Search Results (125)

Background/Objectives: The buccal mucosa offers a promising non-invasive route for systemic drug delivery, particularly for hydrophilic compounds like captopril (CAP), which exhibit low permeability and are subject to gastrointestinal instability and first-pass metabolism. This study aimed to develop and characterize captopril-loaded, chitosan-based mucoadhesive buccal films with different permeation enhancers and to evaluate their physicochemical properties, drug release, cytocompatibility, and in vitro transport across a TR146 buccal epithelial cell model. Methods: Films were prepared by the solvent-casting method using chitosan as the film-forming polymer. Different enhancers were investigated, including organic acid salts of chitosan (ascorbate, citrate, and lactate) and chemical permeation enhancers (sodium lauryl sulfate, polyethylene glycol 400, Span 20, and EDTA). Results: The resulting films exhibited acceptable thickness, moisture content, appropriate mechanical properties, and good mucoadhesive strength. In vitro dissolution studies demonstrated rapid CAP release, with >50% released within 15 min and near-complete release by 180 min across all formulations. Cytotoxicity assessment via a Neutral Red uptake assay in TR146 cells confirmed high cell viability (>81%) after 4 h of exposure, indicating good biocompatibility. In vitro permeation experiments revealed that films prepared with chitosan ascorbate and chitosan lactate enhanced CAP transport compared to other formulations, achieving the highest flux and apparent permeability coefficients. Conclusions: These findings demonstrate that chitosan ascorbate and lactate salts effectively improve the buccal permeability of captopril while maintaining good film properties and biocompatibility. This work highlights the potential of chitosan ascorbate- and lactate-based mucoadhesive films as an efficient platform for the buccal delivery of CAP. Full article

Background: Cyclodextrin (CD) polymers have attracted increasing attention due to their favourable drug delivery properties and broad pharmaceutical applicability. While the bioavailability and biological behaviour of native cyclodextrins have been extensively investigated, considerably less information is available regarding modified cyclodextrin polymers. Therefore, the present study aimed to investigate the permeation and cellular uptake of an epichlorohydrin-crosslinked β-cyclodextrin polymer using multiple in vitro and ex vivo models. Methods: Fluorescently labelled β-cyclodextrin polymers were applied in all experiments. Membrane permeation studies were performed using an in-line diffusion cell system with membranes of different pore sizes. In vitro transport and cellular uptake were investigated on HaCaT, Caco-2, and TR146 cell monolayers, while ex vivo permeation studies were carried out using skin, buccal, and intestinal tissues. Results: The results demonstrated a strong size-dependent transport behaviour across synthetic membranes. Cell monolayer studies revealed cell-line-dependent differences in polymer intracellular distribution. Lysosomal accumulation was observed in HaCaT and Caco-2 cells, whereas no intracellular accumulation was detected in TR146 cells. These findings suggest differences in polymer permeation among the investigated cell models. Ex vivo studies demonstrated the tissue permeation of cyclodextrin polymers, with marked accumulation within skin layers, indicating predominant dermal retention. Furthermore, strong correlations were identified between the in vitro and ex vivo skin and intestinal models. Conclusions: Overall, the findings demonstrate that β-cyclodextrin polymers exhibit complex, barrier-dependent transport behaviour across different biological models. The observed differences in permeation and intracellular localization suggest that multiple transport processes may contribute to their biological interactions, which provide a foundation for future studies aimed at elucidating the molecular mechanisms governing polymer uptake and permeation. Full article

Therapeutic proteins have emerged as a cornerstone of modern medicine due to their high specificity and strong biological effects. However, delivering these proteins poses significant challenges due to their instability, susceptibility to enzymatic breakdown, low permeability, and reliance on invasive parenteral routes. Buccal drug delivery is a promising non-invasive alternative, offering quick systemic absorption while avoiding gastrointestinal degradation and hepatic first-pass metabolism. Three-dimensional (3D) printing as a fabrication method has further enhanced the potential of buccal delivery, enabling precise dosage control, multilayer structures, and patient-specific customization. This review focuses on the current state of the traditional and 3D-printed buccal film platforms using different printing methods for protein delivery, and critically analyzes protein stability challenges, and formulation strategies. The discussion further highlights emerging proof-of-concept studies. Full article

