Nicotinate-Modified Lanthanide-Substituted Selenotungstate and Its Catalase-like Activity for the Detection of H2O2 and Ascorbic Acid.

A rigid nicotinate-modified lanthanide-substituted selenotungstate [H2N(CH3)2]6Na3H[La4SeW8(H2O)16(nica)2O28][SeW9O33]2·32H2O (1, Hnica = nicotinic acid) was synthesized and consists of two trivacant Keggin [B-α-SeW9O33]8- fragments and one unusual [SeW4O18]8- fragment bridged by a heterometallic [La4W4(H2O)16(nica)2O28]18- cluster. In the heterometallic cluster, two carboxyl O atoms in two nicotinate ligands directly coordinate with two W atoms in a stable C-O-W-O-W-O six-membered ring fashion. According to its catalase-like activity, 1 was utilized to catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2 to produce blue oxidized TMB (ox-TMB), which can be used to establish a colorimetric sensing method for the detection of ascorbic acid. This work not only provides a promising platform for detecting H2O2 and ascorbic acid but also expands the application potential of polyoxometalate-based materials in biological and clinical analyses.

[Determination of 11 nutrients in liquid milk by ultra-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish an ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method for simultaneous determination of 11 nutritional components(thiamine, riboflavin, nicotinamide, nicotinic acid, pantothenic acid, pyridoxine, pyridoxal, pyridoxamine, biotin, choline, L-carnitine) in liquid milk. METHODS: Milk samples were shaken with 20 mmol/L ammonium formate solution and heated in a water bath at 100 ℃ for 30 min, then incubated with papain and acid phosphatase at 45 ℃ for 16 h, the lower liquid was collected after centrifugation for analysis. UPLC separation was performed on an ACQUITY~(TM) HSS T3(3.0 mm×150 mm, 1.8 µm) column, 2 mmol/L ammonium formate(containing 0.1% formic acid) solution and acetonitrile(containing 0.1% formic acid) were used as mobile phase. Quantitative detection was performed by internal standard method. RESULTS: 11 nutritional components can be effectively separated and detected in 12 min, and the linear correlation coefficients(R~2) were all above 0.995. The limits of detection(LODs) were between 0.05 and 0.50 µg/L, and the limits of quantification(LOQs) were between 0.20 and 1.25 µg/L. The recovery rates of three-level addition were 85.6%-119.3%, and the precision RSDs were between 3.68% and 7.82%(n=6). Based on the detection of 60 liquid milk samples from 5 different animals, it was found that the contents of 11 nutrients in liquid milk from different milk sources were significantly different, but pyridoxine could not be detected. CONCLUSION: The method can quantitatively detect 11 water-soluble nutrients, including free and bound forms, by effective enzymolysis. It is sensitive, reproducible and can meet the needs of quantitative detection.

Association between Daily Niacin Intake and Glaucoma: National Health and Nutrition Examination Survey.

BACKGROUND AND AIMS: To determine the relationship between dietary intake of niacin and glaucoma using the data from the 2005 to 2008 National Health and Nutrition Examination Survey (NHANES). METHODS: Subjects aged 40 years and older who participated in the dietary intake interview and vision health questionnaire of NHANES were included in the study. Glaucoma diagnosis by self-report was utilized. Additionally, glaucoma diagnosis by fundus imaging and International Society Geographical and Epidemiological Ophthalmology (ISGEO) criteria was used in subjects with available qualified retinal imaging. Survey logistic regression analyses were used to examine the association between daily niacin consumption and glaucoma. RESULTS: A total of 5768 participants were included in the study. There was a significant decrease in the crude odds of self-reported glaucoma in the third (OR 0.57, 95% Cl 0.43-0.76; p < 0.001) and fourth (OR 0.57, 95% Cl 0.37-0.90; p = 0.018) quartiles of daily niacin consumption, which equated to 21.01 to 28.22 mg/day and greater than 28.22 mg/day, respectively. A similar trend was found using fundus imaging of subjects with niacin intake in the third (OR 0.42, 95% Cl 0.25-0.72; p = 0.002) and fourth (OR 0.36, 95% Cl 0.20-0.67; p = 0.002) quartiles. After adjusting for covariates, the odds of glaucoma based on fundus imaging remained significantly lower for niacin intake in the third (OR 0.49, 95% Cl 0.28-0.87; p = 0.016) and fourth (OR 0.48, 95% Cl 0.26-0.89; p = 0.022) quartile levels. Using ISGEO criteria, there was no significant association between glaucoma and daily niacin consumption. CONCLUSIONS: Greater niacin intake may be associated with a lower chance of developing glaucoma.

