Atenolol Research Articles

Effect of nebivolol or atenolol vs. placebo on cardiovascular health in subjects with borderline blood pressure: the EVIDENCE study.

Pharmacotherapy to protect the arteries may be appropriate for individuals with high-normal blood pressure who are at risk for future cardiovascular disease (CVD). Nebivolol (NEB) in contrast to atenolol (ATE) may have a beneficial effect on endothelial function and may be more effective than ATE in preventing CVD. Sixty subjects with preHTN or borderline BP and abnormal small artery elasticity (SAE) underwent evaluation with 10 tests, including large and small artery elasticity, resting and treadmill exercise BP, carotid intimal-media thickness, retinal vascular photography, micro-albuminuria, electrocardiography, echocardiography, and plasma B-type natriuretic peptide level. Each test scored as normal (0), borderline (1), or abnormal (2), and the total disease score (DS) was calculated by adding the test scores. Subjects were randomized double-blind to placebo (PLAC, n = 22), NEB 5/10 mg/day (n = 20),or ATE 25/50 mg/day (n = 18) once daily for 9 months. After 9 months,in the group receiving NEB the mean (standard deviation) DS decreased from baseline 4.3 (2.6) to 2.8 (2.4) (P < 0.007), with ATE from 5.4 (2.5) to 3.5 (1.9) (P = 0.0006), and with PLAC from 5.2 (3.0) to 4.5 (2.6) (P = 0.18). SAE increased in the NEB group from 6.0 (2.2) to 8.4 (3.4) ml/mmHg × 100 (P = 0.0001), whereas there was no significant change in the ATE and PLAC groups. Thus, nebivolol improves small artery function more than atenolol in asymptomatic subjects with preHTN or borderline BP, despite their similar BP-lowering effect.

Facile fabrication and characterization of a novel oral pH-sensitive drug delivery system based on CMC hydrogel and HNT-AT nanohybrid

The main aim of the present study was to design pH-sensitive bionanocomposite hydrogel beads based on CMC and HNT-AT nanohybrid and evaluate whether prepared bionanocomposite beads have the potential to be used in drug delivery applications. Atenolol (AT), as a model drug, was incorporated into the lumen of HA nanotubes via the co-precipitation technique. HNT/AT nanohybrid and CMC/HNT-AT beads were characterized via XRD, SEM, TGA, and FT-IR techniques. Drug loading and encapsulation efficiency was found to be high for CMC/HNT3 beads. Moreover, the swelling and drug release properties of the prepared CMC/HA-AT beads were investigated, and showed a pH sensitive swelling behavior with maximum its content at pH 6.8. Also, it was found that the swelling ratio of CMC/HNT beads was lower than that of pristine CMC beads. Drug release behavior of CMC/HNT-AT bionanocomposite hydrogel beads were investigated. A more sustained and controlled drug releases were observed for CMC/HNT-AT beads.

Degradation of atenolol via heterogeneous activation of persulfate by using BiOCl@Fe3O4 catalyst under simulated solar light irradiation.

Efficient oxidative degradation of pharmaceutical pollutants in aquatic environments is of great importance. This study used magnetic BiOCl@Fe3O4 catalyst to activate persulfate (PS) under simulated solar light irradiation. This degradation system was evaluated using atenolol (ATL) as target pollutant. Four reactive species were identified in the sunlight/BiOCl@Fe3O4/PS system. The decreasing order of the contribution of each reactive species on ATL degradation was as follows: h+≈HO·>O2·->SO4·-. pH significantly influenced ATL degradation, and an acidic condition favored the reaction. High degradation efficiencies were obtained at pH2.3-5.5. ATL degradation rate increased with increased catalyst and PS contents. Moreover, ATL mineralization was higher in the sunlight/BiOCl@Fe3O4/PS system than in the sunlight/BiOCl@Fe3O4 or sunlight/PS system. Nine possible intermediate products were identified through LC-MS analysis, and a degradation pathway for ATL was proposed. The BiOCl@Fe3O4 nanomagnetic composite catalyst was synthesized in this work. This catalyst was easily separated and recovered from a treated solution by using a magnet, and it demonstrated a high catalytic activity. Increased amount of the BiOCl@Fe3O4 catalyst obviously accelerated the efficiency of ATL degradation, and the reusability of the catalyst allowed the addition of a large dosage of BiOCl@Fe3O4 to improve the degradation efficiency.

