Advances in oral transmucosal drug delivery

Is Diclofenac Transbuccal Mucoadhesive Patch Superior to Oral Diclofenac for the Management of Postoperative Sequelae After Third Molar Surgery?

BACKGROUND

Pain, swelling, and trismus are the most common sequalae following the surgical removal of mandibular third molars. They pose significant challenges for clinicians, prompting the exploration of efficacious management approaches.

PURPOSE

The purpose of this study was to assess the efficacy of transbuccal mucoadhesive patch of diclofenac sodium versus an oral tablet in controlling the aforesaid sequelae.

STUDY DESIGN, SETTING, SAMPLE

A prospective split-mouth, single-blinded study was conducted in the Department of Oral and Maxillofacial Surgery at AMC Dental College and Hospital, Ahmedabad. The study sample included patients of either sex, aged 18 to 45 years, requiring surgical removal of bilaterally symmetrical mandibular third molars under local anesthesia. Patients who had consumed analgesics within 24 hours prior to the procedure were excluded.

PREDICTOR VARIABLE

The primary predictor variable was the route of administration of nonsteroidal anti-inflammatory drug. The study group received transbuccal mucoadhesive patches containing 20 mg diclofenac sodium, whereas the control group received oral tablets of 50 mg.

MAIN OUTCOME VARIABLE

Postoperative pain, measured with visual analog scale, was the primary outcome variable, whereas swelling, mouth opening, onset of analgesic effect, and adverse events were assessed as secondary outcome variables.

COVARIATES

Two categories of covariates were considered. First, demographic: age and gender. Second, perioperative: pattern of impaction.

ANALYSES

Intergroup comparison was made using a paired sample t-test and an independent sample t-test, while intragroup differences were assessed with a one-way ANOVA and a paired t-test. P value ≤ .05 was considered statistically significant.

RESULTS

Out of 146 patients screened initially, the final study sample included 37 subjects with a mean age of 26.08 ± 5.09 years (21 (56.75%) males and 16 (43.25%) females). The study group exhibited a significantly lower postoperative pain score compared to the control group on days 0, 1, 2, and 3 postoperatively (P ≤ .05). No statistically significant difference was observed in reduction of facial swelling and improvement in mouth opening on 1st, 2nd, and 3rd days postoperatively between both the groups (P ≥ .05). The mean onset of analgesia was statistically significant in the study group (19.96 ± 5.40 minutes) compared to the control group (52.56 ± 6.33 minutes) (P < .001).

CONCLUSION AND RELEVANCE

Transbuccal mucoadhesive patch of diclofenac sodium offers effective pain control with quicker analgesia and fewer side effects compared to an oral tablet.

Permeability of triamcinolone acetonide, released from mucoadhesive films, through a buccal mucosa-mimetic barrier: Permeapad™

OBJECTIVES

The permeability of triamcinolone acetonide (TA), from bilayer mucoadhesive buccal films, through a biomimetic membrane, Permeapad™, was investigated employing Franz diffusion cell. The delivery systems composition and ethyl cellulose (EC) backing layer, on drug permeability, were assessed.

METHODS

Three TA-loaded films were tested; hydroxypropyl methylcellulose (HPMC K4M; bilayer [F1] and monolayer), HPMC K4M/Polyvinylpyrrolidone (PVP): 90/10 [F2], and HPMC K15M film [F3]. All films contained propylene glycol (PG-plasticiser). TA solution alone was used as a control. TA permeability via a Permeapad™ barrier, simulating buccal mucosa, was assessed over 8 h using a Franz diffusion cell. TA permeated into the receptor compartment, released in the donor compartment, and located on/within the Permeapad™ barrier were analysed using UV-spectrophotometer.

RESULTS

45.7 % drug retention within the Permeapad™ barrier was delivered from F1 (highest). F1, F2, and F3 significantly improved the TA's permeability through Permeapad™, compared to TA solution alone (e.g., 8.5 % TA-solution, 21.5 %-F1), attributed to the synergy effect of HPMC and propylene glycol acting as penetration enhancers. F1 displayed a significant increase in drug permeability (receptor compartment; 21.5 %) compared to F3 (17.0 %). PVP significantly enhanced drug permeability (27.5 %). Impermeable EC backing layer controlled unidirectional drug release and reduced drug loss into the donor compartment (e.g., ∼28 % for monolayer film to ∼10 % for bilayer film, F1).

SIGNIFICANCE

The mucoadhesive films demonstrated improved TA permeability via Permeapad™. The findings suggest that these bilayer mucoadhesive films, particularly F1, hold promise for the effective topical treatment of oral mucosa disorders, such as recurrent aphthous stomatitis and oral lichen planus.

In vitro Models for Predicting Bioadhesion Fracture Strength to Ex Vivo Animal Buccal Tissue

Commitment to the 3Rs principle (Replacement, Reduction, and Refinement) led to the development of a cell-based system to measure buccal bioadhesion in vitro and replace the use of porcine buccal and esophageal tissues (PBT and PET, respectively). Additionally, the aim is to bridge the gap in knowledge regarding the bioadhesion properties of PBT and PET. The in vitro models are based on the human buccal epithelial cell line-TR146 without ("Model I") or with ("Model II") 5% (w/v) mucous layer. The in vitro setup also provides a method to evaluate the bioadhesion between two soft materials. Standard bioadhesive hydrogels (alginate, chitosan, and gelatin) are used to test and compare the results from the in vitro models to the ex vivo tissues. The ex vivo and in vitro models show increased bioadhesion as the applied force and contact time increases. Furthermore, Model I exhibits bioadhesion values-of alginate, chitosan, and gelatin-comparable to those obtained with PBT. It is also found that contact time and applied force similarly affect PBT and PET bioadhesion, while PET exhibits greater values. In conclusion, Model I can replace PBT for measuring bioadhesion and be incorporated into the experimental design of bioadhesive DDS, thus minimizing animal tissue usage.

Leading Paediatric Infectious Diseases-Current Trends, Gaps, and Future Prospects in Oral Pharmacotherapeutic Interventions

Paediatric infectious diseases contribute significantly to global health challenges. Conventional therapeutic interventions are not always suitable for children, as they are regularly accompanied with long-standing disadvantages that negatively impact efficacy, thus necessitating the need for effective and child-friendly pharmacotherapeutic interventions. Recent advancements in drug delivery technologies, particularly oral formulations, have shown tremendous progress in enhancing the effectiveness of paediatric medicines. Generally, these delivery methods target, and address challenges associated with palatability, dosing accuracy, stability, bioavailability, patient compliance, and caregiver convenience, which are important factors that can influence successful treatment outcomes in children. Some of the emerging trends include moving away from creating liquid delivery systems to developing oral solid formulations, with the most explored being orodispersible tablets, multiparticulate dosage forms using film-coating technologies, and chewable drug products. Other ongoing innovations include gastro-retentive, 3D-printed, nipple-shield, milk-based, and nanoparticulate (e.g., lipid-, polymeric-based templates) drug delivery systems, possessing the potential to improve therapeutic effectiveness, age appropriateness, pharmacokinetics, and safety profiles as they relate to the paediatric population. This manuscript therefore highlights the evolving landscape of oral pharmacotherapeutic interventions for leading paediatric infectious diseases, crediting the role of innovative drug delivery technologies. By focusing on the current trends, pointing out gaps, and identifying future possibilities, this review aims to contribute towards ongoing efforts directed at improving paediatric health outcomes associated with the management of these infectious ailments through accessible and efficacious drug treatments.