Comparison of Micronutrient Intervention Strategies in Ghana and Benin to Cover Micronutrient Needs: Simulation of Bene-Fits and Risks in Women of Reproductive Age.

Overlapping micronutrient interventions might increase the risk of excessive micronutrient intake, with potentially adverse health effects. To evaluate how strategies currently implemented in Benin and Ghana contribute to micronutrient intake in women of reproductive age (WRA), and to assess the risk for excess intakes, scenarios of basic rural and urban diets were built, and different on-going interventions were added. We estimated micronutrient intakes for all different scenarios. Four types of intervention were included in the scenarios: fortification, biofortification, supplementation and use of locally available nutrient-rich foods. Basic diets contributed poorly to daily micronutrient intake in WRA. Fortification of oil and salt were essential to reach daily requirements for vitamin A and iodine, while fortified flour contributed less. Biofortified products could make an important contribution to the coverage of vitamin A needs, while they were not sufficient to cover the needs of WRA. Iron and folic acid supplementation was a major contributor in the intake of iron and folate, but only in pregnant and lactating women. Risk of excess were found for three micronutrients (vitamin A, folic acid and niacin) in specific contexts, with excess only coming from voluntary fortified food, supplementation and the simultaneous overlap of several interventions. Better regulation and control of fortification and targeting of supplementation could avoid excess intakes.

Use of non-volatile compounds for the classification of specialty and traditional Brazilian coffees using principal component analysis.

Coffee beans contain different volatile and non-volatile compounds that are responsible for their flavor and aroma. Herein, principal component analysis (PCA) was employed to correlate the non-volatile composition of specialty and traditional coffees with drink quality. The quantified non-volatile compounds included caffeine, chlorogenic acid, caffeic acid, and nicotinic acid in both types of coffee samples, while 5-hydroxymethylfurfural was only quantified in the specialty coffee samples. The most abundant compounds present in specialty coffees were associated with the aroma and flavor, affording a high drink quality. In traditional coffees, the most abundant compounds included nicotinic acid and caffeine, indicating a stronger roasting process, loss of sensory characteristics, and blended formulations. PCA showed a distinction between the traditional and specialty coffees such that a relationship between the contents of the compounds in each type of coffee, quality, and classification could be established.

Evaluation of Dietary Niacin and New-Onset Hypertension Among Chinese Adults.

Importance: The relationship of dietary niacin intake with the risk of hypertension remains unknown. Objective: To determine the prospective association between dietary niacin intake and new-onset hypertension, and examine factors that may modify the association among Chinese adults. Design, Setting, and Participants: This nationwide cohort study of 12 243 Chinese adults used dietary intake data from 7 rounds of the China Health and Nutrition Survey. Dietary intake was measured by 3 consecutive 24-hour dietary recalls from participants in combination with a weighing inventory taken over the same 3 days at the household level. Statistical analysis was conducted from May 2020 to August 2020. Exposures: Dietary intake. Main Outcomes and Measures: The study outcome was new-onset hypertension, defined as systolic blood pressure 140 mm Hg or greater and/or diastolic blood pressure 90 mm Hg or greater, diagnosis by physician, or current antihypertensive treatment during the follow-up. Results: The mean (SD) age of the study population was 41.2 (14.2) years, and 5728 (46.8%) of participants were men. The mean (SD) dietary niacin intake level was 14.8 (4.1) mg/d. A total of 4306 participants developed new-onset hypertension during a median (interquartile range) follow-up duration of 6.1 (3.6-11.3) years. When dietary niacin was assessed in quartiles, the lowest risk of new-onset hypertension was found in participants in quartile 3 (14.3 to <16.7 mg/d; adjusted hazard ratio, 0.83; 95% CI, 0.75-0.90) compared with those in quartile 1 (<12.4 mg/d). Consistently in the threshold analysis, for every 1 mg/d increase in dietary niacin, there was a 2% decrease in new-onset hypertension (adjusted HR, 0.98; 95% CI, 0.96-1.00) in those with dietary niacin intake less than 15.6 mg/d, and a 3% increase in new-onset hypertension (adjusted HR, 1.03; 95% CI, 1.02-1.04) in participants with dietary niacin 15.6 mg/d or greater. Based on these results, there was a J-shaped association between dietary niacin intake and new-onset hypertension in the general population of Chinese adults, with an inflection point at 15.6 mg/d and a minimal risk at 14.3 to 16.7 mg/d (quartile 3) of dietary niacin intake. Conclusions and Relevance: The results of this study provide some evidence for maintaining the optimal dietary niacin intake levels for the primary prevention of hypertension.

