Socioeconomic inequalities in avoidable mortality in Italy: results from a nationwide longitudinal cohort.

BACKGROUND: Disparities in avoidable mortality have never been evaluated in Italy at the national level. The present study aimed to assess the association between socioeconomic status and avoidable mortality. METHODS: The nationwide closed cohort of the 2011 Census of Population and Housing was followed up for 2012-2019 mortality. Outcomes of preventable and of treatable mortality were separately evaluated among people aged 30-74. Education level (elementary school or less, middle school, high school diploma, university degree or more) and residence macro area (North-West, North-East, Center, South-Islands) were the exposures, for which adjusted mortality rate ratios (MRRs) were calculated through multivariate quasi-Poisson regression models, adjusted for age at death. Relative index of inequalities was estimated for preventable, treatable, and non-avoidable mortality and for some specific causes. RESULTS: The cohort consisted of 35,708,459 residents (48.8% men, 17.5% aged 65-74), 34% with a high school diploma, 33.5% living in the South-Islands; 1,127,760 deaths were observed, of which 65.2% for avoidable causes (40.4% preventable and 24.9% treatable). Inverse trends between education level and mortality were observed for all causes; comparing the least with the most educated groups, a strong association was observed for preventable (males MRR = 2.39; females MRR = 1.65) and for treatable causes of death (males MRR = 1.93; females MRR = 1.45). The greatest inequalities were observed for HIV/AIDS and alcohol-related diseases (both sexes), drug-related diseases and tuberculosis (males), and diabetes mellitus, cardiovascular diseases, and renal failure (females). Excess risk of preventable and of treatable mortality were observed for the South-Islands. CONCLUSIONS: Socioeconomic inequalities in mortality persist in Italy, with an extremely varied response to policies at the regional level, representing a possible missed gain in health and suggesting a reassessment of priorities and definition of health targets.

Suicide among adolescents in Italy: a nationwide cohort study of the role of family characteristics.

Suicide is a leading cause of death among adolescents and is recognized as a serious public health problem. This study aimed to investigate the relationship between family characteristics and the risk of suicide among adolescents in Italy using nationwide official data. We carried out a cohort study based on the record linkage between the 15th Italian Population Census, the Italian Population Register, and the National Register of Causes of Death. Suicides in adolescents aged 10-19 years from 2012 to 2016 were analyzed. Hazard ratios of mortality from suicide were estimated through a multivariable Cox regression model using time-on-study as the time scale. We included 8,284,359 children and adolescents (51% males, 49% females). Over the 5-year follow-up, we registered 330 deaths from suicides (74% males), mostly occurred in the age class 15-19 years (86%). The suicide rate was 1.71 per 100,000 person-years among males and 0.65 among females. We found some familial characteristics associated with a higher risk of dying by suicide, including: living in single-parent or reconstructed families (among boys), a 40-year or more age gap between mother and child (among girls), having highly educated parents, an age difference between parents greater than 5 years. Furthermore, the study showed a lower risk for boys living in urban areas and for both boys and girls living in South Italy. Our results could help in identifying adolescents at high risk of suicide who could benefit from the planning of targeted intervention strategies.

Infant mortality in Italy: large geographic and ethnic inequalities.

