The advancement of efficient drug delivery systems continues to pose a significant problem in pharmaceutical sciences, especially for compounds with limited water solubility. Lipid-based systems, including solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), have emerged as viable options owing to their biocompatibility, capability to safeguard labile chemicals, and potential for prolonged release. Nonetheless, the encapsulation efficiency (EE) and release dynamics of these carriers can be enhanced by including cyclodextrins (CDs)—cyclic oligosaccharides recognized for their ability to form inclusion complexes with hydrophobic compounds. This article offers an extensive analysis of CD-modified SLNs and NLCs as multifunctional drug delivery systems. The article analyses the fundamental principles of these systems, highlighting the pre-complexation of the drug with cyclodextrins before lipid incorporation, co-encapsulation techniques, and surface adsorption after formulation. Attention is concentrated on the physicochemical interactions between cyclodextrins and lipid matrices, which influence essential factors such as particle size, encapsulation efficiency, and colloidal stability. The review includes characterization techniques, such as particle size analysis, zeta potential measurement, drug release studies, and Fourier-transform infrared spectroscopy (FT-IR)/Nuclear Magnetic Resonance (NMR) analyses. The study highlights the application of these systems across many routes of administration, including oral, topical, and mucosal, illustrating their adaptability and potential for targeted delivery. The review outlines current formulation challenges, including stability issues, drug leakage, and scalability concerns, and proposes solutions through advanced approaches, such as stimuli-responsive release mechanisms and computer modeling for system optimization. The study emphasizes the importance of regulatory aspects and outlines future directions in the development of CD-lipid hybrid nanocarriers, showcasing its potential to revolutionize the delivery of poorly soluble drugs.

Many antifungal agents, including isoconazole nitrate (ISN), suffer from low aqueous solubility and inconsistent dissolution kinetics, which limit their therapeutic potential. To address these challenges, this study aimed to enhance the solubility and stability of ISN through the development of inclusion complexes with hydroxypropyl-β-cyclodextrin (HP-β-CD). HP-β-CD inclusion complexes were prepared using a spray-drying technique and characterized through phase-solubility studies, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (¹H-NMR), and differential scanning calorimetry (DSC). The inclusion complex significantly improved ISN solubility, increasing from 0.5088 mg/mL to 3.6550 mg/mL. These complexes were incorporated into a thermosensitive, mucoadhesive in situ gel system using Pluronic^® F127 and hydroxypropyl methylcellulose (HPMC) to optimize vaginal drug delivery. The formulations were evaluated for gelation temperature, viscosity, swelling behavior, and pH, confirming their suitability for vaginal application. Antimicrobial studies demonstrated that the ISN/HP-β-CD gels exhibited superior activity against Candida albicans, C. glabrata, and C. krusei compared to ISN alone. In vitro release studies further revealed sustained drug release following Peppas-Sahlin kinetics, supporting enhanced bioavailability and prolonged therapeutic action. This study demonstrates that the ISN/HP-β-CD-loaded in situ gel system offers a promising and effective approach for improving the solubility, stability, and antifungal efficacy of ISN for the treatment of vaginal infections.

Isoconazole nitrate (ISN) is a broad-spectrum antifungal agent whose therapeutic potential is limited by poor aqueous solubility and low bioavailability. This study aimed to enhance the solubility and physicochemical properties of ISN through the formation of inclusion complexes with methyl-β-cyclodextrin (M-β-CD) using freeze-drying (FD) and spray-drying (SD) methods. The prepared inclusion complexes were comprehensively characterized by high-performance liquid chromatography (HPLC), phase solubility analysis, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance (¹H-NMR). Phase solubility studies revealed an AL-type solubility diagram with a 1:1 molar ratio and an apparent stability constant (K_S) of 2711 M⁻¹. Structural and thermal analyses confirmed successful inclusion complex formation and reduced crystallinity. The solubility assessment showed that ISN/M-β-CD complexes prepared by SD exhibited an approximately seven-fold higher aqueous solubility than ISN and performed better than those prepared by FD. Moreover, SD complexes demonstrated a higher drug content. These findings highlight the potential of M-β-CD-based inclusion complexation, particularly via spray-drying, as an effective strategy to enhance the solubility and bioavailability of poorly water-soluble drugs, such as ISN.

Multidrug resistance (MDR) and chemotherapy-associated toxicity remain major challenges limiting the success of cancer treatments. In this context, berberine (BBR), an isoquinoline derivative belonging to the barberry family, has emerged as a promising adjuvant that can enhance the efficacy of chemotherapy while potentially mitigating its side effects. The findings indicate that berberine enhances the therapeutic effect of several drugs, such as doxorubicin, cisplatin, tamoxifen, and 5-fluorouracil, through multiple mechanisms including the inhibition of ABC transporters, regulation of autophagy, and synergistic enhancement of reactive oxygen species generation. Advanced pharmaceutical and nanotechnological formulations, including cyclodextrin complexes, solid dispersions, liposomes, solid lipid nanoparticles, nanostructured lipid carriers, polymeric nanoparticles, chitosan-based systems, and inorganic nanoplatforms, have demonstrated significant improvements in the solubility, stability, cellular uptake, and oral bioavailability of berberine. However, knowledge gaps remain regarding optimal dosage determination, safety assessment in combination therapy, and establishing efficacy in large-scale clinical trials. Incorporating berberine into combination therapy strategies may improve treatment outcomes, overcome drug resistance, and potentially reduce the toxic burden associated with chemotherapy. Therefore, this review provides a comprehensive analytical framework for berberine’s potential as an adjuvant, elucidates its mechanistic synergistic interactions with standard therapies, explores pharmaceutical strategies to overcome bioavailability limitations, and suggests future research avenues to further its clinical development.

Historically, pharmaceutical formulation development relied heavily on trial-and-error experimentation, which was useful for empirical progress but often provided limited mechanistic understanding and insufficient efficiency for increasingly complex drug products. The introduction of Design of Experiments (DoE) and Quality by Design (QbD) established a more systematic framework for studying formulation variables, manufacturing parameters, and Critical Quality Attributes (CQAs). Approaches such as factorial designs, response-surface methodology, and mixture designs have therefore become central to modern pharmaceutical development because they improve experimental efficiency and support the definition of design space. However, as formulations become more nonlinear, high-dimensional, and multi-objective, these classical approaches may no longer be sufficient on their own. This review examines the evolution of experimental design in pharmaceutical research, from one-factor-at-a-time experimentation to structured DoE/QbD strategies, and then to emerging intelligent optimization methods. Its central objective is to clarify when conventional DoE/QbD remains appropriate and when it should be complemented by machine learning, Bayesian optimization, digital twins, and closed-loop experimental systems. The review first summarizes the foundations and strengths of classical experimental design; then, it discusses its practical limitations in complex formulation settings, and finally evaluates how data-driven and hybrid approaches can extend pharmaceutical development. Evidence from tablets, capsules, nanocarriers, transdermal patches, and biotherapeutic systems suggests that intelligent optimization can improve predictive performance and experimental efficiency when used alongside, rather than instead of, established pharmaceutical development principles.