Mucoadhesive polymers: Design of S-protected thiolated cyclodextrin-based hydrogels

AIM

This study aims to design chemically crosslinked thiolated cyclodextrin-based hydrogels and to evaluate their mucoadhesive properties via mucosal residence time studies on porcine small intestinal mucosa and on porcine buccal mucosa.

METHODS

Free thiol groups of heptakis(6-deoxy-6-thio)-β-cyclodextrin (β-CD-SH) were S-protected with 2-mercaptoethanesulfonic acid (MESNA) followed by crosslinking with citric acid. Cytotoxicity was assessed by hemolysis as well as resazurin assay. Hydrogels were characterized by their rheological and mucoadhesive properties. Ritonavir was employed as model drug for in vitro release studies from these hydrogels.

RESULTS

The structure of S-protected β-CD-SH was confirmed by IR and 1H NMR spectroscopy. Degree of thiolation was 390 ± 7 µmol/g. Hydrogels based on native β-CD showed hemolysis of 12.5 ± 2.5 % and 13.6 ± 2.7 % within 1 and 3 h, whereas hemolysis of just 3.5 ± 2.8 % and 3.9 ± 3.0 % was observed for the S-protected thiolated CD hydrogels, respectively. Both native and S-protected thiolated hydrogels showed minor cytotoxicity on Caco-2 cells. Rheological investigations of S-protected thiolated β-CD-based hydrogel (16.2 % m/v) showed an up to 13-fold increase in viscosity in contrast to the corresponding native β-CD-based hydrogel. Mucosal residence time studies showed that thiolated β-CD-based hydrogel is removed to a 16.6- and 2.4-fold lower extent from porcine small intestinal mucosa and porcine buccal mucosa in comparision to the native β-CD-based hydrogel, respectively. Furthermore, a sustained release of ritonavir from S-protected thiolated β-CD-based hydrogels was observed.

CONCLUSION

Because of their comparatively high mucoadhesive and release-controlling properties, S-protected thiolated β-CD-based hydrogels might be promising systems for mucosal drug delivery.

Systemic delivery of proteins using novel peptides via the sublingual route

Therapeutic proteins often require needle-based injections, which compromise medication adherence especially for those with chronic diseases. Sublingual administration provides a simple and non-invasive alternative. Herein, two novel peptides (lipid-conjugated protamine and a protamine dimer) were synthesized to enable sublingual delivery of proteins through simple physical mixing with the payloads. It was found that the novel peptides promoted intracellular delivery of proteins via increased pore formation on the cell surface. Results from in vitro models of cell spheroids and human sublingual tissue substitute indicated that the novel peptides enhanced protein penetration through multiple cell layers compared to protamine. The novel peptides were mixed with insulin or semaglutide and sublingually delivered to mice for blood glucose (BG) control. The effects of these sublingual formulations were comparable to the subcutaneous preparations and superior to protamine. In addition to peptide drugs, the novel peptides were shown to enable sublingual absorption of larger proteins with molecular weights from 22 to 150 kDa in mice, including human recombinant growth hormone (rhGH), bovine serum albumin (BSA) and Immunoglobulin G (IgG). The novel peptides given sublingually did not induce any measurable toxicities in mice.

Combining the potential of 3D printed buccal films and nanostructured lipid carriers for personalised cannabidiol delivery

Cannabidiol (CBD) has been recognized for its numerous therapeutic benefits, such as neuroprotection, anti-inflammatory effects, and cardioprotection. However, CBD has some limitations, including unpredictable pharmacokinetics and low oral bioavailability. To overcome the challenges associated with CBD delivery, we employed Design of Experiments (DoE), lipid carriers, and 3D printing techniques to optimize and develop buccal film loaded with CBD-NLCs. Three-factor Box-Behnken Design was carried out to optimise the NLCs and analyse the effect of independent factors on dependent factors. The emulsification-ultrasonication technique was used to prepare the NLCs. A pressure-assisted micro-syringe printing technique was used to produce the films. The produced films were studied for physicochemical, and mechanical properties, release profiles, and predicted in vivo performance. The observed particle size of the NLCs ranged from 12.17 to 84.91 nm whereas the PDI varied from 0.099 to 0.298. Lipid and sonication time positively affected the particle size whereas the surfactant concentration was inversely related. CBD was incorporated into the optimal formulation and the observed particle size, PDI, and zeta potential for the CBD-NLCs were 94.2 ± 0.47 nm, 0.11 ± 0.01 and - 11.8 ± 0.52 mV. Hydroxyethyl cellulose (HEC)-based gel containing the CBD-NLCs was prepared and used as a feed for 3D printing. The CBD-NLCs film demonstrated a slow and sustained in vitro release profile (84. 11 ± 7.02% in 6 h). The predicted AUC0-10 h, Cmax, and Tmax were 201.5 µg·h/L, 0.74 µg/L, and 1.28 h for a film with 0.4 mg of CBD, respectively. The finding demonstrates that a buccal film of CBD-NLCs can be fabricated using 3D printing.

Assessment of Patient Characteristics Influencing the Analgesic Effects of Ibuprofen Gargle After Mandibular Third Molar Extractions

Introduction In our previous work, we investigated the analgesic effects of ibuprofen gargle after mandibular third molar extractions. However, a subsequent detailed review of individual patient data revealed variations in postoperative pain reduction among patients. Consequently, the present study was designed to conduct post-hoc subanalyses that identified factors contributing to variation in the analgesic response to ibuprofen gargle after third molar extractions. Materials and methods This study involved thirty-five Japanese patients from a prior randomized, double-blind, placebo-controlled, crossover study, which focused on the analgesic effects of ibuprofen gargle after mandibular third molar extractions. Participants were categorized as responders (n = 13) and non-responders (n = 22) based on the within-subject difference (ibuprofen-placebo, IP) of visual analog scale (VAS) changes. Baseline characteristics were compared, along with variables, such as age, sex, the reason for extraction, extraction site, Pell Gregory (space and depth) classification, Winter's classification, surgeon's experience, and surgery time. Baseline characteristics predicting responder status were examined using multivariate logistic regression. Results In the univariate analysis, variables such as age, sex, and baseline VAS scores with p-values <0.2 were evaluated using a stepwise approach. This analysis identified age (per -10 years) with an odds ratio of 4.163 (95% confidence interval (CI): 1.170-31.952, p = 0.0233) and sex (female) with an odds ratio of 9.977 (95% CI: 1.336-208.256, p = 0.0213) as significant predictors of responder status. Conclusions In young and female patients, ibuprofen gargle decreased postoperative pain after mandibular third molar extractions.

Salivary Amylase-Responsive Buccal Tablets Wipe Out Chemotherapy-Rooted Refractory Oral Mucositis

Oral mucositis (OM) is the most common and refractory complication of cancer chemotherapy and radiotherapy, severely affecting patients' life quality, lowering treatment tolerance, and discouraging patient compliance. Current OM delivery systems mostly affect the comfort of patient use and lead to poor compliance and unsatisfactory effects. Herein, salivary amylases (SAs)-responsive buccal tablets consisting of porous manganese-substituted Prussian blue (PMPB) nanocubes (NCs), anti-inflammatory apremilast (Apr) and starch controller have been engineered. PMPB NCs with large surface area can serve as carriers to load Apr, and their multienzyme-mimicking activity enables them to scavenge reactive oxygen species (ROS), which thus synergize with Apr to mitigate inflammation. More significantly, the starch controller can respond to abundant SAs in the oral cavity and realize the cascade, continuous, and complete drug release after enzymatic decomposition, which not only aids with high tissue affinity to prolong the resistance time but also improves the comfort of use. The preclinical study reveals that contributed by the above actions, such buccal tablets mitigate inflammation, promote endothelium proliferation and migration, and accelerate wound healing for repressing chemotherapy-originated intractable OM with positive oral microenvironment and shorter recovery time, thus holding high potentials in clinical translation.

