Search Results (34)

The low water solubility of numerous drug candidates and phytochemicals continues to pose a significant challenge in pharmaceutical development, greatly limiting their bioavailability and therapeutic performance. This review presents a detailed overview of formulation strategies aimed at improving the solubility and dissolution of poorly aqueous-soluble compounds. The biopharmaceutics classification system and the relevance of in vitro–in vivo correlation, as well as key challenges in formulation development, are briefed. Solid-state and particle engineering approaches, including micronization, supercritical fluid technology, electrospinning, and cryogenic techniques, are discussed. Extensive critical examination of amorphous solid dispersions and their preparation methods, as well as crystallization inhibition strategies, is covered. Cocrystallization is highlighted as a promising approach, with emphasis on design principles and preparation methods. Various solubilization techniques, such as pH modification, cosolvency, hydrotropy, micellar solubilization, and cyclodextrin-based complexation, including advanced hybrid systems, are also explored. Emerging solvent platforms, such as deep eutectic systems and lipid-based and nanotechnology-driven approaches, are reviewed for their role in improving solubility and drug delivery. Additionally, enabling technologies such as liquisolid systems and hydrophilic polymers are addressed. Despite notable progress, limitations such as scalability, reproducibility, regulatory constraints, and long-term safety persist. Overall, this review provides integrated insights into formulation design approaches to enhance the solubility and therapeutic efficacy of poorly soluble drugs. Full article

Nepafenac is an anti-inflammatory drug used in ophthalmology, marketed as a suspension due to its low aqueous solubility. A solution formulation could provide better bioavailability than suspension and facilitate single unit doses, avoiding the use of preservatives which are required to maintain sterility in multidose packaging. In this study, solubilization of nepafenac was achieved in the presence of randomly methylated β-cyclodextrin (RAMEB) and the actual complexation was assessed by NMR and phase-solubility studies. It was also found that the addition of hydrophilic polymers plays an important role in allowing increased solubilization of nepafenac at the same cyclodextrin concentration. Compared to complexes of nepafenac with other cyclodextrins, only 5% RAMEB was sufficient to solubilize 0.3% (w/v) nepafenac, enabling for the first time the development of an ophthalmic solution that proved chemically and physically stable for 12 months at 25 °C. The formulated solutions of nepafenac were tested for cytotoxicity on human corneal epithelial cells (HCE-2) and the results suggest their potential as a valuable and safe alternative to the commercially available 0.3% (w/v) suspension of the drug. Full article

Background: Rheumatoid arthritis is a chronic autoimmune disease that leads to severe disability and requires improved therapeutic strategies to optimize anti-inflammatory treatment. This study aimed to address this challenge by developing and characterizing an extended-release polymer matrix tablet containing ketoprofen and a ketoprofen–β-cyclodextrin complex with enhanced therapeutic properties. The objective was to improve inflammation management and therapeutic outcomes using a novel delivery system based on the inclusion of the active substance in cyclodextrin complexes. Methods: Tablets were formulated using ketoprofen and ketoprofen–β-cyclodextrin complexes combined with hydrophilic polymers such as Carbopol^® 971P NF, Kollidon^® VA 64, and Methocel^TM K4M. The complexes were obtained via the coprecipitation method to improve bioavailability. The kinetics of the release of ketoprofen, ketoprofen–β-cyclodextrin complex (2:1), and ketoprofen–β-cyclodextrin complex (1:1) from the tablets were investigated in vitro in artificial gastric and intestinal fluids, and drug release profiles were established. Advanced mathematical models were used to describe the nonlinear behavior of the drug–polymer systems. Results: The inclusion of ketoprofen in the β-cyclodextrin complexes was confirmed, revealing distinct release profiles. Tablets (K-3 F-3) containing the 1:1 complex showed rapid release (96.2% in 4–7 h), while tablets (K-1 F-4) containing free ketoprofen released 76% over 9–11 h. Higher polymer concentrations slowed the release due to gel barrier formation. Pharmacotechnical and stability tests supported their suitability as extended-release forms. A multifractal modeling approach described the release dynamics, treating the polymer–drug matrix as a complex system, with release curves characterized by variations in the fractal dimension and resolution. Conclusions: Specific hydrophilic polymer combinations effectively prolonged ketoprofen release. The developed matrix tablets, which were evaluated via in vitro studies and mathematical modeling, show promise for improving therapeutic outcomes and patient compliance during rheumatoid arthritis treatment. Full article

