How Does the Addition of Kollidon®VA64 Inhibit the Recrystallization and Improve Ezetimibe Dissolution from Amorphous Solid Dispersions?

Investigation of Stabilized Amorphous Solid Dispersions to Improve Oral Olaparib Absorption

In this study, we investigated the formulation of stable solid dispersions to enhance the bioavailability of olaparib (OLA), a therapeutic agent for ovarian cancer and breast cancer characterized as a BCS class IV drug with low solubility and low permeability. Various polymers were screened based on solubility tests, and OLA-loaded solid dispersions were prepared using spray drying. The physicochemical properties of these dispersions were investigated via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier Transform Infrared Spectroscopy (FT-IR). Subsequent dissolution tests, along with assessments of morphological and crystallinity changes in aqueous solutions, led to the selection of a hypromellose (HPMC)-based OLA solid dispersion as the optimal formulation. HPMC was effective at maintaining the supersaturation of OLA in aqueous solutions and exhibited a stable amorphous state without recrystallization. In an in vivo study, this HPMC-based OLA solid dispersion significantly enhanced bioavailability, increasing AUC0-24 by 4.19-fold and Cmax by more than 10.68-fold compared to OLA drug powder (crystalline OLA). Our results highlight the effectiveness of HPMC-based solid dispersions in enhancing the oral bioavailability of OLA and suggest that they could be an effective tool for the development of oral drug formulations.

Enhancing hepatoprotective action: oxyberberine amorphous solid dispersion system targeting TLR4

Oxyberberine (OBB) is a significant natural compound, with excellent hepatoprotective properties. However, the poor water solubility of OBB hinders its release and absorption thus resulting in low bioavailability. To overcome these drawbacks of OBB, amorphous spray-dried powders (ASDs) of OBB were formulated. The dissolution, characterizations, and pharmacokinetics of OBB-ASDs formulation were investigated, and its hepatoprotective action was disquisitive in the D-GalN/LPS-induced acute liver injury (ALI) mouse model. The characterizations of OBB-ASDs indicated that the crystalline form of OBB active pharmaceutical ingredients (API) was changed into an amorphous form in OBB-ASDs. More importantly, OBB-ASDs showed a higher bioavailability than OBB API. In addition, OBB-ASDs treatment restored abnormal histopathological changes, improved liver functions, and relieved hepatic inflammatory mediators and oxidative stress in ALI mice. The spray drying techniques produced an amorphous form of OBB, which could significantly enhance the bioavailability and exhibit excellent hepatoprotective effects, indicating that the OBB-ASDs can exhibit further potential in hepatoprotective drug delivery systems. Our results provide guidance for improving the bioavailability and pharmacological activities of other compounds, especially insoluble natural compounds. Meanwhile, the successful development of OBB-ASDs could shed new light on the research process of poorly soluble medicine.

Nanoparticles Targeting Lymph Nodes for Cancer Immunotherapy: Strategies and Influencing Factors

Immunotherapy has emerged as a potent strategy in cancer treatment, with many approved drugs and modalities in the development stages. Despite its promise, immunotherapy is not without its limitations, including side effects and suboptimal efficacy. Using nanoparticles (NPs) as delivery vehicles to target immunotherapy to lymph nodes (LNs) can improve the efficacy of immunotherapy drugs and reduce side effects in patients. In this context, this paper reviews the development of LN-targeted immunotherapeutic NP strategies, the mechanisms of NP transport during LN targeting, and their related biosafety risks. NP targeting of LNs involves either passive targeting, influenced by NP physical properties, or active targeting, facilitated by affinity ligands on NP surfaces, while alternative methods, such as intranodal injection and high endothelial venule (HEV) targeting, have uncertain clinical applicability and require further research and validation. LN targeting of NPs for immunotherapy can reduce side effects and increase biocompatibility, but risks such as toxicity, organ accumulation, and oxidative stress remain, although strategies such as biodegradable biomacromolecules, polyethylene glycol (PEG) coating, and impurity addition can mitigate these risks. Additionally, this work concludes with a future-oriented discussion, offering critical insights into the field.