Transferosomes are liposome-derived ultradeformable vesicles designed to improve drug delivery across restrictive biological barriers, particularly in non-invasive administration routes. Their structure is based on phospholipid bilayers modified with edge activators, usually surfactants or bile salts, which increase membrane flexibility while preserving vesicular organization. This balance between deformability and stability distinguishes transferosomes from conventional liposomes and has supported their use in dermal, transdermal, ocular, nasal, buccal, and other mucosal delivery systems. However, despite extensive experimental interest, the field remains limited by inconsistent terminology, heterogeneous formulation strategies, non-harmonized deformability assays, and incomplete translation from laboratory formulations to clinically relevant products. This review critically examines transferosomes from a formulation-development perspective, focusing on the relationship between lipid composition, edge-activator selection, vesicle properties, deformability, drug release, and biological performance. Particular attention is given to critical quality attributes, analytical characterization, mechanistic interpretations of barrier interaction, and the unresolved debate between intact vesicle penetration, drug-release-dominated delivery, and barrier perturbation. Transferosomes are also positioned in comparison with conventional liposomes, ethosomes, and transethosomes. Finally, the review identifies key unmet needs related to standardization, reproducibility, scalability, storage stability, and regulatory uncertainty. By integrating formulation design with mechanistic and translational analysis, this review aims to clarify when transferosomes offer a genuine delivery advantage and which parameters must be controlled to support their further pharmaceutical development. Full article

Mucoadhesive drug delivery systems have emerged as a promising strategy to enhance the therapeutic efficacy of pharmaceuticals by improving drug residence time, bioavailability, and site-specific targeting. Among various materials investigated, biopolysaccharides have gained significant attention due to their biocompatibility, biodegradability, non-toxicity, and inherent mucoadhesive properties. Natural polymers such as chitosan, alginate, pectin, hyaluronic acid, and cellulose derivatives exhibit strong interactions with mucosal surfaces through hydrogen bonding, electrostatic interactions, and polymer chain entanglement. These properties enable prolonged drug retention at mucosal sites, controlled drug release, and enhanced permeation across biological barriers. Mucoadhesive biopolysaccharides have been explored for diverse routes of administration, including oral, buccal, nasal, ocular, vaginal, and pulmonary delivery. Furthermore, chemical modification and nanostructuring of these polymers have expanded their functionality, enabling targeted delivery of small molecules, proteins, peptides, and nucleic acids. This review highlights the mechanisms of mucoadhesion, key biopolysaccharides used in drug delivery, formulation approaches, and recent advances in their application as versatile platforms for novel therapeutic delivery systems. The continued development of mucoadhesive biopolysaccharide-based carriers holds substantial potential for improving treatment outcomes and patient compliance. Full article

Background: Oral protein delivery is a major challenge in the field of pharmaceutical technology due to poor stability and limited permeability through intestinal barriers. Buccal delivery is a promising alternative with less restricting physiological conditions; however, low protein permeability is still a limiting factor. Multiple nanocarriers have been proposed to improve buccal protein delivery with lipid–polymer hybrid nanoparticles (LPHNs) combining the advantages of both polymeric and lipid-based systems. However, these conventional carriers rely on passive protein protection and lack adaptive release mechanisms. Objectives: This work aimed to develop and systematically optimize an ionic strength-responsive LPHN system that can minimize protein release in buccal ionic conditions while offering a triggered release in plasma after absorption. Methods: LPHNs were prepared by a two-step approach where polymeric cores of Eudragit-L100 were prepared by electrostatic complexation with Lysozyme (LYZ) followed by lipid shell formation by the ethanol injection method. Systematic optimization was performed using two-level factorial and central composite designs. Moreover, the ionic strength responsiveness and in vitro LYZ release were investigated in different ionic strength media. Results: The final optimized formulations, LPHNs and sodium deoxycholate-containing LPHNs (NaDC-LPHNs), exhibited a particle size of 257.2 ± 1.5 nm and 246 ± 5.7 nm, encapsulation efficiency of 69.89 ± 0.22% and 68.14 ± 0.16%, and high drug loading efficiency of 24.11 ± 0.06% and 23.65 ± 0.04%, respectively. Moreover, both formulations showed minimal protein release at low ionic strength (buccal-like) conditions while demonstrating a triggered release at higher ionic strength (plasma-like) conditions. Conclusions: The developed system may provide a promising smart strategy to improve buccal protein delivery by enhancing buccal protection and improving systemic delivery. Full article