Cyclodextrins (CDs) have revolutionized the pharmaceutical industry with their ability to enhance the stability, solubility, and bioavailability of a wide range of active substances. These cyclic oligosaccharides, with a unique hydrophilic exterior and hydrophobic cavity, form inclusion complexes with poorly soluble drugs, improving their pharmacokinetic profiles and therapeutic efficacy. This review explores the multifaceted roles of cyclodextrins in pharmaceutical formulations, ranging from oral, ophthalmic, parenteral, and topical applications to their emerging use in targeted therapies, gene delivery, and treatment of neurodegenerative, cardiovascular, and infectious diseases. Cyclodextrins not only improve drug solubility and controlled release but also reduce toxicity and side effects, leading to safer and more effective treatments. Recent advancements, such as cyclodextrin-based nanoparticles, offer promising pathways for cancer therapy, chronic disease management, and personalized medicine. As research continues, cyclodextrins remain at the forefront of innovation in drug delivery systems, ensuring better patient outcomes and expanding the possibilities of modern therapeutics. Full article

Most chemotherapeutic agents are poorly soluble in water, have low selectivity, and cannot reach the tumor in the desired therapeutic concentration. On the other hand, sensitive hydrophilic therapeutics like nucleic acids and proteins suffer from poor bioavailability and cell internalization. To solve this problem, new types of controlled release systems based on nano-sized self-assemblies of cyclodextrins able to control the speed, timing, and location of therapeutic release are being developed. Cyclodextrins are macrocyclic oligosaccharides characterized by a high synthetic plasticity and potential for derivatization. Introduction of new hydrophobic and/or hydrophilic domains and/or formation of nano-assemblies with therapeutic load extends the use of CDs beyond the tried-and-tested CD-drug host–guest inclusion complexes. The recent advances in nano drug delivery have indicated the benefits of the hybrid amphiphilic CD nanosystems over individual CD and polymer components. This review provides a comprehensive overview of the most recent advances in the design of CDs self-assemblies and their use for delivery of a wide range of therapeutic molecules. It aims to offer a valuable insight into the many roles of CDs within this class of drug nanocarriers as well as current challenges and future perspectives. Full article

Riluzole (RLZ), a sodium channel-blocking benzothiazole anticonvulsant BCS class II drug, is very slightly soluble in aqueous medium. To improve aqueous solubility and modulate dissolution rate and membrane permeability, complex formation of RLZ with two cyclodextrin, α-cyclodextrin (α-CD) and sulfobutylether-β-cyclodextrin (SBE-β-CD), was studied. The stability constants demonstrated a greater affinity of SBE-β-CD towards RLZ compared to α-CD. A solubility growth of 1.7-fold and 3.7-fold with α-CD and SBE-β-CD, respectively, was detected in the solutions of 1% cyclodextrins and accompanied by the permeability reduction. For 1% CD solutions, several biopolymers (1% w/v) were tested for the membrane permeability under static conditions. The synergistic positive effect of α-CD and polymer on the solubility accompanied by unchanged permeability was revealed in RLZ/α-CD/PG, RLZ/α-CD/PEG400, and RLZ/α-CD/PEG1000 systems. Solid RLZ/CD complexes were prepared. Dynamic dissolution/permeation experiments for the solid samples disclosed the characteristic features of the release processes and permeation rate through different artificial membranes. The maximal permeation rate was determined across the hydrophilic semi-permeable cellulose membrane followed by the lipophilic PermeaPad barrier (model of intestinal and buccal absorption) and polydimethylsiloxane-polycarbonate membrane (simulating transdermal delivery way). Different mode of the permeation between the membranes was estimated and discussed. Full article