Studies on the performance of annular photo reactor (APR) for pharmaceutical wastewater treatment

Heterogeneous photocatalysis in presence of nanoparticles has become a promising pathway for treatment of wastewater containing pharmaceutical components. In the present research work, degradation of aqueous solution of chlorhexidine digluconate (CHD), an antibacterial drug, has been investigated using TiO2 nanoparticles suspension in the annular photo reactor (APR) under continuous mode having the provision of catalyst recovery. During the degradation of CHD, the effects of major influencing parameters, i.e., substrate to catalyst ratio, flow rate, recycle ratio and temperature on the performance of the photo reactor and its optimization has been performed using Response Surface Methodology (RSM). Moreover, the photocatalytic efficiency of the reactor has been validated by studying the degradation of other antibiotic drugs i.e. ibuprofen (IBP), atenolol (ATL) and carbamazepine (CBZ). The continuous mode operation in photo reactor has ensured the applicability of the present system in the large volume wastewater treatment. The percentage removal of drugs using such reactor having the facility of catalyst recovery is almost same as compared to typical batch photocatalytic system. Thus, the present developed system can be utilized for the treatment of wastewater containing pharmaceutical components which are photo catalytically degradable.

Facile formation of co-amorphous atenolol and hydrochlorothiazide mixtures via cryogenic-milling: Enhanced physical stability, dissolution and pharmacokinetic profile

The development of poorly water-soluble drugs faces the risk of low bioavailability and therapeutic efficacy. The co-amorphous drug delivery system has recently gained considerable interest because it offers an alternative approach to modify properties of poorly water-soluble drugs. Herein, we developed a co-amorphous system of atenolol (ATE) and poorly water-soluble hydrochlorothiazide (HCT) by means of cryogenic milling. The co-administration of ATE and HCT has been reported to show therapeutic advantages for patients with uncomplicated hypertension. The co-amorphous ATE-HCT sample with 1:1 molar ratio showed excellent physical stability, which could be attributed to the formation of strong molecular interactions between ATE and HCT as evidenced by FT-IR spectra. Compared to the pure crystalline form, amorphous form and physical mixture, HCT in the co-amorphous form exhibited the significantly increased intrinsic dissolution rate, as well as the enhanced bioavailability in the pharmacokinetic study. It was found that the enhanced bioavailability of HCT in the co-amorphous formulation was achieved by the synergistic effect of amorphized HCT and the water-soluble coformer ATE. The present study provides an improved approach to implement the combination therapy of ATE and HCT for potential clinical treatments.

Extraction of clarithromycin and atenolol by cuttlefish bone powder

ABSTRACTPharmaceutical products including analgesics, antibiotics, and antiepileptics are often present in wastewater treatment effluents, lakes, and rivers and have been found in waterways of many countries. The adsorption of two common pharmaceuticals present in surface waters, clarithromycin (CLR) and atenolol (ATN), onto cuttlefish bone powder treated with HCl has been investigated. Adsorption experiments were carried out at different pH conditions and the experimental equilibrium data were fitted to the Langmuir and Freundlich. For the same experimental conditions (pH = 7), the estimated adsorption capacities are from 34.5 mg g−1 for CLR and 39.5 mg g−1 for ATN. The influence of adsorption pH was established for each compound. The negative values of ΔG at different temperatures for all samples indicate the spontaneous nature of the sorption process.

