A Comparative Study of the Pharmaceutical Properties between Amorphous Drugs Loaded-Mesoporous Silica and Pure Amorphous Drugs Prepared by Solvent Evaporation

Exploring the Transformative Potential of Functionalized Mesoporous Silica in Enhancing Antioxidant Activity: A Comprehensive Review

Antioxidants are essential for reducing oxidative stress, protecting cells from damage, and supporting overall well-being. Functionalized mesoporous silica materials have garnered interest due to their flexible uses in diverse domains, such as drug delivery systems. This review aims to thoroughly examine and evaluate the progress made in utilizing functionalized mesoporous silica materials as a possible approach to enhancing antioxidant activity. The authors performed a thorough search of reliable databases, including Scopus, PubMed, Google Scholar, and Clarivate Web of Science, using precise keywords linked to functionalized mesoporous silica nanoparticles and antioxidants. The identified journals serve as the major framework for the main discussion in this study. Functionalized mesoporous silica nanoparticles have been reported to greatly enhance antioxidant activity by allowing for an increased loading capacity, controlled release behavior, the targeting of specific drugs, improved biocompatibility and safety, and enhanced penetration. The results emphasize the significant capacity of functionalized mesoporous silica (FSM) to bring about profound changes in a wide range of applications. FSM materials can be designed as versatile nanocarriers, integrating intrinsic antioxidant capabilities and augmenting the efficacy of current drugs, offering substantial progress in antioxidant therapies and drug delivery systems, as well as enhanced substance properties in the pharmaceutical field. Functionalized mesoporous silica materials are a highly effective method for enhancing antioxidant activity. They provide new opportunities for the advancement of cutting-edge treatments and materials in the field of antioxidant research. The significant potential of FSM materials to change drug delivery methods and improve substance properties highlights their crucial role in future breakthroughs in the pharmaceutical field and antioxidant applications.

Physicochemical Characterization of Hydroxyapatite Hybrids with Meloxicam for Dissolution Rate Improvement

Organic-inorganic hybrids represent a good solution to improve the solubility and dissolution rates of poorly soluble drugs whose number has been increasing in the last few years. One of the most diffused inorganic matrices is hydroxyapatite (HAP), which is a biocompatible and osteoconductive material. However, the understanding of the hybrids' functioning mechanisms is in many cases limited; thus, thorough physicochemical characterizations are needed. In the present paper, we prepared hybrids of pure and Mg-doped hydroxyapatite with meloxicam, a drug pertaining to the Biopharmaceutical Classification System (BCS) class II, i.e., drugs with low solubility and high permeability. The hybrids' formation was demonstrated by FT-IR, which suggested electrostatic interactions between HAP and drug. The substitution of Mg in the HAP structure mainly produced a structural disorder and a reduction in crystallite sizes. The surface area of HAP increased after Mg doping from 82 to 103 m2g-1 as well as the pore volume, justifying the slightly high drug amount adsorbed by the Mg hybrid. Notwithstanding the low drug loading on the hybrids, the solubility, dissolution profiles and wettability markedly improved with respect to the drug alone, particularly for the Mg doped one, which was probably due to the main distribution of the drug on the HAP surface.

Lipid-coated nanocrystals of paclitaxel as dry powder for inhalation: Characterization, in-vitro performance, and pharmacokinetic assessment

BACKGROUND

Nanocrystals can be produced as a dry powder for inhalation (DPIs) to deliver high doses of drug to the lungs, owing to their high payload and stability to the shear stress of aerosolization force. Furthermore, lipid-coated nanocrystals can be formulated to improve the drug accumulation and retention in lung.

OBJECTIVE

The present work involved the fabrication of paclitaxel nanocrystals using hydrophilic marine biopolymer fucoidan as a stabilizer. Thereafter, fabricated nanocrystals (FPNC) were surface-modified with phospholipid to give lipid-coated nanocrystals (Lipo-NCs).

METHODS

The nanocrystals were fabricated by antisolvent crystallization followed by the probe sonication. The lipid coating was achieved by thin film hydration followed ultrasonic dispersion technique. Prepared nanocrystals were lyophilized to obtain a dry powder of FPNC and Lipo-NCs, used later for physicochemical, microscopic, and spectroscopic characterization to confirm the successful formation of desired nanocrystals. In-vitro and in-vivo investigations were also conducted to determine the role of nanocrystal powder in pulmonary drug delivery.

RESULTS

Lipo-NCs exhibited slower drug release, excellent flow properties, good aerosolization performance, higher drug distribution, and prolonged retention in the lungs compared to FPNC and pure PTX.

CONCLUSION

Lipid-coated nanocrystals can be a novel formulation for the maximum localization of drugs in the lungs, thereby enhancing therapeutic effects and avoiding systemic side effects in lung cancer therapy.

Characterization of Drug with Good Glass-Forming Ability Loaded Mesoporous Silica Nanoparticles and Its Impact Toward in vitro and in vivo Studies

Solid oral dosage forms are mostly preferred in pharmaceutical formulation development due to patient convenience, ease of product handling, high throughput, low manufacturing costs, with good physical and chemical stability. However, 70% of drug candidates have poor water solubility leading to compromised bioavailability. This phenomenon occurs because drug molecules are often absorbed after dissolving in gastrointestinal fluid. To address this limitation, delivery systems designed to improve the pharmacokinetics of drug molecules are needed to allow controlled release and target-specific delivery. Among various strategies, amorphous formulations show significantly high potential, particularly for molecules with solubility-limited dissolution rates. The ease of drug molecules to amorphized is known as their glass-forming ability (GFA). Specifically, drug molecules categorized into class III based on the Taylor classification have a low recrystallization tendency and high GFA after cooling, with substantial "glass stability" when heated. In the last decades, the application of mesoporous silica nanoparticles (MSNs) as drug delivery systems (DDS) has gained significant attention in various investigations and the pharmaceutical industry. This is attributed to the unique physicochemical properties of MSNs, including high loading capacity, recrystallization inhibition, excellent biocompatibility, and easy functionalization. Therefore, this study aimed to discuss the current state of good glass former drug loaded mesoporous silica and shows its impact on the pharmaceutical properties including dissolution and physical stability, along with in vivo study. The results show the importance of determining whether mesoporous structures are needed in amorphous formulations to improve the pharmaceutical properties of drug with a favorable GFA.

