Shahnaz Mansouri - Academia.edu (original) (raw)
Papers by Shahnaz Mansouri
IntechOpen eBooks, Jul 31, 2023
Nature has always been a resource of inspiration for humans, providing valuable lessons that have... more Nature has always been a resource of inspiration for humans, providing valuable lessons that have led to innovative solutions throughout history. Observing the micronano roughness structure of bio-surfaces has led to the discovery of natural selfcleaning surfaces for over 25 years. This has sparked a new field of research with valuable applications. Numerous self-cleaning products made from plant extracts have been created by replicating the natural purifying abilities of plant surfaces. Significant literature exists on the development, classification, extraction, and production of self-cleaning agents for diverse industries through a thorough understanding of bio-cleaning mechanisms. Various methods have been developed to synthesize these surfaces, including immersion, electrochemical deposition, emulsion, electrospinning, phase-separation, Chemical-Vapor-Deposition (CVD), spray coating, wet chemical reaction, and three-dimensional printing (3D-printing), among others. Currently, the primary objective is to gain knowledge from nature and utilize it to develop novel products for food, pharmaceutical, and related industries. Natural plant-based self-cleaning surfaces can be characterized by their superhydrophobicity and superhydrophilicity regimes. The process of 3D-printing is a computer-based technique that builds up three-dimensional objects through the layer-by-layer deposition of materials. The creation of effective self-cleaning surfaces with unique wettability, chemical properties, and microstructure depends on the design and engineering of solid surfaces.
Drying Technology, Dec 22, 2019
Current computational fluid dynamic (CFD) models of spray dryers lack the capability to predict t... more Current computational fluid dynamic (CFD) models of spray dryers lack the capability to predict the structure of the agglomerates formed; loose or compact agglomerates. This is mainly due to the conventional simplistic approach in numerically "fusing" of the colliding particles forming the agglomerate. A new theoretical treatment is introduced in this work, suitable for implementation in CFD simulations, which numerically fuses the particles and yet retain information on the structure of the agglomerate. This new theoretical treatment is based on tracking the reduction of the agglomerate surface area as the agglomerate is progressively formed. Analysis revealed that the reduction in the agglomerate surface area exhibits a unified correlation with the degree of compactness of the agglomerate. Further analysis comparing this new approach to the conventional numerical fusing of the particles revealed inherent numerical discrepancies, which has not been noted in the literature before. Understanding these discrepancies will provide clarity to the interpretation of the modelling and simulation of spray drying particle agglomeration in CFD. Moreover, this work lays the groundwork for a more comprehensive CFD model for agglomeration which can be potentially utilized to predict final powder properties.
A new antisolvent vapour precipitation technique was developed which enables the production of a ... more A new antisolvent vapour precipitation technique was developed which enables the production of a large amount of micro spheres from a single droplet. This work explores the potential of this technique for encapsulation of oil. Experiments were undertaken on the single droplet drying rig in Monash University, modified to incorporate antisolvent vapour. Using ethanol vapour, lactose micro particles with spiky surfaces were formed. Oil-infused lactose micro particles were also observed delineated by the smooth surfaces analogous to that of full cream milk. Single particle dissolution test revealed that the precipitated particles exhibited drastically higher dissolution rate when compared to particles dried without antisolvent vapour. More analysis is required to ascertain if this is due to differences in morphology or due to possible encapsulation of oil.
The antisolvent vapour precipitation approach was applied to produce micron size uniform whey pro... more The antisolvent vapour precipitation approach was applied to produce micron size uniform whey protein particles. This technique involved exposing a droplet of the whey protein containing liquid to an ethanol vapour laden convective medium. At pH conditions in proximity to the isoelectric point, the antisolvent vapour precipitation technique produced fine and semi-uniform whey protein particles dispersible in water. Precipitation of WPI+lactose droplets revealed that a blend of crystalline lactose with fine particles can be produced simultaneously. The incorporation of lactose also allowed for the precipitation of the WPI particles at a slightly higher pH than the isoelectric point. This could potentially be a one step process in producing drug-excipient blends.