Air-assisted liquid–liquid microextraction using floating organic droplet solidification for simultaneous extraction and spectrophotometric determination of some drugs in biological samples through chemometrics methods

An air assisted liquid–liquid microextraction by applying the solidification of a floating organic droplet method (AALLME-SFOD) coupled with a multivariate calibration method, namely partial least squares (PLS), was introduced for the fast and easy determination of Atenolol (ATE), Propanolol (PRO) and Carvedilol (CAR) in biological samples via a spectrophotometric approach. The analytes would be extracted from neutral aqueous solution into 1-dodecanol as an organic solvent, using AALLME. In this approach a low-density solvent with a melting point close to room temperature was applied as the extraction solvent. The emulsion was immediately formed by repeatedly pulling in and pushing out the aqueous sample solution and extraction solvent mixture via a 10-mL glass syringe for ten times. After centrifugation, the extractant droplet could be simply collected from the aqueous samples by solidifying the emulsion at a lower than the melting point temperature. In the next step, analytes were back extracted simultaneously into the acidic aqueous solution. Derringer and Suich multi-response optimization were utilized for simultaneous optimizing the parameters of three analytes. This method incorporates the benefits of AALLME and dispersive liquid–liquid microextraction considering the solidification of floating organic droplets (DLLME-SFOD). Calibration graphs under optimized conditions were linear in the range of 0.30–6.00, 0.32–2.00 and 0.30–1.40μg mL−1 for ATE, CAR and PRO, respectively. Other analytical parameters were obtained as follows: enrichment factors (EFs) were found to be 11.24, 16.55 and 14.90, and limits of detection (LODs) were determined to be 0.09, 0.10 and 0.08μg mL−1 for ATE, CAR and PRO, respectively. The proposed method will require neither a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly.

Heart Failure and MEF2 Transcriptome Dynamics in Response to \u03b2-Blockers

Myocyte Enhancer Factor 2 (MEF2) mediates cardiac remodelling in heart failure (HF) and is also a target of β-adrenergic signalling, a front-line treatment for HF. We identified global gene transcription networks involved in HF with and without β-blocker treatment. Experimental HF by transverse aortic constriction (TAC) in a MEF2 “sensor” mouse model (6 weeks) was followed by four weeks of β-blockade with Atenolol (AT) or Solvent (Sol) treatment. Transcriptome analysis (RNA-seq) from left ventricular RNA samples and MEF2A depleted cardiomyocytes was performed. AT treatment resulted in an overall improvement in cardiac function of TAC mice and repression of MEF2 activity. RNA-seq identified 65 differentially expressed genes (DEGs) due to TAC treatment with enriched GO clusters including the inflammatory system, cell migration and apoptosis. These genes were mapped against DEGs in cardiomyocytes in which MEF2A expression was suppressed. Of the 65 TAC mediated DEGs, AT reversed the expression of 28 mRNAs. Rarres2 was identified as a novel MEF2 target gene that is upregulated with TAC in vivo and isoproterenol treatment in vitro which may have implications in cardiomyocyte apoptosis and hypertrophy. These studies identify a cohort of genes with vast potential for disease diagnosis and therapeutic intervention in heart failure.

Efficacy and safety of oral vitamin D (cholecalciferol) supplement therapy in Stage I primary hypertension; a prospective, randomized, double-blind, placebo controlled, clinical trial in a tertiary care hospital in central India.

Introduction : Hypertension is one of the most common cardiovascular disorders. Almost all targets in its therapy are exploited and there is a growing need to search for newer targets. Vitamin D is gaining increasing attention in treatment of primary hypertension. Objectives : To study the efficacy and safety of Vitamin D supplementation on systolic and diastolic BP in patients of primary hypertension (JNC 7 stage I) receiving conventional antihypertensive medications (namely Tab atenolol 50mg or Tab amlodipine 5mg). Methods : It was a prospective, randomized, double blind, parallel, placebo controlled clinical trial with 2 groups of 33 patients each. Both groups had patients receiving conventional antihypertensives (Tab atenolol50mg or Tab amlodipine 5mg). Group A patients were given placebo (lactose tablets) and Group B were given oral Vitamin D 3 (60,000 IU) once weekly at bedtime after meals, repeated every fortnightly for 12 weeks. Results : Patients belonging to Group B showed a statistically significant (p < 0.0001) decline in both systolic blood pressure after 12 weeks of receiving vitamin D supplementation. There was no significant change in the safety parameters. Conclusions : Thus, our study shows that Vitamin D supplementation has some role in safely reducing systolic blood pressure after 12 weeks of supplementation and hence it should be supplemented with antihypertensive drugs to the patients with hypertension.

