Preparation, characterization, in vitro and in vivo studies of olmesartan medoxomil in a ternary solid dispersion with N-methyl-D-glucamine and hydroxypropyl-β-cyclodextrin

Host-Guest Interaction Study of Olmesartan Medoxomil with β-Cyclodextrin Derivatives

Olmesartan medoxomil (OLM) is a selective angiotensin II receptor antagonist used in the treatment of hypertension. Its therapeutic potential is limited by its poor water solubility, leading to poor bioavailability. Encapsulation of the drug substance by two methylated cyclodextrins, namely randomly methylated β-cyclodextrin (RM-β-CD) and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CD), was carried out to overcome the limitation related to OLM solubility, which, in turn, is expected to result in an improved biopharmaceutical profile. Supramolecular entities were evaluated by means of thermoanalytical techniques (TG-thermogravimetry; DTG-derivative thermogravimetry), spectroscopic methods including powder X-ray diffractometry (PXRD), universal-attenuated total reflectance Fourier-transform infrared (UATR-FTIR) and UV spectroscopy, saturation solubility studies, and by a theoretical approach using molecular modeling. The phase solubility method reveals an AL-type diagram for both inclusion complexes, indicating a stoichiometry ratio of 1:1. The values of the apparent stability constant indicate the higher stability of the host-guest system OLM/RM-β-CD. The physicochemical properties of the binary systems are different from those of the parent compounds, emphasizing the formation of inclusion complexes between the drug and CDs when the kneading method was used. The molecular encapsulation of OLM in RM-β-CD led to an increase in drug solubility, thus the supramolecular adduct can be the subject of further research to design a new pharmaceutical formulation containing OLM, with improved bioavailability.

Ternary Solid Dispersions: A Review of the Preparation, Characterization, Mechanism of Drug Release, and Physical Stability

The prevalence of active pharmaceutical ingredients (APIs) with low water solubility has experienced a significant increase in recent years. These APIs present challenges in formulation, particularly for oral dosage forms, despite their considerable therapeutic potential. Therefore, the improvement of solubility has become a major concern for pharmaceutical enterprises to increase the bioavailability of APIs. A promising formulation approach that can effectively improve the dissolution profile and the bioavailability of poorly water-soluble drugs is the utilization of amorphous systems. Numerous formulation methods have been developed to enhance poorly water-soluble drugs through amorphization systems, including co-amorphous formulations, amorphous solid dispersions (ASDs), and the use of mesoporous silica as a carrier. Furthermore, the successful enhancement of certain drugs with poor aqueous solubility through amorphization has led to their incorporation into various commercially available preparations, such as ASDs, where the crystalline structure of APIs is transformed into an amorphous state within a hydrophilic matrix. A novel approach, known as ternary solid dispersions (TSDs), has emerged to address the solubility and bioavailability challenges associated with amorphous drugs. Meanwhile, the introduction of a third component in the ASD and co-amorphous systems has demonstrated the potential to improve performance in terms of solubility, physical stability, and processability. This comprehensive review discusses the preparation and characterization of poorly water-soluble drugs in ternary solid dispersions and their mechanisms of drug release and physical stability.

Characterizations of food-derived ellagic acid-Undaria pinnatifida polysaccharides solid dispersion and its benefits on solubility, dispersity and biotransformation of ellagic acid

The current study was aimed to enhance the solubility, dispersibility and biotransformation efficacy of ellagic acid (EA) by preparing food-derived ellagic acid-Undaria pinnatifida polysaccharides solid dispersion (EA/UPP SD). The results demonstrated that the solubility of EA/UPP SD was improved from 0.014 mg/mL to 0.383 mg/mL, and the enhancement was related to converting to a more amorphous state and restraining its self-aggregation during the mechanochemical process. The structure of EA/UPP SDs was mostly maintained by hydrogen bonds and hydrophobic interactions between EA and UPP. Moreover, the result of in vitro anaerobic incubations showed the biotransformation process was improved with EA/UPP SD addition to substrate due to the advance of microbial accessibility in EA dispersion. Altogether, these results indicated that the EA/UPP SDs expanded the application of EA by increasing the solubility and dispersity, and provided a theoretical basis for bioconversion efficiency enhancement.

Mechanochemical Transformations of Polysaccharides: A Systematic Review

Taking into consideration the items of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), this study reviews application of mechanochemical approaches to the modification of polysaccharides. The ability to avoid toxic solvents, initiators, or catalysts during processes is an important characteristic of the considered approach and is in line with current trends in the world. The mechanisms of chemical transformations in solid reactive systems during mechanical activation, the structure and physicochemical properties of the obtained products, their ability to dissolve and swell in different media, to form films and fibers, to self-organize in solution and stabilize nanodispersed inorganic particles and biologically active substances are considered using a number of polysaccharides and their derivatives as examples.

