Preparation and characterization of laminated thiolated chitosan-based freeze-dried wafers for potential buccal delivery of macromolecules

P-gp inhibition and enhanced oral bioavailability of amikacin Sulfate: A novel approach using Thiolated Chito-PEGylated Lipidic Hybrids

This study aimed to develop oral lipidic hybrids of amikacin sulfate (AMK), incorporating thiolated chitosan as a P-glycoprotein (P-gp) inhibitor to enhance intestinal absorptivity and bioavailability. Three formulations were designed: PEGylated Liposomes, Chitosan-functionalized PEGylated (Chito-PEGylated) Lipidic Hybrids, and Thiolated Chito-PEGylated Lipidic Hybrids. The physical characteristics of nanovesicles were assessed. Ex-vivo permeation and confocal laser scanning microscopy (CLSM) studies were conducted to evaluate the formulations' potential to enhance AMK intestinal permeability. In-vivo pharmacokinetic studies in rats and histological/biochemical investigations assessed the safety profile and oral bioavailability. The AMK-loaded Thiolated Chito-PEGylated Lipidic Hybrids exhibited favorable physical characteristics, higher ex-vivo permeation parameters, and verified P-gp inhibition via CLSM. They demonstrated heightened oral bioavailability (68.62% absolute bioavailability) and a sufficient safety profile. Relative bioavailability was significantly higher (1556.3% and 448.79%) compared to PEGylated Liposomes and Chito-PEGylated Lipidic Hybrids, respectively, indicating remarkable oral AMK delivery with fewer doses, reduced side effects, and enhanced patient compliance.

Buccal delivery of small molecules and biologics: Of mucoadhesive polymers, films, and nanoparticles - An update

Buccal delivery of small and large molecules is an attractive route of administration that has been studied extensively over the past few decades. This route bypasses first-pass metabolism and can be used to deliver therapeutics directly to systemic circulation. Moreover, buccal films are efficient dosage forms for drug delivery due to their simplicity, portability, and patient comfort. Films have traditionally been formulated using conventional techniques, including hot-melt extrusion and solvent casting. However, newer methods are now being exploited to improve the delivery of small molecules and biologics. This review discusses recent advances in buccal film manufacturing, using the latest technologies, such as 2D and 3D printing, electrospraying, and electrospinning. This review also focuses on the excipients used in the preparation of these films, with emphasis on mucoadhesive polymers and plasticizers. Along with advances in manufacturing technology, newer analytical tools have also been used for the assessment of permeation of the active agents across the buccal mucosa, the most critical biological barrier and limiting factor of this route. Additionally, preclinical and clinical trial challenges are discussed, and some small molecule products already on the market are explored.

Novel mucoadhesive celecoxib-loaded cubosomal sponges: Anticancer potential and regulation of myeloid-derived suppressor cells in oral squamous cell carcinoma

Oral squamous-cell carcinoma (OSCC) is a widespread health problem. Myeloid-derived suppressor cells (MDSCs) are major tumor microenvironment (TME) population that govern many carcinogenesis aspects by establishing immunosuppressive milieu favoring tumor aggressiveness and treatment resistance. Cyclooxygenase-2 (COX-2) regulates MDSCs activity, hence, COX-2-selective inhibition by celecoxib (CXB) showed good anticancer effect at relatively high doses with possible subsequent cardiovascular complications. Therefore, targeted CXB delivery to MDSCs may represent a promising OSCC treatment strategy. Novel mucoadhesive-cubosomal buccal sponges were prepared for MDSCs targeting and were evaluated for their in-vitro quality attributes, ex-vivo mucoadhesion using buccal chicken-mucosa. Optimally-selected formulation showed considerable uptake by CD33⁺/11b⁺MDSCs in human OSCC cell-line (SCC-4) when quantitatively analyzed by flow-cytometry and examined using confocal-laser microscope. Optimum formulations loaded with low CXB doses (12 mg) were promoted to in-vivo studies via local application, using 4-nitroquinoline-1-oxide-induced OSCC in rats, and compared to their corresponding CXB gels. SP16 revealed the highest ability to decrease MDSC activation, recruitment and TME-immunosuppression in the isolated tumors. Consequently, SP16 exerted the greatest capacity to reduce histologic tumor grade, the OSCC-specific serum tumor markers levels, cancer hallmarks and stemness markers. CXB-loaded cubosomal sponges preferentially target MDSCs with noticeable anticancer potential and may exemplify novel mucoadhesive nanocarriers for OSCC treatment.