Preparation of magnetic nanoparticles functionalized with poly (styrene‐2‐acrylamido‐2‐methyl propanesulfonic acid) as novel adsorbents for removal of pharmaceuticals from aqueous solutions

AbstractThis work describes the removal of three pharmaceuticals, namely ceftriaxone sodium (CFX), diclofenac sodium (DCF) and atenolol (ATN) from water using magnetic poly (styrene‐2‐acrylamido‐2‐methyl propanesulfonic acid) (St‐AMPS) adsorbent. This adsorbent was characterized by several techniques such as FTIR, TEM, TGA, VSM and DLS. Three kinetic models, pseudo‐first‐order, pseudo‐second‐order and intra‐particle diffusion models were used to study the adsorption kinetics. The results showed that the adsorption kinetics of pharmaceuticals onto magnetic poly (St‐AMPS) adsorbent followed the pseudo‐second‐order model and were relatively rapid. In addition, it was found that the intra‐particle diffusion was not the sole rate‐controlling step and the adsorption of pharmaceuticals onto adsorbent occurred via two steps adsorption process. The experimental data were fitted with three isotherm models including Freundlich, Langmuir and Dubinin‐Radushkevich (D‐R). It was found that the adsorption of pharmaceuticals onto magnetic poly (St‐AMPS) nanoparticles was the best described by the Langmuir model. Maximum adsorption capacities of 150.602, 47.824 and 119.904 mg/g were obtained for DCF, ATN and CFX, respectively. Also the obtained free energy from D‐R isotherm (6.19, 4.93 and 6.45 kJ/mol for DCF, ATN and CFX respectively) indicated that the adsorption process was a physiosorption. Magnetic poly (St‐AMPS) adsorbent could be recycled for removal of CFX, DCF and ATN by alkaline aqueous solution (pH 8). Therefore, this adsorbent can act as a promising adsorbent for water treatment processes.

Advanced sensing performance towards simultaneous determination of quaternary mixture of antihypertensives using boron-doped diamond electrode

An advanced, simple and rapid voltammetric method for a quaternary mixture determination of antihypertensive drugs, namely amlodipine besylate (AML), amiloride hydrochloride (AMI), hydrochlorothiazide (HCTZ) and atenolol (ATN), is described. An anodically pretreated boron-doped diamond electrode (using +0.5Acm−2 during 30s in 0.5molL−1 H2SO4) was employed for square-wave voltammetric determination of these drugs with very well-resolved and reproducible oxidative peaks at 0.68, 0.89, 1.04 and 1.21V (vs Ag/AgCl (3.0molL−1 KCl)), respectively, in ammonium buffer solution (pH9.0). Using optimized experimental conditions, the corresponding peaks heights increased linearly within the concentration range of 0.90–31, 8.7–125, 29–260 and 11–91μmolL−1 with detection limit of 0.30, 0.09, 0.08 and 0.06μmolL−1 for AML, AMI, HCTZ and ATN, respectively. The viability of the proposed method was successfully assessed by simultaneous quantification of the studied drugs in commercially available pharmaceutical formulations and also in spiked tap water sample with the recovery values ranged from 93.9 to 104%. The accuracy of the developed protocol was proven statistically by comparison with high performance liquid chromatography as a reference (comparative) method. The accomplished results fortify the fact that the boron-doped diamond electrode in connection with the square-wave voltammetric technique may constitute an advanced electroanalytical platform for simple and rapid simultaneous determination of various biologically active substances to replace chemically modified electrodes, especially in drug sensing.