The design of new drug delivery systems has been widely sought after. The stability, solubility, and difficulty of targeting active sites for new drugs have always been challenging and remain one of the major drawbacks to the efficiency of certain drugs. Liposomes are phospholipid vesicles enclosing one or more aqueous compartments. Depending on its properties, a drug is embedded in the lipid bilayer or the aqueous medium. Thus, liposomes can act as drug carriers for both lipo- and hydrophilic compounds. New strategies such as “drug-in-cyclodextrin-in liposomes” (DCLs) have been developed as safe and effective carriers for exploiting the inclusion properties of water-soluble cyclodextrins known to form host–guest complexes with lipophilic molecules. Once inclusion complexes are formed, they can be inserted into a liposome aqueous core in order to stabilize it and better control the drug release. Our review will provide an update on the use of DCLs in the field of drug delivery for various kinds of active compounds. While previous reviews focused on the interesting advantages of using this method, such as enhancing the solubility and stability of a drug or controlling and improving drug release, the authors intend to highlight the impact of these nanocarriers on the pharmacokinetic and/or pharmacodynamic properties of drugs. Full article

The present study reports the effects of two pharmaceutical excipients of differing natures—non-ionic surfactant pluronic F127 (F127) and anionic sulfobutylether-β-cyclodextrin (SBE-β-CD)—on the permeation of the model compound, carbamazepine (CBZ). The permeability coefficients of CBZ at three concentrations of the excipients were measured through two different artificial barriers: hydrophilic cellulose membrane (RC) and lipophilic polydimethylsiloxane–polycarbonate membrane (PDS). The equilibrium solubility of CBZ in F127 and SBE-β-CD solutions was determined. The micellization, complexation, and aggregation tendencies were investigated. Systemically increasing the solubility and the reduction of permeation upon the excipients’ concentration growth was revealed. The quantitative evaluation of the permeability tendencies was carried out using a P_ratio parameter, a quasi-equilibrium mathematical mass transport model, and a correction of permeability coefficients for the free drug concentration (“true” permeability values). The results revealed the mutual influence of the excipient properties and the membrane nature on the permeability variations. Full article

Generally, NSAIDs are weakly soluble in water and contain both hydrophilic and hydrophobic groups. One of the most widely used NSAIDs is ibuprofen, which has a poor solubility and high permeability profile. By creating dynamic, non-covalent, water-soluble inclusion complexes, cyclodextrins (CDs) can increase the dissolution rate of low aqueous solubility drugs, operating as a drug delivery vehicle, additionally contributing significantly to the chemical stability of pharmaceuticals and to reducing drug-related irritability. In order to improve the pharmacological and pharmacokinetics profile of ibuprofen, new thiazolidin-4-one derivatives of ibuprofen (4b, 4g, 4k, 4m) were complexed with β-CD, using co-precipitation and freeze-drying. The new β-CD complexes (β-CD-4b, β-CD-4g, β-CD-4k, β-CD-4m) were characterized using scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction and a phase solubility test. Using the AutoDock-VINA algorithm included in YASARA-structure software, we investigated the binding conformation of ibuprofen derivatives to β-CD and measured the binding energies. We also performed an in vivo biological evaluation of the ibuprofen derivatives and corresponding β-CD complexes, using analgesic/anti-inflammatory assays, as well as a release profile. The results support the theory that β-CD complexes (β-CD-4b, β-CD-4g, β-CD-4k, β-CD-4m) have a similar effect to ibuprofen derivatives (4b, 4g, 4k, 4m). Moreover, the β-CD complexes demonstrated a delayed release profile, which provides valuable insights into the drug-delivery area, focused on ibuprofen derivatives. Full article

