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<p>The XRD pattern corresponding to <i>foraminifera,</i> β-TCP and Zn-TCP showing peaks matching calcium carbonate (JCPDS 5-0586) and tricalcium phosphate (JCPDS 9-169).</p
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<p>The result shows slower release of both ions with the apatite coating.</p
Research Interests: Chemistry, Biotechnology, Calcium, Magnesium, Coating, and 5 moreDissolution, SBF, Apatite, PLoS one, and Simulated Body Fluid
The delivery of chemotherapeutic agents to bone via systemic routes of administration is problematic because of the serious side effects of these agents and the poor circulation to the bone. Hence, local delivery is an attractive option... more
The delivery of chemotherapeutic agents to bone via systemic routes of administration is problematic because of the serious side effects of these agents and the poor circulation to the bone. Hence, local delivery is an attractive option for these compounds.
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ABSTRACT
Research Interests: Chemistry, Biomedical Engineering, Calcium, Drug delivery, Drug Delivery System, and 15 moreMedicine, Drug, Controlled release, Differential scanning calorimetry, Biomedical Materials, Pharmaceutical Sciences, Cement, Bone Cement, Crystallinity, Phosphoric acid, Phosphoric Acid, Phosphate, Calcium Phosphate Cement, Simulated Body Fluid, and Pharmacology and pharmaceutical sciences
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Research Interests: Materials Science, Chemistry, Biomedical Engineering, Drug delivery, Drug Delivery System, and 13 moreMedicine, Drug, Controlled release, Porosity, Biomedical Materials, Pharmaceutical Sciences, Cement, Bone Cement, Crystallinity, Calcium Phosphate Cement, Simulated Body Fluid, Drug Release, and Pharmacology and pharmaceutical sciences
Resistance to compressive strength after setting of the calcium phosphate cement consisting of tetracalcium phosphate (TECP), dicalcium phosphate dihydrate (DCPD), and 40 wt/wt% of a synthetic hydroxyapatite (HAP) was tested. An equimolar... more
Resistance to compressive strength after setting of the calcium phosphate cement consisting of tetracalcium phosphate (TECP), dicalcium phosphate dihydrate (DCPD), and 40 wt/wt% of a synthetic hydroxyapatite (HAP) was tested. An equimolar mixture of the calcium phosphate powder containing DCPD (particle diameter [D] 0.52–3.33 μm) and TECP (D, 1.1–13.1 μm) transformed into HAP at 37°C, 100% RH after being mixed with 25 mM phosphoric acid. X‐ray diffraction suggested that the cement containing fine particles of DCPD and TECP completely transformed to HAP, but that mixtures containing larger particles did not. Because particle size of both DCPD and TECP affected the compressive strength of the cement, the crystal growth of HAP during cement formation depended on the specific surface area (Sw) of the raw materials. The crystallite size of transformed HAP was estimated based on X‐ray diffraction peaks at 25.8 and 32.8° attributable to the 002 and 300 planes. The crystallite size attributable to the 300 plane decreased with increasing Sw, but that attributable to the 002 plane showed no significant relationship. The compressive strength of the cement after hardening increased with an increase of its Sw. This suggested that the harder calcium phosphate cement was (derived) from the smaller particle size of the raw materials. © 1995 John Wiley &amp; Sons, Inc.