On-line double focusing of atenolol and metoprolol in human urine using capillary electrophoresis with the aid of β-cyclodextrin

A maneuverable and sensitive on-line double focusing technique combined field amplified sample stacking (FASS) with micelle to solvent stacking (MSS) with the aid of β-cyelodextrin (β-CD) is developed to detect the contents of AT and ME in human urine by capillary electrophoresis (CE) with UV detector. Small amount of β-CD not only increase the critical micelle concentration (CMC) of SDS, but also strengthen the interaction between SDS and the aimed compound by forming inclusion complexes. The result indicates that the addition of β-CD affords 5.5- and 3.5-fold improvements for atenolol (AT) and metoprolol (ME) in sensitivity than that of in the absence of β-CD in the double focusing system, respectively. Under the optimal conditions, about 200-fold improvement in sensitivity for analytes is achieved compared with conventional CE method. The limits of detection (LODs) at a signal-to-noise of 3 (S/N = 3) of the two β-blockers can be reached 3.3 and 3.7 ng mL−1 respectively, which are lower than minimum required performance levels (MRPLs) set by the World Anti Doping Agency. The relative standard deviations (RSDs) of peak areas of intra-day and inter-day are 3.51–3.38% and 2.34–4.28% (n = 6), respectively. AT and ME in urine without special pretreatment and additional instrument are analyzed. The recoveries are 82–98% with RSDs less than 2.0%.

Mechanistic study of atenolol, acebutolol and carbamazepine adsorption on waste biomass derived activated carbon

Palm kernel shell (PKS) was physically activated by carbon dioxide at 900°C for 1.5h and tested for its ability to remove Atenolol (ATE), Acebutolol (ACE) and Carbamazepine (CBM), which are pharmaceutically active compounds (PhACs). Rapid adsorption of PhACs took place in the first 90min and reached equilibrium after 4h. The kinetic data were best fitted by the Ritchie-second-order model and confirmed by the diffusion-chemisorption model implying a predominantly chemisorption mechanism. The isotherm adsorption studies showed that the maximum adsorption capacities of ATE, ACE and CBM were 0.69, 0.67 and 0.72mmol/g respectively. The best fit isotherm was the Sips equation.

The relative risk and its distribution of endocrine disrupting chemicals, pharmaceuticals and personal care products to freshwater organisms in the Bohai Rim, China

In this study, the risks to aquatic organisms posed by 12 commonly detected pharmaceuticals and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs) that are extensively used in Bohai coastal region of China were examined. These were linear alkylbenzene sulfonate (LAS), nonylphenol (NP), diethylhexyl phthalate (DEHP), norfloxacin (NOR), sulfamethoxazole (SMX), erythromycin (ERY), bisphenol A (BPA), ofloxacin (OFL), carbamazepine (CBZ), naproxen (NPX), atenolol (ATL) and metoprolol (MET). Their relative risk was ranked based on the proximity between the medians of the reported effect concentrations and measured river or lake water concentrations. The surfactants (LAS) and endocrine disrupting chemicals NP (a breakdown product of the surfactant nonylphenol polyethoxylate) and DEHP (a plasticizer) were identified as posing the greatest risk from this range of chemicals. LAS had a hundred-fold higher risk than any of the pharmaceuticals. The highest risk ranked pharmaceuticals were all antibiotics. Zinc (Zn) and mercury (Hg) were added to the comparison as representative heavy metals. Zn posed a risk higher than all the organics. The risk posed by Hg was less than the surfactants but greater than the selected pharmaceuticals. Whereas LAS and DEHP could cause harmful effects to all the wildlife groups, NP and BPA posed the greatest risk to fish. Antibiotics showed the highest risk to algae. Spatial and temporal distributions of PPCPs and EDCs were conducted for risk identification, source analysis and seasonal change exploration. Municipal sewage effluent linked to urban areas was considered to be the major source of pharmaceuticals. With regard to seasonal influence the risk posed by LAS to the aquatic organisms was significantly affected by wet and dry seasonal change. The dilution effects were the common feature of LAS and ERY risks. The difference in LAS and ERY risk patterns along the rivers was mainly affected by the elimination process.