Development of selective preconcentration/clean-up method for imidazolinone herbicides determination in natural water and rice samples by HPLC-PAD using an imazethapyr imprinted poly(vinylimidazole-TRIM).

The development of a novel molecularly imprinted solid-phase extraction (MISPE) method for simultaneous preconcentration of imazapyr (IMP), imazapic (IMZ) and imazethapyr (IMT) with determination by HPLC-PAD (High performance liquid chromatography - photodiode-array detector) is proposed. The polymer synthesis was performed using imazethapyr as template molecule and 1-vinylimidazole as functional monomer. The method is based on preconcentration of 100.0 mL of sample through 200.0 mg of molecularly imprinted poly(vinylimidazole-TRIM) (MIP-1VN) at pH 4.0, followed by elution with 2.0 mL of MeOH:CH2Cl2:HAc (34:62:4, v/v). The range of analytical curve (0.29-200.0, 0.21-200.0 and 0.15-200.0 µg L-1), limits of detection (0.09, 0.06 and 0.04 µg L-1) and preconcentration factors (92, 96 and 98) determined for the herbicides, IMP, IMZ and IMT, respectively, were greatly superior when compared with those ones obtained with commercial adsorbents. The analytical method was successfully applied to spiked surface water and rice samples with good results of recovery values (86-107%).

Two Multivariate Calibration Models for Assay of Niacin in Complex Mixtures with Its Official Impurities: A Pharmaceutical Application.

BACKGROUND: Niacin (NIA) is a water-soluble vitamin and the primary treatment of pellagra. No analytical method was found to assess NIA in complex mixtures with its official impurities. OBJECTIVE: Two validated, accurate, and selective chemometric models were developed to assay NIA in the presence of its four official impurities, including pyridine, a nephrotoxic and hepatotoxic substance. Additionally, the two selective chemometric models were compared by processing UV spectra in the range 220-305 nm and applying partial least squares regression (PLSR) and support vector regression (SVR) models. METHOD: A five levels five factors experimental design was chosen to exhibit a training set of 25 mixtures that had numerous variable percentages of tested substances. A test set consisting of 10 mixtures was designed to confirm the predictive power of the suggested models. RESULTS: The presented results substantiate the strength of the developed multivariate calibration models to assay NIA specifically with high selectivity and accuracy (100.02 ± 1.312 and 100.04 ± 1.272 for PLSR and SVR models, respectively). The root mean square error of prediction for the validation set mixtures was applied as a main comparison tool and it was found to be 0.2016 and 0.1890 for PLSR and SVR models, respectively. CONCLUSIONS: The results of the developed models and the reported HPLC method were statistically compared, where F-values and Student's t-tests did not show significant difference in regards to accuracy and precision. The SVR model proved to be more accurate than the PLSR model, producing a high generalization capacity, while PLSR was easy to implement and fast.

Sociodemographic Factors Associated with Dietary Intake of Thiamine, Riboflavin, and Niacin among Chinese Adults in 2015.

OBJECTIVE: To estimate the association between three B-vitamin intakes and sociodemographic factors among adults in China. METHODS: We derived our data from the China Health and Nutrition Survey (CHNS) among 12,241 individuals aged 18-64 years. Log binomial regression was used to estimate adjusted prevalence ratios for factors associated with the inadequate intake of B-vitamins. RESULTS: Females with low incomes and living in the north had a higher prevalence of inadequate riboflavin intake than those with high incomes and living in the south. Both males and females living in a village had a higher prevalence of inadequate riboflavin intake than adults living in a city. Adults with low income, low education, and living in the north or in a village had a higher prevalence of inadequate niacin intake than adults with a high income, high education, and living in the south or in a city. CONCLUSION: We found that income, region, and area of residence were associated with riboflavin intake. Education, income, region, and area of residence were associated with niacin intake. Well-tailored strategies and policies are needed to improve nutritional status in China.