Research Interests: Materials Science, Biomedical Engineering, Calcium, Medicine, Biomedical Materials, and 15 moreCompressive Strength, Cement, Calcium Phosphates, Calcium Phosphate, Particle Size, Surface Properties, Phosphoric acid, Phosphoric Acid, Bone Cements, Phosphate, Durapatite, Calcium Phosphate Cement, Crystallite, Brushite, and Mechanical strength
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Research Interests: Chemistry, Biomedical Engineering, Calcium, Drug delivery, Drug Delivery System, and 15 moreMedicine, Nuclear Chemistry, Drug, Controlled release, Differential scanning calorimetry, Biomedical Materials, Pharmaceutical Sciences, Cement, Bone Cement, Crystallinity, Phosphate, Bovine Serum Albumin, Calcium Phosphate Cement, Drug Release, and Pharmacology and pharmaceutical sciences
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Research Interests: Chemistry, Biomedical Engineering, Calcium, Drug delivery, Drug Delivery System, and 15 moreMedicine, Drug, Controlled release, Differential scanning calorimetry, Biomedical Materials, Pharmaceutical Sciences, Cement, Bone Cement, Crystallinity, Phosphoric acid, Phosphoric Acid, Phosphate, Calcium Phosphate Cement, Drug Release, and Pharmacology and pharmaceutical sciences
ABSTRACT
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ABSTRACT
Research Interests: Chemistry, Biomedical Engineering, Calcium, Drug delivery, Drug Delivery System, and 15 moreMedicine, Drug, Controlled release, Differential scanning calorimetry, Biomedical Materials, Pharmaceutical Sciences, Cement, Bone Cement, Crystallinity, Phosphoric Acid, Phosphate, Calcium Phosphate Cement, Drug Release, Anticancer Drug, and Pharmacology and pharmaceutical sciences
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The relationship between in vitro and in vivo drug release from a self-setting bioactive calcium phosphate cement containing indomethacin (IMC) as a model drug was investigated. The in vitro IMC release rate from 1, 2 and 5% drug-loaded... more
The relationship between in vitro and in vivo drug release from a self-setting bioactive calcium phosphate cement containing indomethacin (IMC) as a model drug was investigated. The in vitro IMC release rate from 1, 2 and 5% drug-loaded cement systems in simulated body fluid (SBF) at pH 7.25, 37°C increased with increase of drug concentration in the cement. The decreasing
Research Interests: Chemistry, Biomedical Engineering, Hydroxyapatite, Calcium, Drug delivery, and 14 moreDrug Delivery System, In Vitro, Controlled release, Biomedical Materials, Pharmaceutical Sciences, Cement, Bone Cement, In Vivo, Calcium Phosphate, Calcium Phosphate Cement, Simulated Body Fluid, Drug Release, Area Under the Curve, and Pharmacology and pharmaceutical sciences
The manufacturing of solid pharmaceutical dosage forms composed of cocrystals requires numerous processes during which there is risk of dissociation into parent molecules. Resonant acoustic wet granulation (RAG) was devised in an effort... more
The manufacturing of solid pharmaceutical dosage forms composed of cocrystals requires numerous processes during which there is risk of dissociation into parent molecules. Resonant acoustic wet granulation (RAG) was devised in an effort to complete theophylline–citric acid (THPCIT) cocrystal formation during the granulation process, thereby reducing the number of operations. In addition, the influence of granulation liquid was investigated. A mixture of anhydrous THP (drug), anhydrous CIT (coformer), and hydroxypropyl cellulose (granulating agent) was processed by RAG with water or ethanol as a granulation liquid. The purposes were to (i) form granules using RAG as a breakthrough method; (ii) accomplish the cocrystallization during the integrated unit operation; and (iii) characterize the final solid product (i.e., tablet). The RAG procedure achieved complete cocrystal formation (>99%) and adequately sized granules (d50: >250 μm). The granulation using water (GW) facilitated f...
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Gentamicin sulphate is a potent antibiotic, widely used by clinicians to treat Staphylococcus aureus bacterial complications in orthopaedic surgery and osteomyelitis. Antibiotics as administered are poorly localised and can accumulate... more
Gentamicin sulphate is a potent antibiotic, widely used by clinicians to treat Staphylococcus aureus bacterial complications in orthopaedic surgery and osteomyelitis. Antibiotics as administered are poorly localised and can accumulate with toxic effects. Achieving a better targeted release and controlled dosage has been an ongoing unmet microengineering challenge. In this study we evaluated the antibiotic release potential of beta tricalcium phosphate (β-TCP) micro and macrospheres to eradicate Staphylococcus aureus and maintain osteoblast biocompatibility. Gentamicin was absorbed onto and within the spheres at an average amount of 4.2 mg per sample. Human osteoblast cell studies at five days incubation showed attachment and growth on the spheres surface with no detrimental effect on the cell viability. A time delayed antibacterial efficacy test was designed with the bacteria introduced at predetermined time intervals from 0–60 minutes. We demonstrated that hydroxyapatite covered Foraminifera nano-, micro- macrospheres facilitated the slow release of the encapsulated pharmaceutical agent. Principally, this arises owing to their unique architecture of pores, struts and channels, which amplifies physiological degradation and calcium phosphate dissolution to release attached pharmaceuticals in a controlled manner. The Staphylococcus aureus growth response following exposure to the gentamicin incorporated microspheres at various time intervals showed the complete elimination of the bacteria within 30 minutes. Gentamicin release continued with no re-emergence of bacteria. β-TCP nano to macro size spheres show promise as potential bone void filler particles with, in this case, supplementary delivery of antibiotic agent. Owing to their unique structure, excellent drug retention and slow release properties, they could be used in reconstructive orthopaedics to treat osteomyelitis caused by Staphylococcus aureus and possibly other sensitive organisms.