Powder Technology, 2018
Antisolvent vapour drying precipitation is a new spray drying technique in which each droplet beh... more Antisolvent vapour drying precipitation is a new spray drying technique in which each droplet behaves like an individual 'precipitation vessel'. As the aqueous droplet absorbs the convective ethanol vapour, the initially dissolved solutes precipitates out as ultrafine particles within the droplet. This work sought to examine the feasibility of applying the antisolvent vapour drying method to produce salt particles. Using the modified single droplet drying rig, spherical magnesium sulphate and iron sulphate particles b10 μm were produced from relative large droplets of 1-2 mm in diameter. The fine particles produced exhibited rough gravel-like surface morphology. Mixtures of iron sulphate and vitamin C at different proportions were tested and gravel-like iron sulphate particles within a bulk vitamin C matrix were produced. Rough gravel-like surface morphology was also observed for sodium chloride particles. Lactose was then incorporated into the formulation to assess if spherical ultrafine particles of a lactose-salt matrix can be produced. The precipitated particles, however, resembled the smooth ultrafine amorphous particles of lactose without distinct indication on the location of the salt material.
Drying Technology, May 31, 2016
ABSTRACT Spray drying conventionally necessitates relatively large or elongated drying chambers. ... more ABSTRACT Spray drying conventionally necessitates relatively large or elongated drying chambers. The present study examined the possibility in shrinking the spray drying chamber into narrow tube-like geometry. The key was in utilizing fine droplets which had low transport response time. A narrow copper/steel tube spray dryer (internal diameters between 12.7 and 48.0 mm) was constructed and was fitted with a two-fluid atomizer producing droplets in the size range smaller than 10 µm. Maltodextrin, lactose, and sucrose were spray-dried. The narrow tube approach allowed direct manipulation of the drying conditions via heating or cooling along the wall of the tube. This form of manipulation in the drying conditions, surprisingly, resulted in very distinctly crystalline spray-dried sucrose particles. The tube spray dryer was further modified with a long coiled-up tube, extending the particle residence time with minimal space requirements. Endoscopic analysis revealed that particle deposition within the tube resembled loosely attached particle and granules. The tube spray drying concept can potentially be used to provide precise control of the particle drying history along the length of the drying chamber, not limited to the control of the drying conditions at the inlet or outlet of a spray dryer.
Chemical engineering research & design, Sep 1, 2013
Abstract A new antisolvent vapour precipitation technique was developed which enables the product... more Abstract A new antisolvent vapour precipitation technique was developed which enables the production of a large amount of micro spheres from a single droplet. This work explores the potential of this technique for encapsulation of oil and in precipitating multi-component solutes from a droplet. Experiments were undertaken on the single droplet drying rig in Monash University, modified to incorporate antisolvent vapour. Using ethanol vapour, lactose micro particles with spiky surfaces were formed. Oil-infused lactose micro particles were also observed delineated by the smooth surfaces analogous to that of full cream milk. Precipitation of multi-component solutes resulted in partial segregation of the protein and lactose. Precipitated particles with different proportions of protein and lactose exhibited contrasting particles. Particles with higher protein content resulted in smaller particle sizes.
Zenodo (CERN European Organization for Nuclear Research), Nov 4, 2014
Folic acid (FA) is known to be an important supplement to prevent neural tube defect (NTD) in pre... more Folic acid (FA) is known to be an important supplement to prevent neural tube defect (NTD) in pregnant women. Similar to some commercial formulations, sodium bicarbonate solution is used as a solvent for FA. This work uses the antisolvent vapour precipitation (AVP), incorporating ethanol vapour as the convective drying medium in place of air to produce branch-like micro-structure FA particles. Interestingly, the dissolution rate of the resultant particle is 2-3 times better than the particle produce from conventional air drying due to the higher surface area of particles produced. The higher dissolution rate could possibly improve the delivery and absorption of FA in human body. This application could potentially be extended to other commercial products, particularly in less soluble drugs to improve its solubility.