Impurity profiling high-performance-thin-layer chromatography method involving the assay of essential human micronutrient niacin with eco-scale assessment.

Currently, analytical scientists are paying special attention to reducing reliance on hazardous chemicals in various analytical methods. By embracing this concept, we developed an eco-friendly high-performancethin-layer chromatography (HPTLC) method as an alternative for the conventional HPLC method for the determination of an essential human micronutrient, niacin (NIA), which is used improve the lipid profile of patients. Furthermore, the proposed HPTLC method is capable of determining the structurally related impurities of NIA such as pyridine-2,5-dicarboxylic acid, isonicotinic acid, pyridine, and 5-ethyl-2-methylpyridine, which exhibit nephrotoxic and hepatotoxic effects. The separation of this challenging mixture was achieved on HPTLC sheets using a mixture of ethyl acetate/ethanol/ammonia solution (6:4:0.05, v/v/v), and then the dried plates were scanned at 254 nm. The analytical eco-scale assessment protocol was used to assess the greenness profile of the presented method and compare it with the reported HPLC method. The suggested method was found to be greener with regard to the consumption of solvents and the yielding of waste. The results suggest that the described method can be safely implemented for the routine analysis of NIA pharmaceutical dosage without the interference of potential impurities in quality control laboratories.

Residues and Dissipation of the Herbicide Imazapyr after Operational Use in Irrigation Water.

Imazapyr is a herbicide that can be used in irrigation canals to control a range of aquatic weed species, however, its residual nature, combined with its phytotoxicity to crops at low concentrations, means that the water in canals must be carefully managed following imazapyr application. Residues of the herbicide imazapyr (isopropylamine salt) in irrigation water were analysed and modelled after application to irrigation canals in south-eastern Australia. A treatment program to control delta arrowhead (sagittaria; Sagittaria platyphylla (Engelm.) J.G. Sm.) in over 400 km of irrigation canals was enacted by applying imazapyr to dewatered canals during winter. Following imazapyr application, canals were left dewatered for a period (up to eight weeks) and then refilled. After refilling, canals were ponded for a period (up to 28 days) to allow degradation of imazapyr in the water via photolysis. Upon refilling canals, ~650 water samples containing imazapyr were collected across the treatment area and data modelled to measure the extent of water contamination and to guide efforts to reduce the subsequent irrigation hazard to crops. Modelled data demonstrates that imazapyr behaviour in irrigation water following canal refilling was predictable when 1) amount of imazapyr applied, 2) the dewatered period following herbicide application, 3) the water ponding period, and 4) solar exposure during water ponding were taken into account. Minimising the amount applied (g imazapyr per km of canal) and maximising the time between spraying and refilling (dewatered period) reduced the initial concentration in the water following canal refilling. The amount of imazapyr in the canal water following refilling was reduced by half for every 16 days (confidence interval = 10-38 days) that the canal remained dewatered after imazapyr application. Imazapyr dissipation during the ponding period following canal refilling occurred at a rate that depended on solar exposure. Dissipation did not occur when solar exposure was <8.5 MJ m-2. However, when solar exposure was >10 MJ m-2, imazapyr concentration in the water reduced by half for every 4.4 days of ponding period (confidence interval = 2.9-9.5 days). Our two models, combined with local climate data on solar exposure, can be used by canal managers to determine the optimal time to refill canals so that imazapyr dissipation is maximised, and thus risk of damaging irrigated crops is minimised.

Preservation of vitamins content in Cuccìa using an innovative method of processing.

Cuccìa is a traditional Sicilian food prepared by boiling whole durum wheat kernels, in water, for many hours. This process destroys the vitamins E and B contents of crude kernels. It was rated a method to prepare the Cuccìa, preserving the vitamin content. Four varieties of durum wheat were processed comparing the traditional cooking method (TR-boiling for 5/6 hours), and an innovative one (IN-grains scarification, germination, and cooking at 50 °C for 2 hours). On soups obtained the content of biotin, niacin and α-amylase activity were determined. ANOVA showed the cooking method influences biotin and niacin content having values from 0.56 and 0.72 ng ml-1 (raw grain) and values close to 0 (TR), while only a 10% decrease (IN) respectively for both vitamins. On the contrary, α-amylase activity was reduced with IN method. The IN method combined with ancient grains, produces the soup with a good vitamin B amount.

Adsorption-Desorption Behavior of Polar Imidazolinone Herbicides in Tropical Paddy Fields Soils.

