International Journal of Pharmaceutics, Sep 1, 2021
Porous silicon has found increased attention as a drug delivery system due to its unique features... more Porous silicon has found increased attention as a drug delivery system due to its unique features such as high drug payloads, surface area and biodegradation. In this study supercritical fluid (SCF) assisted drying of ultrahigh porosity (> 90%) silicon particles and flakes was shown to result in much higher mesopore volumes (∼ 4.66 cm3/g) and surface areas (∼ 680 m2/g) than with air-drying. The loading and physical state of the model drug (S)-(+)-Ibuprofen in SCF dried matrices was quantified and assessed using thermogravimetric analysis, differential scanning calorimetry, UV-Vis spectrophotometry, gravimetric analysis, gas adsorption and electron microscopy. Internal drug payloads of up to 72% were achieved which was substantially higher than values published for both conventionally dried porous silicon (17-51%) and other mesoporous materials (7-45%). In-vitro degradability kinetics of SCF-dried matrices in simulated media was also found to be faster than air-dried controls. The in-vitro release studies provided improved but sustained drug dissolution at both pH 2.0 and pH 7.4.
Supercritical fluids offer a considerable promise as a processing media for the formation of micr... more Supercritical fluids offer a considerable promise as a processing media for the formation of microparticles of drugs and pharmaceutical excipients. There are two main reasons for using this technique. Firstly, the selective solvating power of supercritical fluids makes it possible to separate a particular component from a multi-component mixture. Secondly, the favourable mass transfer properties and high solubility of solvent in supercritical fluid make the formation of the microparticles rapid and efficient. Supercritical fluids also offer various other advantages such as use of organic solvents, high temperatures, high sheer stresses can be avoided which can therefore aid in the effective, safe and green processing of APIs and pharmaceutical excipients. Solubility behaviour of supercritical fluid can be altered or tuned by the fine adjustment of pressure and temperature. Supercritical fluids can also be utilised as a solute and can help in the depression of melting point or glass transition temperature of an excipient, allowing microparticle production at far lower temperatures. The processing of excipients and APIs with supercritical CO2 and utilisation of this approach in the development of novel drug delivery systems (NDDS) is an attractive proposition because of above mentioned advantages. Our group is particularly interested in the "safe" formulation of NDDS for biologics for oral delivery which also entails incorporation of bio-molecules and proteins into inorganic host materials. Immobilisation of biologics on a solid surface improves their thermal and chemical stability. These biologics on an inorganic host can then be safely coated with lipids and/or other suitable excipient using supercritical fluid processing. This approach can provide sustained, targeted and safe passage to a drug to the lower intestine where it can be released and absorbed.
The melting behaviour of saturated fatty acids and Pluronics® was investigated in liquid or super... more The melting behaviour of saturated fatty acids and Pluronics® was investigated in liquid or supercritical carbon dioxide (SCCO2). Fatty acids included in this study were lauric acid, myristic acid, palmitic acid and stearic acid while Pluronics® used were F-77, F-127, F-68, F-38 and F-108. The melting point of fatty acids and Pluronics® was determined at pressure values from (7.0 to 50.0) MPa and (8.0 to 50) MPa respectively. Unprocessed and CO2-processed samples of all fatty acids and Pluronics® were analysed by differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). A melting point depression in the range of (18.1 to 19.3) °C was observed for the Pluronics® whereas the fatty acids showed a depression of (10.8 to 19.5) °C in their melting point. Interestingly, in case of fatty acids, the depression in melting point was found to be inversely proportional to the carbon chain length i.e. smaller the chain length, larger the depression.
Objectives Carotenoids are increasingly explored as nutraceuticals but their low bioavailability ... more Objectives Carotenoids are increasingly explored as nutraceuticals but their low bioavailability due to poor aqueous solubility limits their applications. This study discusses the development of a novel and organic solvent-free method to develop carotenoid-containing polymeric nanoparticles via temperature-induced phase transition (TIPT) of pluronic F-68 to obtain formulations with the improved dissolution of carotenoids. Methods The nanoencapsulation of carotenoids in pluronic F-68 was performed in supercritical carbon dioxide (scCO2) to avoid oxidative or temperature/solvent-induced degradation. The nanoencapsulates were prepared in scCO2 at 40 or 60 °C and 10 MPa without the aid of any organic solvent. The formulations thereafter were characterised for particle size via dynamic light scattering (DLS), particle morphology via Scanning Electron Microscopy (SEM) and carotenoid content/release via high-performance liquid chromatography (HPLC). Key findings HPLC results showed caroten...