Elucidation of Molecular Interactions Between Drug-Polymer in Amorphous Solid Dispersion by a Computational Approach Using Molecular Dynamics Simulations

Introduction

Amorphous drug dispersion is frequently used to enhance the solubility and dissolution of poorly water-soluble drugs, thereby improving their oral bioavailability. The dispersion of these drugs into polymer matrix can inhibit their recrystallization. The inter-molecular interactions between drug and polymer plays a role in the improvement of the dissolution rate, solubility, and physical stability of drug.

Aim

This study aims to investigate the formation and interactions of ritonavir (RTV)/poloxamer (PLX) amorphous formulation using a computational approach via molecular dynamics (MD) simulations, which mimicked solvent evaporation and melt-quenching method.

Methods

TheRoot Mean Square Deviation (RMSD) value, Root Mean Square Fluctuation (RMSF), Radial Distribution Function (RDF), Radius of Gyration (Rg), Solvent Accessible Surface Area (SASA), and hydrogen bond interactions were analyzed to determine interaction mechanisms between RTV and PLX in amorphous solid dispersion.

Results

The pi-alkyl bonds between RTV and PLX were formed after simulations of solvent evaporation, while the hydrogen bond interactions of RTV-PLX was observed during melt method simulations. These results indicate the successful formulation of amorphous solid dispersion (ASD) from RTV and PLX. The RMSD values obtained from the solvent evaporation, melt-cooling-A, melt-cooling-B, and melt-cooling-C methods were 3.33 Å, 1.97 Å, 1.30 Å, and 1.29 Å, respectively, while the average RMSF values were 2.65 Å, 1.04 Å, 1.05 Å, and 1.07 Å, respectively. This indicates that the suppression of translational motion of RTV from the melt method can be stronger than solvent evaporation caused by the intermolecular interactions of RTV-PLX.

Conclusion

MD simulations helped in understanding the formation and interaction mechanisms of ASD formulations that were difficult to detect by experimental approaches.

Effect of Drug-Polymer Interaction in Amorphous Solid Dispersion on the Physical Stability and Dissolution of Drugs: The Case of Alpha-Mangostin

Improving drug solubility is necessary for formulations of poorly water-soluble drugs, especially for oral administration. Amorphous solid dispersions (ASDs) are widely used in the pharmaceutical industry to improve the physical stability and solubility of drugs. Therefore, this study aims to characterize interaction between a drug and polymer in ASD, as well as evaluate the impact on the physical stability and dissolution of alpha-mangostin (AM). AM was used as a model of a poorly water-soluble drug, while polyvinylpyrrolidone (PVP) and eudragit were used as polymers. The amorphization of AM-eudragit and AM-PVP was confirmed as having a halo pattern with powder X-ray diffraction measurements and the absence of an AM melting peak in the differential scanning calorimetry (DSC) curve. The solubility of amorphous AM increased in the presence of either eudragit or PVP due to amorphization and interactions of AM-polymer. Furthermore, FT-IR spectroscopy and in silico studies revealed hydrogen bond interactions between the carbonyl group of AM and the proton of eudragit as well as PVP. AM-eudragit with a ratio of 1:1 recrystallized after 7 days of storage at 25 °C and 90% RH, while the AM-PVP 1:4 and 1:10 samples retained the X-ray halo patterns, even under humid conditions. In a dissolution test, the presence of polymer in ASD significantly improved the dissolution profile due to the intermolecular interaction of AM-polymer. AM-eudragit 1:4 maintained AM supersaturation for a longer time compared to the 1:1 sample. However, a high supersaturation was not achieved in AM-PVP 1:10 due to the formation of large agglomerations, leading to a slow dissolution rate. Based on the results, interaction of AM-polymer in ASD can significantly improve the pharmaceutical properties of AM including the physical stability and dissolution.

Supersaturation and Precipitation Applicated in Drug Delivery Systems: Development Strategies and Evaluation Approaches

Supersaturation is a promising strategy to improve gastrointestinal absorption of poorly water-soluble drugs. Supersaturation is a metastable state and therefore dissolved drugs often quickly precipitate again. Precipitation inhibitors can prolong the metastable state. Supersaturating drug delivery systems (SDDS) are commonly formulated with precipitation inhibitors, hence the supersaturation is effectively prolonged for absorption, leading to improved bioavailability. This review summarizes the theory of and systemic insight into supersaturation, with the emphasis on biopharmaceutical aspects. Supersaturation research has developed from the generation of supersaturation (pH-shift, prodrug and SDDS) and the inhibition of precipitation (the mechanism of precipitation, the character of precipitation inhibitors and screening precipitation inhibitors). Then, the evaluation approaches to SDDS are discussed, including in vitro, in vivo and in silico studies and in vitro-in vivo correlations. In vitro aspects involve biorelevant medium, biomimetic apparatus and characterization instruments; in vivo aspects involve oral absorption, intestinal perfusion and intestinal content aspiration and in silico aspects involve molecular dynamics simulation and pharmacokinetic simulation. More physiological data of in vitro studies should be taken into account to simulate the in vivo environment. The supersaturation theory should be further completed, especially with regard to physiological conditions.