Competition and enhancement effect in coremoval of atenolol and copper by an easily regenerative magnetic cation exchange resin

This paper aimed to investigate the removal of combined Cu2+ and atenolol (ATL) in aqueous solution by using a newly synthesized magnetic cation exchange resin (MCER) as the adsorbent. The MCER exhibited efficient removal performance in sole, binary, pre-loading and saline systems. The adsorption kinetics of Cu2+ and ATL fitted both pseudo-first-order and pseudo-second order model, while better described by pseudo-second order model in binary system. In mixed Cu2+ and ATL solution, the adsorption of ATL was suppressed due to direct competition of carboxylic groups, while Cu2+ adsorption was enhanced because of the formation of surface complexes. This increasing in heterogeneity was demonstrated by adsorption isotherms, which were more suitable for Freundlich model in binary system, while better described by Langmuir model in sole system. As proved by FTIR and XPS spectra, both amino and hydroxyl groups of ATL could form complexes with Cu2+. Decomplexing-bridging interaction was elucidated as the leading mechanism in coremoval of Cu2+ and ATL, which involved [Cu-ATL] decomplexing and newly created Cu- or ATL sites for additional bridging. For saline system, the resulting competition and enhancement effects in mixed solution were amplified with the addition of co-existing cations. Moreover, the MCER could be effectively regenerated by 0.01 M HCl solution and maintain high stability over 5 adsorption-desorption cycles, which render it great potential for practical applications.

Effect of Atenolol or Nebivolol Administration on Blood Pressure Variability and its Impact on White Organ Damage in Spontaneously Hypertensive Rats

Effect of Atenolol or Nebivolol Administration on Blood Pressure Variability and its Impact on White Organ Damage in Spontaneously Hypertensive Rats

Evaluating the performance of xanthophyll, chlorophyll and structure-sensitive spectral indices to detect water stress in five fruit tree species

This study assessed the capability of several xanthophyll, chlorophyll and structure-sensitive spectral indices to detect water stress in a commercial farm consisting of five fruit tree crop species with contrasting phenology and canopy architecture. Plots irrigated and non-irrigated for eight days of each species were used to promote a range of plant water status. Multi-spectral and thermal images were acquired from an unmanned aerial system while concomitant measurements of stomatal conductance (gs), stem water potential (Ψs) and photosynthesis were taken. The Normalized Difference Vegetation Index (NDVI), red-edge ratio (R700/R670), Transformed Chlorophyll Absorption in Reflectance Index normalized by the Optimized Soil Adjusted Vegetation Index (TCARI/OSAVI), the Photochemical Reflectance Index using reflectance at 530 (PRI) and 515 nm [PRI(570–515)] and the normalized PRI (PRInorm) were obtained from the narrow-band multi-spectral images and the relationship with the in-field measurements explored. Results showed that within the Prunus species, Ψs yielded the best correlations with PRI and PRI(570–515) (r2 = 0.53) in almond trees, with TCARI/OSAVI (r2 = 0.88) in apricot trees and with PRInorm, R700/R670 and NDVI (r2 from 0.72 to 0.88) in peach trees. Weak or no correlations were found for the Citrus species due to the low level of water stress reached by the trees. Results from the sensitivity analysis pointed out the canopy temperature (Tc) and PRI(570–515) as the first and second most sensitive indicators to the imposed water conditions in all the crops with the exception of apricot trees, in which Ψs was the most sensitive indicator at midday. PRInorm was the least sensitive index among all the water stress indicators studied. When all the crops were analyzed together, PRI(570–515) and NDVI were the indices that better correlations yielded with Crop Water Stress Index, gs and, particularly, Ψs (r2 = 0.61 and 0.65, respectively). This work demonstrated the feasibility of using narrow-band multispectral-derived indices to retrieve water status for a variety of crop species with contrasting phenology and canopy architecture.

