Kumquat peel-derived biochar to support zeolitic imidazole framework-67 (ZIF-67) for enhancing peracetic acid activation to remove acetaminophen from aqueous solution

This study presents the synthesis of a novel composite catalyst, ZIF-67, doped on sodium bicarbonate-modified biochar derived from kumquat peels (ZIF-67@KSB3), for the enhanced activation of peracetic acid (PAA) in the degradation of acetaminophen (APAP) in aqueous solutions. The composite demonstrated a high degradation efficiency, achieving 94.3% elimination of APAP at an optimal condition of 200 mg L-1 catalyst dosage and 0.4 mM PAA concentration at pH 7. The degradation mechanism was elucidated, revealing that superoxide anion (O2•-) played a dominant role, while singlet oxygen (1O2) and alkoxyl radicals (R-O•) also contributed significantly. The degradation pathways of APAP were proposed based on LC-MS analyses and molecular electrostatic potential calculations, identifying three primary routes of transformation. Stability tests confirmed that the ZIF-67@KSB3 catalyst retained an 86% efficiency in APAP removal after five successive cycles, underscoring its durability and potential for application in pharmaceutical wastewater treatment.

Cu/N co-doped biochar activating PMS for selective degrading paracetamol via a non-radical pathway dominated by singlet oxygen and electron transfer

The non-free radical oxidation pathway (PMS-NOPs) of peroxymonosulfate (PMS) holds significant promise for practical wastewater treatment applications, owing to its low oxidation potential, high PMS utilization rate, and robust anti-interference capability in the degradation of pollutants. A novel activator copper nitrogen co-doped porous biochar (Cu-N-BC) with rich defect edges and functional groups was obtained by adding Cu and N to the biochar matrix generated by sodium alginate through pyrolysis in this study. Under the condition of 1 mM PMS, 30 mg/L activator was used to activate PMS and achieve efficient degradation of 10 mg/L paracetamol (PCT) within 15 min, with a high reaction rate constants (kobs) of 0.391 min-1. The activation mechanism of the Cu-N-BC/PMS/PCT system was a non-radical activation pathway with the dominance of singlet oxygen (1O2) and the presence of catalyst-mediated electron transfer. The graphite nitrogen, pyridine nitrogen, and Cu-N coordination introduced by Cu/N co-doping, as well as the carbon skeleton and CO functional group of biochar, were considered active sites that promote the 1O2 generation. The Cu-N-BC/PMS system exhibits strong stability, eco-friendliness, effective mineralization, and interference resistance across diverse pH levels (3-11) and interfering ions, including Cl-, H2PO4-, NO3-, SO42-, and humic acid. Remarkably, it efficiently degrades PCT in tap and lake water, achieving a notable 63.73% TOC mineralization rate, with leached copper ions below 0.02 mg/L. This research introduces a novel method for obtaining metal nitrogen carbon activators and enhances understanding of PMS non-radical activation pathways and active sites.

In Situ Self-Assembling Liver Spheroids with Synthetic Nanoscaffolds for Preclinical Drug Screening Applications

Drug-induced liver injury (DILI) is one of the most common reasons for acute liver failure and a major reason for the withdrawal of medications from the market. There is a growing need for advanced in vitro liver models that can effectively recapitulate hepatic function, offering a robust platform for preclinical drug screening applications. Here, we explore the potential of self-assembling liver spheroids in the presence of electrospun and cryomilled poly(caprolactone) (PCL) nanoscaffolds for use as a new preclinical drug screening tool. This study investigated the extent to which nanoscaffold concentration may have on spheroid size and viability and liver-specific biofunctionality. The efficacy of our model was further validated using a comprehensive dose-dependent acetaminophen toxicity protocol. Our findings show the strong potential of PCL-based nanoscaffolds to facilitate in situ self-assembly of liver spheroids with sizes under 350 μm. The presence of the PCL-based nanoscaffolds (0.005 and 0.01% w/v) improved spheroid viability and the secretion of critical liver-specific biomarkers, namely, albumin and urea. Liver spheroids with nanoscaffolds showed improved drug-metabolizing enzyme activity and greater sensitivity to acetaminophen compared to two-dimensional monolayer cultures and scaffold-free liver spheroids. These promising findings highlight the potential of our nanoscaffold-based liver spheroids as an in vitro liver model for drug-induced hepatotoxicity and drug screening.

A Novel Low-Frequency Electromagnetic Active Inertial Sensor for Drug Detection

The purpose of this paper is to demonstrate a new discovery regarding the interaction between materials and very low radio frequencies. Specifically, we observed a feedback response on an inertia active sensor when specific frequencies (around 2-4 kHz) are used to irradiate targeted pharmaceutical samples like aspirin or paracetamol drugs. The characteristics of this phenomenon, such as excitation and relaxation time, the relation between deceleration and a material's quantity, and signal amplitude, are presented and analyzed. Although the underlying physics of this phenomenon is not yet known, we have shown that it has potential applications in remote identification of compounds, detection, and location sensing, as well as identifying substances that exist in plants without the need for any processing. This method is fast, accurate, low-cost, non-destructive, and non-invasive, making it a valuable area for further research that could yield spectacular results in the future.

AI-driven design of customized 3D-printed multi-layer capsules with controlled drug release profiles for personalized medicine

Personalized medicine aims to effectively and efficiently provide customized drugs that cater to diverse populations, which is a significant yet challenging task. Recently, the integration of artificial intelligence (AI) and three-dimensional (3D) printing technology has transformed the medical field, and was expected to facilitate the efficient design and development of customized drugs through the synergy of their respective advantages. In this study, we present an innovative method that combines AI and 3D printing technology to design and fabricate customized capsules. Initially, we discretized and encoded the geometry of the capsule, simulated the dissolution process of the capsule with classical drug dissolution model, and verified it by experiments. Subsequently, we employed a genetic algorithm to explore the capsule geometric structure space and generate a complex multi-layer structure that satisfies the target drug release profiles, including stepwise release and zero-order release. Finally, Two model drugs, isoniazid and acetaminophen, were selected and fused deposition modeling (FDM) 3D printing technology was utilized to precisely print the AI-designed capsule. The reliability of the method was verified by comparing the in vitro release curve of the printed capsules with the target curve, and the f2 value was more than 50. Notably, accurate and autonomous design of the drug release curve was achieved mainly by changing the geometry of the capsule. This approach is expected to be applied to different drug needs and facilitate the development of customized oral dosage forms.

Electrosprayed Eudragit RL100 nanoparticles with Janus polyvinylpyrrolidone patches for multiphase release of paracetamol

Advanced nanotechniques and the corresponding complex nanostructures they produce represent some of the most powerful tools for developing novel drug delivery systems (DDSs). In this study, a side-by-side electrospraying process was developed for creating double-chamber nanoparticles in which Janus soluble polyvinylpyrrolidone (PVP) patches were added to the sides of Eudragit RL100 (RL100) particles. Both sides were loaded with the poorly water-soluble drug paracetamol (PAR). Scanning electron microscope results demonstrated that the electrosprayed nanoparticles had an integrated Janus nanostructure. Combined with observations of the working processes, the microformation mechanism for creating the Janus PVP patches was proposed. XRD, DSC, and ATR-FTIR experiments verified that the PAR drug was present in the Janus particles in an amorphous state due to its fine compatibility with the polymeric matrices. In vitro dissolution tests verified that the Janus nanoparticles were able to provide a typical biphasic drug release profile, with the PVP patches providing 43.8 ± 5.4% drug release in the first phase in a pulsatile manner. In vivo animal experiments indicated that the Janus particles, on one hand, could provide a faster therapeutic effect than the electrosprayed sustained-release RL100 nanoparticles. On the other hand, they could maintain a therapeutic blood drug concentration for a longer period. The controlled release mechanism of the drug was proposed. The protocols reported here pioneer a new process-structure-performance relationship for developing Janus-structure-based advanced nano-DDSs.

Circular economical approach of extracting nanocarbons from waste pea peel for sensing of p-nitrophenol and its conversion into paracetamol

An important paradigm shift towards the circular economy is to prioritize waste prevention, reuse, recycling, and recovery before disposal is necessary. In this context, a sustainable protocol of converting waste pea peel (wPP) into low-cost carbon nanomaterials for sensing and conversion of p-nitrophenol (p-NP) into value-added paracetamol is being reported. Two fractions of the carbonaceous nanomaterials were obtained after the hydrothermal treatment (HT) of wPP, firstly an aqueous portion containing water-soluble carbon dots (wPP-CDs) and a solid residue, which was converted into carbonized biochar (wPP-BC). Blue-colored fluorescent wPP-CDs displayed excitation-dependent and pH-independent properties with a quantum yield (QY) of 8.82 %, which were exploited for the fluorescence sensing of p-NP with 4.20 μM limit of detection. Pyrolyzed biochar acting as an efficient catalyst effectively reduces p-NP to p-aminophenol (p-AP) in just 16 min with a 0.237 min-1 rate of conversion. Furthermore, the produced p-AP was converted into paracetamol, an analgesic and antipyretic drug, to achieve zero waste theory. Thus, this study provides the execution of sustainable approaches based on the integral valorization of biowaste that can be further recycled and reused, offering an effective way to attain a profitable circular economy.