International Journal of Pharmaceutics, Apr 1, 2019
&NA; The surface structure of crystalline particles affects the functionality of the particle... more &NA; The surface structure of crystalline particles affects the functionality of the particles in drug delivery. Prediction of the final structure of particles that crystallize easily within the spray drying process is of interests for many applications. A theoretical framework was developed for the prediction of crystal structure precipitating on the surface of the particle. This model was based on the dimensionless Damkohler number (Da), to be an indicator of final particle morphology. Timescales of evaporation and reaction were required for calculation of the Damkohler number. The modified evaporation time scale was estimated based on the time that is available for the crystal to precipitate after supersaturation. The reaction time scale was estimated based on the time scale for induction time. Mannitol was produced under different processing conditions in order to validate the theoretical model. Results showed for the high Damkohler numbers, the surface structure of the particle was rough, while smaller Damkohler numbers led to relatively smooth particle surfaces. Additionally, although the beta polymorph was dominant in all of the experiments, alpha polymorph was precipitated in the experiments with a large Damkohler number. The theoretical framework developed will be a useful predictive tool to guide the manipulation of particle crystallization in spray dryers. Graphical abstract Figure. No caption available.
Powder Technology, 2018
In-situ crystallization of particles in spray drying has several advantages particularly for prod... more In-situ crystallization of particles in spray drying has several advantages particularly for product quality modification in the pharmaceutical industry. This process was investigated in a counter current spray dryer using lactose as a model material by manipulation of the local humidity within the drying chamber. Sample collection and humidity injection at different location of the dryer were carried out to better understand the mechanism of particle formation and solidification which are essential components of in-situ crystallization. They revealed that particle formation can be delayed by local humidity elevation. Differential scanning calorimetry and XRD of the yields showed that humidity manipulation was capable to produce semi crystalline lactose of up to 90 precent crystallinity. The results confirmed that there is a critical period for crystallization such that extending this period would significantly increase the degree of crystallization. Comparison on different requirements of crystallization indicated that extending the time for nucleation and the growth at the critical period via humidity manipulation has the most significant effect on the in-situ crystallization process.
Expert Opinion on Drug Delivery, Jan 13, 2014
Pulmonary drug delivery requires particles with a fine and uniform size distribution, 1 - 5 µ hyd... more Pulmonary drug delivery requires particles with a fine and uniform size distribution, 1 - 5 µ hydrodynamic diameter, for targeted delivery and higher uptake within the pulmonary tract. The antisolvent vapor precipitation method is a new alternative method to generate particles with such characteristics. Development so far has shown that the technique is applicable to disaccharides (lactose), magnesium sulfate, hydrophobic and protein particles. The method may also be extended to generate fine encapsulation particles and to produce disaccharides (lactose) and protein particles blend in a single step.
Advanced Powder Technology, Nov 1, 2016
This paper evaluated the potential of counter current spray drying to produce engineered crystall... more This paper evaluated the potential of counter current spray drying to produce engineered crystalline particles in-situ. One main feature of the counter current spray dryer is in inducing droplet drying history with a progressively increasing drying rate; in contrast to a co-current spray dryer in which the particle is immediately confronted with high driving force of evaporation. In addition, counter current dryer provides higher residence time for particles within the drying chamber. This work explored the manipulation of these unique features of counter current spray drying to control the crystallinity of the particles formed. Sucrose, lactose and mannitol were spray dried as model materials exhibit contrasting crystallization. Counter current spray drying was suitable in producing well defined crystalline lactose particles mainly due to the higher residence time. The produced lactose particles were composed of agglomeration of fine thin lactose crystals. Surprisingly, the counter current spray drying with relatively lower initial evaporation rate resulted in amorphous mannitol particles. Fully crystalline mannitol was produced when the feed spray temperature was elevated leading to rapid supersaturation. This may be an important strategy to control the crystallinity of mannitol particles particularly for pharmaceutical application. Similar feed pre-heating strategy in conjunction with counter current spray drying was used for sucrose drying. Crystalline sucrose was achieved with relatively lower drying temperature. This will be a valuable strategy for producing free flowing sucrose particles specifically for the food industry.