Development of Mucoadhesive Buccal Film for Rizatriptan: In Vitro and In Vivo Evaluation

The reduced therapeutic efficacy of rizatriptan in migraine treatment is primarily due to low oral bioavailability and extensive first pass metabolism. The purpose of this investigation was to optimize the thin mucoadhesive buccal film of rizatriptan and assess the practicability of its development as a potential substitute for conventional migraine treatment. Buccal films (FR1-FR10) were fabricated by a conventional solvent casting method utilizing a combination of polymers (Proloc, hydroxypropyl methylcellulose and Eudragit RS 100). Drug-loaded buccal films (F1-F4) were examined for mechanical, mucoadhesive, swelling and release characteristics. In vivo pharmacokinetics parameters of selected buccal film (F1) in rabbits were compared to oral administration. Films F1-F4 displayed optimal physicomechanical properties including mucoadhesive strength, which can prolong the buccal residence time. A biphasic, complete and higher drug release was seen in films F1 and F4, which followed Weibull model kinetics. The optimized film, F1, exhibited significantly higher (p < 0.005) rizatriptan buccal flux (71.94 ± 8.26 µg/cm²/h) with a short lag time. Film features suggested the drug particles were in an amorphous form, compatible with the polymers used and had an appropriate surface morphology suitable for buccal application. Pharmacokinetic data indicated a significantly higher rizatriptan plasma level (p < 0.005) and C_max (p < 0.0001) upon buccal film application as compared to oral solution. The observed AUC_0-12h (994.86 ± 95.79 ng.h/mL) in buccal treatment was two-fold higher (p < 0.0001) than the control, and the relative bioavailability judged was 245%. This investigation demonstrates the prospective of buccal films as a viable and alternative approach for effective rizatriptan delivery.

In vitro, ex vivo and in vivo evaluation of taste masked low dose acetylsalicylic acid loaded composite wafers as platforms for buccal administration in geriatric patients with dysphagia

This study reports the development and characterization of taste masked, freeze-dried composite wafers for potential oral and buccal delivery of low dose aspirin (acetylsalicylic acid) to prevent thrombosis in elderly patients with dysphagia. The wafers were formulated by combining metolose (MET) with carrageenan (CAR), MET with chitosan (CS) at low molecular weight or CAR with CS using 45% v/v ethanol as solvent for complete solubilization of acetylsalicylic acid. Each wafer contained 75 mg of acetylsalicylic acid and sweetener (sucralose, stevia or aspartame) with a drug: sweetener ratio of 1:1 w/w. The formulations were characterized for physical properties using texture analyzer (hardness and mucoadhesion), scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, swelling capacity, and in vitro drug dissolution. Further, permeation studies with three different models (Permeapad™ artificial barrier, EpiOral™ and porcine buccal mucosa) using HPLC, cell viability using MTT assay and in vivo taste masking evaluation using human volunteers were undertaken. The sweeteners increased the hardness and adhesion of the wafers, XRD showed the crystalline nature of the samples which was attributed to acetylsalicylic acid, SEM confirmed a compacted polymer matrix due to recrystallized acetylsalicylic acid and sweeteners dispersed over the surface. Drug dissolution studies showed that acetylsalicylic acid was rapidly released in the first 20 min and then continuously over 1 h. EpiOral™ had a higher cumulative permeation than porcine buccal tissue and Permeapad™ artificial barrier, while MTT assay using Vero cells (ATCC® CCL-81) showed that the acetylsalicylic acid loaded formulations were non-toxic. In vivo taste masking study showed the ability of sucralose and aspartame to mask the bitter taste of acetylsalicylic acid and confirm that acetylsalicylic acid loaded MET:CAR, CAR:CS and MET:CS composite wafers containing sucralose or aspartame have potential for buccal delivery of acetylsalicylic acid in geriatric patients with dysphagia.