BACKGROUND: Neonatal and infant mortality rates are among the most significant indicators for assessing a country's healthcare and social development. This study examined the trends in neonatal, post-neonatal, and infant mortality in Italy from 2016 to 2020 and analysed differences between children of Italian and foreign parents based on areas of residence, as well as the leading causes of death. Special attention was given to the analysis of mortality in 2020, the first year of the Covid-19 pandemic, and its comparison with previous years. METHODS: Data from 2016 to 2020 were collected by the Italian National Institute of Statistics and extracted from two national databases, the Causes of Death register and Live births registered in the population register. Neonatal, post-neonatal, and infant mortality rates were calculated using conventional definitions. The main analyses were conducted by comparing Italian citizens to foreigners and contrasting residents of the North with those of the South. Group comparisons were made using mortality rate ratios. The main causes of death were examined, and Poisson log-linear regression models were employed to investigate the relationships between mortality rate ratios for each cause of death and citizenship, place of residence and calendar year. RESULTS: In Italy, in 2020, the neonatal mortality rate was 1.76 deaths per thousand live births and it was 55% higher in foreign children than in Italian children. Foreign children had a higher mortality rate than Italians for almost all significant causes of death. Children born in the South of Italy, both Italian and foreign, had an infant mortality rate about 70% higher than residents in the North. Regions with higher infant mortality were Calabria, Sicily, Campania, and Apulia. In the South, mortality from neonatal respiratory distress and prematurity was higher. In the first months of 2020, between March and June, the first Covid-19 wave, Italy experienced an increase in neonatal and infant mortality compared to the same period in 2016-2019, not directly related to SARS-CoV-19 infection. The primary cause was neonatal respiratory distress. CONCLUSIONS: The neonatal and infant mortality rates indicate the persistence of profound inequalities in Italy between the North and the South and between Italian and foreign children.

Investigation of a potential mechanism for the inhibition of SmTGR by Auranofin and its implications for Plasmodium falciparum inhibition.

Schistosoma mansoni and Plasmodium falciparum are pathogen parasites that spend part of their lives in the blood stream of the human host and are therefore heavily exposed to fluxes of toxic reactive oxygen species (ROS). SmTGR, an essential enzyme of the S. mansoni ROS detoxification machinery, is known to be inhibited by Auranofin although the inhibition mechanism has not been completely clarified. Auranofin also kills P. falciparum, even if its molecular targets are unknown. Here, we used computational and docking techniques to investigate the molecular mechanism of interaction between SmTGR and Auranofin. Furthermore, we took advantage of the homology relationship and of docking studies to assess if PfTR, the SmTGR malaria parasite homologue, can be a putative target for Auranofin. Our findings support a recently hypothesized molecular mechanism of inhibition for SmTGR and suggest that PfTR is indeed a possible and attractive drug target in P. falciparum.

Risk of stillbirth in older mothers: a specific delivery plan might be considered for prevention.

OBJECTIVE: In recent decades, the trend for women is to delay childbearing. However, worldwide, advanced maternal age is an independent risk factor for stillbirth, as well as advanced gestational age. National data are not available about stillbirths in the Italian population. We explored whether, at term of pregnancy, advanced maternal age is associated with an increased risk of stillbirth in Italy. We speculate that a policy of induction of labor at term of pregnancy in older mothers may significantly reduce the stillbirth. METHODS: Data provided by Italian Ministry of Health and National Statistical Institute were used to identify all singleton deliveries ≥22 weeks of gestation during a four years study period. We evaluated the outcome of pregnancy (livebirths or stillbirths) and we stratified data by gestational age and by maternal age at delivery. The hazard risk and the relative risk of stillbirth were calculated. RESULTS: The overall stillbirth rate was 3.4 per 1000, with a total of 6451 cases of stillbirths in the four years study period. Overall, the risk of stillbirth increases at term of pregnancy in all maternal age groups, especially in older mothers. A total of 674 stillbirths occurred in women aged 40 years or older and 24.2% of them (n = 163) occurred at term of pregnancy. Among women aged 40 years and above, 7.3% of stillbirths (49/674) occurred beyond 39 weeks of gestation. The hazard risk doubles from 39 to 40 weeks, from 0.60 per 1000 ongoing pregnancies to 1.16 per 1000 ongoing pregnancies; the relative risk at 40 weeks of gestation was the highest in the older mothers and was 5.17 (95% CI 3.16-8.46). CONCLUSIONS: The effect of maternal age on birth outcomes is a relevant aspect in Italy. If the association between maternal age and stillbirth is supposed to be part of the pathophysiology of fetal death, our data indicate that induction of labor before 40 weeks of gestation in women aged 40 years old or older might prevent overall 7.3% of stillbirths for induction at 39 weeks, 13% of stillbirths for induction at 38 weeks. To reduce potentially preventable stillbirths, caregivers should perform a specific risk assessment for each pregnant woman. The impact of maternal age should be seriously considered, and an individualized approach should be planned at term of pregnancy in older mothers, including the possibility of a slightly anticipation of induction of labor if spontaneously undelivered.