Polymer Journal, Apr 5, 2017
Noble hydrogel beads based on gelatin and oxidized corn starch were synthesized, and their useful... more Noble hydrogel beads based on gelatin and oxidized corn starch were synthesized, and their usefulness and feasibility in treating effluent with dyes were studied in this work. Tartrazine was introduced as a model material. The kinetics of the tartrazine adsorption of the hydrogel beads were of a pseudo-second-order, and its adsorption isotherm is better fitted with the Langmuir model in comparison with the Freundlich model. With a pH of 2.5 coupled with a stirring speed of 400 r.p.m. and bath temperature of 35°C, a maximum adsorption capacity of 293 mg g − 1 was achieved. The hydrogel beads were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The results revealed that the blends have a uniform porous structure and can form stable Schiff base structures. The blend also had good stability and compatibility on mixing with electrolyte solutions, and swelling behavior measurements revealed that the hydrogel beads had excellent water-absorbing capacity.
Drying Technology, Jan 22, 2018
Superheated steam drying has been receiving research attention in recent years due to its increas... more Superheated steam drying has been receiving research attention in recent years due to its increasing industry prevalence in the food and agricultural sector. There is however a gap of knowledge in superheated steam spray drying involving the drying of droplets with dissolved solids as most application to date are solely on solid materials. With this constraint, it is vital to understand and study the effect of superheated steam on the particle formation process as well as on the final particle. The aim of this work is to explore the potential of superheated steam in the spray drying of milk. Specifically, this report examines how superheated steam influences the migration of fats, protein, and lactose in milk during the particle formation process. Studies were conducted by drying fresh milk, using a single droplet drying technique in a superheated steam environment and a hot air environment at a fixed temperature of 110°C. The wettability of the dried single particle was examined using contact angle measurements. The surface of superheated steam-dried milk particles revealed a relatively higher wettability when compared to air-dried milk particles. This suggests that superheated steam promoted the presence of hydrophilic components such as lactose on the exterior surface of the particle. These results have therefore shown the possibility of using superheated steam to control component relocation in multicomponent solutions based on the component hydrophilicity. By recognizing the potential of application of superheated steam in spray drying, engineered multicomponent particles with specific features can be produced.
Expert Opinion on Drug Delivery, Dec 20, 2016
Simultaneous solidification and in situ crystallization (or partial crystallization) of droplets ... more Simultaneous solidification and in situ crystallization (or partial crystallization) of droplets within the drying chamber are commonly encountered in the spray drying of pharmaceuticals. The crystallinity developed will determine the functionality of the powder and its stability during storage. This review discusses strategies that can be used to control the in situ crystallization process. Areas covered: The premise of the strategies discussed focuses on the manipulation of the droplet drying rate relative to the timescale of crystallization. This can be undertaken by the control of the spray drying operation, by the use of volatile materials and by the inclusion of additives. Several predictive approaches for in situ crystallization control and new spray dryer configuration strategies are further discussed. Expert opinion: Most reports, hitherto, have focused on the crystallinity of the spray dried material or the development of crystallinity during storage. More mechanistic understanding of the in situ crystallization process during spray drying is required to guide product formulation trials. The key challenge will be in adapting the mechanistic approach to the myriad possible formulations in the pharmaceutical industry.
Langmuir, Sep 17, 2012
A simultaneous convection-dehydration and antisolvent precipitation approach has been shown to pr... more A simultaneous convection-dehydration and antisolvent precipitation approach has been shown to produce uniform microsized lactose particles from aqueous droplet at atmospheric pressure. Microparticles with high uniformity having diameters of between 1.0 and 2.4 μm have been obtained. The precipitation of the microparticles is driven by a unique self-assembly mechanism that cannot be fully elucidated by supersaturation alone. Further analysis suggests that structural changes in the solvent/antisolvent mixture, due to hydrophobic hydration, could play a role in the precipitation process observed.