DIRECT SPECTROPHOTOMETRIC DETERMINATION OF ATENOLOL AND TIMOLOL ANTI-HYPERTENSIVE DRUGS

Objective: Direct and sensitive spectrophotometric method is described for the quantitative determination of some anti-hypertensive drugs such as atenolol (ATN) and timolol (TIM) in pure forms as well as in their dosage forms.Methods: The proposed method is based on the redox reaction between the selected drugs and KMnO4 in alkaline medium. The method involves treating the aqueous solution of the selected drugs with KMnO4 in alkaline medium and measuring the bluish-green product at 610 nm. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized.Results: The fixed-time method is adopted for constructing the calibration curves, which were found to be linear over the concentration ranges of 2.0–14 mg/ml and 2.0–28 mg/ml for ATN and TIM, respectively. The determination of the studied drugs by initial rate, variable time and rate constant method was workable with the calibration equations obtained but the fixed time method has been found to be more applicable.Conclusion: The applicability of the proposed method was demonstrated by the determination of the selected drugs in both pure and in commercial dosage forms and has met the validation requirements.

Potential Use of Polyvinyl Acetate-Polyvinylpyrrolidone Mixture for the Development of Atenolol Sustained Release Matrix Tablets: Optimization of Formulation through in Vitro-in Vivo Assessment Study.

The objective of this study was to develop sustained release matrix tablets of atenolol (AT) using different concentrations of polyvinyl acetate-polyvinylpyrrolidone mixture (KSR) (20, 30, or 40%) with various types of fillers such as spray dried lactose (SP.D.L), avicel pH 101 (AV), and emcompress (EMS). The physical characteristics of the prepared tablets were evaluated. Characterization of the optimized formulation was performed using Fourier transform (FT)-IR spectroscopy and differential scanning calorimetry (DSC). Moreover, the in vitro release profiles of AT formulations were investigated in different pH dissolution media. Drug release kinetics and mechanisms were also determined. The results revealed that there was no potential incompatibility of the drug with the polymer. The release profiles of AT were affected by the concentration of KSR, fillers used, and pH of the dissolution media. The drug release kinetic from most of the formulations obeyed Higuchi diffusion model. The selected formulae were investigated for their stability by storage at 30 and 40°C with atmospheric humidity and 75% relative humidity (RH), respectively. The results demonstrated that no change in the physicochemical properties of the tablets stored at 30°C/atmospheric RH in comparison with some changes at 40°C/75% RH. Finally, the in vivo study provided an evidence that the optimized AT tablet containing 40% KSR and SP.D.L exhibited prominent higher oral bioavailability and more efficient sustained-release effect than the drug alone or the commercial tablet product. It is noteworthy that KSR could be considered as a promising useful release retardant for the production of AT sustained release matrix tablets.

H2Ti3O7 Nanotubes Decorated with Silver Nanoparticles for Photocatalytic Degradation of Atenolol

The photocatalytic degradation/adsorption process of the β-blocker atenolol (ATL) under UV irradiation is described using two types of silver decorated catalysts: silver/titania and silver/titanates. The silver ions were reduced on the surface of TiO2-P25-Degussa using gallic acid. Silver/titanates were prepared by a microwave-assisted hydrothermal method using the silver/titania as the starting material to obtain the hydrogen titanate (H2Ti3O7) structure with tubular morphology. These materials were characterized by X-ray diffraction, UV-Vis spectroscopy, N2 physisorption, temperature programmed reduction, TEM, and FTIR spectroscopy. During the photocatalytic process, the ATL molecules were completely converted to amino-diol byproducts. It is the first time that these materials have been applied during the photocatalytic process in the degradation of pharmaceuticals products. The success of the silver nanoparticles (2 nm) consists of the homogeneous distribution over the surface of titanate nanotubes inhibiting the hole/electron recombination promoting the oxidation process. The Ag@H2Ti3O7 with a concentration of silver as 1.0% shows the highest adsorption/degradation of ATL than the Ag@TiO2 and the P25-Degussa. The great performance in the reuse test consists in the strong attachment of the silver nanoparticles on the titanium surface that inhibits the silver lixiviation during the photocatalytic tests.