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Research Interests: Chemistry, Biomedical Engineering, Biomimetics, Drug delivery, Medicine, and 15 moreMultidisciplinary, Humans, Controlled release, Calcium Phosphates, Foraminifera, Drug Delivery Systems, Dissolution, PLoS one, Coral, Aquatic organisms, Fourier transform infrared spectroscopy, Osteogenesis, Apatites, Body Fluids, and Biomimetic
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Aims: This study gives a detailed evaluation of the antibiotic potential of a marine structure-based new drug delivery system produced by hydrothermally converting foraminifera exoskeletons to β-tricalcium phosphate (β-TCP) to treat... more
Aims: This study gives a detailed evaluation of the antibiotic potential of a marine structure-based new drug delivery system produced by hydrothermally converting foraminifera exoskeletons to β-tricalcium phosphate (β-TCP) to treat clinical strain Staphylococcus aureus (MW2). Materials & methods: Foraminifera precursor materials were hydrothermally converted at 250°C for 48 h to produce β-TCP and loaded with gentamicin sulfate by adsorption for 24 h. The physicochemical properties of the material were characterized by scanning electron microscopy, powder x-ray diffraction and for pore size distribution profiles. The antibacterial efficacy of the system was tested for inhibition of S. aureus growth and in vitro cellular behavior were tested with human osteoblast cells (MG63) for cell viability. Discussion: Pore size distribution profiles showed that the structure allows the uniform distribution of nanopores of 1.5 nm and micropores of approximately 5 µm. The in vitro release profile...
Research Interests: Materials Science, Drug delivery, Nanomedicine, Nanotechnology, Medicine, and 13 moreCell line, Humans, Porosity, Medical Biotechnology, Staphylococcus aureus, Calcium Phosphates, Foraminifera, Anti-Bacterial Agents, Scanning Electron Microscope, Drug Carriers, Biomimetic, Gentamicins, and Gentamicin
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Research Interests: Chemistry, Biomedical Engineering, Medicine, Controlled release, Mice, and 15 moreFemur, Female, Animals, Calcium Phosphates, Bone Density, Medical Physiology, Tissue engineering and regenerative medicine, Clinical Sciences, Coral, Osteogenesis, Simvastatin, Biomimetic, Biomechanical Phenomena, Ovariectomy, and Tissue Scaffolds
Research Interests: Chemistry, Biomedical Engineering, Tissue Engineering, Calcium, Medicine, and 15 moreCell Differentiation, Mesenchymal stem cells, Animals, Male, Calcium Phosphates, Mesenchymal Stem Cell, Medical Physiology, Alkaline phosphatase, Clinical Sciences, Rats, Biomimetic materials, Osteogenesis, Mesenchymal Stromal Cells, Biomimetic, and Alizarin red
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An in-line near-infrared spectroscopy monitoring method was developed for analyzing granule properties during a high shear wet granulation process.