The inherent nature of N/P heteroatoms in Sargassum fusiforme seaweed biochar enhanced the nonradical activation of peroxymonosulfate for acetaminophen degradation in aquatic environments

This study investigated the catalytic activity of biochar materials derived from algal biomass Sargassum fusiforme (S. fusiforme) for groundwater remediation. A facile single-step pyrolysis process was used to prepare S. fusiforme biochar (SFBCX), where x denotes pyrolysis temperatures (600 °C-900 °C). The surface characterization revealed that SFBC800 possesses intrinsic N and P heteroatoms. The optimum experimental condition for acetaminophen (AAP) degradation (>98.70%) was achieved in 60 min using 1.0 mM peroxymonosulfate (PMS), 100 mg L-1 SFBC800, and pH 5.8 (unadjusted). Moreover, the degradation rate constant (k) was evaluated by the pseudo-first-order kinetic model. The maximum degradation (>98.70%) of AAP was achieved within 60 min of oxidation. Subsequently, the k value was calculated to be 6.7 × 10-2 min-1. The scavenger tests showed that radical and nonradical processes are involved in the SFBC800/PMS system. Moreover, the formation of reactive oxygen species (ROS) in the SFBC800/PMS system was confirmed using electron spin resonance (ESR) spectroscopy. Intriguingly, both radical (O2•-, •OH, and SO4•-) and nonradical (1O2) ROS were formed in the SFBC800/PMS system. In addition, electrochemical studies were conducted to verify the electron transfer process of the nonradical mechanism in the SFBC800/PMS system. The scavenger and electron spin resonance (ESR) spectroscopy showed that singlet oxygen (1O2) is the predominant component in AAP degradation. Under optimal condition, the SFBC800/PMS system reached ∼81% mineralization of AAP within 5 min and continued to ∼85% achieved over 60 min of oxidation. Coexisting ions and different aqueous matrices were investigated to examine the feasibility of the catalyst system, and the SFBC800/PMS system was found to be effective in the remediation of AAP-contaminated groundwater, river water, and effluent water obtained from wastewater treatment plants. Moreover, the SFBC800-activated PMS system demonstrated reusability. Our findings indicate that the SFBC800 catalyst has excellent catalytic activity for AAP degradation in aquatic environments.

Synthesis of poly(ionic liquid-OH) mediated deacetylated chitin and its hydrogels: A study on their applications in controlled release of paracetamol and urea

Due to the biodegradable and biocompatible nature of chitin and chitosan, they are extensively used in the synthesis of hydrogels for various applications. In this work, deacetylation of chitin is carried out with alkaline poly(dimethyldiallylammonium-hydroxide) that gave a higher amount of water-soluble chitin (with 84 % of the degree of deacetylation = chitosan0.84) compared to deacetylation using NaOH. The water-soluble chitosan0.84 is used as intercalating chains for the preparation of acrylic acid and vinylimidazole-based hydrogels. The quaternization of imidazole groups is done with 1,ω-dibromoalkanes, which sets off the crosslinking in the above polymer network. A set of three chitosan0.84 intercalated hydrogels, namely Cs-C4-hydrogel, Cs-C5-hydrogel, and Cs-C10-hydrogel are prepared bearing butyl, pentyl, and decyl chains as respective crosslinkers. The swell ratios of these intercalated hydrogels are compared with those of non-intercalated hydrogels (C4-hydrogel, C5-hydrogel, and C10-hydrogel). Chitosan0.84 intercalated Cs-C10-hydrogel has excellent swelling properties (2330 % swelling ratio) among six synthesized hydrogels. SEM analysis reveals that decyl crosslinker-bearing hydrogels are highly porous. The multi-functionality of Cs-C10-hydrogel and C10-hydrogel is explored towards -the controlled release of paracetamol/urea, and methyleneblue dye absorption. These studies disclose that chitosan0.84 intercalated hydrogels are showing superior-swelling behavior, high paracetamol/urea loading capacities and better dye entrapment than their non-intercalated counterparts.

Impact of dry coating lactose as a brittle excipient on multi-component blend processability

Previous work demonstrated the benefits of dry coating fine-grade microcrystalline cellulose (MCC) for enabling direct compression (DC), a favored tablet manufacturing method, due to enhanced flowability while retaining good compactability of placebo and binary blends of cohesive APIs. Here, fine brittle excipients, Pharmatose 450 (P450, 19 μm) and Pharmatose 350 (P350, 29 μm), having both poor flowability and compactability are dry coated with silica A200 or R972P to assess DC capability of multi-component cohesive API (coarse acetaminophen, 22 μm, and ibuprofen50, 47 μm) blends. Dry coated P450 and P350 not only attained excellent flowability and high bulk density but also heightened tensile strength hence processability, which contrasts with reported reduction for dry coated ductile MCC. Although hydrophobic R972P imparted better flowability, hydrophilic A200 better enhanced tensile strength, hence selected for dry coating P450 in multi-component blends that included fine Avicel PH-105. For coarse acetaminophen blends, substantial bulk density and flowability increase without any detrimental effect on tensile strength were observed; a lesser amount of dry coated P450 was better. Increased flowability, bulk density, and tensile strength, hence enhanced processability by reaching DC capability, were observed for 60 wt% ibuprofen50, using only 18 wt% of the dry coated P450, i.e. 0.18 wt% silica in the blend.

Comparison of Properties of Acetaminophen Tablets Prepared by Wet Granulation Using Freeze-Dried Versus Phase-Inversion Bacterial Cellulose as Diluent

Bacterial cellulose (BC) is an interesting material for drug delivery applications due to its high purity. This study aimed to compare the properties of tablets prepared by the wet granulation method using bacterial cellulose prepared by different methods as a diluent, using acetaminophen as a model drug. BC used as diluents were prepared using two different methods: freeze-drying (BC-FD) and phase-inversion (BC-PI), and their characteristics were analyzed and compared with that of commercial microcrystalline cellulose PH 101 (Comprecel® M101). Acetaminophen tablets were prepared by wet granulation using BC-FD, BC-PI, or Comprecel® M101 as diluents, and their tablet properties were examined. The result showed that the morphology, polymorph, and crystallinity of BC-PI and Comprecel® M101 were similar but they were different compared with that of BC-FD. Tablets could be successfully formed using BC-PI and Comprecel® M101 as diluents without any physical defects but the tablet prepared using BC-FD as diluent appeared chipped edge. The characteristics (thickness, weight variation, hardness, friability, disintegration, drug content, and dissolution) of the tablets prepared using BC-PI diluent were also similar to those prepared using Comprecel® M101 diluent, but those of BC-FD diluent were inferior. This indicates that BC prepared in BC-PI can potentially be used as a diluent for tablets prepared by wet granulation.

Improvement of ferrioxalate assisted Fenton and photo-Fenton processes for paracetamol degradation by hydrogen peroxide dosage

This work aimed to investigate the impact of hydrogen peroxide (HP) punctual dosage on paracetamol (PCT) degradation, through Fenton and photo-Fenton processes under near-neutral pH conditions, using ferrioxalate and artificial sunlight. The assays were performed using a D-optimal experimental design, to statistically evaluate the influence of radiation (ON or OFF), HP concentration (94.5-756 mg L-1), and HP dosage (YES or NO), on PCT conversion. The optimal conditions determined from the study were: HP = 378 mg L-1, DOS = YES, and RAD = ON, achieving a predicted PCT conversion of 99.68% in 180 min. This result obtained from the model was very close to the experimental one (98.80%). It was verified that HP dosage positively influenced the iron catalytic cycle since higher Fe2+ concentrations were reached at shorter reaction times, accelerating not only PCT conversion but also its by-products hydroquinone and 1,4-benzoquinone, leading to better performances of Fenton and photo-Fenton reactions. Under optimal conditions and employing real water matrices (an artificial matrix with inorganic anions, a real groundwater sample, and a synthetic industrial wastewater), HP dosage demonstrated the ability to mitigate the negative effects caused by the content of different ions and other organic compounds and significantly improve HP consumption in challenging wastewater conditions.