Preparation of protamine-hyaluronic acid coated core-shell nanoparticles for enhanced solubility, permeability, and oral bioavailability of decoquinate

Decoquinate (DQ) has low oral bioavailability owing to its poor water solubility. In this study, a DQ solid dispersion (DQ-SD) was fabricated using mechanochemical technology to encapsulate DQ and improve its oral bioavailability. DQ-SD is easily generated via self-assembly in the aqueous phase to form micelles consisting of disodium glycyrrhizinate (Na₂GA) nanoparticles with a protamine (PRM) and anionic hyaluronic acid (HA) layers. The spherical DQ nanoparticles with an average diameter of 114.95 nm were obtained in an aqueous phase with a critical micelle concentration of 0.157 mg/mL, zeta potential of -38.38 mV, polydispersity index of 0.200, and drug loading of 5.66 %. The dissolution rate and cumulative release of DQ-SD were higher than those of pure DQ. Furthermore, the bioavailability of DQ-SD was approximately 6.3 times higher than that of pure DQ. Pharmacokinetic and biodistribution studies indicated that DQ-SD possessed a significantly higher concentration in the blood and preferential liver tissue accumulation, than that of pure DQ. The developed DQ-SD exhibited considerable potential for developing old DQ for a new application as a hematogenous parasite drug and provides a reference for developing more efficient delivery systems for hydrophobic bioactive agents.

Solid dispersions based on chitosan/hypromellose phthalate blends to modulate pharmaceutical properties of zidovudine

Zidovudine (AZT) has been widely used alone or in combination with other antiretroviral drugs for the treatment of human immunodeficiency virus. Its erratic oral bioavailability necessitates frequent administration of high doses, resulting in severe side effects. In this study, the design of mucoadhesive solid dispersions (SDs) based on chitosan (CS) and hypromellose phthalate (HP) was rationalized as a potential approach to modulate AZT physicochemical and pharmaceutical properties. SDs were prepared at different drug:polymer ratios, using an eco-friendly technique, which avoids the use of organic solvents. Particles with diameter from 56 to 73 µm and negative zeta potentials (-27 to -32 mV) were successfully prepared, achieving high drug content. Infrared spectroscopy revealed interactions between polymers but no interactions between the polymers and AZT. Calorimetry and X-ray diffraction analyses showed that AZT was amorphized into the SDs. The mucoadhesive properties of SDs were evidenced, and the control of AZT release rates from the matrix was achieved, mainly in acid media. The simple, low-cost and scalable technology proposed for production of SDs as a carrier platform for AZT is an innovative approach, and it proved to be a feasible strategy for modulation the physico-chemical, mucoadhesive and release properties of the drug.

Ternary solid dispersions: classification and formulation considerations

The number of active pharmaceutical compounds from the biopharmaceutical classification system (BCS) belonging to Class II and IV have significantly increased in recent years. These compounds have high therapeutic potential but are difficult to formulate as oral dosage forms due to their poor aqueous solubility. The solubility and bioavailability of these poorly water-soluble compounds can be increased by various formulation approaches, such as amorphous solid dispersions (ASD), salt formation, complexations, etc. Out of these techniques, the ASD approach, where compounds are converted into amorphous form and embedded in the hydrophilic matrix, have been successfully used in many marketed preparations. The recent advancement of this ASD approach is the design of ternary solid dispersions (TSD), where an additional component is added to further improve their performance in terms of solubility, stability, and processability. This review discusses the classification, mechanism of performance improvement, preparation techniques, and characterizations for TSD.

Fast-Dissolving Solid Dispersions for the Controlled Release of Poorly Watersoluble Drugs

Solid dispersions offer many advantages for oral drug delivery of poorly water-soluble drugs over other systems, including an increase in drug solubility and drug dissolution. An improvement in drug absorption and the higher bioavailability of active pharmaceutical ingredients in the gastrointestinal tract have been reported in various studies. In certain circumstances, a rapid pharmacological effect is required for patients. Fastdissolving solid dispersions provide an ideal formulation in such cases. This report will provide an overview of current studies on fast-dissolving solid dispersions, including not only solid dispersion powders with fast dissolution rates but also specific dose form for the controlled release of poorly water-soluble drugs. Specifically, the applications of fast-dissolving solid dispersions will be described in every specific case. Moreover, pharmaceutical approaches and the utilization of polymers will be summarized. The classification and analysis of fastdissolving solid dispersions could provide insight into strategies and potential applications in future drug delivery developments.

Inositol hexanicotinate self-micelle solid dispersion is an efficient drug delivery system in the mouse model of non-alcoholic fatty liver disease

Inositol hexanicotinate (IHN) self-micelle solid dispersion (SD) with glycyrrhizic acid (GA) and arabic gum (AG) was prepared by mechanical ball milling process to improve the solubility, stability of amorphous state, and bioavailability of IHN, which enhanced the treatment of IHN on hyperlipidemia and nonalcoholic fatty liver disease (NAFLD). The physicochemical properties of IHN/GA/AG SDs in solid state were characterized by differential scanning calorimetry, X-ray diffraction studies, and scanning electron microscopy. The characteristics of the sample solutions were analyzed by reverse-phase HPLC, particle characterization, critical micelle concentration, and transmission electron microscopy. Further pharmacokinetic study of this SD formulation in rats showed a significant 3.3-fold increase in bioavailability compared to pure IHN. Moreover, biomarkers in serum and liver of NAFLD mice were significantly ameliorated after oral administration of IHN/GA/AG SDs for 15 days. Altogether, these results establish the mechanochemically prepared IHN/GA/AG SDs as an efficacious formulation for the treatment of hyperlipidemia and NAFLD.