Progesterone (PRG) and testosterone (TST) were impregnated on mesoporous silica (ExP) particles ... more Progesterone (PRG) and testosterone (TST) were impregnated on mesoporous silica (ExP) particles via supercritical carbon dioxide (scCO2) processing at various pressures (10–18 MPa), temperatures (308.2–328.2 K), and time (30–360 min). The impact of a co-solvent on the impregnation was also studied at the best determined pressure and temperature. The properties of the drug embedded in silica particles were analysed via gas chromatography (GC), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and nitrogen adsorption. An impregnation of 1 to 82 mg/g for PRG and 0.1 to 16 mg/g for TST was obtained depending on the processing parameters. There was a significant effect of pressure, time, and co-solvent on the impregnation efficiency. Generally, an increase in time and pressure plus the use of co-solvent led to an improvement in drug adsorption. Conversely, a rise in temperature resulted in l...
Supercritical fluids (SCF) are substances above their critical pressure and temperature. Once abo... more Supercritical fluids (SCF) are substances above their critical pressure and temperature. Once above this critical point, they exist as a single phase with unique properties such as liquid-like densities resulting in solvating characteristics that are similar to those of liquids and mass transfer properties similar to gases. A number of different SCFs have been used in various applications. However, carbon dioxide (CO2) is the most widely used SCF because it is environmentally benign, nontoxic, nonflammable, noncorrosive, readily available, inexpensive, and easy to remove from the reaction systems in comparison to many organic solvents. CO2 also has a low critical point of 73.8 bar and 31.1°C, which allows processing in ambient conditions and presents exciting prospects in the processing of thermo-labile materials with relevance to pharmaceutical and biotechnology industries. Supercritical CO2 (scCO2) is an excellent solvent for numerous small molecules but not so for high molecular ...
Carbon dioxide (CO2) is the most commonly used SCF because of the relatively mild operating condi... more Carbon dioxide (CO2) is the most commonly used SCF because of the relatively mild operating conditions (31.1°C and 72.8 bar) and easily tuneable properties. Moreover, the ability of CO2 to act as a solvent and solute has made it highly desirable in the field of excipient processing, particle formation and drug encapsulation. The dissolution of CO2 is known to affect glass transition or melting temperature of polymers and fats [1]. In this work, the effect of the dissolution of liquid (l.CO2) or supercritical (sc. CO2) was studied on the melting point of various poloxamers (Pluronic™ F77, F127, F38, F68, F108) at the pressure ranging from 70 to 250 bar in a supercritical phase monitor. The treated and untreated samples were analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).
The study was designed to investigate the feasibility of supercritical carbon dioxide (scCO2) pro... more The study was designed to investigate the feasibility of supercritical carbon dioxide (scCO2) processing for the preparation of simvastatin (SIM) solid dispersions (SDs) in Soluplus® (SOL) at temperatures below polymer’s glass transition. The SIM content in the SDs experimental design was kept at 10, 20 and 30% to study the effect of the drug–polymer ratio on the successful preparation of SDs. The SIM–SOL formulations, physical mixtures (PMs) and SDs were evaluated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and dissolution studies. The scCO2 processing conditions and drug–polymer ratio were found to influence the physicochemical properties of the drug in formulated SDs. SIM is a highly crystalline drug; however, physicochemical characterisation carried out by SEM, DSC, and XRD demonstrated the presence of SIM in amorphous nature within the...
The melting behaviour of the triblock polymers, Pluronic F38, F68, F77, F108, and F127, was inves... more The melting behaviour of the triblock polymers, Pluronic F38, F68, F77, F108, and F127, was investigated in pressurised CO2 and in the presence of menthol. The melting points of the polymers combined with 0, 10, 25, and 50 wt% of menthol were studied at atmospheric pressure and compared with those at 10 and 20 MPa in supercritical carbon dioxide (scCO2). The highest melting point depressions of 16.8 ± 0.5 °C and 29.0 ± 0.3 °C were observed at 10 and 20 MPa, respectively. The melting point of triblock polymers in pressurised CO2 was found to be dependent on molecular weight, poly(propylene oxide) (PPO) content, and menthol percentage. The melting point of most of the polymers studied in this work can be reduced to room temperature, which can be pivotal to the formulation development of thermolabile substances using these polymers.