Revisited and innovative perspectives of oral ulcer: from biological specificity to local treatment

Mouth ulcers, a highly prevalent ailment affecting the oral mucosa, leading to pain and discomfort, significantly impacting the patient's daily life. The development of innovative approaches for oral ulcer treatment is of great importance. Moreover, a deeper and more comprehensive understanding of mouth ulcers will facilitate the development of innovative therapeutic strategies. The oral environment possesses distinct traits as it serves as the gateway to the digestive and respiratory systems. The permeability of various epithelial layers can influence drug absorption. Moreover, oral mucosal injuries exhibit distinct healing patterns compared to cutaneous lesions, influenced by various inherent and extrinsic factors. Furthermore, the moist and dynamic oral environment, influenced by saliva and daily physiological functions like chewing and speaking, presents additional challenges in local therapy. Also, suitable mucosal adhesion materials are crucial to alleviate pain and promote healing process. To this end, the review comprehensively examines the anatomical and structural aspects of the oral cavity, elucidates the healing mechanisms of oral ulcers, explores the factors contributing to scar-free healing in the oral mucosa, and investigates the application of mucosal adhesive materials as drug delivery systems. This endeavor seeks to offer novel insights and perspectives for the treatment of oral ulcers.

Formulation optimization and evaluation of oromucosal in situ gel loaded with silver nanoparticles prepared by green biosynthesis

Treating oral diseases remains challenging as API is quickly washed out of the application site by saliva turnover and mouth movements. In situ gels are a class of application forms that present sol-gel transition's ability as a response to stimuli. Their tunable properties are provided using smart polymers responsible for stimuli sensitivity, often providing mucoadhesivity. In this study, antimicrobial in situ gels of thermosensitive and pH-sensitive polymers loaded with silver nanoparticles were prepared and evaluated. The nanoparticles were prepared by green synthesis using Agrimonia eupatoria L. extract. According to the data analysis, the in situ gel with the most promising profile contained 15 % of Pluronic® F-127, 0.25 % of methylcellulose, and 0.1 % of Noveon® AA-1. Pluronic® F-127 and methylcellulose significantly increased the viscosity of in situ gels at 37 °C and shear rates similar to speaking and swallowing. At 20 °C, a behavior close to a Newtonian fluid was observed while being easily injectable (injection force 13.455 ± 1.973 N). The viscosity of the formulation increased with temperature and reached 2962.77 ± 63.37 mPa·s (37 °C). A temperature increase led to increased adhesiveness and rigidity of the formulation. The critical sol-gel transition temperature at physiological pH was 32.65 ± 0.35 °C. 96.77 ± 3.26 % of Ag NPs were released by erosion and dissolution of the gel after 40 min. The determination of MIC showed effect against E. coli and S. aureus (0.0625 mM and 0.5000 mM, respectively). The relative inhibition zone diameter of the in situ gel was 73.32 ± 11.06 % compared to gentamicin sulfate. This work discusses the optimization of the formulation of novel antibacterial in situ gel for oromucosal delivery, analyses the impact of the concentration of excipients on the dependent variables, and suggests appropriate evaluation of the formulation in terms of its indication. This study offers a promising dosage form for local treatment of oral diseases.

Rapid dissolution microneedle based on polyvinyl alcohol/chitosan for local oral anesthesia

At present, the main clinical methods of oral local anesthesia are direct injection of anesthetic and surface ointment. However, the pain and fear caused by the injection, the discomfort of topical anesthetic creams, and the scour and moist oral environment during the procedure pose great challenges to oral anesthesia. Herein, we designed a Lido-PVP/PVA DMNP microneedle (MN) for oral local anesthesia. The microneedle tip was consisted of Polyvinylpyrrolidone/Polyvinyl alcohol (PVP/PVA), which can quickly dissolve and release the lidocaine hydrochloride (Lido) drug within 5 min to achieve rapid anesthesia. The backing was composed of polyvinyl alcohol/chitosan (PVA/CS), and its excellent adhesion can overcome saliva erosion and anchor firmly to the oral mucosa, significantly improving the utilization rate of drugs, as well as the patient compliance. MNs have good mechanical properties for tissue insertion while possessing high drug loading (3 mg/MNs). Von Frey tests proved that MNs showed a faster and more effective local anesthetic effect (anesthesia takes effect at 5 min) compared to cream (anesthesia takes effect at 30 min). In addition, the excellent biocompatibility and no skin irritation endowed Lido-PVP/PVA DMNP MNs a great potential for oral local anesthesia in the oral cavity.

Advances in the Application of Microneedles in the Treatment of Local Organ Diseases

In recent years, microneedles (MNs) have attracted a lot of attention due to their microscale sizes and high surface area (500-1000 µm in length), allowing pain-free and efficient drug delivery through the skin. In addition to the great success of MNs based transdermal drug delivery, especially for skin diseases, increasing studies have indicated the expansion of MNs to diverse nontransdermal applications, including the delivery of therapeutics for hair loss, ocular diseases, and oral mucosal. Here, the current treatment of hair loss, eye diseases, and oral disease is discussed and an overview of recent advances in the application of MNs is provided for these three noncutaneous localized organ diseases. Particular emphasis is laid on the future trend of MNs technology development and future challenges of expanding the generalizability of MNs.

Is imiquimod a promising drug to treat oral mucosa diseases? A scoping review and new perspectives

Imiquimod (IMQ) is a chemotherapeutic and immunostimulant drug that is applied topically, demonstrating antitumor and antiviral activities. The objective of this review was to compile data on the off-label use of IMQ in oral mucosal diseases. IMQ has exhibited effectiveness in the treatment of various oral mucosal conditions, including oral carcinogenic lesions, neoplasms, HPV-related lesions and autoimmune disorders. Although IMQ holds promise as a potential strategy for addressing oral mucosal lesions, it is important to note that significant side effects have been frequently reported. Nonetheless, it is crucial to develop and test new technological systems, such as the combination of nanotechnology with innovative drug delivery platforms. These advancements aim to minimize side effects and prolong the drug's contact time with the mucosa, preventing its removal by salivary flow.

Preclinical pharmacokinetics-related pharmacological effects of orally administered polysaccharides from traditional Chinese medicines: A review

Polysaccharides (TCMPs) derived from traditional Chinese medicines (TCMs), such as Ganoderma lucidum, Astragalus membranaceus, Lycium barbarum, and Panax ginseng, are considered to be the main active constituents in TCMs. However, the significant pharmacological effects of orally administered TCMPs do not align well with their poor pharmacokinetics. This article aims to review the literature published mainly from 2010 to 2022, focusing on the relationship between pharmacokinetics and pharmacological effects. It has been found that unabsorbed TCMPs can exert local pharmacological effects in the gut, including anti-inflammation, anti-oxidation, regulation of intestinal flora, modulation of intestinal immunity, and maintenance of intestinal barrier integrity. Unabsorbed TCMPs can also produce systemic pharmacological effects, such as anti-tumor activity and immune system modulation, by regulating intestinal flora and immunity. Conversely, some TCMPs can be absorbed and distributed to various tissues, especially the liver, where they exhibit tissue-protecting effects against inflammation and oxidative stress-induced damage and improve glucose and lipid metabolism. In future studies, it is important to improve quality control and experimental design. Furthermore, research on enhancing the oral bioavailability of TCMPs, exploring the activity of TCMP metabolites, investigating pharmacokinetic interactions between TCMPs and oral drugs, and developing oral drug delivery systems using TCMPs holds great significance.