Preparation of astaxanthin-loaded composite micelles with coaxial electrospray technology for enhanced oral bioavailability and improved antioxidation capability

BACKGROUND

Astaxanthin (AST) is approved by the US Food and Drug Administration (FDA) as a safe dietary supplement for humans. As a potent lipid-soluble keto-carotenoid, it is widely used in food, cosmetics, and the pharmaceutical industry. However, its low solubility limits its powerful biological activity and its application in these fields. This study aims to develop a delivery system to address the low solubility and bioavailability of AST and to enhance its antioxidant capacity.

RESULTS

Astaxanthin-loaded composite micelles were successfully prepared via coaxial electrospray technology. Astaxanthin existed in the amorphous state in the electro-sprayed formulation with an approximate particle size of 186.28 nm and with a polydispersity index of 0.243. In this delivery system, Soluplus and copovidone (PVPVA 64) were the main polymeric matrix for AST, which then released the drug upon contact with aqueous media, resulting in an overall increase in drug solubility and a release rate of 94.08%. Meanwhile, lecithin, and Polyethylene glycol-grafted Chitosan (PEG-g-CS) could support the absorption of AST in the gastrointestinal tract, assisting transmembrane transport. The relative bioavailability reached about 308.33% and the reactive oxygen species (ROS) scavenging efficiency of the formulation was 44.10%, which was 1.57 times higher than that of free astaxanthin (28.10%) when both were at the same concentration level based on astaxanthin.

CONCLUSION

Coaxial electrospray could be applied to prepare a composite micelles system for the delivery of poorly water-soluble active ingredients in functional food, cosmetics, and medicine. © 2023 Society of Chemical Industry.

Solid amorphous formulations for enhancing solubility and inhibiting Erlotinib crystallization during gastric-to-intestinal transfer

The objective of this study was to improve the solubility and inhibit the crystallisation during the gastric-to-intestinal transfer of Erlotinib (ERL), a small molecule kinase inhibitor (smKI) compound class, which is classified as class II drug in the Biopharmaceutical Classification System (BCS). A screening approach combining different parameters (solubility in aqueous media, inhibitory effect of drug crystallisation from supersaturated drug solutions) was applied to selected polymers for the development of solid amorphous dispersions of ERL. ERL solid amorphous dispersions formulations were then prepared with 3 different polymers (Soluplus®, HPMC-AS-L, HPMC-AS-H) at a fixed drug: polymer ratio (1:4) by two different production methods (spray drying and hot melt extrusion). The spray-dried particles and cryo-milled extrudates were characterized by thermal properties, shape and particle size, solubility and dissolution behavior in aqueous media. The influence of the manufacturing process on these solid characteristics was also identified during this study. Based on the obtained results, it is concluded that the cryo-milled extrudates of HPMC-AS-L displayed better performance (enhanced solubility, reduced ERL crystallization during the simulated gastric-to-intestinal transfer) and represents a promising amorphous solid dispersion formulation for oral administration of ERL.

Hot Melt Extrusion for Improving the Physicochemical Properties of Polydatin Derived from Polygoni cuspidati Extract; A Solution Recommended for Buccal Applications

Three different types of solid dispersions based on polyvinyl polymers and related copolymers (Kollidon® VA64, Soluplus® and Kollicoat IR®) comprising polydatin-rich Polygoni cuspidati extract were prepared by hot melt extrusion. The systems were characterized using X-ray powder diffraction, infrared spectroscopy as well as by polydatin release and in vitro permeability. Mucoadhesive tablets were prepared from the extrudates based on Kollidon® VA64 and Soluplus® to obtain a suitable pharmaceutical form, where (hydroxypropyl)methyl cellulose was added as a mucoadhesive agent. The tablets were evaluated in terms of the kinetics of polydatin release as well as their mucoadhesive properties. The best tabletability properties, polydatin release profile and adequate mucoadhesive properties were obtained by the formulation containing the Kollidon® VA64-based extrudate, which makes it an excellent prototype for enhancing the release of poorly water-soluble compounds.

