Mechanism of alizarin red S and methylene blue biosorption onto olive stone: isotherm study in single and binary systems

The biosorption process of anionic dye Alizarin Red S (ARS) and cationic dye methylene blue (MB) as a function of contact time, initial concentration and solution pH onto olive stone (OS) biomass has been investigated. Equilibrium biosorption isotherms in single and binary systems and kinetics in batch mode were also examined. The kinetic data of the two dyes were better described by the pseudo second-order model. At low concentration, ARS dye appeared to follow a two-step diffusion process, while MB dye followed a three-step diffusion process. The biosorption experimental data for ARS and MB dyes were well suited to the Redlich-Peterson isotherm. The maximum biosorption of ARS dye, qmax = 16.10 mg/g, was obtained at pH 3.28 and the maximum biosorption of MB dye, qmax = 13.20 mg/g, was observed at basic pH values. In the binary system, it was indicated that the MB dye diffuses firstly inside the biosorbent particle and occupies the biosorption sites forming a monodentate complex and then the ARS dye enters and can only bind to untaken sites; forms a tridentate complex with OS active sites

Cracking the code for continuous processing and personalised medicine

Personalised medicine is the next great global challenge for the pharmaceutical industry. The vision of the pharmacy of the future is one in which pharmacies employ disruptive technologies to enable on-demand manufacture of drugs designed to individual needs. For example, multiple medications may be prescribed that treat a patient’s exact age-profile and medical history. These medications could then be 3D printed into one tablet, on-demand at the patient’s local drug supplier Central to this vision is the concept of continuous processing. Currently, active pharmaceutical ingredients (APIs) are manufactured in large batches at distinctly separate times. Continuous processing replaces this large-batch process with the manufacture of lower volumes but at a constant rate. This process enables the continuous flow of product, reduces inventories, and has less batch-to-batch variation, giving higher process control and higher quality. Researchers led by Prof Gavin Walker at the Bernal Institute, University of Limerick (UL), are generating the chemical engineering solutions for the challenges of personalised medicine. This highly cited research is changing how we train chemical engineers, impacting industry competitiveness, and attracting R&D investment into Ireland

Insights into the ameliorating ability of mesoporous silica in modulating drug release in ternary amorphous solid dispersion prepared by hot melt extrusion

In this work, the application of various mesoporous silica grades in the preparation of stabilized ternary amorphous solid dispersions of Felodipine using hot melt extrusion was explored. We have demonstrated the effectiveness of mesoporous silica in these dispersions without the need for any organic solvents i.e., no preloading or immersion steps required. The physical and chemical properties, release profiles of the prepared formulations and the surface concentrations of the various molecular species were investigated in detail. Formulations containing 25 wt% and 50 wt% of Felodipine demonstrated enhanced stability and solubility of the drug substance compared to its crystalline counterpart. Based on the Higuchi model, ternary formulations exhibited a 2-step or 3-step release pattern which can be ascribed to the release of drug molecules from the organic polymer matrix and the external silica surface, followed by a release from the silica pore structure. According to the Korsmeyer-Peppas model, the release rate and release mechanism are governed by a complex quasi-Fickian release mechanism, in which multiple release mechanisms are occurring concurrently and consequently. Stability studies indicated that after 6 months storage of all formulation at 30% RH and 20 ◦C, Felodipine in all formulations remained stable in its amorphous state except for the formulation comprised of 40 wt% Syloid AL-1FP with a 50 wt% drug load

A state-of-the-art review on the application of various pharmaceutical nanoparticles as a promising technology in cancer treatment

Recently, rapid advancement in nanomedicine has opened new horizons towards the treatment of disparate types of cancer. Nanomedicine is considered as the science of applying nanoparticles (NPs) for various diagnostic or therapeutic aims. Nanoparticles (NPs) have attracted increasing interest all over the world for the treatment of disparate types of cancer due to their note worthy properties such as negligible toxicity and great bioactivity. The main objective of this paper is to present a comprehensive review about the potential of various NPs including silver NPs (AgNPs), gold NPs (AuNPs), selenium NPs (SeNPs), titanium oxide NPs (TiO2NPs) and iron oxide NPs (FeONPs) to treat tumoral cells, and investigate the molecular interaction at the cellular level. Moreover, different synthesis mechanisms of NPs along with their operational roles in enhancing the efficiency of conventional chemotherapeutic agents and reducing the toxicity are discussed in detail. Finally, future challenges towards the application of NPs in the field of cancer treatment are presented, and appropriate solutions to remove the ambiguities are suggested

Extraction of penicillin G from aqueous solution using a membrane contactor: numerical investigation

In the current study, the treatment of pharmaceutical wastewater containing penicillin G treatment using a hollow fibre membrane contactor was investigated. A mathematical model based on the finite element method was developed. The extraction was performed using Shellsol TK as organic solvent containing 5% Aliquat 336. The effect of feed pH, flow rate and temperature were examined for the extraction of penicillin G from aqueous solution. The results showed that there is reasonable good agreement between experimental data and modelling values. It was found that increasing temperature from 10 -C to 30 -C increases the penicillin G extraction from 33% to 54%. Also, penicillin G extraction was decreased from 34.7% to 25.1% with increasing pH from 5.5 to 6.5 while it grew to 45.8% when the pH of feed solution was 7. Furthermore, the results showed the diffusive flux is favourable for the system and penicillin G extraction but the convective flux has negative impact on the system in terms of penicillin G extraction. It was concluded that a hollow fibre membrane contactor has the potential for use in wastewater treatment through it is important to improve diffusive flux in the system to enhance penicillin G extraction