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To achieve ideal functional and aesthetic requirements, ridge augmentation is often required before dental implant placement. Bone augmentation (especially vertical), which normally consists of complex and invasive surgeries, still... more
To achieve ideal functional and aesthetic requirements, ridge augmentation is often required before dental implant placement. Bone augmentation (especially vertical), which normally consists of complex and invasive surgeries, still remains challenge. This study seeks to investigate the feasibility of an injectable in situ gel-forming system containing strontium hydroxyapatite (SrHA) and alginate for minimally invasive bone augmentation in a rat calvarial model. SrHA-alginate solution was prepared by mixing SrHA powder with alginate solution (20 mg/mL) to the final concentration of 0.5% (w/v). Each animal received a 200-μL single subperiosteal injection of either SrHA-alginate solution or alginate solution. The new bone formation was assessed at 0, 4, and 8 weeks histologically and radiologically. The SrHA-alginate solution materials could form solid gel once injected. As such, no sutures were required to close the injection site. Significantly greater amount of new bone formation wa...
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In the presence of urea in solid states, the stability of unpulverized homosulfamine hydrate (phase I; UHH) is significantly decreased whereas that of unpulverized homosulfamine anhydrate (UHA) is not. The stability of UHH is decreased... more
In the presence of urea in solid states, the stability of unpulverized homosulfamine hydrate (phase I; UHH) is significantly decreased whereas that of unpulverized homosulfamine anhydrate (UHA) is not. The stability of UHH is decreased slightly more by pulverization (PHH). The major objective of this study was to investigate the effects of urea, dehydration, and pulverization on the stability of homosulfamine in solid states. Binary mixtures of UHH and urea, PHH and urea, and UHA and urea in a ratio of 1:1 (wt/wt) were prepared as physical mixtures and were analyzed by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier transform infrared (FTIR) spectroscopy to study their appearance and structural changes before and after storage. PXRD analysis revealed that physical mixtures comprising UHH and urea and PHH and urea have the same diffraction pattern as that of the mixture of UHA and urea after preparation. The dehydration rate of the crystal water of UHH was accelerated by the presence of urea in addition to pulverization. Moreover, the PXRD patterns of the physical mixtures of UHH/urea and PHH/urea were significantly altered during storage, whereas that of UHA/urea was not, which was consistent with the SEM and FTIR results. The particle shape and appearance of UHH varied significantly as a result of pulverization. The stability of homosulfamine was influenced not only by the presence of urea and dehydration but also by the surface state and particle size of the crystalline form.
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Cocrystallisation can enhance the solubility and bioavailability of active pharmaceutical ingredients (APIs); this method may be applied to improve the availability of materials that were previously considered unsuitable. Terahertz (THz)... more
Cocrystallisation can enhance the solubility and bioavailability of active pharmaceutical ingredients (APIs); this method may be applied to improve the availability of materials that were previously considered unsuitable. Terahertz (THz) spectroscopy provides clear, substance-specific fingerprint spectra; the transparency of the THz wave allows us to probe inside a sample to identify medicinal materials. In this study, THz and infrared (IR) spectroscopy were used to characterise cocrystallisation in solid-phase reactions between ibuprofen and nicotinamide. Multivariate curve resolution with alternating least squares (MCR-ALS) was applied to both time-dependent THz and IR spectra to identify the intermolecular interactions between these cocrystallising species. The analytical results revealed cocrystal formation through a two-step reaction, in which the steps were dominated by thermal energy and water vapour, respectively. We infer that the presence of water molecules significantly l...
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The granulation process of pharmaceutical standard formulation in a high-speed shear wet granulation (HSWG) was measured by in-line near-infrared spectroscopy (NIRS) and agitation power consumption (APC) methods. The F-1, F-2, and F-3... more
The granulation process of pharmaceutical standard formulation in a high-speed shear wet granulation (HSWG) was measured by in-line near-infrared spectroscopy (NIRS) and agitation power consumption (APC) methods. The F-1, F-2, and F-3 formulations (500 g) contained 96% w/w α-lactose monohydrate (LA), potato starch (PS), and a LA:PS = 7:3 mixture, respectively, and all the formulations contained 4% w/w hydroxypropyl cellulose. While adding purified water at 10 mL/min, the sample powder was mixed. The calibration models to measure the amount of binding water (Wa) and APC of the HSWG formulations were established based on NIRS of the samples measured for 60 min by partial least-squares regression analysis (PLS). Molecular interaction related to APC between the particle surface and binding liquor was analyzed based on NIRS. The predicted values of Wa and APC for all formulations were superimposed with the measured values on a straight line, respectively. The regression vector (RV) of th...