Simultaneous monitoring of amoxicillin and paracetamol in synthetic biological fluids using a 3D printed disposable electrode with a lab-made conductive filament

In this work, we are pleased to present for the first time a 3D-printed electrochemical device using a lab-made conductive filament based on graphite (Gr) and polylactic acid (PLA) polymer matrix for the simultaneous detection of amoxicillin (AMX) and paracetamol (PAR). The sensor was properly characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). Compared to the commercial glassy carbon electrode (GCE), the superior performance of the 3D-Gr/PLA electrode was verified with a 3.8-fold more favored charge transfer. A differential pulse voltammetry (DPV) method was proposed providing a linear working range of 4 to 12 μmol L-1 for both analytes and a limit of detection (LOD) of 0.80 and 0.51 μmol L-1 for AMX and PAR, respectively. Additionally, repeatability studies (n = 5, RSD < 5.7%) indicated excellent precision, and recovery percentages ranging from 89 to 109% when applied to synthetic human urine, saliva, and plasma samples, attested to the accuracy of the method. The studies also indicate that the sensor does not suffer significant interference from common substances (antibiotics and biomarkers) present in the biological fluids, which makes it a promising analytical tool considering its low-cost, ease of manufacturing, robustness, and electrochemical performance.

High-resolution mass spectrometry identifies delayed biomarkers for improved precision in acetaminophen/paracetamol human biomonitoring

Paracetamol/acetaminophen (N-acetyl-p-aminophenol, APAP) is a top selling analgesic used in more than 600 prescription and non-prescription pharmaceuticals. To study efficiently some of the potential undesirable effects associated with increasing APAP consumption (e.g., developmental disorders, drug-induced liver injury), there is a need to improve current APAP biomonitoring methods that are limited by APAP short half-life. Here, we demonstrate using high-resolution mass spectrometry (HRMS) in several human studies that APAP thiomethyl metabolite conjugates (S-methyl-3-thioacetaminophen sulfate and S-methyl-3-thioacetaminophen sulphoxide sulfate) are stable biomarkers with delayed excretion rates compared to conventional APAP metabolites, that could provide a more reliable history of APAP ingestion in epidemiological studies. We also show that these biomarkers could serve as relevant clinical markers to diagnose APAP acute intoxication in overdosed patients, when free APAP have nearly disappeared from blood. Using in vitro liver models (HepaRG cells and primary human hepatocytes), we then confirm that these thiomethyl metabolites are directly linked to the toxic N-acetyl-p-benzoquinone imine (NAPQI) elimination, and produced via an overlooked pathway called the thiomethyl shunt pathway. Further studies will be needed to determine whether the production of the reactive hepatotoxic NAPQI metabolites is currently underestimated in human. Nevertheless, these biomarkers could already serve to improve APAP human biomonitoring, and investigate, for instance, inter-individual variability in NAPQI production to study underlying causes involved in APAP-induced hepatotoxicity. Overall, our findings demonstrate the potential of exposomics-based HRMS approach to advance towards a better precision for human biomonitoring.

Supramolecular chemistry enables vat photopolymerization 3D printing of novel water-soluble tablets

Vat photopolymerization has garnered interest from pharmaceutical researchers for the fabrication of personalised medicines, especially for drugs that require high precision dosing or are heat labile. However, the 3D printed structures created thus far have been insoluble, limiting printable dosage forms to sustained-release systems or drug-eluting medical devices which do not require dissolution of the printed matrix. Resins that produce water-soluble structures will enable more versatile drug release profiles and expand potential applications. To achieve this, instead of employing cross-linking chemistry to fabricate matrices, supramolecular chemistry may be used to impart dynamic interaction between polymer chains. In this study, water-soluble drug-loaded printlets (3D printed tablets) are fabricated via digital light processing (DLP) 3DP for the first time. Six formulations with varying ratios of an electrolyte acrylate monomer, [2-(acryloyloxy)ethyl]trimethylammonium chloride (TMAEA), and a co-monomer, 1-vinyl-2-pyrrolidone (NVP), were prepared to produce paracetamol-loaded printlets. 1H NMR spectroscopy analysis confirmed the integration of TMAEA and NVP in the polymer, and residual TMAEA monomers were found to be present only in trace amounts (0.71 - 1.37 %w/w). The apparent molecular mass of the photopolymerised polymer was found to exceed 300,000 Da with hydrodynamic radii of 15 - 20 nm, estimated based on 1H DOSY NMR measurements The loaded paracetamol was completely released from the printlets between 45 minutes to 5 hours. In vivo single-dose acute toxicity studies in rats suggest that the printlets did not cause any tissue damage. The findings reported in this study represent a significant step towards the adoption of vat photopolymerization-based 3DP to produce personalised medicines.

Impact of Silica Dry Coprocessing with API and Blend Mixing Time on Blend Flowability and Drug Content Uniformity

This paper considers two fine-sized (d50 ∼10 µm) model drugs, acetaminophen (mAPAP) and ibuprofen (Ibu), to examine the effect of API dry coprocessing on their multi-component medium DL (30 wt%) blends with fine excipients. The impact of blend mixing time on the bulk properties such as flowability, bulk density, and agglomeration was studied. The hypothesis tested is that blends with fine APIs at medium DL require good blend flowability to have good blend uniformity (BU). Moreover, the good flowability could be achieved through dry coating with hydrophobic (R972P) silica, which reduces agglomeration of not only fine API, but also of its blends while using fine excipients. For uncoated APIs, the blend flowability was poor, i.e. cohesive regime at all mixing times, and the blends failed to achieve acceptable BU. In contrast, for dry coated APIs, their blend flowability improved to easy-flow regime or better, improving with mixing time, and as hypothesized, all blends consequently achieved desired BU. All dry coated API blends exhibited improved bulk density and reduced agglomeration, attributed to mixing induced synergistic property enhancements, likely due to silica transfer. Despite coating with hydrophobic silica, tablet dissolution was improved, attributed to the reduced agglomeration of fine API.

3D screen printing technology enables fabrication of oral drug dosage forms with freely tailorable release profiles

3D printing offers new opportunities to customize oral dosage forms of pharmaceuticals for different patient populations, improving patient safety, care, and compliance. Although several notable 3D print technologies have been developed, such as inkjet printing, powder-based printing, selective laser sintering (SLS) printing, and fused deposition modelling (FDM), among others, their capacity is often limited by the number of printing heads. 3D screen-printing (3DSP) is based on a classic flatbed screen printing that is widely used in industrial applications for technical applications. 3DSP can build up thousands of units per screen simultaneously, enabling mass customization of pharmaceuticals. Here, we use 3DSP to investigate two novel paste formulations: immediate-release (IR) and extended-release (ER) using Paracetamol (acetaminophen) as the active pharmaceutical ingredient (API). Both disk-shaped and donut-shaped tablets were fabricated using one or both pastes to design drug delivery systems (DDS) with tailored API release profiles. The size and mass of the produced tablets demonstrated high uniformity. Characterization of the tablets physical properties, such as breaking force (25-39 N) and friability (0.002-0.237%), adhering to Ph. Eur (10th edition). Finally, drug release tests with a phosphate buffer at pH 5.8 showed Paracetamol release depended on the IR- and ER paste materials and their respective compartment size of the composite DDS, which can be readily varied using 3DSP. This work further demonstrates the potential of 3DSP to manufacture complex oral dosage forms exhibiting custom release functionalities for mass production.

Highly Efficient Electrochemical Sensing of Acetaminophen by Cobalt Oxide-Embedded Nitrogen-Doped Hollow Carbon Spheres

With respect to sensor application investigations, hollow mesoporous carbon sphere-based materials of the spinel type of cobalt oxide (Co₃O₄) and heteroatom-doped materials are gaining popularity. In this contribution, dopamine hydrochloride (DA) and cobalt phthalocyanine (CoPc) precursors were employed to construct a highly homogeneous Co₃O₄-embedded N-doped hollow carbon sphere (Co₃O₄@NHCS) by a straightforward one-step polymerization procedure. The resulting Co₃O₄@NHCS materials may effectively tune the surface area, defect sites, and doping amount of N and Co elements by altering the loading amount of CoPc. The relatively high surface area, greater spherical wall thickness, enriched defect sites, and better extent of N and Co sites are all visible in the best 200 mg loaded Co₃O₄@NHCS-2 material. This leads to significant improvement in pyridine and graphitic N site concentrations, which offers exceptional electrochemical performance. Electrochemical analysis was used to study the electrocatalytic activity of Co₃O₄@NHCSs towards the sensing of pharmacologically active significant compounds (acetaminophen). Excellent sensor properties include the linear range (0.001-0.2 and 1.0-8.0 mM), sensitivity, limit of detection (0.07 and 0.11 μM), and selectivity in the modified Co₃O₄@NHCSs/GCE. The authentic sample (acetaminophen tablet) produces a satisfactory result when used practically.