Utilization of experimental design in the formulation and optimization of hyaluronic acid-based nanoemulgel loaded with a turmeric-curry leaf oil nanoemulsion for gingivitis

Numerous problems affect oral health, and intensive research is focused on essential oil-based nanoemulsions that might treat prevent or these problems. Nanoemulsions are delivery systems that enhance the distribution and solubility of lipid medications to targeted locations. Turmeric (Tur)- and curry leaf oil (CrO)-based nanoemulsions (CrO-Tur-self-nanoemulsifying drug delivery systems [SNEDDS]) were developed with the goal of improving oral health and preventing or treating gingivitis. They could be valuable because of their antibacterial and anti-inflammatory capabilities. CrO-Tur-SNEDDS formulations were produced using the response surface Box-Behnken design with different concentrations of CrO (120, 180, and 250 mg), Tur (20, 35, and 50 mg), and Smix 2:1 (400, 500, and 600 mg). The optimized formulation had a bacterial growth inhibition zone of up to 20 mm, droplet size of less than 140 nm, drug-loading efficiency of 93%, and IL-6 serum levels of between 950 ± 10 and 3000 ± 25 U/ml. The optimal formulation, which contained 240 mg of CrO, 42.5 mg of Tur, and 600 mg of Smix 2:1, was created using the acceptable design. Additionally, the best CrO-Tur-SNEDDS formulation was incorporated into a hyaluronic acid gel, and thereafter it had improved ex-vivo transbuccal permeability, sustained in-vitro release of Tur, and large bacterial growth suppression zones. The optimal formulation loaded into an emulgel had lower levels of IL-6 in the serum than the other formulations evaluated in rats. Therefore, this investigation showed that a CrO-Tur-SNEDDS could provide strong protection against gingivitis caused by microbial infections.

Efficacy and safety of ibuprofen gargle for postoperative pain after mandibular third molar extraction: A phase II, placebo-controlled, double-blind, randomized crossover trial

OBJECTIVE

This study was designed to evaluate the postoperative efficacy and safety of using an ibuprofen gargle as a pain management strategy for patients who have undergone mandibular third molar extraction. We also ensured that the quality of treatment was not compromised throughout the study.

MATERIAL AND METHODS

Patients were randomized in a 1:1 ratio into two groups: the ibuprofen-placebo (IP) group and the placebo-ibuprofen (PI) group. On postoperative Day (POD) 1, the IP group initiated ibuprofen administration, while the PI group started taking placebo. On POD 2, the IP group switched to using placebo, whereas the PI group switched to ibuprofen. From PODs 3-5, both groups were prescribed ibuprofen gargle. The primary endpoint was within-subject visual analog scale (VAS) score before and 5 min after the first use of the ibuprofen or placebo gargle on PODs 1 and 2 (ΔVAS5_ibuprofen  - ΔVAS5_placebo ). The incidence and severity of adverse events were assessed using the Common Terminology Criteria for Adverse Events version 5.0 and a subjective rating scale.

RESULTS

This study enrolled 40 patients. The within-subject VAS5 of the IP and PI groups were 1.25 ± 12.0 and -5.26 ± 8.93 mm, respectively. The treatment effect of ibuprofen gargle was -2.01 ± 10.62 mm (p = .246). None of the patients in each group presented with serious adverse events or clinically significant complications (including dry sockets) after extraction. Transient adverse events, such as throat tingling and oral discomfort (grade 1), were observed in each group.

CONCLUSION

Ibuprofen gargle was safe but did not provide significant pain relief when used after mandibular third molar extraction.

Combination therapy using multifunctional dissolvable hyaluronic acid microneedles for oral ulcers

Oral ulcers are common in the oral mucosa. Frequent occurrences of oral ulcers commonly afflict patients, seriously impacting their daily life. Treatments with good anti-inflammatory and antibacterial properties are important for promoting the healing of oral ulcers. In this study, a multifunctional, soluble hyaluronic acid (HA) microneedle (MN) patch was prepared to promote oral ulcer healing. The tip layer of the MN patch was loaded with triamcinolone acetonide (TA) and epidermal growth factor (EGF) to inhibit inflammation and promote angiogenesis. Zeolitic imidazolate framework-8 (ZIF-8) was loaded onto the base layer of the MN patch, which effectively released Zn2+ to mediate antibacterial effects. In addition, HA exerts a protective effect on the mucous membrane. Owing to these properties, the multifunctional MN patches were found to have good anti-inflammatory, antibacterial, and tissue-healing abilities, indicating that the multifunctional MN patch design successfully promoted the healing of oral ulcers.

Nanotechnology-based mucoadhesive and mucus-penetrating drug-delivery systems for transbuccal drug delivery

Buccal drug-delivery systems present a promising approach for the drug delivery to the buccal mucosa, addressing oral cavity-specific problems, enabling systemic delivery and minimizing adverse effects on biological systems. Numerous strategies have been proposed to load drug-containing nanoparticles (NPs) to the buccal mucosa for local and systemic applications. There has been considerable interest in the development of mucoadhesive buccal formulations, particularly hydrogel composites utilizing mucoadhesive films incorporating NPs. Drug permeability and controlled drug release through buccal drug delivery continues to pose a challenge despite the availability of various remedies. This review highlights the need for, mechanisms and latest advances in NP-based transbuccal drug delivery with a focus on various pathological disorders and examples and limitations of the different methods.

Recent developments in natural biopolymer based drug delivery systems

Targeted delivery of drug molecules to diseased sites is a great challenge in pharmaceutical and biomedical sciences. Fabrication of drug delivery systems (DDS) to target and/or diagnose sick cells is an effective means to achieve good therapeutic results along with a minimal toxicological impact on healthy cells. Biopolymers are becoming an important class of materials owing to their biodegradability, good compatibility, non-toxicity, non-immunogenicity, and long blood circulation time and high drug loading ratio for both macros as well as micro-sized drug molecules. This review summarizes the recent trends in biopolymer-based DDS, forecasting their broad future clinical applications. Cellulose chitosan, starch, silk fibroins, collagen, albumin, gelatin, alginate, agar, proteins and peptides have shown potential applications in DDS. A range of synthetic techniques have been reported to design the DDS and are discussed in the current study which is being successfully employed in ocular, dental, transdermal and intranasal delivery systems. Different formulations of DDS are also overviewed in this review article along with synthesis techniques employed for designing the DDS. The possibility of these biopolymer applications points to a new route for creating unique DDS with enhanced therapeutic qualities for scaling up creative formulations up to the clinical level.

Intraoral Drug Delivery: Highly Thiolated κ-Carrageenan as Mucoadhesive Excipient

AIM

This study aims to design a novel thiolated κ-carrageenan (κ-CA-SH) and evaluate its potential as an excipient for the design of mucoadhesive drug delivery systems.

METHODS

Native κ-carrageenan (κ-CA) was thiolated with phosphorous pentasulfide in sulfolane and characterized via ¹H NMR, FTIR, as well as Ellman's test. Cytotoxicity was assessed via resazurin assay. In vitro release of the model drug, benzydamine hydrochloride, was determined. Tensile and mucosal residence time studies were performed on buccal and small intestinal mucosa. Mucoadhesive features were investigated via rheological studies with freshly isolated porcine mucus.

