Purpose: To prepare solid lipid nanoparticles employing softisan 100 (SOFTI) or tristearin (TS) as solid lipid carriers for celecoxib (CXB) to overcome its dissolution challenge. Methods: The solid lipid nanoparticles (SLN) of CXB were prepared by ultrasonic melt-emulsification technique. SLN was characterized using differential scanning calorimetry (DSC), Fourier transform infra spectroscopy (FTIR), as well as for entrapment efficiency, particle size, zeta potential and CXB release. Results: The SLN formulations exhibited high CXB entrapment efficiency (91.6 % for SOFTI and 94.6 % for TS) while mean particle size was 181.0 ± 4.6 and 346.3 ± 3.8 nm for SOFTI and TS, respectively. The DSC thermograms showed the disappearance of CXB peak due to its molecular distribution in the lipid nanoparticles while FTIR spectra revealed physical interaction of CXB with the tested lipids. The tendency of SOFTI to liberate CXB in 24 h was higher than that of TS (55.5 ± 1.07 vs 49.2 ± 2.94 %, p 0.05). Drug release was by non-Fickian mechanism. Conclusion: Formulation of CXB in SLN using TS or SOFTI produces sustained drug release delivery that can overcome the dissolution limitation of the drug and thus, improve its therapeutic efficacy.

Purpose: To study the effect of compritol ATO888 and kollidon SR blend on the release of chlorpheniramine maleate (CPM) from its matrix tablets prepared by direct compression. Methods: Different ratios of compritol and kollidon SR (containing 50 % matrix component) in 1:1, 1:2, 1:3 and 3:1 ratios were formulated using direct compression. The formulations were organoleptically tested and investigated for CPM release. Results: The release kinetics showed Fickian diffusion mode for kollidone and anomalous release mechanism for compritol matrices. Combining compritol as a lipophilic material and kollidone produced a matrix with controlled drug release. Retardation of drug release rate depended on the ratio of compritol to kollidon. The lower the compritol component, the slower the drug release rate. CPM in matrix tablets containing compritol:kollidone SR in a ratio of 1: 3 achieved optimized sustained release, where 44 % of the drug was released within 8 h (versus 94.5 % for compritol and 54.2 % for kollidon matrix systems). The kinetics of drug release followed Fickian diffusion at low compritol concentration in the blend, reflecting the importance of pore formation. However, when compritol proportion was increased, drug release followed non-Fickian anomalous kinetics due to the water-repelling effect of compritol. Conclusion: Compritol content of CPM matrix tablets can be used to modulate drug release rate as well as release kinetics.

Purpose: To study the effect of compritol ATO888 and kollidon SR blend on the release of chlorpheniramine maleate (CPM) from its matrix tablets prepared by direct compression. Methods: Different ratios of compritol and kollidon SR (containing 50 % matrix component) in 1:1, 1:2, 1:3 and 3:1 ratios were formulated using direct compression. The formulations were organoleptically tested and investigated for CPM release. Results: The release kinetics showed Fickian diffusion mode for kollidone and anomalous release mechanism for compritol matrices. Combining compritol as a lipophilic material and kollidone produced a matrix with controlled drug release. Retardation of drug release rate depended on the ratio of compritol to kollidon. The lower the compritol component, the slower the drug release rate. CPM in matrix tablets containing compritol:kollidone SR in a ratio of 1: 3 achieved optimized sustained release, where 44 % of the drug was released within 8 h (versus 94.5 % for compritol and 54.2 % for kollidon matrix systems). The kinetics of drug release followed Fickian diffusion at low compritol concentration in the blend, reflecting the importance of pore formation. However, when compritol proportion was increased, drug release followed non-Fickian anomalous kinetics due to the water-repelling effect of compritol. Conclusion: Compritol content of CPM matrix tablets can be used to modulate drug release rate as well as release kinetics.