Journal of Food Engineering, Apr 1, 2022
IntechOpen eBooks, Jul 31, 2023
Nature has always been a resource of inspiration for humans, providing valuable lessons that have... more Nature has always been a resource of inspiration for humans, providing valuable lessons that have led to innovative solutions throughout history. Observing the micronano roughness structure of bio-surfaces has led to the discovery of natural selfcleaning surfaces for over 25 years. This has sparked a new field of research with valuable applications. Numerous self-cleaning products made from plant extracts have been created by replicating the natural purifying abilities of plant surfaces. Significant literature exists on the development, classification, extraction, and production of self-cleaning agents for diverse industries through a thorough understanding of bio-cleaning mechanisms. Various methods have been developed to synthesize these surfaces, including immersion, electrochemical deposition, emulsion, electrospinning, phase-separation, Chemical-Vapor-Deposition (CVD), spray coating, wet chemical reaction, and three-dimensional printing (3D-printing), among others. Currently, the primary objective is to gain knowledge from nature and utilize it to develop novel products for food, pharmaceutical, and related industries. Natural plant-based self-cleaning surfaces can be characterized by their superhydrophobicity and superhydrophilicity regimes. The process of 3D-printing is a computer-based technique that builds up three-dimensional objects through the layer-by-layer deposition of materials. The creation of effective self-cleaning surfaces with unique wettability, chemical properties, and microstructure depends on the design and engineering of solid surfaces.
Drying Technology, Dec 22, 2019
Current computational fluid dynamic (CFD) models of spray dryers lack the capability to predict t... more Current computational fluid dynamic (CFD) models of spray dryers lack the capability to predict the structure of the agglomerates formed; loose or compact agglomerates. This is mainly due to the conventional simplistic approach in numerically "fusing" of the colliding particles forming the agglomerate. A new theoretical treatment is introduced in this work, suitable for implementation in CFD simulations, which numerically fuses the particles and yet retain information on the structure of the agglomerate. This new theoretical treatment is based on tracking the reduction of the agglomerate surface area as the agglomerate is progressively formed. Analysis revealed that the reduction in the agglomerate surface area exhibits a unified correlation with the degree of compactness of the agglomerate. Further analysis comparing this new approach to the conventional numerical fusing of the particles revealed inherent numerical discrepancies, which has not been noted in the literature before. Understanding these discrepancies will provide clarity to the interpretation of the modelling and simulation of spray drying particle agglomeration in CFD. Moreover, this work lays the groundwork for a more comprehensive CFD model for agglomeration which can be potentially utilized to predict final powder properties.
A new antisolvent vapour precipitation technique was developed which enables the production of a ... more A new antisolvent vapour precipitation technique was developed which enables the production of a large amount of micro spheres from a single droplet. This work explores the potential of this technique for encapsulation of oil. Experiments were undertaken on the single droplet drying rig in Monash University, modified to incorporate antisolvent vapour. Using ethanol vapour, lactose micro particles with spiky surfaces were formed. Oil-infused lactose micro particles were also observed delineated by the smooth surfaces analogous to that of full cream milk. Single particle dissolution test revealed that the precipitated particles exhibited drastically higher dissolution rate when compared to particles dried without antisolvent vapour. More analysis is required to ascertain if this is due to differences in morphology or due to possible encapsulation of oil.
The antisolvent vapour precipitation approach was applied to produce micron size uniform whey pro... more The antisolvent vapour precipitation approach was applied to produce micron size uniform whey protein particles. This technique involved exposing a droplet of the whey protein containing liquid to an ethanol vapour laden convective medium. At pH conditions in proximity to the isoelectric point, the antisolvent vapour precipitation technique produced fine and semi-uniform whey protein particles dispersible in water. Precipitation of WPI+lactose droplets revealed that a blend of crystalline lactose with fine particles can be produced simultaneously. The incorporation of lactose also allowed for the precipitation of the WPI particles at a slightly higher pH than the isoelectric point. This could potentially be a one step process in producing drug-excipient blends.