RESULTS

Thiolated κ-CA (κ-CA-SH) with 1213.88 ± 52 µmol/g thiol groups showed no cytotoxicity at a concentration of 1% (m/v) and low cytotoxicity up to 2% (m/v). Benzydamine hydrochloride showed slow release in solution for both polymers. Tensile studies on buccal and intestinal mucosa showed an up to 2.7-fold and 7.7-fold enhancement in the maximum detachment force (MDF) and total work of adhesion (TWA) of κ-CA-SH vs. κ-CA, respectively. The κ-CA-SH exhibited an up to 4.4-fold improved dynamic viscosity with mucus and significantly prolonged residence time on mucosa compared to native κ-CA.

CONCLUSION

Since highly thiolated κ-CA shows a slow release of positively charged active pharmaceutical ingredients and enhanced mucoadhesive properties, it might be a promising excipient for local drug delivery in the oral cavity.

Microneedles for oral mucosal delivery - Current trends and perspective on future directions

INTRODUCTION

Oral cavity drug and vaccine delivery has the potential for local targeting, dose reduction, minimization of systemic side effects, and generation of mucosal immunity. To overcome current limitations of delivery into the oral cavity mucosa, microneedles (MNs) have emerged as a promising technology.

AREAS COVERED

We reviewed the literature on MN application in the oral cavity, including in vitro studies, in vivo animal studies, and human clinical trials.

EXPERT OPINION

MNs are sufficiently robust to cross the oral cavity epithelium and nearly painless when applied to different parts of the human oral mucosa including the lip, cheek, tongue, and palate. In recent years, MNs have been evaluated for different applications, including vaccination, topical anesthetic delivery, and treatment of local oral pathologies such as oral lesions or carcinomas. MNs are attractive because they have the potential to produce a better treatment outcome with reduced side effects. Over the coming years, we project a significant increase in research related to the development of MNs for use in dentistry and other medical conditions of the mouth.

Localized Drug Delivery Systems: An Update on Treatment Options for Head and Neck Squamous Cell Carcinomas

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers in the world, with surgery, radiotherapy, chemotherapy, and immunotherapy being the primary treatment modalities. The treatment for HNSCC has evolved over time, due to which the prognosis has improved drastically. Despite the varied treatment options, major challenges persist. HNSCC chemotherapeutic and immunotherapeutic drugs are usually administered systemically, which could affect the patient's quality of life due to the associated side effects. Moreover, the systemic administration of salivary stimulating agents for the treatment of radiation-induced xerostomia is associated with toxicities. Localized drug delivery systems (LDDS) are gaining importance, as they have the potential to provide non-invasive, patient-friendly alternatives to cancer therapy with reduced dose-limiting toxicities. LDDSs involve directly delivering a drug to the tissue or organ affected by the disease. Some of the common localized routes of administration include the transdermal and transmucosal drug delivery system (DDSs). This review will attempt to explore the different treatment options using LDDSs for the treatment of HNSCC and radiotherapy-induced damage and their potential to provide a better experience for patients, as well as the obstacles that need to be addressed to render them successful.

Formulation and Evaluation of Chitosan-PLGA Biocomposite Scaffolds Incorporated with Quercetin Liposomes Made by QbD Approach for Improved Healing of Oral Lesions

The current research aims to develop and evaluate chitosan-PLGA biocomposite scaffolds in combination with quercetin liposomes to accomplish the desired impact in oral lesions where pharmacotherapeutic agent treatment through circulation could only reach the low content at the target. Optimization of quercetin-loaded liposomes was carried out using 32 factorial design. The preparation of porous scaffolds comprising produced quercetin-loaded liposomes by thin-film method was carried out in the current study using a unique strategy combining solvent casting and gas foaming procedures. The prepared scaffolds were tested for physicochemical properties, in vitro quercetin release study, ex vivo drug permeation and retention research using goat mucosa, antibacterial activity, and cell migration studies on fibroblast L929 cell lines. Improved cell growth and migration were seen in the order control < liposomes < proposed system. The proposed system has been examined for its biological and physicochemical features, and it has the potential to be utilized as an efficient therapy for oral lesions.

Oral Mucosa Models to Evaluate Drug Permeability

Due to its numerous advantages, such as excellent drug accessibility, rapid absorption, and bypass of first-pass metabolism, the route of drug administration that involves crossing the oral mucosa is highly favored. As a result, there is significant interest in investigating the permeability of drugs through this region. The purpose of this review is to describe the various ex vivo and in vitro models used to study the permeability of conveyed and non-conveyed drugs through the oral mucosa, with a focus on the most effective models. Currently, there is a growing need for standardized models of this mucosa that can be used for developing new drug delivery systems. Oral Mucosa Equivalents (OMEs) may provide a promising future perspective as they are capable of overcoming limitations present in many existing models.

Three-Dimensional Oral Mucosal Equivalents as Models for Transmucosal Drug Permeation Studies

Oral transmucosal administration, where drugs are absorbed directly through the non-keratinized, lining mucosa of the mouth, represents a solution to drug delivery with several advantages. Oral mucosal equivalents (OME) developed as 3D in vitro models are of great interest since they express the correct cell differentiation and tissue architecture, simulating the in vivo conditions better than monolayer cultures or animal tissues. The aim of this work was to develop OME to be used as a membrane for drug permeation studies. We developed both full-thickness (i.e., connective plus epithelial tissue) and split-thickness (i.e., only epithelial tissue) OME using non-tumor-derived human keratinocytes OKF6 TERT-2 obtained from the floor of the mouth. All the OME developed here presented similar transepithelial electrical resistance (TEER) values, comparable to the commercial EpiOral™. Using eletriptan hydrobromide as a model drug, we found that the full-thickness OME had similar drug flux to EpiOral™ (28.8 vs. 29.6 µg/cm²/h), suggesting that the model had the same permeation barrier properties. Furthermore, full-thickness OME showed an increase in ceramide content together with a decrease in phospholipids in comparison to the monolayer culture, indicating that lipid differentiation occurred due to the tissue-engineering protocols. The split-thickness mucosal model resulted in 4-5 cell layers with basal cells still undergoing mitosis. The optimum period at the air-liquid interface for this model was twenty-one days; after longer times, signs of apoptosis appeared. Following the 3R principles, we found that the addition of Ca²⁺, retinoic acid, linoleic acid, epidermal growth factor and bovine pituitary extract was important but not sufficient to fully replace the fetal bovine serum. Finally, the OME models presented here offer a longer shelf-life than the pre-existing models, which paves the way for the further investigation of broader pharmaceutical applications (i.e., long-term drug exposure, effect on the keratinocytes' differentiation and inflammatory conditions, etc.).

Alginate Hydrogel Formulation with Ketorolac for the Treatment of Pain Related Sialolithiasis

Sialolithiasis mainly affects the oral salivary glands due to the presence of small stones that obstruct the secretion of saliva. The treatment and control of pain and inflammation during the course of this pathology is essential to guarantee the patient's comfort. For this reason, a ketorolac calcium cross-linked alginate hydrogel was developed, and it was then applied in the area of the buccal cavity. The formulation was characterized (swelling and degradation profile, extrusion, extensibility, surface morphology, viscosity, and drug release). The drug release was studied ex vivo in static Franz cells and with a dynamic ex vivo method under artificial saliva continuous flow. The product exhibits adequate physicochemical properties considering the intended purpose, and the drug concentrations retained in the mucosa were high enough to deliver a therapeutic local concentration able to reduce the pain associated with the patient's conditions. The results confirmed the suitability of the formulation for application in the mouth.