Nimesulide sustained release matrix pellets containing 10 % w/w of the drug were prepared using an extrusion-spheronization technique. Different polymers, ethyl cellulose, Kollicoat, mannitol, lactose and polyethylene glycol (PEG 2000), were mixed at different weight ratios (5, 10 and 20 % w/w) with Avicel PH 101. Mixer torque rheometer (MTR) was used to quantitatively determine the suitable pellets’ moisture content before the extrusion process. The studies revealed that magnitude of torque decreased as the polymer concentration increased. The in vitro release of nimesulide from pellets was dependent upon the type and concentration of the added polymer, which affected the peak torque of the wet mass. In conclusion, the formulation of nimesulide sustained release matrix pellets successfully controlled the drug release, which might be beneficial in lowering the risk of side effects and improving patient convenience as an advantage of the pellets as a drug delivery system.

Nimesulide sustained release matrix pellets containing 10 % w/w of the drug were prepared using an extrusion-spheronization technique. Different polymers, ethyl cellulose, Kollicoat, mannitol, lactose and polyethylene glycol (PEG 2000), were mixed at different weight ratios (5, 10 and 20 % w/w) with Avicel PH 101. Mixer torque rheometer (MTR) was used to quantitatively determine the suitable pellets’ moisture content before the extrusion process. The studies revealed that magnitude of torque decreased as the polymer concentration increased. The in vitro release of nimesulide from pellets was dependent upon the type and concentration of the added polymer, which affected the peak torque of the wet mass. In conclusion, the formulation of nimesulide sustained release matrix pellets successfully controlled the drug release, which might be beneficial in lowering the risk of side effects and improving patient convenience as an advantage of the pellets as a drug delivery system.

Current development of drug microcarriers is mainly based on spherical shapes, which are not biologically favorable geometries for complex interactions with biological systems. Scalable synthesis of drug carriers with nonspherical and anisotropic shapes featuring sustained drug-releasing performances, biocompatibility, degradability, and sensing capabilities is challenging. These challenges are addressed in this work by employing Nature’s optimized designs obtained from low-cost diatomaceous earth mineral derived from single-cell algae diatoms. Silica diatoms with unique shapes and 3D microcapsule morphology are converted into silicon diatom replicas with identical structure by a magnesiothermic reduction process. The results reveal that prepared silicon diatoms have a set of unique properties including favorable microcapsule structure with high surface area and micro/mesoporosity providing high drug loading, fast biodegradability, and intrinsic luminescence, which make them highly suitable for low-cost production of advanced drug microcarriers. Their sustained drug release >30 days combined with self-reporting function based on silicon luminescence properties using nonluminescent and luminescent drugs for intravitreal drug therapy is successfully demonstrated. These silicon diatoms offer promising potential toward scalable production of low-cost and advanced microcarriers for broad medical therapies, including theranostics and microrobotic guided drug delivery devices.

Current development of drug microcarriers is mainly based on spherical shapes, which are not biologically favorable geometries for complex interactions with biological systems. Scalable synthesis of drug carriers with nonspherical and anisotropic shapes featuring sustained drug-releasing performances, biocompatibility, degradability, and sensing capabilities is challenging. These challenges are addressed in this work by employing Nature’s optimized designs obtained from low-cost diatomaceous earth mineral derived from single-cell algae diatoms. Silica diatoms with unique shapes and 3D microcapsule morphology are converted into silicon diatom replicas with identical structure by a magnesiothermic reduction process. The results reveal that prepared silicon diatoms have a set of unique properties including favorable microcapsule structure with high surface area and micro/mesoporosity providing high drug loading, fast biodegradability, and intrinsic luminescence, which make them highly suitable for low-cost production of advanced drug microcarriers. Their sustained drug release >30 days combined with self-reporting function based on silicon luminescence properties using nonluminescent and luminescent drugs for intravitreal drug therapy is successfully demonstrated. These silicon diatoms offer promising potential toward scalable production of low-cost and advanced microcarriers for broad medical therapies, including theranostics and microrobotic guided drug delivery devices.