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In this study, we established a robust feed-forward control model for the tableting process by partial least squares regression using the near-infrared (NIR) spectra and physical attributes of the granules to be compressed. The NIR... more
In this study, we established a robust feed-forward control model for the tableting process by partial least squares regression using the near-infrared (NIR) spectra and physical attributes of the granules to be compressed. The NIR spectra of granules are rich in information about chemical attributes, such as the compositions of any ingredients and moisture content. Polymorphism and pseudo-polymorphism can also be quantitatively evaluated by NIR spectra. We used the particle size distribution, flowability, and loose and tapped density as the physical attributes of the granules. The tableting process was controlled by the lower punch fill depth and the minimum distance between the upper and lower punches at compression, which were specifically related to the tablet weight and thickness, respectively. The feed-forward control of the process would be expected to provide some advantages for automated and semi-automated continuous pharmaceutical manufacturing. As a result, our model, usi...
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In this study, we established a robust feed-forward control model for the tableting process by partial least squares regression using the near-infrared (NIR) spectra and physical attributes of the granules to be compressed. The NIR... more
In this study, we established a robust feed-forward control model for the tableting process by partial least squares regression using the near-infrared (NIR) spectra and physical attributes of the granules to be compressed. The NIR spectra of granules are rich in information about chemical attributes, such as the compositions of any ingredients and moisture content. Polymorphism and pseudo-polymorphism can also be quantitatively evaluated by NIR spectra. We used the particle size distribution, flowability, and loose and tapped density as the physical attributes of the granules. The tableting process was controlled by the lower punch fill depth and the minimum distance between the upper and lower punches at compression, which were specifically related to the tablet weight and thickness, respectively. The feed-forward control of the process would be expected to provide some advantages for automated and semi-automated continuous pharmaceutical manufacturing. As a result, our model, using a combination of NIR spectra and the physical attributes of granules to control the distance between punches, resulted in respectable agreement between the predicted process parameters and actual settings to produce tablets of the desired thickness.
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Three‐dimensional (3‐D) printers are widely expected to provide a novel manufacturing method in the future to make personalized medicines in hospitals.
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ABSTRACT
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Although near infrared (NIR) spectra are primarily influenced by undesired variations, i.e., baseline shifts and non-linearity, and many applications of NIR spectroscopy to the real-time monitoring of wet granulation processes have been... more
Although near infrared (NIR) spectra are primarily influenced by undesired variations, i.e., baseline shifts and non-linearity, and many applications of NIR spectroscopy to the real-time monitoring of wet granulation processes have been reported, the granulation mechanisms behind these variations have not been fully discussed. These variations of NIR spectra can be canceled out using appropriate pre-processing techniques prior to spectral analysis. The present study assessed the feasibility of directly using baseline shifts in NIR spectra to monitor granulation processes, because such shifts can reflect changes in the physical properties of the granular material, including particle size, shape, density, and refractive index. Specifically, OPUSGRAN®, a novel granulation technology, was investigated by in-line NIR monitoring. NIR spectra were collected using a NIR diffuse reflectance fiber optic probe immersed in a high-shear granulator while simultaneously examining the morphology, p...
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We developed a method for the optimization of dissolution properties of solid oral dosage forms manufacturing using high shear wet granulation (HSWG) by using near-infrared spectroscopy (NIRS) with chemometrics in small-scale experiments.... more
We developed a method for the optimization of dissolution properties of solid oral dosage forms manufacturing using high shear wet granulation (HSWG) by using near-infrared spectroscopy (NIRS) with chemometrics in small-scale experiments. The changes in rheology and NIR spectra of the granules were monitored to verify the granulation mechanism and determine the suitable water amount for model formulation during the HSWG. Tablets were manufactured by altering the added water amount to investigate the impact of the granulation mechanism on drug product qualities. Model formulation granules were prepared with 10% w/w to 20% w/w water in a funicular state, corresponding to the plateau region in score plots obtained by principal component analysis (PCA). The dissolution rate of model formulation tablets manufactured with more than 20% w/w of water was significantly delayed while tablets manufactured with 15% w/w water showed 100% dissolution at 15 min. NIRS and PCA are applicable to the ...