β-Glucan and Fatty Acid Based Mucoadhesive Carrier for Gastrointestinal Tract Specific Local and Sustained Drug Delivery

The oral route is considered the most convenient route of drug administration for both systemic and local delivery. Besides stability and transportation, another unmet but important issue regarding oral medication is retention duration within the specific region of the gastrointestinal (GI) tract. We hypothesize that an oral vehicle that can adhere and maintain retention within the stomach for a longer duration can be more effective to treat stomach-related diseases. Therefore, in this project, we developed a carrier that is highly specific to the stomach and maintains its retention for a longer duration. We developed a vehicle composed of β-Glucan And Docosahexaenoic Acid (GADA) to observe its affinity and specificity to the stomach. GADA forms a spherical-shaped particle with negative zeta potential values that vary based on the feed ratio of docosahexaenoic acid. Docosahexaenoic acid is an omega-3 fatty acid that has transporters and receptors throughout the GI tract, such as CD36, plasma membrane-associated fatty acid-binding protein (FABP (pm)), and a family of fatty acid transport proteins (FATP1-6). The in vitro studies and characterization data showed that GADA has the capability to carry a payload of hydrophobic molecules and specifically deliver the payload to the GI tract, exert its therapeutic effects, and help to maintain stability for more than 12 h in the gastric and intestinal fluid. The particle size and surface plasmon resonance (SPR) data showed that GADA has a strong binding affinity with mucin in the presence of simulated gastric fluids. We observed a comparatively higher drug release of lidocaine in gastric juice than that in intestinal fluids, demonstrating the influence of the pH values of the media on drug-release kinetics. In vivo and ex vivo imaging of mice demonstrated that GADA maintains its retention within the stomach for at least 4 hr. This stomach-specific oral vehicle holds strong promise to translate various injectable therapeutic drugs to oral form upon further optimizations.

Instantaneous Formation of Silk Protein Aerosols and Fibers with a Portable Spray Device Under Ambient Conditions

A variety of artificial silk spinning approaches have been attempted to mimic the natural spinning process found in silkworms and spiders, yet instantaneous silk fiber formation with hierarchical structure under physiological and ambient conditions without post-treatment procedures remains unaddressed. Here, we report a new strategy to fabricate silk protein-based aerosols and silk fibers instantaneously (< 1 s) in situ using a simple, portable, spray device, avoiding complicated and costly advanced manufacturing techniques. The key to success is the instantaneous conformational transition of silk fibroin from random coil to β-sheet right before spraying by mixing silk and polyethylene glycol (PEG) solutions in the spray device, allowing aerosols and silk fibers to be sprayed in situ, with further control achieved via the molecular weight of silk. The spinning process of the spray device is based on the use of green solvents, i.e., all steps of instant conformational transition of silk fibroin are carried out in aqueous conditions or with buffers at ambient conditions, in combination with shear and elongational flow caused by the hydraulic pressure generated in the spray container. The system supports a portable and user-friendly system that could be used for drug delivery carriers, wound coating materials and rapid silk fiber conformal coatings on surfaces.

Thermoresponsive mucoadhesive hybrid gels in advanced drug delivery systems

Thermoresponsive polymers have seen extensive use in the development of stimuli-responsive drug formulations for oral, buccal, nasal, ocular, topical, rectal, parenteral, and vaginal routes of administration. Despite their great potential, their use has been limited by various obstacles, such as undesirable high polymer concentration, wide gelation temperature, low gel strength, poor mucoadhesiveness, and short retention. Mucoadhesive polymers have been suggested to improve the mucoadhesive features of thermoresponsive gels, leading to increased drug bioavailability and efficacy. This article highlights the use of in-situ thermoresponsive mucoadhesive hydrogel blends or hybrids that have been developed and assessed in various routes of administration.

Novel Double-Layer Dissolving Microneedles for Transmucosal Sequential Delivery of Multiple Drugs in the Treatment of Oral Mucosa Diseases

The development of transmucosal drug delivery systems is a practical requirement in oral clinical practice, and controlled sequential delivery of multiple drugs is usually required. On the basis of the previous successful construction of monolayer microneedles (MNs) for transmucosal drug delivery, we designed transmucosal double-layer sequential dissolving MNs using hyaluronic acid methacryloyl (HAMA), hyaluronic acid (HA), and polyvinyl pyrrolidone (PVP). MNs have the advantages of small size, easy operation, good strength, rapid dissolution, and one-time delivery of two drugs. Morphological test results showed that the HAMA-HA-PVP MNs were small and intact in structure. The mechanical strength and mucosal insertion test results indicated the HAMA-HA-PVP MNs had appropriate strength and could penetrate the mucosal cuticle quickly to achieve transmucosal drug delivery. The in vitro and in vivo experiment results of the double-layer fluorescent dyes simulating drug release revealed that MNs had good solubility and achieved stratified release of the model drugs. The results of the in vivo and in vitro biosafety tests also indicated that the HAMA-HA-PVP MNs were biosafe materials. The therapeutic effect of drug-loaded HAMA-HA-PVP MNs in the rat oral mucosal ulcer model demonstrated that these novel HAMA-HA-PVP MNs quickly penetrated the mucosa, dissolved and effectively released the drug, and achieved sequential drug delivery. Compared to monolayer MNs, these HAMA-HA-PVP MNs can be used as double-layer drug reservoirs for controlled release, effectively releasing the drug in the MN stratification by dissolution in the presence of moisture. The need for secondary or multiple injections can be avoided, thus improving patient compliance. This drug delivery system can serve as an efficient, multipermeable, mucosal, and needle-free alternative for biomedical applications.

Formulation and Characterization of Buccal Films Containing Valsartan with Additional Support from Image Analysis

The present study was aimed to the development and characterization of valsartan-containing buccal films with an introduction to a novel technique of image analysis. Visual inspection of the film provided a wealth of information that was difficult to quantify objectively. The obtained images of the films observed under the microscope were embedded in a convolutional neural network (CNN). The results were clustered according to their visual quality and on the basis of data distances. Image analysis proved to be a promising method to characterize buccal films appearance and their visual properties. The differential behavior of film composition was investigated using a reduced combinatorial experimental design. Formulation properties such as dissolution rate, moisture content, valsartan particle size distribution, film thickness, and drug assay were evaluated. In addition, more advanced methods such as Raman microscopy and image analysis were used to characterize the developed product in more detail. The results of dissolution tests using four different dissolution apparatuses showed a significant difference between the formulations containing the active ingredient in different polymorphic states. The dynamic contact angle of a water droplet on the surface of the films was measured, which correlated well with the dissolution times at 80% of the released drug (t80).

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.

Advances in formulation and manufacturing strategies for the delivery of therapeutic proteins and peptides in orally disintegrating dosage forms

Therapeutic proteins and peptides (TPPs) are increasingly favoured above small drug molecules due to their high specificity to the site of action and reduced adverse effects resulting in increased use of these agents for medical treatments and therapies. Consequently, there is a need to formulate TPPs in dosage forms that are accessible and suitable for a wide range of patient groups as the use of TPPs becomes increasingly prevalent in healthcare settings worldwide. Orally disintegrating dosage forms (ODDF) are formulations that can ensure easy-to-administer medication to a wider patient population including paediatrics, geriatrics and people in low-resource countries. There are many challenges involved in developing suitable pharmaceutical strategies to protect TPPs during formulation and manufacturing, as well as storage, and maintenance of a cold-chain during transportation. This review will discuss advances being made in the research and development of pharmaceutical and manufacturing strategies used to incorporate various TPPs into ODDF systems.