The aim of this study was to understand the effect of high shear homogenization (HSH) and ultraso... more The aim of this study was to understand the effect of high shear homogenization (HSH) and ultrasonication (US) on the physicochemical properties of blank and olanzapine loaded nanostructured lipid carriers (NLCs) along with their drug loading potential and drug release profiles from formulated particles. NLCs were prepared with different ratios of Compritol and Miglyol as the solid and liquid lipids, respectively, under changing HSH and US times between 0 to 15 min. The surfactants (Poloxamer 188 (P188) and tween 80) and the drug content was kept constant in all formulations. The prepared NLCs were evaluated for particle size, polydispersity index, zeta potential, drug crystallinity and chemical interactions between lipids and OLZ. The in-vitro drug release was performed using dialysis tube method in phosphate buffer solution (PBS) at pH 7.4. The formulated NLCs were negatively charged, spherically shaped and monodisperse, with particle sizes ranging from 112 to 191 nm. There was a ...
Recent changes in regulatory requirements for paediatric formulations demand development of age-a... more Recent changes in regulatory requirements for paediatric formulations demand development of age-appropriate dosage forms that are stable for ease of dosing, compliance and dose flexibility while maintaining accuracy and safety. Films were developed by optimising various formulation variables including type of solvent (water, ethanol), polyethylene glycol (PEG 400) as plasticiser and different film forming polymers [(metolose (MET), hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), sodium alginate (SA), and carrageenan (CA)], drug stabilization and loading capacity. Films were subsequently functionally characterised using various techniques.
Biodegradable porous silicon (pSi) is under assessment for the controlled release of both protein... more Biodegradable porous silicon (pSi) is under assessment for the controlled release of both proteins and poorly-soluble API formulations. Super-critical drying of ultrahigh porosity (90%) porous silicon is shown here to preserve much higher mesopore volumes (up to 4mL/g) and surface areas (up to 600m2M/g) than achievable with standardair drying. The payloads and physical state of the model drug (S) (+) ibuprofen, as loaded within a super-critically dried porous silicon carrier matrix,were quantified and assessed using TGA, DSC, cross-sectional EDX, XRD, Raman mapping andFT-IR. In-vitro biodegradability was assessed using Mmolybdenum blue assay and drug release using RPHPLC. Entrapped drug payloads as high as 70%w/w have been achieved, substantially higher than values reported for other mesoporous materials. The entrapped (S) (+) ibuprofen showed faster release than bulk (S) (+) ibuprofen.
Poor water solubility and the resulting low oral bioavailability of drugs is one of the major cha... more Poor water solubility and the resulting low oral bioavailability of drugs is one of the major challenges encountered by drug discovery and development scientists. Drug candidates with a solubility of less than 1 μg/ml are considered poorly soluble which show unacceptable bioavailability from conventional dosage forms. Formulation plays a major role in determining the rate and extent of absorption of such drugs. There are a number of formulation strategies that could be used to improve the bioavailability of such drugs, primarily either by increasing the dissolution rate or by presenting the drug in solution. Various approaches to enhance the solubility and dissolution rate of drugs have been already reported e.g. inclusion complexation, colloidal systems, solid lipid nanoparticles and nano-structured lipid carriers etc.
Twin-screw granulation (TSG) is a pharmaceutical process that has gained increased interest from ... more Twin-screw granulation (TSG) is a pharmaceutical process that has gained increased interest from the pharmaceutical industry for its potential for the development of oral dosage forms. The technology has evolved rapidly due to the flexibility of the equipment design, the selection of the process variables and the wide range of processed materials. Most importantly, TSG offers the benefits of both batch and continuous manufacturing for pharmaceutical products, accompanied by excellent process control, high product quality which can be achieved through the implementation of Quality by Design (QbD) approaches and the integration of Process Analytical Tools (PAT). Here, we present basic concepts of the various twin-screw granulation techniques and present in detail their advantages and disadvantages. In addition, we discuss the detail of the instrumentation used for TSG and how the critical processing paraments (CPP) affect the critical quality attributes (CQA) of the produced granules....
In this study a solid core drug delivery system (SCDDS) is prepared with silica as a model core, ... more In this study a solid core drug delivery system (SCDDS) is prepared with silica as a model core, fatty acid as a shell material and supercritical fluid technology as the process. SCDDS can be developed as targeted delivery systems or as sustained/controlled release platforms. SCDDS are coated with fatty acids using supercritical fluid technology (SCFT), allowing the creation of nano-particulate and micro-particulate delivery systems. The operating conditions of low temperature and pressure used to formulate these systems make it attractive for pharmaceutical research, especially for thermo-labile or sensitive bio-materials.