Identification of the Schistosoma mansoni molecular target for the antimalarial drug artemether.

Plasmodium falciparum and Schistosoma mansonii are the parasites responsible for most of the malaria and schistosomiasis cases in the world. Notwithstanding their many differences, the two agents have striking similarities in that they both are blood feeders and are targets of an overlapping set of drugs, including the well-known artemether molecule. Here we explore the possibility of using the known information about the mode of action of artemether in Plasmodium to identify the molecular target of the drug in Schistosoma and provide evidence that artemether binds to SmSERCA, a putative Ca²âº-ATPase of Schistosoma . We also predict the putative binding mode of the molecule for both its Plasmodium and Schistosoma targets. Our analysis of the mode of binding of artemether to Ca²âº-ATPases also provides an explanation for the apparent paradox that, although the molecule has no side effect in humans, it has been shown to possess antitumoral activity.

Evolution of Pathology Patterns in Persons Who Died From COVID-19 in Italy: A National Study Based on Death Certificates.

Background: In Italy, during the first epidemic wave of 2020, the peak of coronavirus disease 2019 (COVID-19) mortality was reached at the end of March. Afterward, a progressive reduction was observed until much lower figures were reached during the summer, resulting from the contained circulation of SARS-CoV-2. This study aimed to determine if and how the pathological patterns of the individuals deceased from COVID-19 changed during the phases of epidemic waves in terms of: (i) main cause of death, (ii) comorbidities, and (iii) complications related to death. Methods: Death certificates of persons who died and tested positive for SARS-CoV-2, provided by the National Surveillance system, were coded according to ICD rev10. Deaths due to COVID-19 were defined as those in which COVID-19 was the underlying cause of death. Results: The percentage of COVID-19 deaths varied over time. It decreased in the downward phase of the epidemic curve (76.6 vs. 88.7%). In February-April 2020, hypertensive heart disease was mentioned as a comorbidity in 18.5% of death certificates, followed by diabetes (15.9% of cases), ischemic heart disease (13.1%), and neoplasms (12.1%). In May-September, the most frequent comorbidity was neoplasms (17.3% of cases), followed by hypertensive heart disease (14.9%), diabetes (14.8%), and dementia/Alzheimer's disease (11.9%). The most mentioned complications in both periods were pneumonia and respiratory failure with a frequency far higher than any other condition (78.4% in February-April 2020 and 63.7% in May-September 2020). Discussion: The age of patients dying from COVID-19 and their disease burden increased in the May-September 2020 period. A more serious disease burden was observed in this period, with a significantly higher frequency of chronic pathologies. Our study suggests better control of the virus' lethality in the second phase of the epidemic, when the health system was less burdened. Moreover, COVID-19 care protocols had been created in hospitals, and knowledge about the diagnosis and treatment of COVID-19 had improved, potentially leading to more accurate diagnosis and better treatment. All these factors may have improved survival in patients with COVID-19 and led to a shift in mortality to older, more vulnerable, and complex patients.

The Role of COVID-19 in the Death of SARS-CoV-2-Positive Patients: A Study Based on Death Certificates.

Background: Death certificates are considered the most reliable source of information to compare cause-specific mortality across countries. The aim of the present study was to examine death certificates of persons who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to (a) quantify the number of deaths directly caused by coronavirus 2019 (COVID-19); (b) estimate the most common complications leading to death; and (c) identify the most common comorbidities. Methods: Death certificates of persons who tested positive for SARS-CoV-2 provided to the National Surveillance system were coded according to the 10th edition of the International Classification of Diseases. Deaths due to COVID-19 were defined as those in which COVID-19 was the underlying cause of death. Complications were defined as those conditions reported as originating from COVID-19, and comorbidities were conditions independent of COVID-19. Results: A total of 5311 death certificates of persons dying in March through May 2020 were analysed (16.7% of total deaths). COVID-19 was the underlying cause of death in 88% of cases. Pneumonia and respiratory failure were the most common complications, being identified in 78% and 54% of certificates, respectively. Other complications, including shock, respiratory distress and pulmonary oedema, and heart complications demonstrated a low prevalence, but they were more commonly observed in the 30-59 years age group. Comorbidities were reported in 72% of certificates, with little variation by age and gender. The most common comorbidities were hypertensive heart disease, diabetes, ischaemic heart disease, and neoplasms. Neoplasms and obesity were the main comorbidities among younger people. Discussion: In most persons dying after testing positive for SARS-CoV-2, COVID-19 was the cause directly leading to death. In a large proportion of death certificates, no comorbidities were reported, suggesting that this condition can be fatal in healthy persons. Respiratory complications were common, but non-respiratory complications were also observed.