Incorporating sodium deoxycholate endorsed the buccal administration of avanafil to heighten the bioavailability and duration of action

The highly effective phosphodiesterase type 5 inhibitor (avanafil; AVA) is routinely prescribed to treat erectile dysfunction. The drug has poor oral bioavailability and undergoes a significant first-pass metabolism. Therefore, altering AVA's solubility and choosing a different delivery method may boost its effectiveness. Nine different solid dispersion formulations utilizing polyvinylpyrrolidone (PVP) at three different ratios were prepared and characterized. The Box-Behnken design was employed to optimize AVA-buccal tablets. The pre-compression and post-compression characteristics of the tablets were assessed. The mucoadhesion strength of the optimized tablet was investigated using cow buccal mucosal tissue. In vivo performance of the optimized tablets was examined on human volunteers compared to the commercial tablets. PVP K90 at 2:1 drug to polymer ratio showed the highest solubilization capacity. The mucoadhesive polymer type and percentage and the mucopenetration enhancer percentage were significantly affect the mucoadhesion strength, tablet hardness, and the initial and cumulative AVA released from the prepared tablets. The optimized AVA-buccal tablet showed 4.96 folds increase in the mean residence time, higher plasma exposure, and an improvement in the relative bioavailability of AVA by 1076.27% compared with the commercial tablet. Therefore, a successful approach to deal with AVA first-pass metabolism and low bioavailability could be to employ buccal tablets containing a solubility-enhanced form of AVA.

Microenvironmental pH Modification in Buccal/Sublingual Dosage Forms for Systemic Drug Delivery

Many drug candidates are poorly water-soluble. Microenvironmental pH (pH_M) modification in buccal/sublingual dosage forms has attracted increasing interest as a promising pharmaceutical strategy to enhance the oral mucosal absorption of drugs with pH-dependent solubility. Optimizing drug absorption at the oral mucosa using pH_M modification is considered to be a compromise between drug solubility and drug lipophilicity (Log D)/permeation. To create a desired pH_M around formulations during the dissolution process, a suitable amount of pH modifiers should be added in the formulations, and the appropriate methods of pH_M measurement are required. Despite pH_M modification having been demonstrated to be effective in enhancing the oral mucosal absorption of drugs, some potential risks, such as oral mucosal irritation and teeth erosion caused by the pH modifiers, should not been neglected during the formulation design process. This review aims to provide a short introduction to the pH_M modification concept in buccal/sublingual dosage forms, the properties of saliva related to pH_M modification, as well as suitable drug candidates and pH modifiers for pH_M modifying buccal/sublingual formulations. Additionally, the methods of pH_M measurement, pH_M modification methods and the corresponding challenges are summarized in the present review.

Water-soluble chitosan eases development of mucoadhesive buccal films and wafers for children

Oromucosal films and wafers are user-friendly solid dosage forms offering easy and convenient administration, as well as rapid or controlled drug delivery. The aim of this study was to develop prednisolone containing child-friendly chitosan-based mucoadhesive films and wafers with a prolonged residence time on the buccal mucosa. Four different chitosan types (different molecular weights, degree of deacetylation (DDA), pattern of deacetylation) were studied for films prepared by solvent-cast-evaporation and wafers by freeze-drying. Mucoadhesive properties correlated with swelling abilities and were dependent on the chitosan type, the solvent, and the preparation method. Mucoadhesive forces were higher for formulations containing chitosan with higher DDA and for wafers compared to films. The drug release was relatively fast, especially for films (approx. 90 % in 15 minutes) and steadier for wafers (90 % in 45-120 minutes). Permeability was evaluated using artificial membranes and HT29-MTX cell-monolayers. The developed formulations exhibited good biocompatibility. Organoleptic properties can be improved by choosing a homogenously deacetylated chitosan type that provides a more neutral pH. Using hydroxypropyl-beta-cyclodextrin-complexation for taste masking of bitter drugs also reduced wafers' drug release rate. Mucoadhesive wafers are promising alternatives to films with a slower drug release rate and stronger mucoadhesion.

Evaluation of Oral Transmucosal Administration of Pentobarbital for Euthanasia of Conscious Wild Birds

This prospective study evaluated oral transmucosal pentobarbital sodium at three doses in 110 wild-caught wild birds requiring euthanasia. Birds received transmucosal pentobarbital at five (430 mg/kg), six (516 mg/kg), and seven times (602 mg/kg) the intravenous dose for mammals. Time to first effects and loss of consciousness, presence of pupillary light and corneal reflexes, apnea, and asystole were recorded each minute. When asystole was not achieved at 5 minutes, IV pentobarbital was administered. Combining data for all doses, loss of consciousness occurred at a median (range) of 2 minutes (0-4.75 min), apnea at 3 minutes (0-6 min), and asystole at 4 minutes (0.5-5 min). Loss of consciousness and apnea occurred significantly faster in the 602 mg/kg dose group than in the 430 mg/kg group (p = 0.009, difference of 0.6 ± 0.2 min; p = 0.024, difference of 0.7 ± 0.3 min), respectively. Apnea and asystole were achieved in 80/110 birds within 5 minutes. Oral transmucosal pentobarbital results in rapid loss of consciousness and respiratory arrest and provides a reliable alternative euthanasia method compared to intravenous administration.

Design and development of orally disintegrating films: A platform based on hydroxypropyl methylcellulose and guar gum

From a design of experiments (DOE) performed under four independent variables, with the filmogenicity conditions and shortest disintegration time as the answers, a new oral disintegrating film (ODF) based on hydroxypropyl methylcellulose (HPMC) and guar gum (GG) with the essential oil of Plectranthus amboinicus L. (EOPA) was developed. Sixteen formulations were tested for filmogenicity, homogeneity, and viability. The better selected ODF required 230.1 s for complete disintegration. The retention rate of the EOPA was quantified using the nuclear magnetic resonance hydrogen technique (H¹ NMR), which identified the presence of 0.14 % carvacrol. The scanning electron microscopy showed a smooth and homogeneous surface with the presence of small white dots. Through the disk diffusion test, the EOPA was able to inhibit the growth of clinical strains of the Candida genus and gram-positive and gram-negative bacterial strains. This work opens new perspectives for the development of antimicrobial ODFS used in clinical practice.

Antifungal Activity of Camelus-Derived LFA-LFC Chimeric Peptide Gelatin Film and Effect on Oral Bacterial Biofilm

The objective of this study was to construct lactoferrin (LFA-LFC) chimeric peptide gelatin drug-loaded fiber film by tissue engineering strategy, and study its bacteriostatic effect on oral pathogens (especially Candida albicans) and its effect on biofilm. First of all, LFA-LFC chitosan nanoparticles were prepared firstly, and then fluconazole gelatin (LF/GH/F) film loaded with LFA-LFC was prepared by electrospinning. Scanning electron microscope (SEM), mechanical strength, drug release, cytotoxicity, and real-time PCR were used to test the properties of the synthesized materials. SEM showed that there was the reticular structure for fiber film before and after cross-linking. LF/GH/F film had no obvious cytotoxicity, with good biocompatibility and drug release; real-time PCR and antibacterial test showed that the LF/GH/F film had good antibacterial activity. LF/GH/F film has a good inhibitory effect on oral pathogens, and its mechanism is related to biofilm. The antibacterial experiments of nanofiber membrane in vitro and the effect of bacterial biofilm were carried out. The effect of LF/GH/F on oral microbial flora structure was studied by fluorescence quantitative pest techniques.