Advances in the development of amorphous solid dispersions: The role of polymeric carriers

Amorphous solid dispersion (ASD) is one of the most effective approaches for delivering poorly soluble drugs. In ASDs, polymeric materials serve as the carriers in which the drugs are dispersed at the molecular level. To prepare the solid dispersions, there are many polymers with various physicochemical and thermochemical characteristics available for use in ASD formulations. Polymer selection is of great importance because it influences the stability, solubility and dissolution rates, manufacturing process, and bioavailability of the ASD. This review article provides a comprehensive overview of ASDs from the perspectives of physicochemical characteristics of polymers, formulation designs and preparation methods. Furthermore, considerations of safety and regulatory requirements along with the studies recommended for characterizing and evaluating polymeric carriers are briefly discussed.

Amorphous System of Hesperetin and Piperine-Improvement of Apparent Solubility, Permeability, and Biological Activities

The low bioaccessibility of hesperetin and piperine hampers their application as therapeutic agents. Piperine has the ability to improve the bioavailability of many compounds when co-administered. The aim of this paper was to prepare and characterize the amorphous dispersions of hesperetin and piperine, which could help to improve solubility and boost the bioavailability of both plant-origin active compounds. The amorphous systems were successfully obtained by means of ball milling, as confirmed by XRPD and DSC studies. What's more, the FT-IR-ATR study was used to investigate the presence of intermolecular interactions between the systems' components. Amorphization enhanced the dissolution rate as a supersaturation state was reached, as well as improving the apparent solubility of both compounds by 245-fold and 183-fold, respectively, for hesperetin and piperine. In the in vitro permeability studies simulating gastrointestinal tract and blood-brain barrier permeabilities, these increased by 775-fold and 257-fold for hesperetin, whereas they were 68-fold and 66-fold for piperine in the GIT and BBB PAMPA models, respectively. Enhanced solubility had an advantageous impact on antioxidant as well as anti-butyrylcholinesterase activities-the best system inhibited 90.62 ± 0.58% of DPPH radicals and 87.57 ± 1.02% butyrylcholinesterase activity. To sum up, amorphization considerably improved the dissolution rate, apparent solubility, permeability, and biological activities of hesperetin and piperine.

Considerations in the Development of Physically Stable High Drug Load API- Polymer Amorphous Solid Dispersions in the Glassy State

In this Commentary, the authors expand on their earlier studies of the solid-state long-term isothermal crystallization of amorphous API from the glassy state in amorphous solid dispersions, and focus on the effects of polymer concentration, and its implications for producing high load API doses with minimum polymer concentration. After presenting an overview of the various mechanistic factors which influence the ability of polymers to inhibit API crystallization, including the chemical structure of the polymer relative to the API, the nature and strength of API-polymer noncovalent interactions, polymer molecular weight, impact on primary diffusive molecular mobility, as well as on secondary motions in the bulk and surface phases of the glass, we consider in more detail, the effects of polymer concentration. Here, we examine the factors that appear to allow relatively low polymer concentrations, i.e., less than 10%w/w polymer, to greatly reduce crystallization, including a focus on the heterogeneous structure of the glassy state, and the possible spatial distribution and concentration of polymer in certain key regions of the glass. This is followed by a review and analysis of examples in the recent literature focused on determining the minimum polymer concentration in an amorphous solid dispersion, capable of producing optimally stable high drug load amorphous dispersions.