Three-dimensional (3D) printing has emerged as a versatile platform in pharmaceutical sciences, enabling fabrication of personalized dosage forms with controlled drug release and tailored properties using printable hydrogel bioinks. This study aimed to develop mucoadhesive hydrogel buccal films for cannabinoid delivery using extrusion-based 3D bioprinting. The films incorporated cannabidiol (CBD) and tetrahydrocannabinol (THC) as cyclodextrin inclusion complexes with HPMC or Carbopol as mucoadhesive hydrogel-forming polymers, while terpenes were evaluated as permeation enhancers. Terpenes including 1,8-cineole, d-limonene, α-pinene, and L-menthol were investigated individually and in combinations to assess their ability to enhance buccal cannabinoid permeation. Hydrogel bioinks were prepared and characterized for viscosity, pH, and drug content prior to printing under optimized conditions. The printed films were evaluated for mechanical properties, swelling behaviour, mucoadhesion, in vitro drug release, and ex vivo buccal mucosal penetration. Ex vivo penetration studies demonstrated that combinations of natural terpenes significantly improved CBD penetration compared with individual terpenes and the synthetic enhancer Azone. HPMC-based hydrogel films exhibited superior mechanical strength, cohesive gel matrices, and sustained non-Fickian cannabinoid release, while enhancing transmucosal penetration compared with unformulated drugs. Carbopol-based films showed higher mucoadhesion but weaker mechanical properties and faster erosion-driven release. These findings demonstrate the potential of 3D-printed mucoadhesive hydrogel films as gel-based systems for transmucosal cannabinoid delivery. Full article

Background: Erectile dysfunction (ED) and premature ejaculation (PE) are prevalent conditions affecting men’s sexual health, for which tadalafil and dapoxetine have shown promise in their treatment, respectively. Conventional oral dosage forms face limitations, including variable absorption and delayed onset of action. In this study, we developed electrospun nanofibers using polyvinylpyrrolidone for buccal drug delivery as an alternative dosage form to oral tablets. This route offers advantages such as easy administration, suitability for those with difficulty swallowing, particularly the elderly, and a rapid onset of action via the blood capillaries, which might improve bioavailability. Methods: PVP nanofibers loaded with tadalafil and dapoxetine were fabricated using a modified electrospinning procedure with the Spraybase system, where an 8% (w/v) PVP ethanol solution containing 1.5% dapoxetine and 0.5% tadalafil was electrospun under controlled conditions (800 µL/h flow rate, 15 cm distance, 0.55 mm needle, and 8–10 kV) to produce uniform fibers. Results: The morphology of the nanofibers was characterized using SEM, revealing smooth, uniform fibers with an average diameter of 218 ± 50 nm for drug-loaded nanofibers. This nanofibrous system also demonstrated ultra-rapid disintegration occurring within 4 ± 1 s and consistent drug loading and encapsulation efficiency for both drugs. The release profile showed a burst drug release after 15 min, which accounted for >45% for tadalafil and >50% for dapoxetine, followed by a sustained increment in the drug release that reached > 60% for tadalafil and >78% for dapoxetine after 30 min until a complete drug release (100%) for both drugs after 180 min. In vitro cytotoxicity studies on human dermal fibroblasts confirmed the safety of both medications, with cell viability exceeding 50%, at concentrations of 1.56 to 25 µg/mL for tadalafil and 4.69 to 9.38 µg/mL for dapoxetine after 24 and 48 h of incubation. Conclusions: These findings highlight the potential of PVP-based nanofibers as a novel buccal delivery system for the combined treatment of ED and PE. Full article