International Journal of Pharmaceutics, Sep 1, 2021
Porous silicon has found increased attention as a drug delivery system due to its unique features... more Porous silicon has found increased attention as a drug delivery system due to its unique features such as high drug payloads, surface area and biodegradation. In this study supercritical fluid (SCF) assisted drying of ultrahigh porosity (> 90%) silicon particles and flakes was shown to result in much higher mesopore volumes (∼ 4.66 cm3/g) and surface areas (∼ 680 m2/g) than with air-drying. The loading and physical state of the model drug (S)-(+)-Ibuprofen in SCF dried matrices was quantified and assessed using thermogravimetric analysis, differential scanning calorimetry, UV-Vis spectrophotometry, gravimetric analysis, gas adsorption and electron microscopy. Internal drug payloads of up to 72% were achieved which was substantially higher than values published for both conventionally dried porous silicon (17-51%) and other mesoporous materials (7-45%). In-vitro degradability kinetics of SCF-dried matrices in simulated media was also found to be faster than air-dried controls. The in-vitro release studies provided improved but sustained drug dissolution at both pH 2.0 and pH 7.4.
Supercritical fluids offer a considerable promise as a processing media for the formation of micr... more Supercritical fluids offer a considerable promise as a processing media for the formation of microparticles of drugs and pharmaceutical excipients. There are two main reasons for using this technique. Firstly, the selective solvating power of supercritical fluids makes it possible to separate a particular component from a multi-component mixture. Secondly, the favourable mass transfer properties and high solubility of solvent in supercritical fluid make the formation of the microparticles rapid and efficient. Supercritical fluids also offer various other advantages such as use of organic solvents, high temperatures, high sheer stresses can be avoided which can therefore aid in the effective, safe and green processing of APIs and pharmaceutical excipients. Solubility behaviour of supercritical fluid can be altered or tuned by the fine adjustment of pressure and temperature. Supercritical fluids can also be utilised as a solute and can help in the depression of melting point or glass transition temperature of an excipient, allowing microparticle production at far lower temperatures. The processing of excipients and APIs with supercritical CO2 and utilisation of this approach in the development of novel drug delivery systems (NDDS) is an attractive proposition because of above mentioned advantages. Our group is particularly interested in the "safe" formulation of NDDS for biologics for oral delivery which also entails incorporation of bio-molecules and proteins into inorganic host materials. Immobilisation of biologics on a solid surface improves their thermal and chemical stability. These biologics on an inorganic host can then be safely coated with lipids and/or other suitable excipient using supercritical fluid processing. This approach can provide sustained, targeted and safe passage to a drug to the lower intestine where it can be released and absorbed.
The melting behaviour of saturated fatty acids and Pluronics® was investigated in liquid or super... more The melting behaviour of saturated fatty acids and Pluronics® was investigated in liquid or supercritical carbon dioxide (SCCO2). Fatty acids included in this study were lauric acid, myristic acid, palmitic acid and stearic acid while Pluronics® used were F-77, F-127, F-68, F-38 and F-108. The melting point of fatty acids and Pluronics® was determined at pressure values from (7.0 to 50.0) MPa and (8.0 to 50) MPa respectively. Unprocessed and CO2-processed samples of all fatty acids and Pluronics® were analysed by differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD). A melting point depression in the range of (18.1 to 19.3) °C was observed for the Pluronics® whereas the fatty acids showed a depression of (10.8 to 19.5) °C in their melting point. Interestingly, in case of fatty acids, the depression in melting point was found to be inversely proportional to the carbon chain length i.e. smaller the chain length, larger the depression.
Objectives Carotenoids are increasingly explored as nutraceuticals but their low bioavailability ... more Objectives Carotenoids are increasingly explored as nutraceuticals but their low bioavailability due to poor aqueous solubility limits their applications. This study discusses the development of a novel and organic solvent-free method to develop carotenoid-containing polymeric nanoparticles via temperature-induced phase transition (TIPT) of pluronic F-68 to obtain formulations with the improved dissolution of carotenoids. Methods The nanoencapsulation of carotenoids in pluronic F-68 was performed in supercritical carbon dioxide (scCO2) to avoid oxidative or temperature/solvent-induced degradation. The nanoencapsulates were prepared in scCO2 at 40 or 60 °C and 10 MPa without the aid of any organic solvent. The formulations thereafter were characterised for particle size via dynamic light scattering (DLS), particle morphology via Scanning Electron Microscopy (SEM) and carotenoid content/release via high-performance liquid chromatography (HPLC). Key findings HPLC results showed caroten...