Powder Technology, 2018
Antisolvent vapour drying precipitation is a new spray drying technique in which each droplet beh... more Antisolvent vapour drying precipitation is a new spray drying technique in which each droplet behaves like an individual 'precipitation vessel'. As the aqueous droplet absorbs the convective ethanol vapour, the initially dissolved solutes precipitates out as ultrafine particles within the droplet. This work sought to examine the feasibility of applying the antisolvent vapour drying method to produce salt particles. Using the modified single droplet drying rig, spherical magnesium sulphate and iron sulphate particles b10 μm were produced from relative large droplets of 1-2 mm in diameter. The fine particles produced exhibited rough gravel-like surface morphology. Mixtures of iron sulphate and vitamin C at different proportions were tested and gravel-like iron sulphate particles within a bulk vitamin C matrix were produced. Rough gravel-like surface morphology was also observed for sodium chloride particles. Lactose was then incorporated into the formulation to assess if spherical ultrafine particles of a lactose-salt matrix can be produced. The precipitated particles, however, resembled the smooth ultrafine amorphous particles of lactose without distinct indication on the location of the salt material.
Drying Technology, May 31, 2016
ABSTRACT Spray drying conventionally necessitates relatively large or elongated drying chambers. ... more ABSTRACT Spray drying conventionally necessitates relatively large or elongated drying chambers. The present study examined the possibility in shrinking the spray drying chamber into narrow tube-like geometry. The key was in utilizing fine droplets which had low transport response time. A narrow copper/steel tube spray dryer (internal diameters between 12.7 and 48.0 mm) was constructed and was fitted with a two-fluid atomizer producing droplets in the size range smaller than 10 µm. Maltodextrin, lactose, and sucrose were spray-dried. The narrow tube approach allowed direct manipulation of the drying conditions via heating or cooling along the wall of the tube. This form of manipulation in the drying conditions, surprisingly, resulted in very distinctly crystalline spray-dried sucrose particles. The tube spray dryer was further modified with a long coiled-up tube, extending the particle residence time with minimal space requirements. Endoscopic analysis revealed that particle deposition within the tube resembled loosely attached particle and granules. The tube spray drying concept can potentially be used to provide precise control of the particle drying history along the length of the drying chamber, not limited to the control of the drying conditions at the inlet or outlet of a spray dryer.
Chemical engineering research & design, Sep 1, 2013
Abstract A new antisolvent vapour precipitation technique was developed which enables the product... more Abstract A new antisolvent vapour precipitation technique was developed which enables the production of a large amount of micro spheres from a single droplet. This work explores the potential of this technique for encapsulation of oil and in precipitating multi-component solutes from a droplet. Experiments were undertaken on the single droplet drying rig in Monash University, modified to incorporate antisolvent vapour. Using ethanol vapour, lactose micro particles with spiky surfaces were formed. Oil-infused lactose micro particles were also observed delineated by the smooth surfaces analogous to that of full cream milk. Precipitation of multi-component solutes resulted in partial segregation of the protein and lactose. Precipitated particles with different proportions of protein and lactose exhibited contrasting particles. Particles with higher protein content resulted in smaller particle sizes.
Zenodo (CERN European Organization for Nuclear Research), Nov 4, 2014
Folic acid (FA) is known to be an important supplement to prevent neural tube defect (NTD) in pre... more Folic acid (FA) is known to be an important supplement to prevent neural tube defect (NTD) in pregnant women. Similar to some commercial formulations, sodium bicarbonate solution is used as a solvent for FA. This work uses the antisolvent vapour precipitation (AVP), incorporating ethanol vapour as the convective drying medium in place of air to produce branch-like micro-structure FA particles. Interestingly, the dissolution rate of the resultant particle is 2-3 times better than the particle produce from conventional air drying due to the higher surface area of particles produced. The higher dissolution rate could possibly improve the delivery and absorption of FA in human body. This application could potentially be extended to other commercial products, particularly in less soluble drugs to improve its solubility.