Background/Objective: Buccal delivery offers a potential route to circumvent gastrointestinal degradation and hepatic first-pass metabolism, but hydrophilic peptides typically exhibit limited mucosal permeation. Nanostructured lipid carriers (NLCs) have been proposed as delivery platforms capable of modulating interfacial interactions and improving mucosal transport. This study aimed to quantitatively evaluate the ex vivo buccal permeation of angiotensin II (Ang II), used as a hydrophilic peptide model, when associated with NLCs compared with free peptide under matched Franz diffusion cell conditions. Methods: Ang II-associated NLCs were prepared by melt emulsification combined with a low-energy injection technique. Particle size, polydispersity index, and zeta potential were determined by dynamic light scattering and laser Doppler electrophoresis. Association efficiency and drug loading were quantified by indirect spectrofluorometric analysis. Ex vivo permeation studies were conducted using porcine buccal mucosa mounted in Franz diffusion cells, and cumulative permeation, steady-state flux, and apparent permeability coefficients were calculated. Results: The NLCs exhibited nanometric size, moderate polydispersity, and association efficiency above 80%, and remained colloidally stable at 4 °C for 28 days. In ex vivo experiments, Ang II-associated NLCs showed measurable cumulative permeation, reaching approximately 9% after 2 h, whereas free Ang II was not detected in the receptor compartment under the tested conditions. Conclusions: This work provides a quantitative ex vivo buccal transport comparison of a hydrophilic peptide model delivered as NLC-associated versus free peptide under matched Franz cell conditions. The findings support further investigation of NLC-based approaches for buccal delivery of vasoactive peptides and provide a rational basis for future in vivo evaluation of mucosal delivery performance and systemic exposure. Full article

Background/Objectives: This study aimed to develop and formulation-design curcumin-loaded buccal films using a green deep eutectic solvent (DES) to improve drug solubility and support localized mucosal delivery, with the help of a Design of Experiments (DoE) approach. Methods: Various DESs with different components and molar ratios were prepared, characterized, and the optimal DES was selected. Curcumin-loaded buccal films were prepared by solvent casting, employing the optimal DES as the solvent system. A three-factor and five-level central composite design was applied to systematically investigate the amounts of HPMC K100, Kollicoat^® IR, and DES in buccal films, and mucoadhesive strength, elongation (%), swelling index, swelling time, and thickness were identified as critical responses. Based on these responses, characterization, in vitro release, ex vivo permeation, and in vitro biological activity studies were performed on the model-predicted optimal formulations. Results: Choline chloride: propylene glycol (1:4 molar ratio) was selected as the optimal DES due to its viscosity, pH, organoleptic properties, and the highest curcumin solubility (11.90 ± 0.15 mg/mL). While DES increased curcumin solubility, buccal films were successfully obtained. Six formulations identified through model-based DoE optimization were advanced to detailed experimental evaluation. The drug release exhibited sustained curcumin release profiles over 24 h, and ex vivo studies showed <2% mucosal permeation. The lead formulations demonstrated in vitro cell compatibility, anti-inflammatory and antioxidant activities, and enhanced wound-healing-related bioactivity. Conclusions: Curcumin-loaded buccal films containing DES and developed using a DoE-guided formulation strategy successfully demonstrated the acceptable formulation properties and screening-level in vitro biological activities, offering a promising formulation platform for localized buccal delivery applications. Full article

Background: Buccal administration offers direct access to systemic circulation, improving drug bioavailability when compared with the conventional oral route. This advantage depends on the formulation’s ability to remain in contact with the buccal mucosa. Attributes such as adhesion and viscosity are suggested to be correlated and contribute to enhanced residence time at the administration site. Methods: Buccal formulations with varying hydroxypropyl cellulose concentrations were prepared. Adhesion, viscosity, and residence time were assessed using a novel combined qualitative and quantitative approach. Drug permeation was evaluated in vitro using a biomimetic membrane and ex vivo using porcine buccal tissue, and it was further enhanced by adding the permeation enhancer benzalkonium chloride. Permeability measurements were integrated with residence time to estimate effective drug delivery. Results: Increasing HPC concentration improved both adhesion and viscosity, with 2% HPCs (F2) showing the strongest effect (45.5 ± 13.7 g), correlating with longer residence time (43.4% drug retained at 2 min vs. ~20% for 0–1% HPC). Although the polymer slightly reduced apparent permeability, when residence time was considered, drug flux increased 1.6-fold compared to the polymer-free formulation (F0), rising from 12.9 × 10⁻⁵ cm/min (F0) to 19.4 × 10⁻⁵ cm/min (F2) after 2 min. The addition of BKC further enhanced permeation, with apparent permeability increasing 1.5-fold vs. F2 and 2.5-fold vs. F0. Conclusions: Buccal liquid preparations’ efficacy is influenced by residence time and subsequent drug permeation. Residence time benefits from the synergistic effects of adhesion and viscosity, highlighting the importance of experimentally assessing these parameters during the development of oromucosal products. Full article