Evaluation of Different Thermoanalytical Methods for the Analysis of the Stability of Naproxen-Loaded Amorphous Solid Dispersions

The aim of this research was to investigate three thermoanalytical techniques from the glass transition temperature (T_g) determination point of view. In addition, the examination of the correlation between the measured T_g values and the stability of the amorphous solid dispersions (ASDs) was also an important part of the work. The results showed that a similar tendency of the T_g can be observed in the case of the applied methods. However, T_g values measured by thermally stimulated depolarization currents showed higher deviation from the theoretical calculations than the values measured by modulated differential scanning calorimetry, referring better to the drug-polymer interactions. Indeed, the investigations after the stress stability tests revealed that micro-thermal analysis can indicate the most sensitive changes in the T_g values, better indicating the instability of the samples. In addition to confirming that the active pharmaceutical ingredient content is a crucial factor in the stability of ASDs containing naproxen and poly(vinylpyrrolidone-co-vinyl acetate), it is worthwhile applying orthogonal techniques to better understand the behavior of ASDs. The development of stable ASDs can be facilitated via mapping the molecular mobilities with suitable thermoanalytical methods.

3D printed oral solid dosage form: Modified release and improved solubility

Oral solid dosage form is currently the most common used form of drug. 3D Printing, also known as additive manufacturing (AM), can quickly print customized and individualized oral solid dosage form on demand. Compared with the traditional tablet manufacturing process, 3D Printing has many advantages. By rationally selecting the formulation composition and cleverly designing the printing structure, 3D printing can improve the solubility of the drug and achieve precise modify of the drug release. 3D printed oral solid dosage form, however, still has problems such as limitations in formulation selection. And the selection process of the formulation lacks scientificity and standardization. Structural design of some 3D printing approaches is relatively scarce. This article reviews the formulation selection and structure design of 3D printed oral solid dosage form, providing more ideas for achieving modified drug release and solubility improvement of 3D printed oral solid dosage form through more scientific and extensive formulation selection and more sophisticated structural design.

The Effect of Various Poly (N-vinylpyrrolidone) (PVP) Polymers on the Crystallization of Flutamide

In this study, several experimental techniques were applied to probe thermal properties, molecular dynamics, crystallization kinetics and intermolecular interactions in binary mixtures (BMs) composed of flutamide (FL) and various poly(N-vinylpyrrolidone) (PVP) polymers, including a commercial product and, importantly, samples obtained from high-pressure syntheses, which differ in microstructure (defined by the tacticity of the macromolecule) from the commercial PVP. Differential Scanning Calorimetry (DSC) studies revealed a particularly large difference between the glass transition temperature (T_g) of FL+PVPsynth. mixtures with 10 and 30 wt% of the excipient. In the case of the FL+PVPcomm. system, this effect was significantly lower. Such unexpected findings for the former mixtures were strictly connected to the variation of the microstructure of the polymer. Moreover, combined DSC and dielectric measurements showed that the onset of FL crystallization is significantly suppressed in the BM composed of the synthesized polymers. Further non-isothermal DSC investigations carried out on various FL+10 wt% PVP mixtures revealed a slowing down of FL crystallization in all FL-based systems (the best inhibitor of this process was PVP M_n = 190 kg/mol). Our research indicated a significant contribution of the microstructure of the polymer on the physical stability of the pharmaceutical—an issue completely overlooked in the literature.

Fabrication of a Shell-Core Fixed-Dose Combination Tablet Using Fused Deposition Modeling 3D Printing

Fixed-dose combinations (FDCs) achieve optimal goals for treatment with minimal side effects, decreased administration of large number of tablets, thus, greater convenience, and improved patient compliance. However, conventional FDCs do not have a guaranteed place in the future of patient-centered drug development because of the difficulty in achieving dose titration of each drug for individualized specific health needs and desired therapeutic outcomes. In the current study, FDCs of two antihypertensive drugs were fabricated with two distinct compartments using fused deposition modeling three-dimensional printing (FDM-3DP). Atorvastatin calcium and Amlodipine besylate loaded filaments were prepared by hot-melt extrusion. Shell-core FDC tablets were designed to have different infills for individualized dosing. Differential scanning calorimetry and powder X-ray diffraction revealed that both drugs were transformed into amorphous forms within the polymeric carriers. The fabricated tablets met the United States Pharmacopeia acceptance criteria for friability, content uniformity, and dissolution testing. The fabricated tablets were stable at room temperature with respect to drug content and thermal behavior over six months. This dynamic dosage form provides flexibility in dose titration and maintains the advantages of FDCs, thus achieving optimal therapeutic outcomes in different healthcare facilities.