Progesterone (PRG) and testosterone (TST) were impregnated on mesoporous silica (ExP) particles ... more Progesterone (PRG) and testosterone (TST) were impregnated on mesoporous silica (ExP) particles via supercritical carbon dioxide (scCO2) processing at various pressures (10–18 MPa), temperatures (308.2–328.2 K), and time (30–360 min). The impact of a co-solvent on the impregnation was also studied at the best determined pressure and temperature. The properties of the drug embedded in silica particles were analysed via gas chromatography (GC), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and nitrogen adsorption. An impregnation of 1 to 82 mg/g for PRG and 0.1 to 16 mg/g for TST was obtained depending on the processing parameters. There was a significant effect of pressure, time, and co-solvent on the impregnation efficiency. Generally, an increase in time and pressure plus the use of co-solvent led to an improvement in drug adsorption. Conversely, a rise in temperature resulted in l...
Supercritical fluids (SCF) are substances above their critical pressure and temperature. Once abo... more Supercritical fluids (SCF) are substances above their critical pressure and temperature. Once above this critical point, they exist as a single phase with unique properties such as liquid-like densities resulting in solvating characteristics that are similar to those of liquids and mass transfer properties similar to gases. A number of different SCFs have been used in various applications. However, carbon dioxide (CO2) is the most widely used SCF because it is environmentally benign, nontoxic, nonflammable, noncorrosive, readily available, inexpensive, and easy to remove from the reaction systems in comparison to many organic solvents. CO2 also has a low critical point of 73.8 bar and 31.1°C, which allows processing in ambient conditions and presents exciting prospects in the processing of thermo-labile materials with relevance to pharmaceutical and biotechnology industries. Supercritical CO2 (scCO2) is an excellent solvent for numerous small molecules but not so for high molecular ...
Carbon dioxide (CO2) is the most commonly used SCF because of the relatively mild operating condi... more Carbon dioxide (CO2) is the most commonly used SCF because of the relatively mild operating conditions (31.1°C and 72.8 bar) and easily tuneable properties. Moreover, the ability of CO2 to act as a solvent and solute has made it highly desirable in the field of excipient processing, particle formation and drug encapsulation. The dissolution of CO2 is known to affect glass transition or melting temperature of polymers and fats [1]. In this work, the effect of the dissolution of liquid (l.CO2) or supercritical (sc. CO2) was studied on the melting point of various poloxamers (Pluronic™ F77, F127, F38, F68, F108) at the pressure ranging from 70 to 250 bar in a supercritical phase monitor. The treated and untreated samples were analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).
The study was designed to investigate the feasibility of supercritical carbon dioxide (scCO2) pro... more The study was designed to investigate the feasibility of supercritical carbon dioxide (scCO2) processing for the preparation of simvastatin (SIM) solid dispersions (SDs) in Soluplus® (SOL) at temperatures below polymer’s glass transition. The SIM content in the SDs experimental design was kept at 10, 20 and 30% to study the effect of the drug–polymer ratio on the successful preparation of SDs. The SIM–SOL formulations, physical mixtures (PMs) and SDs were evaluated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and dissolution studies. The scCO2 processing conditions and drug–polymer ratio were found to influence the physicochemical properties of the drug in formulated SDs. SIM is a highly crystalline drug; however, physicochemical characterisation carried out by SEM, DSC, and XRD demonstrated the presence of SIM in amorphous nature within the...
The melting behaviour of the triblock polymers, Pluronic F38, F68, F77, F108, and F127, was inves... more The melting behaviour of the triblock polymers, Pluronic F38, F68, F77, F108, and F127, was investigated in pressurised CO2 and in the presence of menthol. The melting points of the polymers combined with 0, 10, 25, and 50 wt% of menthol were studied at atmospheric pressure and compared with those at 10 and 20 MPa in supercritical carbon dioxide (scCO2). The highest melting point depressions of 16.8 ± 0.5 °C and 29.0 ± 0.3 °C were observed at 10 and 20 MPa, respectively. The melting point of triblock polymers in pressurised CO2 was found to be dependent on molecular weight, poly(propylene oxide) (PPO) content, and menthol percentage. The melting point of most of the polymers studied in this work can be reduced to room temperature, which can be pivotal to the formulation development of thermolabile substances using these polymers.