Background/Objectives: Empagliflozin (EMPA) was repurposed for Alzheimer’s disease (AD) treatment via buccal delivery, exploiting novel nanofibers (NFs) integrating chitosan (Cs), silk fibroin (Fb), and poly(lactic acid) (PLA). Methods: EMPA-loaded Cs/Fb/PLA NFs were electrospun in different formulations to optimize the formulation parameters. The optimized formulation was then investigated for its enhanced in vivo effect. Results: Optimized nanofiber diameters ranged from 459 ± 173 to 668 ± 148 nm, possessing bead-free morphology confirmed by SEM and satisfactory mechanical properties. EMPA was successfully well-dispersed in the polymer matrix as evidenced by FTIR, XRD, and drug content. The optimized NFs displayed a hydrophilic surface (contact angle < 90°), and biphasic drug release with sustained EMPA liberation (84.98% over 24 h). In vivo, buccal EMPA-Cs/Fb/PLA NFs in an AlCl₃-induced AD rat model significantly reduced brain-amyloid-β, phosphorylated tau, IL-1β, and AGER expression by 2.88-, 2.64-, 2.87-, and 2.50-fold, respectively, compared to positive controls, and improved locomotor activity (1.86-fold) and cognitive performance (T-maze) (4.17-fold). Compared to pure EMPA, the nanofiber formulation achieved further reductions in amyloid-β (1.78-fold), p-tau (1.42-fold), IL-1β (1.89-fold), and AGER (1.38-fold), with efficacy comparable to memantine. Histopathological examination revealed preservation of the hippocampal neuronal structure. Conclusions: The findings suggest EMPA-loaded Cs/Fb/PLA NFs as a promising non-invasive, sustained-release buccal delivery platform for AD therapy, offering multimodal neuroprotection through modulation of the Aβ–AGER–p-tau axis. Full article

Background/Objectives: Oral administration remains the most widely used route for drug delivery but is unsuitable for many central nervous system (CNS) therapeutics due to extensive hepatic first-pass metabolism and the restrictive blood–brain barrier (BBB). Acetyl salicylic acid (ASA), despite its neuroprotective and anti-inflammatory potential, exhibits poor brain bioavailability when delivered orally, limiting its therapeutic utility in ischemic stroke and chronic neurodegenerative conditions. Methods: This study reports the first use of three-dimensional (3D) bioprinting to develop brain-targeting ASA nanoparticle (NP)-loaded orally disintegrating films (ODFs) for direct systemic uptake and enhanced CNS delivery. The ODFs were fabricated using a CELLINK INKREDIBLE plus^® bioprinter and optimized for uniformity, rapid dissolution, and nanoparticle stability. Results: The films displayed consistent physicochemical properties (weight 10.86 ± 0.28 mg; thickness 0.47 ± 0.26 mm; pH 7.5–7.7) and disintegrated within 2.38 ± 0.28 min. In vitro testing on BEND3 brain endothelial cells confirmed biocompatibility, with no inflammatory response or cytotoxicity up to 62 µg/mL. In vivo biodistribution in murine models demonstrated substantial brain accumulation, achieving 14.15 ng/mg tissue following buccal administration. Conclusions: This work establishes a novel, non-invasive CNS drug delivery platform combining 3D bioprinting with ligand-functionalized ASA NPs to bypass hepatic metabolism and improve brain targeting. The rapid-dissolving ODFs demonstrated high reproducibility, safety, and effective brain deposition, highlighting their translational potential for neurological therapeutics. This approach may be extended to other small molecules with limited CNS penetration, offering a versatile pathway toward precision neuropharmacology. Full article