Molten-salts assisted preparation of iron-nitrogen-carbon catalyst for efficient degradation of acetaminophen by periodate activation

Highly efficient and stable heterogeneous catalysts were desired to activate periodate (PI) for sustainable pollution control. Herein, iron-nitrogen-carbon catalyst was synthesized using a facile molten-salts mediated pyrolysis strategy (denoted as FeNC-MS) and employed to activate PI for the degradation of acetaminophen (ACE). Compared with iron-nitrogen-carbon catalyst prepared by direct pyrolysis method (marked as FeNC), FeNC-MS exhibited superior catalytic activity due to its large specific surface area (1600 m² g^-1) and the abundance of FeN_x sites. The batch experiments revealed that FeNC/PI process achieved 37 % ACE removal within 20 min, while ACE removal in FeNC-MS/PI process was 98 % under the identical conditions. Integrated with electron paramagnetic resonance tests, quenching experiments, chemical probe identification, and electrochemical experiments, we demonstrated that FeNC-MS-PI complexes-mediated electron transfer was the predominant mechanism for the oxidation of ACE. Further analysis disclosed that FeN_x sites in FeNC-MS were the main active sites for the activation of PI. Additionally, FeNC-MS/PI process exhibited significant resistance to humic acid and background electrolyte, and avoided the secondary pollution imposed by Fe leaching. The possible degradation pathways of ACE were proposed. The germination experiments of lettuce seeds showed that the ecotoxicity of ACE solution was significantly reduced after treatment with FeNC-MS/PI process. Overall, this study provided a facile strategy for the synthesis of efficient iron-nitrogen-carbon catalysts and gained fundamental insight into the mechanism of PI activation by iron-nitrogen-carbon catalysts for pollutants degradation.

Effective and reproducible biosynthesis of nanogold-composite catalyst for paracetamol oxidation

Pharmaceutical products are some of the most serious emergent pollutants in the environment, especially nowadays of the COVID-19 pandemic. In this study, nanogold-composite was prepared, and its catalytic activity for paracetamol degradation was investigated. Moreover, for the first time, recycled waste diatomite earth (WDE) from beer filtration was used for reproducible gold nanoparticle (Au NPs) preparation. We studied Au NPs by various psychical-chemical and analytical methods. Transmission and scanning electron microscopy were used for nanogold-composite morphology, size and shape characterization. Total element concentrations were determined using inductively coupled plasma mass and X-ray fluorescence spectrometry. X-ray powder diffraction analysis was used for crystal structure characterization of samples. Fourier transform infrared spectrometer was used to study the chemical changes before and after Au NP formation. The results revealed that the WDE served as both a reducing and a stabilizing agent for crystalline spherical 30 nm Au NPs as well as acting as a direct support matrix. The kinetics of paracetamol degradation was studied by high-performance liquid chromatography with a photodiode array detector. The conversion of paracetamol was 62% and 67% after 72 h in the absence or presence of light irradiation, respectively, with 0.0126 h^-1 and 0.0148 h^-1 reaction rate constants. The presented study demonstrates the successful use of waste material from the food industry for nanogold-composite preparation and its application as a promising catalyst in paracetamol removal.

A novel temperature-responsive electrochemical sensing platform for reversible switch-sensitive detection of acetamidophenol

A novel facile, quick, and temperature-controlled sensor was constructed based on a polystyrene-poly-N,N-diethyl acrylamide-polystyrene (PS-PDEAM)/carboxylated multi-walled carbon nanotube (MWCNT) composite modified glass carbon electrode. The sensor achieves acetaminophen (AP) reversibility through better temperature sensitivity. PS-PDEAM shrinks when the temperature exceeds its lower critical temperature (LCST). When AP molecules pass through the modified interface, the electron transfer rate is accelerated, and the sensor is turned on. In the off state, the electrochemical response of AP cannot be detected. Under ideal experimental conditions, for composite modified films, there is a wide detection range of AP between 1.5-85.1 μM and 85.1-235.1 μM, and the limit of detection of acetaminophen is as low as 0.57 μM (S/N = 3). This method has been successfully applied to the determination of AP in tablets, and shows high stability, good reproducibility and excellent anti-interference ability. The on-off sensor opens up a wide range of possibilities for the use of temperature-sensitive polymers in electro-catalysis, sensors, and environmental pollutant monitoring.

Electrocatalytic performance of oxygen-activated carbon fibre felt anodes mediating degradation mechanism of acetaminophen in aqueous environments

Carbon felts are flexible and scalable, have high specific areas, and are highly conductive materials that fit the requirements for both anodes and cathodes in advanced electrocatalytic processes. Advanced oxidative modification processes (thermal, chemical, and plasma-chemical) were applied to carbon felt anodes to enhance their efficiency towards electro-oxidation. The modification of the porous anodes results in increased kinetics of acetaminophen degradation in aqueous environments. The utilised oxidation techniques deliver single-step, straightforward, eco-friendly, and stable physiochemical reformation of carbon felt surfaces. The modifications caused minor changes in both the specific surface area and total pore volume corresponding with the surface morphology. A pristine carbon felt electrode was capable of decomposing up to 70% of the acetaminophen in a 240 min electrolysis process, while the oxygen-plasma treated electrode achieved a removal yield of 99.9% estimated utilising HPLC-UV-Vis. Here, the electro-induced incineration kinetics of acetaminophen resulted in a rate constant of 1.54 h^-1, with the second-best result of 0.59 h^-1 after oxidation in 30% H₂O₂. The kinetics of acetaminophen removal was synergistically studied by spectroscopic and electrochemical techniques, revealing various reaction pathways attributed to the formation of intermediate compounds such as p-aminophenol and others. The enhancement of the electrochemical oxidation rates towards acetaminophen was attributed to the appearance of surface carbonyl species. Our results indicate that the best-performing plasma-chemical treated CFE follows a heterogeneous mechanism with only approx. 40% removal due to direct electro-oxidation. The degradation mechanism of acetaminophen at the treated carbon felt anodes was proposed based on the detected intermediate products. Estimation of the cost-effectiveness of removal processes, in terms of energy consumption, was also elaborated. Although the study was focussed on acetaminophen, the achieved results could be adapted to also process emerging, hazardous pollutant groups such as anti-inflammatory pharmaceuticals.

Solvent-Mediated Polymorphic Transformations in Molten Polymers: The Account of Acetaminophen

Solvent-mediated polymorphic transformations (SMPTs) employing nonconventional solvents (polymer melts) is an underexplored research topic that limits the application of polymer-based formulation processes. Acetaminophen (ACM), a widely studied active pharmaceutical ingredient (API), is known to present SMPTs spontaneously (<30 s) in conventional solvents such as ethanol. In situ Raman spectroscopy was employed to monitor the induction time for the SMPT of ACM II to I in polyethylene glycol (PEG) melts of different molecular weights (Mw, 4000, 10 000, 20 000, 35 000 g/mol). The results presented here demonstrate that the induction time for the SMPT of ACM II to I in PEG melts is driven by its diffusivity through the polymer melts. Compared to conventional solvents (i.e., ethanol) the mass transfer (diffusion coefficient, D) in melts is significantly hindered (Dethanol = 4.84 × 10-9 m2/s > DPEGs = 5.32 × 10-11-8.36 × 10-14 m2/s). Ultimately, the study proves that the induction time for the SMPT can be tuned by understanding the dispersant's physicochemical properties (i.e., η) and, thus, the D of the solute in the dispersant. This allows one to kinetically access and stabilize metastable forms or delay their transformations under given process conditions.

Simultaneous Determination of Paracetamol, Ibuprofen, and Caffeine in Tablets by Molecular Absorption Spectroscopy Combined with Classical Least Square Method

In this paper, the classical least-squares (CLS) method with molecular absorption spectrophotometric measurement was used to determine simultaneously paracetamol (PAR), ibuprofen (IBU), and caffeine (CAF) in tablets. The absorbance spectra of the standard solutions and samples were measured over a wavelength from 220 to 300 nm with a 0.5 nm step. The concentration of PAR, IBU, and CAF in the sample solutions was calculated by using Visual Basic for Applications (VBA) and a program called CLS-Excel written in Microsoft Excel 2016. The method and the CLS-Excel program were tested on mixed standard laboratory samples with different PAR, IBU, and CAF concentration ratios, and they showed only small errors and a satisfying repeatability. An analytical procedure for tablets containing PAR, IBU, and CAF was developed. The reliability of the procedure was proved via the recovery and repeatability of the analysis results with an actual tablet sample and by comparing the mean contents of active substances in the tablets obtained from the analytical procedure with the HPLC method. The procedure is simple with a reduced cost compared with the HPLC standard method.