Solubility and Permeability Enhancement of Oleanolic Acid by Solid Dispersion in Poloxamers and γ-CD

Oleanolic acid (OA) is a pentacyclic triterpenoid widely found in the Oleaceae family, and it represents 3.5% of the dry weight of olive leaves. OA has many pharmacological activities, such as hepatoprotection, anti-inflammatory, anti-oxidant, anti-diabetic, anti-tumor, and anti-microbic activities. Its therapeutic application is limited by its poor water solubility, bioavailability, and permeability. In this study, solid dispersions (SDs) were developed to overcome these OA limitations. Solubility studies were conducted to evaluate different hydrophilic polymers, drug-to-polymer ratios, and preparation methods. Poloxamer 188, Poloxamer 407, and γ-CD exhibited the highest increases in terms of OA solubility, regardless of the method of preparation. Binary systems were characterized using differential scanning calorimetry (DSC), X-ray diffraction (XRPD), and Fourier transform infrared spectroscopy (FTIR). In addition, pure compounds and SDs were analyzed using scanning electron microscopy (SEM) in order to observe both the morphology and the particle surface. In vitro dissolution studies were performed for P407, P188, and γ-CD SDs. Preparation using the solvent evaporation method (SEM) produced the highest increase in the dissolution profiles of all three polymers with respect to the OA solution. Finally, the effect of SDs on OA permeability was evaluated with an in vitro parallel artificial membrane permeability assay (PAMPA). The formulation improved passive permeation across the simulated barrier due to OA increased solubility. The dissolution and PAMPA results indicate that the amorphization of OA by SD preparation could be a useful method to enhance its oral absorption, and it is also applicable on an industrial scale.

Multi-directionally evaluating the formation mechanism of 1,4-dihydropyridine drug nanosuspensions through experimental validation and computer-aided drug design

The poor aqueous solubility of 1,4-dihydropyridine drugs needs to be solved urgently to improve the bioavailability. Nanotechnology can improve drug solubility and dissolution by reducing particle size, but usually a specific polymer or surfactant is required for stabilization. In this study, Poloxamer-407(P-407) was screened as the optimal stabilize through energy simulation, molecular docking and particle size. morphological study, X-ray diffraction, differential scanning calorimetry, Fourier transform infrared spectroscopy, Raman, in vitro dissolution test and molecular simulation of interactions were utilized to explore the formation mechanisms of four 1,4-dihydropyridine drugs/P-407 nanosuspensions. The result shows that the optimized nanosuspensions had the particle size in the nano-size range and maintained the original crystal state. The in vitro dissolution rate of the nanosuspension was 3-4 times higher than the corresponding API and could reduce the restriction of drug dissolution in different pH environments. Raman spectroscopy, FTIR and molecular docking simulations provided strong supporting evidence for the formation mechanism of 1,4-dihydropyridine drugs/P-407 nanosuspensions at the molecular level, which confirmed that the stable intermolecular hydrogen bond adsorption and hydrophobic interaction were formed between the drug and P-407. This research will provide practical concepts and technologies, which are helpful to develop nanosuspensions for the same class of drugs.