New pyrrole-based histone deacetylase inhibitors: binding mode, enzyme- and cell-based investigations.

Aroyl-pyrrolyl-hydroxy-amides (APHAs) are a class of synthetic HDAC inhibitors described by us since 2001. Through structure-based drug design, two isomers of the APHA lead compound 1, the 3-(2-benzoyl-1-methyl-1H-pyrrol-4-yl)-N-hydroxy-2-propenamide 2 and the 3-(2-benzoyl-1-methyl-1H-pyrrol-5-yl)-N-hydroxy-2-propenamide 3 (iso-APHAs) were designed, synthesized and tested in murine leukemia cells as antiproliferative and cytodifferentiating agents. To improve their HDAC activity and selectivity, chemical modifications at the benzoyl moieties were investigated and evaluated using three maize histone deacetylases: HD2, HD1-B (class I human HDAC homologue), and HD1-A (class II human HDAC homologue). Docking experiments on HD1-A and HD1-B homology models revealed that the different compounds selectivity profiles could be addressed to different binding modes as observed for the reference compound SAHA. Smaller hydrophobic cap groups improved class II HDAC selectivity through the interaction with HD1-A Asn89-Ser90-Ile91, while bulkier aromatic substituents increased class I HDAC selectivity. Taking into account the whole enzyme data and the functional test results, the described iso-APHAs showed a behaviour of class I/IIb HDACi, with 4b and 4i preferentially inhibiting class IIb and class I HDACs, respectively. When tested in the human leukaemia U937 cell line, 4i showed altered cell cycle (S phase arrest), joined to high (51%) apoptosis induction and significant (21%) differentiation activity.

Inequalities in infant mortality in Italy.

BACKGROUND: All the children of the world should be born equal, but this is not so: even in Italy, there are striking differences already at birth. Neonatal and infant mortality are accurate indexes to assess the demographic wellbeing and quality of life of a population. The aim of the present study is to analyze the infant (IMR) and neonatal (NMR) mortality rates of Italian and foreign children and to evaluate if there is a disparity among geographical macro-areas. METHODS: Data from 2006 to 2015 were collected by the Italian Statistics Bureau (ISTAT) and extracted from two different national databases, which considered i) underlying cause of death and ii) birth registry. Mortality rates were calculated using conventional definitions. The main analyses were made comparing Italian versus foreigners as a single category as well as by country origin and contrasting Northern residents versus Southern ones. Comparisons between groups were done using relative risks. RESULTS: Data show disparity in neonatal and infant mortality among immigrant and Italian residents. In 2015, neonatal (3.0 vs. 1.8/1000) and infant (4.5 vs 2.6/1000) mortality rates were higher among foreign children compared to Italian children. Among babies born to immigrant women, there is a higher infant mortality among children born to women coming from Central and South Africa (8.2 /1000). Inequalities are reported even among Italian regions: in Southern Italy, infant mortality is 1.4 fold higher than in Northern Italy. CONCLUSION: Inequalities in neonatal and infant mortality are evident between Italians and immigrants and among geographical macro-areas There is therefore urgent need for a political and social plan focusing on infancy.

Class II-selective histone deacetylase inhibitors. Part 2: alignment-independent GRIND 3-D QSAR, homology and docking studies.