Thiolated Chitosans: A Multi-talented Class of Polymers for Various Applications

Various properties of chitosan can be customized by thiolation for very specific needs in a wide range of application areas. Since the discovery of thiolated chitosans, many studies have proven their advantageous characteristics, such as adhesion to biological surfaces, adjustable cross-linking and swelling behavior, controllable drug release, permeation as well as cellular uptake enhancement, inhibition of efflux pumps and enzymes, complexation of metal ions, antioxidative properties, and radical scavenging activity. Simultaneously, these polymers remain biodegradable without increased toxicity. Within this Review, an overview about the different possibilities to covalently attach sulfhydryl ligands to the polymeric backbone of chitosan is given, and the resulting versatile physiochemical properties are discussed in detail. Furthermore, the broad spectrum of applications for thiolated chitosans in science and industry, ranging from their most advanced use in pharmaceutical and medical science over wastewater treatment to the impregnation of textiles, is addressed.

Chitosan-Based Drug Delivery System: Applications in Fish Biotechnology

Chitosan is increasingly used for safe nucleic acid delivery in gene therapy studies, due to well-known properties such as bioadhesion, low toxicity, biodegradability and biocompatibility. Furthermore, chitosan derivatization can be easily performed to improve the solubility and stability of chitosan-nucleic acid polyplexes, and enhance efficient target cell drug delivery, cell uptake, intracellular endosomal escape, unpacking and nuclear import of expression plasmids. As in other fields, chitosan is a promising drug delivery vector with great potential for the fish farming industry. This review highlights state-of-the-art assays using chitosan-based methodologies for delivering nucleic acids into cells, and focuses attention on recent advances in chitosan-mediated gene delivery for fish biotechnology applications. The efficiency of chitosan for gene therapy studies in fish biotechnology is discussed in fields such as fish vaccination against bacterial and viral infection, control of gonadal development and gene overexpression and silencing for overcoming metabolic limitations, such as dependence on protein-rich diets and the low glucose tolerance of farmed fish. Finally, challenges and perspectives on the future developments of chitosan-based gene delivery in fish are also discussed.

Chitosan Derivatives and Their Application in Biomedicine

Chitosan is a product of the deacetylation of chitin, which is widely found in nature. Chitosan is insoluble in water and most organic solvents, which seriously limits both its application scope and applicable fields. However, chitosan contains active functional groups that are liable to chemical reactions; thus, chitosan derivatives can be obtained through the chemical modification of chitosan. The modification of chitosan has been an important aspect of chitosan research, showing a better solubility, pH-sensitive targeting, an increased number of delivery systems, etc. This review summarizes the modification of chitosan by acylation, carboxylation, alkylation, and quaternization in order to improve the water solubility, pH sensitivity, and the targeting of chitosan derivatives. The applications of chitosan derivatives in the antibacterial, sustained slowly release, targeting, and delivery system fields are also described. Chitosan derivatives will have a large impact and show potential in biomedicine for the development of drugs in future.

Oral thin films as a remedy for noncompliance in pediatric and geriatric patients

Pediatric and geriatric patients experience swallowing difficulties for traditional oral dosage forms, such as tablets. Further, microbial contamination, chemical stability, unpleasant taste and swallowing large volumes of fluids have led to low therapeutic efficacy and patient noncompliance. The emergence of oral thin films has resulted in dramatic improvements in compliance and drug therapy outcomes in pediatric and geriatric patients. Oral thin films do not require water for administration, are readily hydrated upon contact with saliva, adhere to the mucosa and disintegrate ideally under 1 min. This article provides an overview of oral thin films, modern trends in their formulation and characterization, available commercial products, information to fill knowledge gaps and future potential and economic prospects of oral thin film technology, with emphasis on their use in the pediatric and geriatric patient groups.