Tablet Disintegration and Dispersion under In Vivo-like Hydrodynamic Conditions

Disintegration and dispersion are functional properties of tablets relevant for the desired API release. The standard disintegration test (SDT) described in different pharmacopoeias provides only limited information on these complex processes. It is considered not to be comparable to the biorelevant conditions due to the frequent occurrence of high hydrodynamic forces, among other reasons. In this study, 3D tomographic laser-induced fluorescence imaging (3D Tomo-LIF) is applied to analyse tablet disintegration and dispersion. Disintegration time (DT) and time-resolved particle size distribution in close proximity to the tablet are determined in a continuously operated flow channel, adjustable to very low fluid velocities. A case study on tablets of different porosity, which are composed of pharmaceutical polymers labelled with a fluorescent dye, a filler, and disintegrants, is presented to demonstrate the functionality and precision of the novel method. DT results from 3D Tomo-LIF are compared with results from the SDT, confirming the analytical limitations of the pharmacopoeial disintegration test. Results from the 3D Tomo-LIF method proved a strong impact of fluid velocity on disintegration and dispersion. Generally, shorter DTs were determined when cross-linked sodium carboxymethly cellulose (NaCMCXL) was used as disintegrant compared to polyvinyl polypyrrolidone (PVPP). Tablets containing Kollidon VA64 were found to disintegrate by surface erosion. The novel method provides an in-depth understanding of the functional behaviour of the tablet material, composition and structural properties under in vivo-like hydrodynamic forces regarding disintegration and the temporal progress of dispersion. We consider the 3D Tomo-LIF in vitro method to be of improved biorelevance in terms of hydrodynamic conditions in the human stomach.

Preparation and Characterization of pH-Independent Sustained-Release Tablets Containing Hot Melt Extruded Solid Dispersions of Clarithromycin : Tablets Containing Solid Dispersions of Clarithromycin

The limited solubility of clarithromycin (CAM), coupled with low bioavailability and rapid elimination, are major shortcomings, needed to be addressed to achieve optimum therapeutic goals. Therefore, sustained-release (SR) tablets containing solid dispersion (SD) granules of CAM were prepared in this study. Initially, SD granules of CAM were prepared by hot melt extrusion (HME) technique using Kollidon VA64 as a hydrophilic carrier. The saturation solubility of SD showed almost 4.5-fold increase as compared to pure CAM in pH 6.8 medium. In vitro drug dissolution data indicated a substantial increase in the dissolution of SD as compared to that of pure CAM. The thermal stability of drug, carrier, and SD at elevated HME temperatures was evident from the results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Powder X-ray diffraction (PXRD) data and scanning electron microscope (SEM) images revealed a decrease in the crystallinity and the uniform dispersion of drug, respectively. Moreover, Fourier transformed infrared spectroscopy (FT-IR) data confirmed the formation of hydrogen bond between the carbonyl group of drug and the hydroxyl group of carrier. SD loaded sustained-release (SD-SR) matrix tablets were prepared with hydrophobic polymers (Eudragit RS100 and Eudragit RL100). The pH-independent swelling and permeability of both polymers were responsible for the sustained drug release from SD-SR tablets. Pharmacokinetic (PK) studies suggested a 3.4-fold increase in the relative bioavailability of SD-SR tablets as compared to that of pure CAM.

Enhanced Dissolution of Sildenafil Citrate Using Solid Dispersion with Hydrophilic Polymers: Physicochemical Characterization and In Vivo Sexual Behavior Studies in Male Rats

Sildenafil citrate (SLC) is a frequently used medication (Viagra®) for the treatment of erectile dysfunction (ED). Due to its poor solubility, SLC suffers from a delayed onset of action and poor bioavailability. Hence, the aim of the proposed work was to prepare and evaluate solid dispersions (SDs) with hydrophilic polymers (Kolliphor® P188, Kollidon® 30, and Kollidon®-VA64), in order to enhance the dissolution and efficacy of SLC. The SLC-SDs were prepared using a solvent evaporation method (at the ratio drug/polymer, 1:1, w/w) and characterized by Differential Scanning Calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscope (SEM), drug content, yield, and in vitro release studies. Based on this evaluation, SDs (SLC-KVA64) were optimized, with a maximum release of drug (99.74%) after 2 h for all the developed formulas. The SDs (SLC-KVA64) were further tested for sexual behavior activity in male rats, and significant enhancements in copulatory efficiency (81.6%) and inter-copulatory efficiency (44.9%) were noted in comparison to the pure SLC drug, when exposed to the optimized SLC-KVA64 formulae. Therefore, SD using Kollidon®-VA64 could be regarded as a potential strategy for improving the solubility, in vitro dissolution, and therapeutic efficacy of SLC.