(Aryloxopropenyl)pyrrolyl hydroxamates were recently reported by us as first examples of class II-selective HDAC inhibitors and can be useful tools to probe the biology of such enzymes. Molecular modelling and 3-D QSAR studies have been performed on a series of 25 (aryloxopropenyl)pyrrolyl hydroxamates to gain insights about their activity and selectivity against both maize HD1-B and HD1-A, two enzymes homologous of mammalian class I and class II HDACs, respectively. The studies have been accomplished by calculating alignment-independent descriptors (GRIND descriptors) using the ALMOND software. Highly descriptive and predictive 3-D QSAR models were obtained using either class I or class II inhibitory activity displaying r(2)/q(2) values of 0.96/0.81 and 0.98/0.85 for HD1-B and HD1-A, respectively. A deeper inspection revealed that in general a bent molecular shape structure is a prerequisite for HD1-A-selective inhibitory activity, while straight shape molecular skeleton leads to selective HD1-B compounds. The same conclusions could be achieved by molecular docking studies of the most selective inhibitors.

Small molecule inhibitors of histone arginine methyltransferases: homology modeling, molecular docking, binding mode analysis, and biological evaluations.

The screening of the inhibition capabilities of dye-like small molecules from a focused library against both human PRMT1 and Aspergillus nidulans RmtA is reported as well as molecular modeling studies (homology modeling, molecular docking, and 3-D QSAR) of the catalytic domain of the PRMT1 fungal homologue RmtA. The good correlation between computational and biological results makes RmtA a reliable tool for screening arginine methyltransferase inhibitors. In addition, the binding mode analyses of tested derivatives reveal the crucial role of two regions, the pocket formed by Ile12, His13, Met16, and Thr49 and the SAM cisteinic binding site subsite. These regions should be taken into account in the design of novel PRMT inhibitors.

Synthesis and biological properties of novel 2-aminopyrimidin-4(3H)-ones highly potent against HIV-1 mutant strains.

Following the disclosure of dihydro-alkoxy-, dihydro-alkylthio-, and dihydro-alkylamino-benzyl-oxopyrimidines (DABOs, S-DABOs, and NH-DABOs) as potent and selective anti-HIV-1 agents belonging to the non-nucleoside reverse transcriptase inhibitor (NNRTI) class, we report here the synthesis and biological evaluation of a novel series of DABOs bearing a N,N-disubstituted amino group or a cyclic amine at the pyrimidine-C2 position, a hydrogen atom or a small alkyl group at C5 and/or at the benzylic position, and the favorable 2,6-difluorobenzyl moiety at the C6 position (F2-N,N-DABOs). The new compounds were highly active up to the subnanomolar level against both wt HIV-1 and the Y181C mutant and at the submicromolar to nanomolar range against the K103N and Y188L mutant strains. Such derivatives were more potent than S-DABOs, NH-DABOs, and nevirapine and efavirenz were chosen as reference drugs. The higher inhibitor adaptability to the HIV-1 RT non-nucleoside binding site (NNBS) may account for the higher inhibitory effect exerted by the new molecules against the mutated RTs.

Synthesis and biological properties of novel, uracil-containing histone deacetylase inhibitors.

A novel series of compounds containing a uracil moiety as the connection unit between a phenyl/phenylalkyl portion and a N-hydroxy-polymethylenealkanamide or -methylenecinnamylamide group (uracil-based hydroxamic acids, UBHAs) was tested against maize histone deacetylases (HDACs) and mouse HDAC1. Compounds with a phenyl/benzyl ring at the uracil-C6 position and bearing 4-5 carbon units as well as a m- or p-methylenecinnamyl moiety as a spacer were the most potent inhibitors. In cell-based human HDAC1 and HDAC4 assays, the two UBHAs tested inhibited the HDAC1 but not HDAC4 immunoprecipitate activity. When tested in human leukemia U937 cells, some UBHAs produced G1 phase arrest of the cell cycle. Moreover, 1j showed high antiproliferative and dose-dependent granulocytic differentiation properties. The tested UBHAs displayed weak p21WAF1/CIP1 induction in U937 cells, and 1d and 1j showed high histone H3 and alpha-tubulin acetylation effects.

Design, synthesis, and biological evaluation of sirtinol analogues as class III histone/protein deacetylase (Sirtuin) inhibitors.