Cyclodextrins (CDs) are cyclic oligosaccharides that contain a relatively hydrophobic central cavity and a hydrophilic outer surface. They are widely used to form non-covalent inclusion complexes with many substances. Although such inclusion complexes typically exhibit higher aqueous solubility and chemical stability than pure drugs, it has been shown that CDs can promote the degradation of some drugs. This property of stabilizing certain drugs while destabilizing others can be explained by the type of CD used and the structure of the inclusion complex formed. In addition, the ability to form complexes of CDs can be improved through the addition of suitable auxiliary substances, forming multicomponent complexes. Therefore, it is important to evaluate the effect that binary and multicomponent complexes have on the chemical and physical stability of complexed drugs. The objective of this review is to summarize the studies on the stabilizing and destabilizing effects of complexes with CDs on drugs that exhibit stability problems. Full article

Respiratory infectious diseases have challenged medical communities and researchers. Ceftriaxone, meropenem and levofloxacin are widely used for bacterial infection treatment, although they possess severe side effects. To overcome this, we propose cyclodextrin (CD) and CD-based polymers as a drug delivery system for the drugs under consideration. CD polymers demonstrate higher binding affinity for levofloxacin (Ka ≈ 10⁵ M) compared to drug–CD complexes. CDs slightly alter the drugs’ affinity for human serum albumin (HSA), whereas CD polymers increase the drugs’ binding affinity up to 100 times. The most significant effect was observed for more the hydrophilic drugs ceftriaxone and meropenem. The drug’s encapsulation in CD carriers leads to a decrease in the degree of change in the protein’s secondary structure. The drug–CD carrier–HSA complexes demonstrate satisfying antibacterial activity in vitro, and even a high binding affinity does not decrease the drug’s microbiological properties after 24 h. The proposed carriers are promising for a drug form with a prolonged drug release. Full article

Cyclodextrins, representing a versatile family of cyclic oligosaccharides, have extensive pharmaceutical applications due to their unique truncated cone-shaped structure with a hydrophilic outer surface and a hydrophobic cavity, which enables them to form non-covalent host–guest inclusion complexes in pharmaceutical formulations to enhance the solubility, stability and bioavailability of numerous drug molecules. As a result, cyclodextrins are mostly considered as inert carriers during their medical application, while their ability to interact not only with small molecules but also with lipids and proteins is largely neglected. By forming inclusion complexes with cholesterol, cyclodextrins deplete cholesterol from cellular membranes and thereby influence protein function indirectly through alterations in biophysical properties and lateral heterogeneity of bilayers. In this review, we summarize the general chemical principles of direct cyclodextrin–protein interactions and highlight, through relevant examples, how these interactions can modify protein functions in vivo, which, despite their huge potential, have been completely unexploited in therapy so far. Finally, we give a brief overview of disorders such as Niemann–Pick type C disease, atherosclerosis, Alzheimer’s and Parkinson’s disease, in which cyclodextrins already have or could have the potential to be active therapeutic agents due to their cholesterol-complexing or direct protein-targeting properties. Full article

The sustained release of multiple anti-cancer drugs using a single delivery carrier to achieve a synergistic antitumor effect remains challenging in biomaterials and pharmaceutics science. In this study, a supramolecular hydrogel based on the host–guest complexes between pH-responsive micelle derived poly(ethylene glycol) chains and α-cyclodextrin was designed for codelivery of two kinds of anti-cancer agents, hydrophilic 8-hydroxyquinoline glycoconjugate and hydrophobic doxorubicin. The host–guest interactions were characterized using X-ray diffraction and differential scanning calorimetry techniques. The resultant supramolecular hydrogel showed thixotropic properties, which are advantageous to drug delivery systems. In vitro release studies revealed that the supramolecular hydrogel exhibited faster drug release profiles in acidic conditions. The MTT assay demonstrated a synergistic cancer cell proliferation inhibition of DOX/8HQ-Glu mixture. In vitro cytotoxicity studies indicated excellent biocompatibility of the supramolecular hydrogel matrix, whereas the DOX/8HQ-Glu-loaded supramolecular hydrogel showed a sustained inhibition efficacy against cancer cells. The codelivery of hydrophobic anti-cancer drugs and hydrophilic anti-cancer drug glycoconjugates via a pH-responsive supramolecular hydrogel opens up new possibilities for the development of an effective cancer treatment based on the tumor-specific Warburg effect. Full article