International Journal of Pharmaceutics, Apr 1, 2019
&NA; The surface structure of crystalline particles affects the functionality of the particle... more &NA; The surface structure of crystalline particles affects the functionality of the particles in drug delivery. Prediction of the final structure of particles that crystallize easily within the spray drying process is of interests for many applications. A theoretical framework was developed for the prediction of crystal structure precipitating on the surface of the particle. This model was based on the dimensionless Damkohler number (Da), to be an indicator of final particle morphology. Timescales of evaporation and reaction were required for calculation of the Damkohler number. The modified evaporation time scale was estimated based on the time that is available for the crystal to precipitate after supersaturation. The reaction time scale was estimated based on the time scale for induction time. Mannitol was produced under different processing conditions in order to validate the theoretical model. Results showed for the high Damkohler numbers, the surface structure of the particle was rough, while smaller Damkohler numbers led to relatively smooth particle surfaces. Additionally, although the beta polymorph was dominant in all of the experiments, alpha polymorph was precipitated in the experiments with a large Damkohler number. The theoretical framework developed will be a useful predictive tool to guide the manipulation of particle crystallization in spray dryers. Graphical abstract Figure. No caption available.
Powder Technology, 2018
In-situ crystallization of particles in spray drying has several advantages particularly for prod... more In-situ crystallization of particles in spray drying has several advantages particularly for product quality modification in the pharmaceutical industry. This process was investigated in a counter current spray dryer using lactose as a model material by manipulation of the local humidity within the drying chamber. Sample collection and humidity injection at different location of the dryer were carried out to better understand the mechanism of particle formation and solidification which are essential components of in-situ crystallization. They revealed that particle formation can be delayed by local humidity elevation. Differential scanning calorimetry and XRD of the yields showed that humidity manipulation was capable to produce semi crystalline lactose of up to 90 precent crystallinity. The results confirmed that there is a critical period for crystallization such that extending this period would significantly increase the degree of crystallization. Comparison on different requirements of crystallization indicated that extending the time for nucleation and the growth at the critical period via humidity manipulation has the most significant effect on the in-situ crystallization process.
Expert Opinion on Drug Delivery, Jan 13, 2014
Pulmonary drug delivery requires particles with a fine and uniform size distribution, 1 - 5 µ hyd... more Pulmonary drug delivery requires particles with a fine and uniform size distribution, 1 - 5 µ hydrodynamic diameter, for targeted delivery and higher uptake within the pulmonary tract. The antisolvent vapor precipitation method is a new alternative method to generate particles with such characteristics. Development so far has shown that the technique is applicable to disaccharides (lactose), magnesium sulfate, hydrophobic and protein particles. The method may also be extended to generate fine encapsulation particles and to produce disaccharides (lactose) and protein particles blend in a single step.
Advanced Powder Technology, Nov 1, 2016
This paper evaluated the potential of counter current spray drying to produce engineered crystall... more This paper evaluated the potential of counter current spray drying to produce engineered crystalline particles in-situ. One main feature of the counter current spray dryer is in inducing droplet drying history with a progressively increasing drying rate; in contrast to a co-current spray dryer in which the particle is immediately confronted with high driving force of evaporation. In addition, counter current dryer provides higher residence time for particles within the drying chamber. This work explored the manipulation of these unique features of counter current spray drying to control the crystallinity of the particles formed. Sucrose, lactose and mannitol were spray dried as model materials exhibit contrasting crystallization. Counter current spray drying was suitable in producing well defined crystalline lactose particles mainly due to the higher residence time. The produced lactose particles were composed of agglomeration of fine thin lactose crystals. Surprisingly, the counter current spray drying with relatively lower initial evaporation rate resulted in amorphous mannitol particles. Fully crystalline mannitol was produced when the feed spray temperature was elevated leading to rapid supersaturation. This may be an important strategy to control the crystallinity of mannitol particles particularly for pharmaceutical application. Similar feed pre-heating strategy in conjunction with counter current spray drying was used for sucrose drying. Crystalline sucrose was achieved with relatively lower drying temperature. This will be a valuable strategy for producing free flowing sucrose particles specifically for the food industry.