Utilization of Pectin from Okra as Binding Agent in Immediate Release Tablets

Polymeric materials from plants continue to be of interest to pharmaceutical scientists as potential binders in immediate release tablets due to availability, sustainability, and constant supply to feed local pharmaceutical industries. Paracetamol tablet formulations were utilized in investigating the potential binding characteristics of pectin harnessed from various okra genotypes (PC1-PC5) in Ghana. The pectin yields from the different genotypes ranged from 6.12 to 18.84%w/w. The pH of extracted pectin ranged from 6.39 to 6.92, and it had good swelling indices and a low moisture content. Pectin extracted from all genotypes were evaluated as binders (10, 15, and 20%w/v) and compared to tragacanth BP. All formulated tablets (F1-F18) passed the weight uniformity, drug content, hardness, and friability tests. Based on their crushing strength, tablets prepared with pectin from the various genotypes were relatively harder (P ≤ 0.05) than tablets prepared with tragacanth BP. Tablets prepared with pectins as binders at 10%w/v and 15%w/v passed the disintegration and dissolution tests with the exception of PC4 at 15%w/v. Incorporation of pectin from all genotypes (excluding PC5) as a binder at concentrations above 15%w/v (F13, F16, F14, and F15) produced tablets which failed the disintegration test and showed poor dissolution profiles. Thus, pectin from these genotypes can be industrially commodified as binders in immediate release tablets using varying concentrations.

Effect of Coformer Selection on In Vitro and In Vivo Performance of Adefovir Dipivoxil Cocrystals

PURPOSE

This study aimed to improve the in vitro dissolution, permeability and oral bioavailability of adefovir dipivoxil (ADD) by cocrystal technology and clarify the important role of coformer selection on the cocrystal's properties.

METHODS

ADD was cocrystallized with three small molecules (i.e., paracetamol (PA), saccharin (SAC) and nicotinamide (NIC)), respectively. The obtained ADD-PA cocrystal was characterized by DSC, TGA, PXRD and FTIR. Comparative study on dissolution rates among the three ADD cocrystals were conducted in water and pH 6.8 phosphate buffer. Besides, effects of coformers on intestinal permeability of ADD were evaluated via in vitro Caco-2 cell model and in situ single-pass intestinal perfusion model in rats. Furthermore, in vivo pharmacokinetic study of ADD cocrystals was also compared.

RESULTS

Dissolution rates of ADD cocrystals were improved with the order of ADD-SAC cocrystal > ADD-PA cocrystal > ADD-NIC cocrystal. The permeability studies on Caco-2 cell model and single-pass intestinal perfusion model indicated that PA could enhance intestinal absorption of ADD by P-gp inhibition, while SAC and NIC did not. Further in vivo pharmacokinetic study showed that ADD-SAC cocrystal exhibited higher C_max (1.4-fold) and AUC_0-t (1.3-fold) of ADD than administration of ADD alone, and C_max and AUC_0-t of ADD-PA cocrystal were significantly enhanced by 2.1-fold and 2.2-fold, respectively, which was attributed to its higher dissolution and improved intestinal permeability.

CONCLUSION

Coformer selection had an important role on cocrystal's properties, and cocrystallization of ADD with a suitable coformer was an effective approach to enhance both dissolution and bioavailability of ADD.

Ultra-Fast Insulin-Pramlintide Co-Formulation for Improved Glucose Management in Diabetic Rats

Dual-hormone replacement therapy with insulin and amylin in patients with type 1 diabetes has the potential to improve glucose management. Unfortunately, currently available formulations require burdensome separate injections at mealtimes and have disparate pharmacokinetics that do not mimic endogenous co-secretion. Here, amphiphilic acrylamide copolymers are used to create a stable co-formulation of monomeric insulin and amylin analogues (lispro and pramlintide) with synchronous pharmacokinetics and ultra-rapid action. The co-formulation is stable for over 16 h under stressed aging conditions, whereas commercial insulin lispro (Humalog) aggregates in 8 h. The faster pharmacokinetics of monomeric insulin in this co-formulation result in increased insulin-pramlintide overlap of 75 ± 6% compared to only 47 ± 7% for separate injections. The co-formulation results in similar delay in gastric emptying compared to pramlintide delivered separately. In a glucose challenge, in rats, the co-formulation reduces deviation from baseline glucose compared to insulin only, or separate insulin and pramlintide administrations. Further, comparison of interspecies pharmacokinetics of monomeric pramlintide suggests that pharmacokinetics observed for the co-formulation will be well preserved in future translation to humans. Together these results suggest that the co-formulation has the potential to improve mealtime glucose management and reduce patient burden in the treatment of diabetes.

Minute Cu2+ coupling with HCO3- for efficient degradation of acetaminophen via H2O2 activation

Homogeneous Cu²⁺-mediated activation of H₂O₂ has been widely applied for the removal of organic contaminants, but fairly high dosage of Cu²⁺ is generally required and may cause secondary pollution. In the present study, minute Cu²⁺ (2.5 μM) catalyzed H₂O₂ exhibited excellent efficiency in degradation of organic pollutants with the assistant of naturally occurring level HCO₃^- (1 mM). In a typical case, acetaminophen (ACE) was completely eliminated within 10 min which followed the pseudo-first-order kinetics. Singlet oxygen and superoxide radical rather than traditionally identified hydroxyl radical were the predominant reactive oxygen species (ROS) responsible for ACE degradation. Meanwhile, Cu³⁺ was deduced through Cu⁺ and p-hydroxybenzoic acid formation analysis. CuCO₃(aq) was the main complex with high reactivity for the activation of H₂O₂ to form ROS and Cu³⁺. The removal efficiency of ACE depended on the operating parameters, such as Cu²⁺, HCO₃^- and H₂O₂ dosage, solution initial pH. The presence of Cl^-, HPO₄^2-, humic acid were found to retard ACE removal while other anions such as SO₄^2- and NO₃^- had no obvious effect. ACE exhibited lower degradation efficiency in real water matrices than that in ultra-pure water. Nevertheless, 58-100% of ACE was removed from domestic wastewater, lake water and tap water within 60 min. Moreover, eight intermediate products were identified and the possible degradation pathways of ACE were proposed. Additionally, other typical organic pollutants including bisphenol A, norfloxacin, lomefloxacin hydrochloride and sulfadiazine, exhibited great removal efficiency in the Cu²⁺/H₂O₂/HCO₃^- system.

Formulation and Cost-Effectiveness of Fluid Gels as an Age-Appropriate Dosage Form for Older Adults with Dysphagia

Dysphagia is associated with increased dependency and treatment costs, whereby patients resort to extemporaneous compounding that may further increase the number of adverse events and medical errors. In the management of dysphagia, increasing the bolus viscosity of medication such as fluid gels can be practiced. This study aimed to prepare and characterize the fluid gels as well as to estimate the cost of using fluid gels and compare it to the conventional practice of extemporaneous preparation of thickened liquid. Fluid gels were formulated using gellan gum and determined for physicochemical characteristics and in vitro drug release profile. The cost-based price of the fluid gel was estimated and compared to the cost of administering standard medication as well as administering thickened liquid using thickening powder. Fluid gels exhibited good physicochemical properties with the viscosity within nectar and honey consistency. A similar dissolution profile to the reference was observed for the 0.5% w/v gellan gum fluid gel and exhibiting the Higuchi release model. The price for 100 mL unit of 50 mg/mL paracetamol/acetaminophen and 20 mg/mL ibuprofen fluid gel was estimated to be about USD2.30 and USD2.37, respectively. A dose of 1000 mg paracetamol and 400 mg ibuprofen fluid gel was estimated to be about USD0.46 and USD0.47, respectively, which is lower than the cost of administering the same dose using extemporaneous thickened liquid. Fluid gels could be a cost-effective formulation for delivering medication in patients with dysphagia and can be developed on a profitable scale.

Drug-Polymer Interactions in Acetaminophen/Hydroxypropylmethylcellulose Acetyl Succinate Amorphous Solid Dispersions Revealed by Multidimensional Multinuclear Solid-State NMR Spectroscopy

The bioavailability of insoluble crystalline active pharmaceutical ingredients (APIs) can be enhanced by formulation as amorphous solid dispersions (ASDs). One of the key factors of ASD stabilization is the formation of drug-polymer interactions at the molecular level. Here, we used a range of multidimensional and multinuclear nuclear magnetic resonance (NMR) experiments to identify these interactions in amorphous acetaminophen (paracetamol)/hydroxypropylmethylcellulose acetyl succinate (HPMC-AS) ASDs at various drug loadings. At low drug loading (<20 wt %), we showed that 1H-13C through-space heteronuclear correlation experiments identify proximity between aromatic protons in acetaminophen with cellulose backbone protons in HPMC-AS. We also show that 14N-1H heteronuclear multiple quantum coherence (HMQC) experiments are a powerful approach in probing spatial interactions in amorphous materials and establish the presence of hydrogen bonds (H-bond) between the amide nitrogen of acetaminophen with the cellulose ring methyl protons in these ASDs. In contrast, at higher drug loading (40 wt %), no acetaminophen/HPMC-AS spatial proximity was identified and domains of recrystallization of amorphous acetaminophen into its crystalline form I, the most thermodynamically stable polymorph, and form II are identified. These results provide atomic scale understanding of the interactions in the acetaminophen/HPMC-AS ASD occurring via H-bond interactions.