The aim of this study was to understand the effect of high shear homogenization (HSH) and ultraso... more The aim of this study was to understand the effect of high shear homogenization (HSH) and ultrasonication (US) on the physicochemical properties of blank and olanzapine loaded nanostructured lipid carriers (NLCs) along with their drug loading potential and drug release profiles from formulated particles. NLCs were prepared with different ratios of Compritol and Miglyol as the solid and liquid lipids, respectively, under changing HSH and US times between 0 to 15 min. The surfactants (Poloxamer 188 (P188) and tween 80) and the drug content was kept constant in all formulations. The prepared NLCs were evaluated for particle size, polydispersity index, zeta potential, drug crystallinity and chemical interactions between lipids and OLZ. The in-vitro drug release was performed using dialysis tube method in phosphate buffer solution (PBS) at pH 7.4. The formulated NLCs were negatively charged, spherically shaped and monodisperse, with particle sizes ranging from 112 to 191 nm. There was a ...
Recent changes in regulatory requirements for paediatric formulations demand development of age-a... more Recent changes in regulatory requirements for paediatric formulations demand development of age-appropriate dosage forms that are stable for ease of dosing, compliance and dose flexibility while maintaining accuracy and safety. Films were developed by optimising various formulation variables including type of solvent (water, ethanol), polyethylene glycol (PEG 400) as plasticiser and different film forming polymers [(metolose (MET), hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), sodium alginate (SA), and carrageenan (CA)], drug stabilization and loading capacity. Films were subsequently functionally characterised using various techniques.
Biodegradable porous silicon (pSi) is under assessment for the controlled release of both protein... more Biodegradable porous silicon (pSi) is under assessment for the controlled release of both proteins and poorly-soluble API formulations. Super-critical drying of ultrahigh porosity (90%) porous silicon is shown here to preserve much higher mesopore volumes (up to 4mL/g) and surface areas (up to 600m2M/g) than achievable with standardair drying. The payloads and physical state of the model drug (S) (+) ibuprofen, as loaded within a super-critically dried porous silicon carrier matrix,were quantified and assessed using TGA, DSC, cross-sectional EDX, XRD, Raman mapping andFT-IR. In-vitro biodegradability was assessed using Mmolybdenum blue assay and drug release using RPHPLC. Entrapped drug payloads as high as 70%w/w have been achieved, substantially higher than values reported for other mesoporous materials. The entrapped (S) (+) ibuprofen showed faster release than bulk (S) (+) ibuprofen.
Poor water solubility and the resulting low oral bioavailability of drugs is one of the major cha... more Poor water solubility and the resulting low oral bioavailability of drugs is one of the major challenges encountered by drug discovery and development scientists. Drug candidates with a solubility of less than 1 μg/ml are considered poorly soluble which show unacceptable bioavailability from conventional dosage forms. Formulation plays a major role in determining the rate and extent of absorption of such drugs. There are a number of formulation strategies that could be used to improve the bioavailability of such drugs, primarily either by increasing the dissolution rate or by presenting the drug in solution. Various approaches to enhance the solubility and dissolution rate of drugs have been already reported e.g. inclusion complexation, colloidal systems, solid lipid nanoparticles and nano-structured lipid carriers etc.
Twin-screw granulation (TSG) is a pharmaceutical process that has gained increased interest from ... more Twin-screw granulation (TSG) is a pharmaceutical process that has gained increased interest from the pharmaceutical industry for its potential for the development of oral dosage forms. The technology has evolved rapidly due to the flexibility of the equipment design, the selection of the process variables and the wide range of processed materials. Most importantly, TSG offers the benefits of both batch and continuous manufacturing for pharmaceutical products, accompanied by excellent process control, high product quality which can be achieved through the implementation of Quality by Design (QbD) approaches and the integration of Process Analytical Tools (PAT). Here, we present basic concepts of the various twin-screw granulation techniques and present in detail their advantages and disadvantages. In addition, we discuss the detail of the instrumentation used for TSG and how the critical processing paraments (CPP) affect the critical quality attributes (CQA) of the produced granules....
In this study a solid core drug delivery system (SCDDS) is prepared with silica as a model core, ... more In this study a solid core drug delivery system (SCDDS) is prepared with silica as a model core, fatty acid as a shell material and supercritical fluid technology as the process. SCDDS can be developed as targeted delivery systems or as sustained/controlled release platforms. SCDDS are coated with fatty acids using supercritical fluid technology (SCFT), allowing the creation of nano-particulate and micro-particulate delivery systems. The operating conditions of low temperature and pressure used to formulate these systems make it attractive for pharmaceutical research, especially for thermo-labile or sensitive bio-materials.
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