Polymer Journal, Apr 5, 2017
Noble hydrogel beads based on gelatin and oxidized corn starch were synthesized, and their useful... more Noble hydrogel beads based on gelatin and oxidized corn starch were synthesized, and their usefulness and feasibility in treating effluent with dyes were studied in this work. Tartrazine was introduced as a model material. The kinetics of the tartrazine adsorption of the hydrogel beads were of a pseudo-second-order, and its adsorption isotherm is better fitted with the Langmuir model in comparison with the Freundlich model. With a pH of 2.5 coupled with a stirring speed of 400 r.p.m. and bath temperature of 35°C, a maximum adsorption capacity of 293 mg g − 1 was achieved. The hydrogel beads were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The results revealed that the blends have a uniform porous structure and can form stable Schiff base structures. The blend also had good stability and compatibility on mixing with electrolyte solutions, and swelling behavior measurements revealed that the hydrogel beads had excellent water-absorbing capacity.
Drying Technology, Jan 22, 2018
Superheated steam drying has been receiving research attention in recent years due to its increas... more Superheated steam drying has been receiving research attention in recent years due to its increasing industry prevalence in the food and agricultural sector. There is however a gap of knowledge in superheated steam spray drying involving the drying of droplets with dissolved solids as most application to date are solely on solid materials. With this constraint, it is vital to understand and study the effect of superheated steam on the particle formation process as well as on the final particle. The aim of this work is to explore the potential of superheated steam in the spray drying of milk. Specifically, this report examines how superheated steam influences the migration of fats, protein, and lactose in milk during the particle formation process. Studies were conducted by drying fresh milk, using a single droplet drying technique in a superheated steam environment and a hot air environment at a fixed temperature of 110°C. The wettability of the dried single particle was examined using contact angle measurements. The surface of superheated steam-dried milk particles revealed a relatively higher wettability when compared to air-dried milk particles. This suggests that superheated steam promoted the presence of hydrophilic components such as lactose on the exterior surface of the particle. These results have therefore shown the possibility of using superheated steam to control component relocation in multicomponent solutions based on the component hydrophilicity. By recognizing the potential of application of superheated steam in spray drying, engineered multicomponent particles with specific features can be produced.
Expert Opinion on Drug Delivery, Dec 20, 2016
Simultaneous solidification and in situ crystallization (or partial crystallization) of droplets ... more Simultaneous solidification and in situ crystallization (or partial crystallization) of droplets within the drying chamber are commonly encountered in the spray drying of pharmaceuticals. The crystallinity developed will determine the functionality of the powder and its stability during storage. This review discusses strategies that can be used to control the in situ crystallization process. Areas covered: The premise of the strategies discussed focuses on the manipulation of the droplet drying rate relative to the timescale of crystallization. This can be undertaken by the control of the spray drying operation, by the use of volatile materials and by the inclusion of additives. Several predictive approaches for in situ crystallization control and new spray dryer configuration strategies are further discussed. Expert opinion: Most reports, hitherto, have focused on the crystallinity of the spray dried material or the development of crystallinity during storage. More mechanistic understanding of the in situ crystallization process during spray drying is required to guide product formulation trials. The key challenge will be in adapting the mechanistic approach to the myriad possible formulations in the pharmaceutical industry.
Langmuir, Sep 17, 2012
A simultaneous convection-dehydration and antisolvent precipitation approach has been shown to pr... more A simultaneous convection-dehydration and antisolvent precipitation approach has been shown to produce uniform microsized lactose particles from aqueous droplet at atmospheric pressure. Microparticles with high uniformity having diameters of between 1.0 and 2.4 μm have been obtained. The precipitation of the microparticles is driven by a unique self-assembly mechanism that cannot be fully elucidated by supersaturation alone. Further analysis suggests that structural changes in the solvent/antisolvent mixture, due to hydrophobic hydration, could play a role in the precipitation process observed.
Journal of Food Engineering, Apr 1, 2022