Therapeutic peptides have gained significant attention due to their high specificity, potency, and safety profiles in treating various diseases. However, their clinical application via the oral route remains challenging. Peptides are inherently unstable in the gastrointestinal environment, where they are rapidly degraded by proteolytic enzymes and acidic pH, leading to poor bioavailability. Additionally, their large molecular size and hydrophilicity restrict passive diffusion across the epithelial barriers of the gastrointestinal tract. These limitations have traditionally necessitated parenteral administration, which reduces patient compliance and convenience. The oral cavity, comprising the buccal and sublingual mucosa, offers a promising alternative for peptide delivery. Its rich vascularization allows for rapid systemic absorption while bypassing hepatic first-pass metabolism. Furthermore, the mucosal surface provides a relatively permeable and accessible site for drug administration. However, the oral cavities also present significant barriers: the mucosal epithelium limits permeability, the presence of saliva causes rapid clearance, and enzymes in saliva contribute to peptide degradation. Therefore, innovative strategies are essential to enhance peptide stability, retention, and permeation in this environment. Nanoparticle-based delivery systems, including lipid-based carriers such as liposomes and niosomes, as well as polymeric nanoparticles like chitosan and PLGA, offer promising solutions. These nanocarriers protect peptides from enzymatic degradation, enhance mucoadhesion to prolong residence time, and facilitate controlled release. Their size and surface properties can be engineered to improve mucosal penetration, including through receptor-mediated endocytosis or by transiently opening tight junctions. Among these, niosomes have shown high encapsulation efficiency and sustained release potential, making them particularly suitable for oral peptide delivery. Despite advances, challenges remain in translating these technologies clinically, including ensuring biocompatibility, scalable manufacturing, and patient acceptance. Nevertheless, the oral cavity’s accessibility, combined with nanotechnological innovations, offers a compelling platform for personalized, non-invasive peptide therapies that could significantly improve treatment outcomes and patient quality of life. Full article

Nisin, a food preservative lantibiotic produced by Lactococcus lactis, exhibits potent antimicrobial activity against a wide range of Gram-positive pathogens, including antibiotic-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA). This study explores the development of a novel nano drug delivery platform comprising nisin-loaded niosomes, formulated via microfluidic mixing, and integrated into fast-dissolving oral films for targeted buccal administration. Microfluidic synthesis enabled the precise control of critical parameters including the flow rate ratio, surfactant composition, and lipid concentration, resulting in uniform niosomal vesicles with optimal size distribution (100–200 nm), low polydispersity index, and high encapsulation efficiency. Span 40 and Span 60 were employed as non-ionic surfactants, stabilized with cholesterol to improve bilayer rigidity and drug retention. The encapsulated nisin demonstrated improved physicochemical stability over time and protection against proteolytic degradation, thus preserving its antimicrobial potency. The niosomal suspensions were subsequently incorporated into polymer-based oral films as a final dosage form composed of polyvinyl alcohol (PVA) as the primary film-forming polymer, polyethylene glycol 400 (PEG400) as a plasticizer, and sucralose and mint as a sweetener and flavoring agent, respectively. A disintegrant was added to accelerate film dissolution in the oral cavity, facilitating the rapid release of niosomal nisin. The films were cast and evaluated for thickness uniformity, mechanical properties, disintegration time, surface morphology, and drug content uniformity. The dried films exhibited desirable flexibility, rapid disintegration (<30 s), and consistent distribution of nisin-loaded vesicles. In vitro antimicrobial assays confirmed that the bioactivity of nisin was retained post-formulation, showing effective inhibition zones (16 mm) against Bacillus subtilis. This delivery system offers a promising platform for localized antimicrobial therapy in the oral cavity, potentially aiding in the treatment of dental plaque, oral infections, and periodontal diseases. Overall, the integration of microfluidic-synthesized nisin niosomes into oral films presents a novel, non-invasive strategy for enhancing the stability and therapeutic efficacy of peptide-based drugs in mucosal environments. Physicochemical characterization of the niosomes and niosome films was performed using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to evaluate thermal stability and scanning electron microscopy (SEM) to assess surface morphology. In vitro peptide release studies demonstrated sustained release from both niosomal suspensions and film matrices, and the resulting data were further fitted to established kinetic models to elucidate the underlying drug release mechanisms. This delivery system offers a promising platform for localized antimicrobial therapy in the oral cavity, potentially aiding in the treatment of dental plaque, oral infections, and periodontal diseases. Overall, the integration of microfluidic-synthesized nisin niosomes into oral films presents a novel, non-invasive strategy for enhancing the stability and therapeutic efficacy of peptide-based drugs in mucosal environments. Full article