In a search for potent inhibitors of class III histone/protein deacetylases (sirtuins), a series of sirtinol analogues have been synthesized and the degree of inhibition was assessed in vitro using recombinant yeast Sir2, human SIRT1, and human SIRT2 and in vivo with a yeast phenotypic assay. Two analogues, namely, 3- and 4-[(2-hydroxy-1-naphthalenylmethylene)amino]-N-(1-phenylethyl)benzamide (i.e., m- and p-sirtinol), were 2- to 10-fold more potent than sirtinol against human SIRT1 and SIRT2 enzymes. In yeast in vivo assay, these two small molecules were as potent as sirtinol. Compounds lacking the 2-hydroxy group at the naphthalene moiety or bearing several modifications at the benzene 2'-position of the aniline portion (carbethoxy, carboxy, and cyano) were 1.3-13 times less potent than sirtinol, whereas the 2'-carboxamido analogue was totally inactive. Both (R)- and (S)-sirtinol had similar inhibitory effects on the yeast and human enzymes, demonstrating no enantioselective inhibitory effect.

Class II (IIa)-selective histone deacetylase inhibitors. 1. Synthesis and biological evaluation of novel (aryloxopropenyl)pyrrolyl hydroxyamides.

Chemical manipulations performed on aroyl-pyrrolyl-hydroxyamides (APHAs) led to (aryloxopropenyl)pyrrolyl hydroxamates 2a-w, and their inhibition against maize HDACs and their class I or class II HDAC selectivity were determined. In particular, from these studies some benzene meta-substituted compounds emerged as highly class II (IIa)-selective HDAC inhibitors, the most selective being the 3-chloro- and 3-fluoro-substituted compounds 2c (SI = 71.4) and2f (SI = 176.4). The replacement of benzene with a 1-naphthyl ring afforded 2s, highly active against the class II homologue HD1-A (IC(50) = 10 nM) but less class II-selective than 2c,f. When tested against human HDAC1 and HDAC4, 2f showed no inhibitory activity against HDAC1 but was able to inhibit HDAC4. Moreover, in human U937 acute myeloid leukaemia cells 2f did not produce any effect on apoptosis, granulocytic differentiation, and the cell cycle, whereas 2s (that retain class I HDAC inhibitory activity) was 2-fold less potent than SAHA used as reference.

Androgen receptor with elongated polyglutamine tract forms aggregates that alter axonal trafficking and mitochondrial distribution in motor neuronal processes.

The CAG/polyglutamine (polyGln)-related diseases include nine different members that together form the most common class of inherited neurodegenerative disorders; neurodegeneration is linked to the same type of mutation, found in unrelated genes, consisting of an abnormal expansion of a polyGln tract normally present in the wild-type proteins. Nuclear, cytoplasmic, or neuropil aggregates are detectable in CAG/polyGln-related diseases, but their role is still debated. Alteration of the androgen receptor (AR), one of these proteins, has been linked to spinal and bulbar muscular atrophy, an X-linked recessive disease characterized by motoneuronal death. By using immortalized motoneuronal cells (the neuroblastoma-spinal cord cell line NSC34), we analyzed neuropil aggregate formation and toxicity: green fluorescent protein-tagged wild-type or mutated ARs were cotransfected into NSC34 cells with a blue fluorescent protein tagged to mitochondria. Altered mitochondrial distribution was observed in neuronal processes containing aggregates; occasionally, neuropil aggregates and mitochondrial concentration corresponded to axonal swelling. Neuropil aggregates also impaired the distribution of the motor protein kinesin. These data suggest that neuropil aggregates may physically alter neurite transport and thus deprive neuronal processes of factors or components that are important for axonal and dendritic functions. The soma may then be affected, leading to neuronal dysfunctions and possibly to cell death.

Assay of common sunscreen agents in suncare products by high-performance liquid chromatography on a cyanopropyl-bonded silica column.