Analysis of herbicides sorption behavior in soil is critical in predicting their fate and possible harmful side effects in the environment. Application of polar imidazolinone herbicides is growing in tropical agricultural fields. Imidazolinones have high leaching potential and are persistent. In this study, adsorption-desorption of imazapic and imazapyr herbicides were evaluated in different types of Malaysian agricultural soils. Effects of soil parameters were also investigated on the soils' sorption capacities. The adsorption data fitted best to Freundlich isotherm (R2 > 0.991). The herbicides adsorptions were physical and spontaneous processes as ΔG values were negative and below 40 kJ/mol. The adsorption correlated positively with clay content, total organic carbon (TOC) content, and cation exchange capacity (CEC). There were strong negative correlations between hysteresis index and these factors indicating their importance in imidazolinones immobilization and, thus, their pollution reduction in the environment.

Niacin, lutein and zeaxanthin and physical activity have an impact on Charlson comorbidity index using zero-inflated negative binomial regression model: National Health and Nutrition Examination Survey 2013-2014.

BACKGROUND: Combined with the increasing life expectancy, chronic medical conditions have gradually become the dominant cause of death and disability, and multimorbidity became an increasingly serious public health challenge. However, most existing studies have focused on the coexistence of specific diseases or relatively few diseases. Given one person may have multiple diseases at the same time, we applied Charlson Comorbidity Index (CCI) to systematically evaluate one's 10-year mortality. In this study, we explored the effects of nutrients and physical activity on CCI using National Health and Nutrition Examination Survey (NHANES) 2013-2014 data. METHODS: The study sample consists of one continuous cycle (2013-2014) of NHANES, and 4386 subjects were included in the study. Nutrients intake was measured by dietary recall, and physical activity was evaluated by the Global Physical Activity Questionnaire respectively. Besides, CCI was the sum of the scores assigned for each medical condition. We utilized zero-inflated negative binomial (ZINB) model to investigate the effects in nutrients intake and physical activity on CCI by adjusting for seven sociodemographic characteristics, smoking and drinking. RESULTS: Among the 4386 participants, 2018 (68.7%) are Non-Hispanic White, over half participants (78.6%) drink. In count part (CCI ≥ 0), holding other variables constant, the expected change in CCI for a one-unit increase in niacin is 1.621(RR = 1.621, p = 0.016), in lutein + zeaxanthin is 0.974 (RR = 0.974, p = 0.031), and in sedentary time is 1.035 (RR = 1.035, p = 0.005). Moreover, those who do not have vigorous work activity would be more likely to have higher CCI than those who have (RR = 1.275, P = 0.045). In logit part (CCI = 0), the log odds of having CCI equals zero would increase by 0.541 and 0.708 for every additional vigorous recreational activity (OR = 0.541, p = 0.004) and moderate recreational activity (OR = 0.708, p = 0.017) respectively. CONCLUSIONS: Lutein and zeaxanthin intake, vigorous work activity, vigorous recreational activity and moderate recreational activity may be good for one's health. Rather, increasing niacin intake and sedentary activity may be likely to raise 10-year mortality. Our findings may be significant for preventing diseases and improving health, furthermore, reducing people's financial burden on healthcare.

NAD Metabolome Analysis in Human Cells Using ¹H NMR Spectroscopy.

Nicotinamide adenine dinucleotide (NAD) and its phosphorylated form, NADP, are the major coenzymes of redox reactions in central metabolic pathways. Nicotinamide adenine dinucleotide is also used to generate second messengers, such as cyclic ADP-ribose, and serves as substrate for protein modifications including ADP-ribosylation and protein deacetylation by sirtuins. The regulation of these metabolic and signaling processes depends on NAD availability. Generally, human cells accomplish their NAD supply through biosynthesis using different forms of vitamin B3: Nicotinamide (Nam) and nicotinic acid as well as nicotinamide riboside (NR) and nicotinic acid riboside (NAR). These precursors are converted to the corresponding mononucleotides NMN and NAMN, which are adenylylated to the dinucleotides NAD and NAAD, respectively. Here, we have developed an NMR-based experimental approach to detect and quantify NAD(P) and its biosynthetic intermediates in human cell extracts. Using this method, we have determined NAD, NADP, NMN and Nam pools in HEK293 cells cultivated in standard culture medium containing Nam as the only NAD precursor. When cells were grown in the additional presence of both NAR and NR, intracellular pools of deamidated NAD intermediates (NAR, NAMN and NAAD) were also detectable. We have also tested this method to quantify NAD+ in human platelets and erythrocytes. Our results demonstrate that ¹H NMR spectroscopy provides a powerful method for the assessment of the cellular NAD metabolome.