Cyclodextrins (CDs) are macrocyclic oligosaccharides, containing between six and eight alpha(1 → 4)-linked glucopyranoses. CDs have a hydrophobic cone-shaped internal cavity and a hydrophilic exterior surface. They form non-covalent inclusion complexes (ICs) with various drugs by trapping the full or partial inclusions in their cavity. Supramolecular ICs have gained attention in engineering entrapped drug performance field due to their potential to protect and modify the physicochemical properties of entrapped lipophilic and volatile drugs. However, the poor structural and mechanical properties of pure CD-ICs could restrict their application and the need for a suitable carrier system. Electrospun nanofibers have been the center of attention for biomedical applications due to their tunable physicochemical properties. Recent studies have highlighted that the entrapment of drug/CD-based ICs into nanofibers is an active research area since it facilitates high encapsulation, it modulates the release profile of the guest, integrates multi-type drugs, and leads to a synergistic effect. This mini-review first summarizes the potential benefits and shortcomings of drug/CD-ICs and nanofibers, and then, we discuss the advancements in the fabrication and characteristics of CD-ICs embedded nanofibers, along with some practical suggestions for potential biomedical applications. Full article

Flibanserin (FLB) is a drug used for female hypotensive sexual desire disorder approved by the FDA in August 2015. FLB exhibits extensive hepatic first-pass metabolism and low aqueous solubility, hence poor oral bioavailability. In this study, beta hydroxypropyl cyclodextrin-FLB inclusion complexes were incorporated into orally fast dissolving films. This dosage form was expected to improve FLB aqueous solubility, which would give fast onset of action and decrease presystemic metabolism, hence improving oral bioavailability. The inclusion complex at a ratio of 1:1 was prepared by the kneading method. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffractometry (XRD) were used to confirm complex formation. The Box–Behnken design (15 different formulae of FLB fast-dissolving oral films (FLBFDOFs) were utilized for the optimization of the prepared films. The Expert Design 11 program was utilized to examine the effects of three selected factors, polymer concentration (X₁), plasticizer concentration (X₂), and disintegrant concentration (X₃) on four responses: disintegration time (DT), initial dissolution rate (IDR), dissolution efficiency (DE), and film quality (QF). Numerical optimization was performed by minimizing disintegration time (Y1), while maximizing the initial drug dissolution rate (Y₂), dissolution efficiency (Y₃), and the quality factor (Y₄). The statistical analysis showed that X₁ has a significant positive effect on the disintegration time and a significant negative effect on IDR. While X₂ and X₃ produced a nonsignificant negative effect on IDR. Dissolution efficiency was maximized at the middle concentration of both X₂ and X₃. The best film quality was observed at the middle concentration of both X₁ and X₂. In addition, increasing X₃ leads to an improvement in film quality. The optimized film cast from an aqueous solution contains hydroxypropyl cellulose (2%) as a hydrophilic film-forming agent and propylene glycol (0.8%) as a plasticizer and cross povidone (0.2%) as a disintegrant. The prepared film released 98% of FLB after 10 min and showed good physical and mechanical properties. The optimized formula showed a disintegration time of 30 s, IDR of 16.6% per minute, DE₁₅ of 77.7%, and QF of 90%. This dosage form is expected to partially avoid the pre-systemic metabolism with a fast onset of action, hence improving its bioavailability that favors an advantage over conventional dosage forms. Full article