumulation, and byproducts of lipid peroxidation. Carboxyfluorescein-labeled erythrocytes were transfused into healthy mice to determine cell survival.

RESULTS

Compared with pRBCs stored in standard AS3, those stored in alkaline solution exhibited decreased hemolysis, phosphatidylserine externalization, microparticle production, and lipid peroxidation. Lactate levels were greater after storage in alkaline conditions, suggesting that these pRBCs remained more metabolically viable. Storage in acidic AS3 accelerated erythrocyte deterioration. Compared with standard AS3 storage, circulating half-life of cells was increased by alkaline storage but decreased in acidic conditions.

CONCLUSIONS

Storage pH significantly affects the quality of stored RBCs and cell survival after transfusion. Current erythrocyte storage solutions may benefit from refinements in pH levels.

How to recognize and resolve reagent-dependent reactivity: a review

Reagent-dependent reactivity can be described as agglutination of red blood cells (RBCs) in serologic testing that is not related to the interaction of RBC antigens and antibodies that the test system is intended to detect. In other words, reagent-dependent reactivity results in false-positive agglutination reactions in serologic testing. These false-positive reactions can cause confusion in antigen typing and RBC antibody detection and identification procedures, and may result in delays in patient transfusion. It is imperative that reagent-dependent reactivity is recognized and resolved during the investigation of ABO discrepancies, positive RBC antibody screens and antibody identification panels, and crossmatch reactivity.

Preservative-free versus preserved latanoprost eye drops in patients with open-angle glaucoma or ocular hypertension

OBJECTIVE

This study compared the efficacy, safety, and pharmacokinetics of a preservative-free latanoprost formulation to an established, benzalkonium chloride (BAK) containing formulation for the treatment of open-angle glaucoma or ocular hypertension.

METHODS

This was a phase II, randomized, cross-over, investigator-masked, multi-center, pilot study (NCT01494753). A total of 30 untreated adult patients (aged ≥18 years) with primary open angle glaucoma, pseudo-exfoliative glaucoma, pigmentary glaucoma, or ocular hypertension received either preservative-free or preserved latanoprost once daily in both eyes for 6 weeks, before crossing over to receive the other treatment. Efficacy (intraocular pressure [IOP] at 8 am, midday, 4 pm and 8 pm, and global efficacy assessment by investigator), safety (adverse events, ocular symptoms and global tolerance, slit lamp examination, funduscopy, visual field examination, visual acuity, and heart rate), and pharmacokinetics were assessed at Days 0, 42, and 84.

RESULTS

Both treatments resulted in a reduction in IOP that was similar for the preservative-free and the preserved formulation at all time points. Similarly, the overall diurnal reduction was similar in both groups (6.3 mmHg [27.9% reduction] and 6.4 mmHg [28.1% reduction] for preserved and preservative-free latanoprost, respectively). There were no differences in global efficacy assessment or in the safety and tolerance of each treatment. Systemic concentrations of latanoprost were very low; AUC0-30 and Cmax were lower and tmax was longer for preservative-free latanoprost.

CONCLUSIONS

Preservative-free latanoprost showed similar efficacy at all time points compared to BAK preservative containing formulation, with no difference in tolerance, allowing progression to phase III clinical development.

Preliminary safety assessment of C-8 xylitol monoester and xylitol phosphate esters

OBJECTIVES

Most of the cosmetic compounds with preservative properties available in the market pose some risks concerning safety, such as the possibility of causing sensitization. Due to the fact that there are few options, the proper development of new molecules with this purpose is needed. Xylitol is a natural sugar, and the antimicrobial properties of xylitol-derived compounds have already been described in the literature. C-8 xylitol monoester and xylitol phosphate esters may be useful for the development of skincare products. As an initial screen for safety of chemicals, the combination of in silico methods and in vitro testing can aid in prioritizing resources in toxicological investigations while reducing the ethical and monetary costs that are related to animal and human testing. This study was designed to evaluate the safety of C-8 xylitol monoester and xylitol phosphate esters regarding carcinogenicity, mutagenicity, skin and eye irritation/corrosion and sensitization through alternative methods.

METHODS

For the initial safety assessment, quantitative structure-activity relationship methodology was used. The prediction of the parameters carcinogenicity/mutagenicity, skin and eye irritation/corrosion and sensitization was generated from the chemical structure. The analysis also comprised physical-chemical properties, Cramer rules, threshold of toxicological concern and Michael reaction. In silico results of candidate molecules were compared to 19 compounds with preservative properties that are available in the market. Additionally, in vitro tests (Ames test for mutagenicity, cytotoxicity and phototoxicity tests and hen's egg test--chorioallantoic membrane for irritation) were performed to complement the evaluation.

RESULTS

In silico evaluation of both molecules presented no structural alerts related to eye and skin irritation, corrosion and sensitization, but some alerts for micronucleus and carcinogenicity were detected. However, by comparison, C-8 xylitol monoester, xylitol phosphate esters showed similar or better results than the compounds available in the market. Concerning experimental data, phototoxicity and mutagenicity results were negative. As expected for compounds with preservative activity, xylitol-derived substances presented positive result in cytotoxicity test. In hen's egg test, both molecules were irritants.

CONCLUSION

Our results suggested that xylitol-derived compounds appear to be suitable candidates for preservative systems in cosmetics.