Understanding and Characterizing the Drug Sorption to PVC and PE Materials

Characterizing the sorption of drugs onto polyvinylchloride (PVC) and polyethylene (PE) materials in terms of thermodynamic adsorption properties and atomistic details (local arrangements, orientation, and diffusion) is fundamental for the development of alternative materials that would limit drug sorption phenomena and plasticizer release. Here, a combination of experiments and sophisticated calculations of potential of mean forces are carried out to investigate the sorption of paracetamol and diazepam to PE and PVC surfaces. The simulated Gibbs free energies of adsorption are in line with the experimental interpretations. The polymer-drug-water interface is then characterized at the molecular scale by an in-depth investigation of local properties such as density, orientation, and diffusion.

Tracing the origin of paracetamol tablets by near-infrared, mid-infrared, and nuclear magnetic resonance spectroscopy using principal component analysis and linear discriminant analysis

Most drugs are no longer produced in their own countries by the pharmaceutical companies, but by contract manufacturers or at manufacturing sites in countries that can produce more cheaply. This not only makes it difficult to trace them back but also leaves room for criminal organizations to fake them unnoticed. For these reasons, it is becoming increasingly difficult to determine the exact origin of drugs. The goal of this work was to investigate how exactly this is possible by using different spectroscopic methods like nuclear magnetic resonance and near- and mid-infrared spectroscopy in combination with multivariate data analysis. As an example, 56 out of 64 different paracetamol preparations, collected from 19 countries around the world, were chosen to investigate whether it is possible to determine the pharmaceutical company, manufacturing site, or country of origin. By means of suitable pre-processing of the spectra and the different information contained in each method, principal component analysis was able to evaluate manufacturing relationships between individual companies and to differentiate between production sites or formulations. Linear discriminant analysis showed different results depending on the spectral method and purpose. For all spectroscopic methods, it was found that the classification of the preparations to their manufacturer achieves better results than the classification to their pharmaceutical company. The best results were obtained with nuclear magnetic resonance and near-infrared data, with 94.6%/99.6% and 98.7/100% of the spectra of the preparations correctly assigned to their pharmaceutical company or manufacturer.

Preparation and Optimization of PEGylated Nano Graphene Oxide-Based Delivery System for Drugs with Different Molecular Structures Using Design of Experiment (DoE)

Graphene oxide (GO), due to its 2D planar structure and favorable physical and chemical properties, has been used in different fields including drug delivery. This study aimed to investigate the impact of different process parameters on the average size of drug-loaded PEGylated nano graphene oxide (NGO-PEG) particles using design of experiment (DoE) and the loading of drugs with different molecular structures on an NGO-PEG-based delivery system. GO was prepared from graphite, processed using a sonication method, and functionalized using PEG 6000. Acetaminophen (AMP), diclofenac (DIC), and methotrexate (MTX) were loaded onto NGO-PEG particles. Drug-loaded NGO-PEG was then characterized using dynamic light scattering (DLS), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), XRD. The DLS data showed that the drug-loaded NGO-PEG suspensions were in the size range of 200 nm-1.3 µm. The sonication time and the stirring rate were found to be the major process parameters which affected the average size of the drug-loaded NGO-PEG. FTIR, DSC, XRD, and SEM demonstrated that the functionalization or coating of the NGO occurred through physical interaction using PEG 6000. Methotrexate (MTX), with the highest number of aromatic rings, showed the highest loading efficiency of 95.6% compared to drugs with fewer aromatic rings (diclofenac (DIC) 70.5% and acetaminophen (AMP) 65.5%). This study suggests that GO-based nano delivery systems can be used to deliver drugs with multiple aromatic rings with a low water solubility and targeted delivery (e.g., cancer).

Paracetamol analogues conjugated by FAAH induce TRPV1-mediated antinociception without causing acute liver toxicity

Paracetamol, one of the most widely used pain-relieving drugs, is deacetylated to 4-aminophenol (4-AP) that undergoes fatty acid amide hydrolase (FAAH)-dependent biotransformation into N-arachidonoylphenolamine (AM404), which mediates TRPV1-dependent antinociception in the brain of rodents. However, paracetamol is also converted to the liver-toxic metabolite N-acetyl-p-benzoquinone imine already at therapeutic doses, urging for safer paracetamol analogues. Primary amine analogues with chemical structures similar to paracetamol were evaluated for their propensity to undergo FAAH-dependent N-arachidonoyl conjugation into TRPV1 activators both in vitro and in vivo in rodents. The antinociceptive and antipyretic activity of paracetamol and primary amine analogues was examined with regard to FAAH and TRPV1 as well as if these analogues produced acute liver toxicity. 5-Amino-2-methoxyphenol (2) and 5-aminoindazole (3) displayed efficient target protein interactions with a dose-dependent antinociceptive effect in the mice formalin test, which in the second phase was dependent on FAAH and TRPV1. No hepatotoxicity of the FAAH substrates transformed into TRPV1 activators was observed. While paracetamol attenuates pyrexia via inhibition of brain cyclooxygenase, its antinociceptive FAAH substrate 4-AP was not antipyretic, suggesting separate mechanisms for the antipyretic and antinociceptive effect of paracetamol. Furthermore, compound 3 reduced fever without a brain cyclooxygenase inhibitory action. The data support our view that analgesics and antipyretics without liver toxicity can be derived from paracetamol. Thus, research into the molecular actions of paracetamol could pave the way for the discovery of analgesics and antipyretics with a better benefit-to-risk ratio.

Oral drug delivery systems using core-shell structure additive manufacturing technologies: a proof-of-concept study

OBJECTIVES

The aim of this study was to couple fused deposition modelling 3D printing with melt extrusion technology to produce core-shell-structured controlled-release tablets with dual-mechanism drug-release performance in a simulated intestinal fluid medium. Coupling abovementioned technologies for personalized drug delivery can improve access to complex dosage formulations at a reasonable cost. Compared with traditional pharmaceutical manufacturing, this should facilitate the following: (1) the ability to manipulate drug release by adjusting structures, (2) enhanced solubility and bioavailability of poorly water-soluble drugs and (3) on-demand production of more complex structured dosages for personalized treatment.

METHODS

Acetaminophen was the model drug and the extrusion process was evaluated by a series of physicochemical characterizations. The geometries, morphologies, and in vitro drug-release performances were compared between directly compressed and 3D-printed tablets.

KEY FINDINGS

Initially, 3D-printed tablets released acetaminophen more rapidly than directly compressed tablets. Drug release became constant and steady after a pre-determined time. Thus, rapid effectiveness was ensured by an initially fast acetaminophen release and an extended therapeutic effect was achieved by stabilizing drug release.

CONCLUSIONS

The favourable drug-release profiles of 3D-printed tablets demonstrated the advantage of coupling HME with 3D printing technology to produce personalized dosage formulations.

Lyophilized Drug-Loaded Solid Lipid Nanoparticles Formulated with Beeswax and Theobroma Oil

Solid lipid nanoparticles (SLNs) have the potential to enhance the systemic availability of an active pharmaceutical ingredient (API) or reduce its toxicity through uptake of the SLNs from the gastrointestinal tract or controlled release of the API, respectively. In both aspects, the responses of the lipid matrix to external challenges is crucial. Here, we evaluate the effects of lyophilization on key responses of 1:1 beeswax-theobroma oil matrix SLNs using three model drugs: amphotericin B (AMB), paracetamol (PAR), and sulfasalazine (SSZ). Fresh SLNs were stable with sizes ranging between 206.5-236.9 nm. Lyophilization and storage for 24 months (4-8 °C) caused a 1.6- and 1.5-fold increase in size, respectively, in all three SLNs. Zeta potential was >60 mV in fresh, stored, and lyophilized SLNs, indicating good colloidal stability. Drug release was not significantly affected by lyophilization up to 8 h. Drug release percentages at end time were 11.8 ± 0.4, 65.9 ± 0.04, and 31.4 ± 1.95% from fresh AMB-SLNs, PAR-SLNs, and SSZ-SLNs, respectively, and 11.4 ± 0.4, 76.04 ± 0.21, and 31.6 ± 0.33% from lyophilized SLNs, respectively. Thus, rate of release is dependent on API solubility (AMB < SSZ < PAR). Drug release from each matrix followed the Higuchi model and was not affected by lyophilization. The above SLNs show potential for use in delivering hydrophilic and lipophilic drugs.