Niacin, alkaloids and (poly)phenolic compounds in the most widespread Italian capsule-brewed coffees.

Coffee is one of the most popular beverages worldwide and, nowadays, one of the most practical way for its preparation is by prepacked capsules. The aim of this study was comparing the content in caffeine, trigonelline, N-methylpyridinium (NMP), niacin, and chlorogenic acids of 65 different capsule-brewed coffees, commercialised by 5 of the most representative brands in Italy. Coffees were prepared from capsules following manufacturer's instructions and analysed with an optimized UHPLC-MS/MS method able to assess all these phytochemicals in one single run. Inter-lot and capsule variability were also studied for a subset of coffee capsules. Except for decaffeinated coffees, caffeine amount accounted between 54 and 208 mg/serving. Regular espresso coffees showed higher trigonelline, NMP, and niacin concentrations than large (lungo) and decaffeinated samples, with average serving amounts of 17.96, 1.78, and 0.66 mg, respectively. Regarding chlorogenic acids, caffeoylquinic acids were the most relevant ones (20-117 mg/serving). Feruloylquinic acids were quantified between 8 and 50 mg/serving. Coumaroylquinic acids, hydroxycinnamate dimers, caffeoylshikimic acids, and caffeoylquinic lactones were also present at lower concentrations. Multivariate analysis provided comprehensive information on the phytochemical profile of the different types of coffee, showing a great variability among coffees with some brand-related insights. This study supports the need for accurately characterizing espresso coffees while investigating the beneficial effects of coffee on human health.

Aerial parts of maca (Lepidium meyenii Walp.) as functional vegetables with gastrointestinal prokinetic efficacy in vivo.

Lepidium meyenii Walp. (maca) has been utilized in the Andean region because of its edibleness and medicinal value. The aerial parts of maca (APM) were analyzed for protein, total sugar, vitamins, amino acids, and minerals and its characteristic active ingredients at five different growth stages. The results showed the high protein, total sugar, vitamin C, niacin, potassium, and calcium contents of APM. All 17 amino acids and the characteristic active ingredients, namely, macamide, glucosinolates, adenosine, and total saponins, were detected. We examined the effects of maca plant powders on gastric emptying and intestinal propulsion and the levels of serum motilin and gastrin in atropine-treated mice. Benzyl isothiocyanate (BITC) was investigated to identify the potential active material in APM. The results revealed that both maca plant powders and BITC can promote the gastrointestinal prokinetic efficacy. Thus, APM feature potential as new functional vegetable sources.

Development and Validation of Chemometric Spectrophotometric Methods for Simultaneous Determination of Simvastatin and Nicotinic Acid in Binary Combinations.

BACKGROUND: The development and introduction of combined therapy represent a challenge for analysis due to severe overlapping of their UV spectra in case of spectroscopy or the requirement of a long tedious and high cost separation technique in case of chromatography. Quality control laboratories have to develop and validate suitable analytical procedures in order to assay such multi component preparations. METHODS: New spectrophotometric methods for the simultaneous determination of simvastatin (SIM) and nicotinic acid (NIA) in binary combinations were developed. These methods are based on chemometric treatment of data, the applied chemometric techniques are multivariate methods including classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS). In these techniques, the concentration data matrix were prepared by using the synthetic mixtures containing SIM and NIA dissolved in ethanol. The absorbance data matrix corresponding to the concentration data matrix was obtained by measuring the absorbance at 12 wavelengths in the range 216 - 240 nm at 2 nm intervals in the zero-order. The spectrophotometric procedures do not require any separation step. The accuracy, precision and the linearity ranges of the methods have been determined and validated by analyzing synthetic mixtures containing the studied drugs. CONCLUSION: Chemometric spectrophotometric methods have been developed in the present study for the simultaneous determination of simvastatin and nicotinic acid in their synthetic binary mixtures and in their mixtures with possible excipients present in tablet dosage form. The validation was performed successfully. The developed methods have been shown to be accurate, linear, precise, and so simple. The developed methods can be used routinely for the determination dosage form.