Preparation of olmesartan medoxomil solid dispersion with sustained release performance by mechanochemical technology

Hypertension is a common disease for human with high morbidity and mortality, and olmesartan medoxomil (OM) is widely used in the therapy of hypertension. However, poor water solubility and low bioavailability limit its widespread use. To improve the effect of OM, a ternary OM solid dispersion consisting of hydroxypropyl-β-cyclodextrin (HP-β-CD) and hydroxypropyl methylcellulose (HPMC) was prepared by mechanochemical method. The best preparation parameters were OM/HP-β-CD/HPMC-E5 with mass ratio of 1:2.6:1 and milling time of 4 h. Under the optimal preparation conditions, the solubility of the ternary solid dispersion could be increased by 12 times as compared with pure OM. Due to the addition of HPMC-E5, the solid dispersion had sustained release performance with prolonged release time of 12 h. Furthermore, in vivo study demonstrated that the prepared solid dispersion could afford significantly improved bioavailability of ~ 3-fold in comparison with pure drug. Hence, the prepared ternary solid dispersion of OM may be a promise delivery system for clinical application.

Enhancing the Solubility of Curcumin Using a Solid Dispersion System with Hydroxypropyl-β-Cyclodextrin Prepared by Grinding, Freeze-Drying, and Common Solvent Evaporation Methods

Cyclodextrins (CDs) and their derivatives significantly increase drug solubility by forming drug/CD complexes known as solid dispersions (SDs), which consist of an inclusion complex (IC), where the drug is entrapped within the CD cavity, and a non-IC. Here, the SDs of curcumin (CUR) and hydroxypropyl-β-cyclodextrin (HPβCD) were prepared using the grinding, freeze-drying (FD), and common solvent evaporation (CSE) methods and were physicochemically characterized using solubility, powder X-ray diffraction, Fourier transform infrared, differential scanning calorimetry, and dissolution studies. The second or higher order complex of CUR-HPβCD indicated the co-existence of ICs and non-ICs known as the SD system. When comparing the soluble drug amount with CUR crystals, the solubility of SDs was enhanced by up to 299-, 180-, and 489-fold, corresponding to the ground mixtures (GMs), freeze-drying mixtures (FDs), and common solvent evaporation mixtures (CSEs), respectively. The total transformation into the amorphous phase of CUR was observed in GMs and in CSE12, CSE14, and CSE18. The drug was well dispersed within HPβCD in GMs and CSEs, suggesting the formation of hydrogen bonds between CUR and HPβCD, whereas the dispersed behavior of FDs was similar to that of physical mixtures. In SDs, the melting temperature of CUR was in an increased order of CUR in 1:2 ICs, CUR in 1:1 ICs, and CUR crystals. The dissolution rate of CUR was positively improved as the amount of HPβCD in SDs increased. The SD system consisting of CUR and HPβCD significantly increased the drug solubility compared to ICs.

Water-Soluble Substances of Arglabin

The article discusses the results of a study of the water solubility of natural sesquiterpene lactone arglabin, in particular, its ability to complex formation with complexing agents polyvinylpyrrolidone, the disodium salt of glycyrrhizic acid, magnesium carbonate. Mechanocomposites with polyvinylpyrrolidone and disodium salt of glycyrrhizic acid, which have increased water solubility, were obtained by the method of mechanochemical treatment of arglabin native. At the same time, the best result of dissolution in water is achieved by a two-hour treatment with polyvinylpyrrolidone and with disodium salt of glycyrrhizic acid. The water solubility of complex compounds of arglabin with polyvinylpyrrolidone increases by 4.61 times, and with disodium salt of glycyrrhizic acid by 4.42 times.

Molecular Interactions in Solid Dispersions of Poorly Water-Soluble Drugs

Physicochemical characterization is a crucial step for the successful development of solid dispersions, including the determination of drug crystallinity and molecular interactions. Typically, the detection of molecular interactions will assist in the explanation of different drug performances (e.g., dissolution, solubility, stability) in solid dispersions. Various prominent reviews on solid dispersions have been reported recently. However, there is still no overview of recent techniques for evaluating the molecular interactions that occur within solid dispersions of poorly water-soluble drugs. In this review, we aim to overview common methods that have been used for solid dispersions to identify different bond formations and forces via the determination of interaction energy. In addition, a brief background on the important role of molecular interactions will also be described. The summary and discussion of methods used in the determination of molecular interactions will contribute to further developments in solid dispersions, especially for quick and potent drug delivery applications.