Diagnosis of Agglomeration and Crystallinity of Active Pharmaceutical Ingredients in Over the Counter Headache Medication by Electrospray Laser Desorption Ionization Mass Spectrometry Imaging

Agglomeration of active pharmaceutical ingredients (API) in tablets can lead to decreased bioavailability in some enabling formulations. In a previous study, we determined that crystalline APIs can be detected as agglomeration in tablets formulated with amorphous acetaminophen tablets. Multiple method advancements are presented to better resolve agglomeration caused by crystallinity in standard tablets. In this study, we also evaluate three “budget” over-the-counter headache medications (subsequently labeled as brands A, B, and C) for agglomeration of the three APIs in the formulation: Acetaminophen, aspirin, and caffeine. Electrospray laser desorption ionization mass spectrometry imaging (ELDI-MSI) was used to diagnose agglomeration in the tablets by creating molecular images and observing the spatial distributions of the APIs. Brand A had virtually no agglomeration or clustering of the active ingredients. Brand B had extensive clustering of aspirin and caffeine, but acetaminophen was observed in near equal abundance across the tablet. Brand C also had extensive clustering of aspirin and caffeine, and minor clustering of acetaminophen. These results show that agglomeration with active ingredients in over-the-counter tablets can be simultaneously detected using ELDI-MS imaging.

Microwave-Assisted Synthesis, Characterization and Modeling of CPO-27-Mg Metal-Organic Framework for Drug Delivery

The coordination polymer CPO-27-Mg was rapidly synthesized under microwave irradiation. This material exhibits a sufficiently high drug loading towards aspirin (~8% wt.) and paracetamol (~14% wt.). The binding of these two molecules with the inner surface of the metal-organic framework was studied employing the Gaussian and Plane Wave approach of the Density Functional Theory. The structure of CPO-27-Mg persists after the adsorption of aspirin or paracetamol and their desorption energies, being quite high, decrease under solvent conditions.

Adsorption of ibuprofen, ketoprofen, and paracetamol onto activated carbon prepared from effluent treatment plant sludge of the beverage industry

The presence of emerging contaminants such as pharmaceuticals in aquatic means presents as a serious threat, since their real consequences for the environment and human health are not well known. Therefore, this work consisted of preparing and characterize sludge-derived activated carbons (beverage sludge activated carbon - BSAC and acid-treated beverage sludge activated carbon - ABSAC) to investigate their use in the pharmaceuticals adsorption in aqueous media. The morphology study has demonstrated that ABSAC, unlike BSAC, exhibited an abundant porous structure, with smaller particles and bigger roughness. Adsorption results indicated that the ABSAC was more effective that BSAC, since it presented superior surface area (642 m² g^-1) and total pore volume (0.485 cm³ g^-1) values. Pseudo-second-order kinetic model was more suitable to predict experimental data. Sips model best described the equilibrium data, with maximum adsorption capacities of 145, 105, and 57 mg g^-1 for paracetamol, ibuprofen, and ketoprofen, respectively. Besides, the sludge-derived adsorbent was highly efficient in the treatment of a simulated drug effluent, removing 85.16% of the pharmaceutical compounds. Therefore, the material prepared in this work possesses intrinsic characteristics that make it a remarkable adsorbent to be applied in the treatment of pharmaceutical contaminants contained in industrial wastewater.

X-ray and Thermal Analysis of Selected Drugs Containing Acetaminophen

Studies carried out by X-ray and thermal analysis confirmed that acetaminophen (paracetamol), declared by the manufacturers as an Active Pharmaceutical Ingredient (API), was present in all studied medicinal drugs. Positions of diffraction lines (2θ angles) of the studied drugs were consistent with standards for acetaminophen, available in the ICDD PDF database Release 2008. |Δ2θ| values were lower than 0.2°, confirming the authenticity of the studied drugs. Also, the values of interplanar distances d_hkl for the examined samples were consistent with those present in the ICDD. Presence of acetaminophen crystalising in the monoclinic system (form I) was confirmed. Various line intensities for API were observed in the obtained diffraction patterns, indicating presence of the preferred orientation of the crystallites in the examined samples. Thermal analysis of the studied substances confirmed the results obtained by X-ray analysis. Drugs containing only acetaminophen as an API have melting point close to that of pure acetaminophen. It was found that presence of other active and auxiliary substances affected the shapes and positions of endothermal peaks significantly. A broadening of endothermal peaks and their shift towards lower temperatures were observed accompanying an increase in the contents of additional substances being “impurities” in relation to the API. The results obtained by a combination of the two methods, X-ray powder diffraction (XRPD) and differential scanning calorimetry/thermogravimetry (DSC/TGA), may be useful in determination of abnormalities which can occur in pharmaceutical preparations, e.g., for distinguishing original drugs and forged products, detection of the presence of a proper polymorphic form or too low content of the active substance in the investigated drug.

Detoxification and bioaugmentation potential for acetaminophen and its derivatives using Ensifer sp. isolated from activated sludge

Acetaminophen (APAP), a widely used analgesic-antipyretic drug, is frequently detected in the environment and may pose ecological risks to aquatic communities. In this work, an APAP-degrading organism, designated as Ensifer sp. POKHU, was isolated from activated sludge (AS) enriched with APAP. POKHU degraded up to 630 mg/L of APAP without substrate inhibition. The bacterium metabolized APAP to hydroquinone (HQ) via 4-aminophenol (4-AP). APAP derivatives, 4AP, HQ, and 1,4-benzoquinone (BQ), frequently detected in the environment, were found to inhibit nitrogen metabolism (ammonium oxidation) to a greater extent than APAP. POKHU had the ability to degrade varying levels (0.4-40 mg/L) of 4-AP, HQ, and BQ, which indicated a great potential for detoxification in environments contaminated with both APAP and its derivatives. The addition of POKHU to fresh AS samples taken from a wastewater treatment plant greatly increased the biotransformation rates of APAP from 5.6 d^-1 (no POKHU augmentation) to >20.0 d^-1 (5% POKHU). Bioaugmentation with POKHU reduced 400 μg/L of APAP to levels below its ecotoxicity threshold within 4 h, which is shorter than the typical hydraulic retention times for full-scale AS processing. Overall, this study identified a new auxiliary biological agent for APAP detoxification, which could degrade both APAP and its metabolic derivatives (those that can be more toxic than the parent contaminant, APAP). The results have practical implications for developing a biological means (detoxification and bioaugmentation) of treating high-strength pharmaceutical waste streams, such as wastewater from hospitals and drug manufactures, and of landfill leachates.

Virtual Coformer Screening by Crystal Structure Predictions: Crucial Role of Crystallinity in Pharmaceutical Cocrystallization

One of the most popular strategies of the optimization of drug properties in the pharmaceutical industry appears to be a solid form changing into a cocrystalline form. A number of virtual screening approaches have been previously developed to allow a selection of the most promising cocrystal formers (coformers) for an experimental follow-up. A significant drawback of those methods is related to the lack of accounting for the crystallinity contribution to cocrystal formation. To address this issue, we propose in this study two virtual coformer screening approaches based on a modern cloud-computing crystal structure prediction (CSP) technology at a dispersion-corrected density functional theory (DFT-D) level. The CSP-based methods were for the first time validated on challenging cases of indomethacin and paracetamol cocrystallization, for which the previously developed approaches provided poor predictions. The calculations demonstrated a dramatic improvement of the virtual coformer screening performance relative to the other methods. It is demonstrated that the crystallinity contribution to the formation of paracetamol and indomethacin cocrystals is a dominant one and, therefore, should not be ignored in the virtual screening calculations. Our results encourage a broad utilization of the proposed CSP-based technology in the pharmaceutical industry as the only virtual coformer screening method that directly accounts for the crystallinity contribution.

Photoluminescence as a Valuable Tool in the Optical Characterization of Acetaminophen and the Monitoring of Its Photodegradation Reactions

In this work, new evidence for the photodegradation reactions of acetaminophen (AC) is reported by photoluminescence (PL), Raman scattering and FTIR spectroscopy. Under excitation wavelength of 320 nm, AC shows a PL band in the spectral range of 340-550 nm, whose intensity decreases by exposure to UV light. The chemical interaction of AC with the NaOH solutions, having the concentration ranging between 0.001 and 0.3 M, induces a gradual enhancement of the photoluminescence excitation (PLE) and PL spectra, when the exposure time of samples at the UV light increases until 140 min, as a result of the formation of p-aminophenol and sodium acetate. This behavior is not influenced by the excipients or other active compounds in pharmaceutical products as demonstrated by PLE and PL studies. Experimental arguments for the obtaining of p-aminophenol and sodium acetate, when AC has interacted with NaOH, are shown by Raman scattering and FTIR spectroscopy.