Development and functional characterization of composite freeze dried wafers for potential delivery of low dose aspirin for elderly people with dysphagia

The impact of demographic ageing is likely to be of major significance in the coming decades due to low birth rates and higher life expectancy. Older people generally require more prescribed medicines due to the presence of multiple conditions such as dysphagia which can make swallowing medicines challenging. This study involves the development, characterization and optimization of composite wafers for potential oral and buccal delivery of low dose aspirin to prevent thrombosis in elderly patients with dysphagia. Blank (BLK) wafers (no loaded drug) were initially formulated by dissolving combinations of metolose (MET) with carrageenan (CAR) and MET with low molecular weight chitosan (CS) in different weight ratios in water, to identify optimum polymer combinations. However, drug loaded (DL) wafers were prepared using 45% v/v ethanol to help complete solubilization of the aspirin. The formulations were characterized using texture analyzer (hardness, mucoadhesion), scanning electron microscopy (SEM), X-ray diffractometry (XRD), attenuated total reflectance - Fourier transform infrared (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), and swelling capacity. Wafers with higher total polymer concentration were more resistant to penetration (MET:CAR 1:1 samples B2, C2) and MET:CS 1:1 (sample E2) and MET:CS 3:1 (sample F2) and also depended on the ratios between the polymers used. From the characterization, samples C2, B2, E2 and F2 showed the most ideal characteristics. XRD showed that BLK wafers were amorphous, whilst the DL wafers were crystalline due to the presence of aspirin. SEM confirmed the presence of pores within the polymer matrix of the BLK wafers, whilst DL wafers showed a more compact polymeric matrix with aspirin dispersed over the surface. The DL wafers showed a good flexibility required for transportation and patient handling and showed higher swelling capacity and adhesion values with phosphate buffer saline (PBS) than with simulated saliva (SS). Drug dissolution studies showed that aspirin was rapidly released in the first 20 min and then continuously over 1 h. FTIR confirmed the interaction of aspirin with the polymers evidenced by peak shifts around 1750 cm^-1 and the broad peak between 2500 and 3300 cm^-1. Lyophilized CAR: CS 1:3 (sample DL13), MET:CS 1:3 (sample DL8) and MET:CAR 3:1 (sample DL1) wafers seem to be a very promising system for the administration of low dose aspirin for older patients with dysphagia.

Laminated chitosan-based composite sponges for transmucosal delivery of novel protamine-decorated tripterine phytosomes: Ex-vivo mucopenetration and in-vivo pharmacokinetic assessments

In the current study, laminated chitosan (CS):hydroxypropyl methylcellulose (HPMC) composite sponges were exploited as solid matrices for buccal delivery of tripterine phytosomes functionalized with novel mucopenetrating protamine layer (PRT-TRI-PHY). Tripterine (TRI) is a herbal drug widely investigated as a potential anticancer candidate against various types of cancers. However, clinical use of TRI is handicapped by its low oral bioavailability. To surmount TRI pharmaceutical obstacles, TRI phytosomes (TRI-PHY) were prepared using solvent evaporation technique then coated with a protamine layer via electrostatic assembly process. The developed PRT-TRI-PHY showed a nano-metric size of 250 nm and positive zeta potential (+21.6 mV). Sponges loaded with PRT-TRI-PHY demonstrated a sustained release profile with superior mucoadhesion characteristics compared with the counterparts loaded with uncoated TRI-PHY. The ex-vivo permeation study via chicken pouch mucosa revealed that sponges loaded with PRT-TRI-PHY demonstrated 2.3-folds higher flux value compared with sponges loaded with uncoated TRI-PHY. Additionally, in-vivo pharmacokinetic study in healthy rabbits revealed the significantly higher bioavailability of PRT-TRI-PHY compared with TRI-PHY with relative bioavailability of 244%. Conclusively, mucoadhesive CS-HPMC sponges loaded with a novel mucopenetrating nanocarrier, PRT-TRI-PHY, could significantly improve the absorption of tripterine via buccal mucosa which would be of prime importance for its clinical utility.