Removal of ortho-phosphate from aqueous solution by adsorption onto dolomite

An experimental study on the adsorption of phosphate onto cost effective fine dolomite powder is presented. The effect of solution pH, solution ionic strength and adsorption isotherm were examined. The adsorption of phosphate was pH dependent and phosphate adsorption favoured acidic conditions. The adsorption was significantly influenced by solution ionic strength indicating outer-sphere complexation reactions. The experimental data further indicated that the removal of phosphate increased with increase in the ionic strength of solution. The experimental data were modelled with different isotherms: Langmuir, Freundlich and Redlich–Peterson isotherms. It was found that the Redlich–Peterson isotherm depicted the equilibrium data most accurately. The overall kinetic data fitted very well the pseudo-first-order rate model

Application of raman and chemometrics to the mechanochemical synthesis of 4,4-bipyridine/cobalt based MOF using twin screw extrusion

The process optimization of 4,4-bipyridine based metal organic framework (MOF) synthesis by twin screw extrusion (TSE) is investigated using cobalt nitrate hexahydrate (Co(NO3)2⋅6H2O) as the metal precursor. The effects of operating parameters including liquid to solid ratio (L/S), screw speed and feeding rate on the product composition are examined. The collected MOF samples were characterized offline by powder X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, and scanning electron microscopy. It was found that the explored feeding and screw rates are insufficient to generate a pure MOF. However the MOF product was obtained using an optimum L/S ratio i.e., 0.5, which improved the wettability and mixing of reactants to allow effective interactions at a molecular level, facilitating the complete reaction inside the extruder. Partial least square based multivariate analysis of the collected Raman spectra was used to obtain predictive models to quantify MOF purity, which reached a maximum of 87.0 wt% using 0.5 L/S, 100 g/h feeding rate and 100 rpm screw speed.</p

Growth kinetics of nuclei formed from different binders and powders in vertical cylindrical mixing devices

Granulation is the process of forming large aggregates from fine particles using a high shear mixer. This method is used in several industries from pharmaceuticals to chemical and fertilizer production. This research will study the effect of four process variables: speed of mixer rotation in the range 100–200 rpm, powder bed mass (25–40 g), mass of the initial nucleus (0.6–2 g), and binder viscosity (water, carboxymethyl cellulose (CMC) solutions with concentrations in the range 0.5–20 g/L) on single nuclei growth kinetics in low mixing devices. The powders under study were: lactose, tea, sugar, starch, and limestone. The results show the initial size of nuclei, the initial mass of the powder bed and binder viscosity and speed of rotation all influence the rate of nuclei growth. Analysis of the stokes deformation number of the nuclei show that growth rate of the nuclei decreases as the deformation number increases whilst the percentage gain in mass of the nuclei increases with increasing deformation number. The binder viscosity was shown to have the biggest influence of the growth rate of the nuclei. Results show that difference in powder density also has an effect on the growth kinetics of nuclei. The initial position of nuclei was also shown to influence the nuclei growth rate; the closer the starting position of the nuclei to the wall of the vessel the slower the growth rate

Application of raman and chemometrics to the mechanochemical synthesis of 4,4-bipyridine/cobalt based MOF using twin screw extrusion

The process optimization of 4,4-bipyridine based metal organic framework (MOF) synthesis by twin screw extrusion (TSE) is investigated using cobalt nitrate hexahydrate (Co(NO3)2⋅6H2O) as the metal precursor. The effects of operating parameters including liquid to solid ratio (L/S), screw speed and feeding rate on the product composition are examined. The collected MOF samples were characterized offline by powder X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, and scanning electron microscopy. It was found that the explored feeding and screw rates are insufficient to generate a pure MOF. However the MOF product was obtained using an optimum L/S ratio i.e., 0.5, which improved the wettability and mixing of reactants to allow effective interactions at a molecular level, facilitating the complete reaction inside the extruder. Partial least square based multivariate analysis of the collected Raman spectra was used to obtain predictive models to quantify MOF purity, which reached a maximum of 87.0 wt% using 0.5 L/S, 100 g/h feeding rate and 100 rpm screw speed.</p

Investigation of influence of process variables on mechanical strength, size and homogeneity of pharmaceutical granules produced by fluidised hot melt granulation

The overall aim of the project was to study the influence of process variables on the distribution of a model active pharmaceutical ingredient (API) during fluidised melt granulation of pharmaceutical granules with a view of optimising product characteristics. Granules were produced using common pharmaceutical excipients; lactose monohydrate using poly ethylene glycol (PEG1500) as a meltable binder. Methylene blue was used as a model API. Empirical models relating the process variables to the granules properties such as granule mean size, product homogeneity and granule strength were developed using the design of experiment approach. Fluidising air velocity and fluidising air temperature were shown to strongly influence the product properties. Optimisation studies showed that strong granules with homogeneous distribution of the active ingredient can be produced at high fluidising air velocity and at high fluidising air temperature