Innovative spherical biochar for pharmaceutical removal from water: Insight into adsorption mechanism

In this study, we developed an innovative spherical biochar with high porosity and excellent paracetamol (PRC) adsorption capacity. The optimal pyrolysis temperatures for the preparation of spherical biochar (derived from pure glucose) and non-spherical biochar (from pomelo peel wastes) were obtained at 900 °C and 700 °C, respectively. Various advanced techniques were applied to characterize the prepared biochars. Spherical and non-spherical biochars exhibited large specific surface area (1292 and 1033 m²/g) and high total pore volume (0.704 and 1.074 cm³/g), respectively. The adsorption behavior of PRC onto two biochars was conducted utilizing batch experiments. Results demonstrated that the adsorption process was slightly affected by the change of solution pH (2-11) and addition of NaCl (0.05-1.0 M) and was able to achieve fast equilibrium (∼120 min). The maximum adsorption capacity of spherical biochar (286 mg/g) for PRC was approximately double that of non-spherical biochar (147 mg/g). The signal of thermodynamic parameters was negative ΔG° and ΔH° values, but positive ΔS° value. The adsorption mechanism consisted of pore-filling, hydrogen bonding formations, n-π and π-π interactions, and van der Waals force. The adsorption capacities of two biochars were insignificantly dependent on different real water samples containing PRC. Consequently, the biochars can serve as a green and promising material for efficiently removing PRC from water.

FT-IR Spectroscopy for the Detection of Diethylene Glycol (DEG) Contaminant in Glycerin-Based Pharmaceutical Products and Food Supplements

Identification and determination of diethylene glycol (DEG) in glycerin-based products was successfully achieved using FT-IR spectroscopy. Studied samples included 0.5% to 20% by mass DEGspiked into cough syrup, two paracetamol syrup formulations, and two food supplements. The characteristic DEGwavenumbers at 881 cm-1 and 1083 cm-1 were used for its quantitative determination in the studied samples. A very good accuracy in determining the DEG fraction was achieved with a mean error% of ±2.02% to ±7.69% upon using the corrected absorbance at 881 cm-1. The corrected absorbance at 1083 cm-1 band was used in the case of paracetamol formulations and resulted in a mean error% ranging from ±2.50% to ±10.28%. The values of limit of detection of the current method ranged from 0.051% to 0.068% DEG for all studied samples.

Simultaneous investigation of the liquid transport and swelling performance during tablet disintegration

Fast disintegrating tablets have commonly been used for fast oral drug delivery to patients with swallowing difficulties. The different characteristics of the pore structure of such formulations influence the liquid transport through the tablet and hence affect the disintegration time and the release of the drug in the body. In this work, terahertz time-domain spectroscopy and terahertz pulsed imaging were used as promising analytical techniques to quantitatively analyse the impact of the structural properties on the liquid uptake and swelling rates upon contact with the dissolution medium. Both the impact of porosity and formulation were investigated for theophylline and paracetamol based tablets. The drug substances were either formulated with functionalised calcium carbonate (FCC) with porosities of 45% and 60% or with microcrystalline cellulose (MCC) with porosities of 10% and 25%. The terahertz results reveal that the rate of liquid uptake is clearly influenced by the porosity of the tablets with a faster liquid transport observed for tablets with higher porosity, indicating that the samples exhibit structural similarity in respect to pore connectivity and pore size distribution characteristics in respect to permeability. The swelling of the FCC based tablets is fully controlled by the amount of disintegrant, whereas the liquid uptake is driven by the FCC material and the interparticle pores created during compaction. The MCC based formulations are more complex as the MCC significantly contributes to the overall tablet swelling. An increase in swelling with increasing porosity is observed in these tablets, which indicates that such formulations are performance-limited by their ability to take up liquid. Investigating the effect of the microstructure characteristics on the liquid transport and swelling kinetics is of great importance for reaching the next level of understanding of the drug delivery, and, depending on the surface nature of the pore carrier function, in turn controlling the performance of the drug mainly in respect to dissolution in the body.

Cytochrome P450 2E1 and its roles in disease

Cytochrome P450 (P450) 2E1 is the major P450 enzyme involved in ethanol metabolism. That role is shared with two other enzymes that oxidize ethanol, alcohol dehydrogenase and catalase. P450 2E1 is also involved in the bioactivation of a number of low molecular weight cancer suspects, as validated in vivo in mouse models where cancers could be attenuated by deletion of Cyp2e1. P450 2E1 does not have a role in global production of reactive oxygen species but localized roles are possible, e.g. in mitochondria. The structures, conformations, and catalytic mechanisms of P450 2E1 have some unusual features among P450s. The concentration of hepatic P450 varies ≥10-fold among humans, possibly in part due to single nucleotide variants. The level of P450 2E1 may have relevance in the rates of oxidation of drugs, particularly acetaminophen and anesthetics.

Multifunctional magnetic MgMn-oxide composite for efficient purification of Cd2+ and paracetamol pollution: Synergetic effect and stability

A multifunctional magnetic composite (0.3Ma-MgMnLDO-a) with the function of Cd²⁺ adsorption and paracetamol (PAM) degradation was successfully fabricated. Surface morphology showed that Fe₃O₄ agglomeration was overcome on composite. The composite had high specific surface area of 105.32 m² g^-1 and saturation magnetization of 40 emu∙g^-1. 0.3Ma-MgMnLDO-a could reach Cd²⁺ adsorption equilibrium within 5 min with 99 % removal rate. The maximum adsorption capacity was 3.76 mmol·g^-1 (422.62 mg g^-1), which apparently higher than that of Fe₃O₄-a and MgMnLDO-a, indicating that the Fe/Mn synergism results in excellent ability for Cd²⁺ adsorption. Moreover, the composite could efficiently activate peroxymonosulfate (PMS) to rapid degrade PAM with the highest first-order rate constants (k_obs = 0.116 min^-1) and total organic carbon (TOC) removal rate (67.7 %), which also due to the contribution of Fe/Mn synergism in PMS activation. The cycling of Mn^III/Mn^IV and Fe^II/Fe^III played an important role in activating PMS to generateO₂^-•, ¹O₂ and OH for degradation. The composite exhibited both stable adsorption and catalytic performance on wide pH (3-9) and five reuse cycles. Notably, there was mutual promotion between Cd²⁺ and PAM adsorption, while the coexistence of Cd²⁺ had slight inhibition on PAM degradation. Overall, the magnetic composite had promising application for purifying heavy metals and pharmaceuticals.

Three-way analysis of pH-UV absorbance dataset for the determination of paracetamol and its pKa value in presence of excipients

A three-way analysis method, parallel factor analysis (PARAFAC) model was applied to the pH-absorbance dataset for the simultaneous determination of paracetamol and its acid-base dissociation constant in presence of excipient interference in a syrup formulation without using chemical pretreatment or chromatographic separation step. The UV spectroscopic data matrices of calibration set, validation and unknown samples were obtained from the absorbance measurements at the five different pH media, considering conjugate acid/base properties of the related drug. Their pH-absorbance data matrices were arranged as a cubic data array (wavelength x sample x pH) (425x52x5). Three-way array of pH-absorbance dataset was decomposed into a trilinear set of spectral, pH and relative concentration profiles of paracetamol and excipients in the commercial syrup using PARAFAC model. In the PARAFAC implementation, paracetamol in the commercial syrup formulation and its pKa value were simultaneously predicted from the relative concentration and pH profiles, respectively. In the method validation step of this study, the performance of PARAFAC model was checked by analyzing the validation samples in terms of selectivity, sensitivity, accuracy and precision of the method. The determination results of paracetamol and its pKa value provided from PARAFAC application were compared to those obtained by a newly developed ultra-performance liquid chromatography (UPLC) method, in terms of simplicity, applicability, interpretability with low cost and short analysis time.

Injection Molded Capsules for Colon Delivery Combining Time-Controlled and Enzyme-Triggered Approaches

A new type of colon targeting system is presented, combining time-controlled and enzyme-triggered approaches. Empty capsule shells were prepared by injection molding of blends of a high-amylose starch and hydroxypropyl methylcellulose (HPMC) of different chain lengths. The dissolution/erosion of the HPMC network assures a time-controlled drug release, i.e., drug release starts upon sufficient shell swelling/dissolution/erosion. In addition, the presence of high-amylose starch ensures enzyme-triggered drug release. Once the colon is reached, the local highly concentrated bacterial enzymes effectively degrade this polysaccharide, resulting in accelerated drug release. Importantly, the concentration of bacterial enzymes is much lower in the upper gastrointestinal tract, thus enabling site-specific drug delivery. The proposed capsules were filled with acetaminophen and exposed to several aqueous media, simulating the contents of the gastrointestinal tract using different experimental setups. Importantly, drug release was pulsatile and occurred much faster in the presence of fecal samples from patients. The respective lag times were reduced and the release rates increased once the drug started to be released. It can be expected that variations in the device design (e.g., polymer blend ratio, capsule shell geometry and thickness) allow for a large variety of possible colon targeting release profiles.