Buccal delivery of small molecules and biologics: of mucoadhesive polymers, films, and nanoparticles

Buccal delivery of macromolecules (biologics) sets a great challenge for researchers. Although several niche small molecule products have been approved as simple sprays, tablets and oral films, it is not simply a case of adapting existing technologies to biologics. Buccal delivery of insulin has reached clinical trials with two approaches: oromucosal sprays of the peptide with permeation enhancers, and embedded gold nanoparticles in a dissolvable film. However, neither of these approaches have led to FDA approvals likely due to poor efficacy, submaximal peptide loading in the dosage form, and to wide intra-subject variability in pharmacokinetics and pharmacodynamics. It is likely however that printed film designs with lower molecular weight stable biotech payloads including lipophilic glucagon-like 1 (GLP-1) agonists and macrocycles with long half-lives will generate greater efficacy than was achieved to date for insulin.

Oromucosal multilayer films for tailor-made, controlled drug delivery

INTRODUCTION

The oral mucosa has recently become increasingly important as an alternative administration route for tailor-made, controlled drug delivery. Oromucosal multilayer films, assigned to the monograph oromucosal preparations in the Ph.Eur. may be a promising dosage form to overcome the requirements related to this drug delivery site. Areas covered: We provide an overview of multilayer films as drug delivery tools, and discuss manufacturing processes and characterization methods. We focus on the suitability of characterization methods for particular requirements of multilayer films. A classification was performed covering indication areas and APIs incorporated in multilayer film systems for oromucosal use in order to provide a summary of data published in this field. Expert opinion: The shift in drug development to high molecular weight drugs will influence the field of pharmaceutical development and delivery technologies. For a high number of indication areas, such as hormonal disorders, cardiovascular diseases or local treatment of infections, the flexible layer design of oromucosal multilayer films provides a promising option for tailor-made, controlled delivery of APIs to or through defined surfaces in the oral cavity. However, there is a lack of discriminating or standardized testing methods to assess the quality of multilayer films in a reliable way.

Sustained release of bioactive protein from a lyophilized tissue-engineered construct promotes the osteogenic potential of mesenchymal stem cells

Tissue-engineered constructs (TECs) seeded with mesenchymal stem cells (MSCs) represent a therapy for large bone defects. However, massive cell death in TECs in the early postimplantation period prompted us to investigate the osteoinductive mechanism of TECs. Previous studies demonstrated that stem cell extracts retained equivalent levels of bioactive proteins and exhibited an osteoinductive nature similar to that of intact cells. These data led us to hypothesize that despite the massive cell death in TECs, devitalized MSC-derived proteins remain on the scaffolds and are released to improve cell function. Here, TECs were prepared using demineralized bone matrix seeded with human umbilical cord Wharton's jelly-derived MSCs (hWJMSCs), and the cells seeded in TECs were devitalized by lyophilizing the TECs. Scanning electron microscopy, BCA protein assays, quantitative cytokine array analysis and immunofluorescent staining indicated that approximately 3 mg/cm(3) of total protein and 49 types of cytokines derived from hWJMSCs were preserved in the lyophilized TECs (LTECs). The sustainable release of total protein and cytokines from LTECs lasted for more than 2 weeks. The released protein improved the osteogenic behavior of and gene expression in MSCs. Furthermore, the lyophilized hWJMSC-derived proteins had immunoregulatory properties similar to those of live MSCs in mixed lymphocyte reactions. Collectively, we present a novel perspective on the osteoinductive mechanism of TECs and introduce LTECs as new systems for delivering multiple cytokines to enhance MSC behavior.

Pharmacological evaluation of nasal delivery of selegiline hydrochloride-loaded thiolated chitosan nanoparticles for the treatment of depression

The aim of the present study was to investigate the propensity of thiolated chitosan nanoparticles (TCNs) to enhance the nasal delivery of selegiline hydrochloride. TCNs were synthesized by the ionic gelation method. The particle size distribution (PDI), entrapment efficiency (EE), and zeta potential of modified chitosan (CS) nanoparticles were found to be 215 ± 34.71 nm, 70 ± 2.71%, and + 17.06 mV, respectively. The forced swim and the tail suspension tests were used to evaluate the anti-depressant activity, in which elevated immobility time was found to reduce on treatment. TCNs seem to be promising candidates for nose-to-brain delivery in the evaluation of antidepressant activity.