Current development of drug microcarriers is mainly based on spherical shapes, which are not biologically favorable geometries for complex interactions with biological systems. Scalable synthesis of drug carriers with nonspherical and anisotropic shapes featuring sustained drug-releasing performances, biocompatibility, degradability, and sensing capabilities is challenging. These challenges are addressed in this work by employing Nature’s optimized designs obtained from low-cost diatomaceous earth mineral derived from single-cell algae diatoms. Silica diatoms with unique shapes and 3D microcapsule morphology are converted into silicon diatom replicas with identical structure by a magnesiothermic reduction process. The results reveal that prepared silicon diatoms have a set of unique properties including favorable microcapsule structure with high surface area and micro/mesoporosity providing high drug loading, fast biodegradability, and intrinsic luminescence, which make them highly suitable for low-cost production of advanced drug microcarriers. Their sustained drug release >30 days combined with self-reporting function based on silicon luminescence properties using nonluminescent and luminescent drugs for intravitreal drug therapy is successfully demonstrated. These silicon diatoms offer promising potential toward scalable production of low-cost and advanced microcarriers for broad medical therapies, including theranostics and microrobotic guided drug delivery devices.

Current development of drug microcarriers is mainly based on spherical shapes, which are not biologically favorable geometries for complex interactions with biological systems. Scalable synthesis of drug carriers with nonspherical and anisotropic shapes featuring sustained drug-releasing performances, biocompatibility, degradability, and sensing capabilities is challenging. These challenges are addressed in this work by employing Nature’s optimized designs obtained from low-cost diatomaceous earth mineral derived from single-cell algae diatoms. Silica diatoms with unique shapes and 3D microcapsule morphology are converted into silicon diatom replicas with identical structure by a magnesiothermic reduction process. The results reveal that prepared silicon diatoms have a set of unique properties including favorable microcapsule structure with high surface area and micro/mesoporosity providing high drug loading, fast biodegradability, and intrinsic luminescence, which make them highly suitable for low-cost production of advanced drug microcarriers. Their sustained drug release >30 days combined with self-reporting function based on silicon luminescence properties using nonluminescent and luminescent drugs for intravitreal drug therapy is successfully demonstrated. These silicon diatoms offer promising potential toward scalable production of low-cost and advanced microcarriers for broad medical therapies, including theranostics and microrobotic guided drug delivery devices.

Aims: Conventional chitosan nanoparticles (CSNPs) exhibit high encapsulation efficiency for hydrophilic drugs but lack substantial payload capacity for lipophilic drugs. This study explores fabrication of a novel lipid/chitosan nanocomposite suitable for combination therapy using hydrophilic and lipophilic drugs. Methodology: Lipid coating of prefabricated CSNPs that were prepared by ionotropic gelation with tripolyphosphate (TPP) was accomplished in 0.1 M acetate buffer, pH 5.3, using an equimolar mixture of 1, 2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and L-α-dipalmitoylphosphatidyl glycerol (DPPG) or DPPC only. Dynamic laser light scattering (DLS) was used to monitor particle size distribution and zeta potential. Results: Rapid addition of TPP to chitosan (CS) solution prepared in acetate buffer at a final TPP/CS = 0.3:1 (g/g) reproducibly resulted in CSNPs with a mean hydrodynamic diameter of 82.8±1.7 nm and a zeta potential of +20.5±1.2 mV. Hydration of dried phospholipid films using this CSNP suspension progressively increased mean particle size of colloids up to 613.5±13 nm depending on lipid composition and lipid concentration applied. Zeta potential of DPPC/CS nanocomposites was significantly reduced to +8.7±0.1 mV, whereas surface charge of (DPPC/DPPG, 50:50)/CS nanocomposites remained unchanged between +18.8 and +21.6 mV, respectively. Conclusion: Physicochemical assessment of lipid/CS nanocomposites prepared by thin film hydration suggests successful surface immobilization of zwitterionic DPPC on prefabricated CSNPs. The presence of this additional lipid layer surrounding the hydrophilic CS core is predicted to facilitate effective encapsulation of lipophilic drugs enabling combination therapy with hydrophilic and hydrophobic payloads using a single nanodelivery system.