A rapid high-performance liquid chromatographic method was developed for the simultaneous assay of eight of the most common sunscreen agents (octyl-methoxycinnamate, oxybenzone, butyl-methoxydibenzoylmethane, octyl-salicilate, methylbenzylidene camphor, octyl-dimethylamminobenzoate, phenylbenzimidazole sulphonic acid and octocrylene) in sun protection products. Evaluation of the influence of different stationary phases and eluents on the separation selectivity showed that optimal resolution was obtained on a cyanopropyl-silica column eluted with methanol-acetonitrile-tetrahydrofuran-aqueous acetic acid. A small adjustment of the proposed chromatographic system (reduction in the aqueous content of the mobile phase) permitted also the determination of the extremely hydrophobic UV filter, methylene bis-benzotriazolyl tetramethylbutylphenol along with three other sunscreen agents, octyl-methoxycinnamate, oxybenzone, butyl-methoxydibenzoylmethane. Recoveries of the UV filters from the spiked formulation were between 95.7 and 103.7% and the precision of the method was better than 6.1% relative standard deviation. The developed HPLC procedure is suitable for quality control and photostability analyses of commercial suncare products.

Comparative studies of the influence of cyclodextrins on the stability of the sunscreen agent, 2-ethylhexyl-p-methoxycinnamate.

The effects of beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the base-catalyzed degradation and light-induced decomposition of the sunscreen agent, trans-2-ethylhexyl-p-methoxycinnamate (trans-EHMC) were investigated. Reversed-phase liquid chromatography was used to study the interaction between natural and modified cyclodextrins, added to the mobile phase, and the sunscreen. Among the available cyclodextrins (beta-CD, HP-beta-CD, hydroxypropyl-alpha-cyclodextrin and hydroxypropyl-gamma-cyclodextrin), only HP-beta-CD and beta-CD produced a significant decrease in the chromatographic retention of trans-EHMC. The complexation of the sunscreen agent with HP-beta-CD and beta-CD was confirmed by thermal analysis and nuclear magnetic resonance spectroscopy. beta-CD depressed the decomposition of trans-EHMC in alkaline solutions more effectively than HP-beta-CD. Moreover, the irradiation-induced degradation of the sunscreen agent in emulsion vehicles was reduced by complexation with beta-CD (the extent of degradation was 26.1% for the complex compared to 35.8% for free trans-EHMC) whereas HP-beta-CD had no significant effect. Therefore, the complex of beta-CD with trans-EHMC enhances the chemical- and photo-stability of the sunscreen agent. Moreover, it limits adverse interactions of the UV filter with other formulation ingredients.

Influence of hydroxypropyl-beta-cyclodextrin on photo-induced free radical production by the sunscreen agent, butyl-methoxydibenzoylmethane.

The aim of the study was to investigate the effect of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the photo-induced production of free radicals by the sunscreen agent, butyl-methoxydibenzoylmethane (BMDBM). Spin-trapping/electron paramagnetic resonance spectroscopy was used to evaluate the formation of radicals and the extent of BMDBM photodegradation was measured by high-performance liquid chromatography. The stable 2,2,6,6-tetramethylpiperidine-1-oxyl, nitroxide radical (TEMPO) was used as spin-trap. Any free radicals generated during irradiation of the sunscreen agent will couple with the TEMPO radicals giving diamagnetic species and thus a decrease of the signal intensity in the electron paramagnetic resonance spectrum. Following 2-h illumination with simulated sunlight, the solution containing free BMDBM exhibited a 93.9% decrease of the intensity of the TEMPO signal. Under the same irradiation conditions, only a 12.2% reduction of the TEMPO concentration was measured in the sample containing BMDBM complexed with HP-beta-CD. Moreover, the decrease of the spin-trap level observed for the HP-beta-CD/BMDBM complex was not significantly different from that produced when solutions containing TEMPO only or TEMPO in the presence of HP-beta-CD alone were subjected to irradiation. In addition, the photodegradation of the sunscreen agent was reduced by complexation with HP-beta-CD (the extent of degradation was 27.6% for the complex compared with 63.1% for free BMDBM). The results obtained indicate that the free radicals generated by BMDBM when exposed to simulated sunlight are effectively scavenged by inclusion complexation of the sunscreen agent with HP-beta-CD.