Buccal films: A review of therapeutic opportunities, formulations & relevant evaluation approaches

The potential of the mucoadhesive film technology is hard to ignore, owing to perceived superior patient acceptability versus buccal tablets, and significant therapeutic opportunities compared to conventional oral drug delivery systems, especially for those who suffer from dysphagia. In spite of this, current translation from published literature into the commercial marketplace is virtually non-existent, with no authorised mucoadhesive buccal films available in the UK and very few available in the USA. This review seeks to provide an overview of the mucoadhesive buccal film technology and identify key areas upon which to focus scientific efforts to facilitate the wider adoption of this patient-centric dosage form. Several indications and opportunities for development were identified, while discussing the patient-related factors influencing the use of these dosage forms. In addition, an overview of the technologies behind the manufacturing of these films was provided, highlighting manufacturing methods like solvent casting, hot melt extrusion, inkjet printing and three-dimensional printing. Over thirty mucoadhesive polymers were identified as being used in film formulations, with details surrounding their mucoadhesive capabilities as well as their inclusion alongside other key formulation constituents provided. Lastly, the importance of physiologically relevant in vitro evaluation methodologies was emphasised, which seek to improve in vivo correlations, potentially leading to better translation of mucoadhesive buccal films from the literature into the commercial marketplace.

Oral nano-formulation improves pancreatic islets dysfunction via lymphatic transport for antidiabetic treatment

Type 2 diabetes mellitus (T2DM) therapy is facing the challenges of long-term medication and gradual destruction of pancreatic islet β-cells. Therefore, it is timely to develop oral prolonged action formulations to improve compliance, while restoring β-cells survival and function. Herein, we designed a simple nanoparticle with enhanced oral absorption and pancreas accumulation property, which combined apical sodium-dependent bile acid transporter-mediated intestinal uptake and lymphatic transportation. In this system, taurocholic acid (TCA) modified poly(lactic-co-glycolic acid) (PLGA) was employed to achieve pancreas location, hydroxychloroquine (HCQ) was loaded to execute therapeutic efficacy, and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) was introduced as stabilizer together with synergist (PLGA-TCA/DLPC/HCQ). In vitro and in vivo results have proven that PLGA-TCA/DLPC/HCQ reversed the pancreatic islets damage and dysfunction, thus impeding hyperglycemia progression and restoring systemic glucose homeostasis via only once administration every day. In terms of mechanism PLGA-TCA/DLPC/HCQ ameliorated oxidative stress, remodeled the inflammatory pancreas microenvironment, and activated PI3K/AKT signaling pathway without obvious toxicity. This strategy not only provides an oral delivery platform for increasing absorption and pancreas targetability but also opens a new avenue for thorough T2DM treatment.

Lidocaine- and chloramphenicol-loaded nanoparticles embedded in a chitosan/hyaluronic acid/glycerol matrix: Drug-eluting biomembranes with potential for guided tissue regeneration

Guided tissue regeneration (GTR) is a dentistry technique based on the use of polymeric biomembranes as physical barriers for selective cell exclusion, directing the growth of gingival tissue, bone tissue, and periodontal ligaments in a region previously affected by periodontitis. Postoperative pain and microbial infection constitute, however, two major challenges to be tackled right after implantation. To address these challenges, we prepared and characterized eight chitosan/hyaluronic acid/glycerol (CS/HA/GL) bioresorbable membranes embedded with lidocaine- and chloramphenicol-loaded polycaprolactone nanoparticles (LDNP and CHNP, respectively), combining the local anesthetic effects of lidocaine with the antibacterial effects of chloramphenicol. The formulations were prepared with varying amounts of CS, HA, GL, LDNP, and CHNP. As a plasticizing agent, GL could modulate the samples mechanical properties such as thickness, morphology, tensile strength, elongation at break, as well as swelling and degradation in simulated saliva. Two samples exhibited greater resistance to biodegradation and were selected for further studies. Their drug release profiles indicated that LDNP and CHNP first detach from the membrane matrix, and a zeroth order drug release kinetics from the detached NPs dominates the overall process thereafter, with lidocaine being released 3 times faster than chloramphenicol, in a controlled and sustained rate over time. Drug encapsulation efficiency was such that optimal samples exhibited bactericidal activity (inhibition halos) against gram-positive S. aureus and gram-negative A. actinomycetemcomitans strains similar to that observed for free chloramphenicol. Finally, one of these samples showed no intrinsic toxicity against healthy mammalian model cells (99% viability for the unloaded membrane; 80% viability for the fully LDNP- and CHNP-loaded membrane), and may now be further optimized as a drug-eluting biomembrane with potential for GTR.

Deformable Nanovesicle-Loaded Gel for Buccal Insulin Delivery

Deformable nanovesicles (DNVs) have been widely used in oral mucosal delivery studies of biomolecular drugs. However, their development for oral mucosal preparations has been limited by their physical and chemical instability, the need for small oral volumes, and the complexity of the oral microenvironment. This study aimed to develop a more suitable buccal delivery system for DNVs with improved storage stability. Preliminary stability studies investigated different gel types, the effects of different hydrophilic gel matrices, and matrix temperature sensitivity using DNVs loaded with insulin-phospholipid complex (IPC-DNVs). A temperature-sensitive gel encapsulating IPC-DNVs (IPC-DNV-TSG) prepared with 2% w/v gelatin was stable at 4 °C for three months and maintained an excellent hypoglycemic effect. The delivery efficiency of IPC-DNVs and IPC-DNV-TSG was compared using a TR146 cell model, revealing that cell viability remained high. Cellular uptake was slightly lower for IPC-DNV-TSG than for IPC-DNVs, but total transport did not differ significantly between the two groups, which may have been related to the viscosity of IPC-DNV-TSG and the hydrophilicity, cell adhesion properties, and biocompatibility of gelatin. Moreover, neither IPC-DNVs nor IPC-DNV-TSG induced significant mucosal irritation in rabbit tongue tissue sections. The study findings demonstrate a promising method for possible use as oral mucosal delivery of peptide drugs.

Vardenafil-Loaded Bilosomal Mucoadhesive Sponge for Buccal Delivery: Optimization, Characterization, and In Vivo Evaluation

Vardenafil (VDF) is a relatively new phosphodiesterase-5 inhibitor that has limited oral bioavailability (≈15%). The objective of this study was to develop bilosome-based mucoadhesive buccal sponge for augmenting the oral bioavailability of VDF. VDF-loaded bilosomes were fabricated and optimized using a Box-Behnken design. The optimized VDF-loaded bilosomal formulation was assessed for surface morphology, particle size, thermal characteristics, and in vitro release. Afterwards, the optimized bilosomal formulation was incorporated into a cellulose-based matrix to obtain buccal sponge, which was evaluated for ex vivo permeation studies, in vivo oral bioavailability, and in vivo serum concentration of cyclic guanosine monophosphate (cGMP). The mean particle size and entrapment efficiency (%) of optimized bilosome formulation were 282.6 ± 9.5 nm and 82.95 ± 3.5%, respectively. In vitro release studies at pH 6.8 emphasized the potential of optimized bilosomal formulation to sustain VDF release for 12 h. Ex vivo permeation study using sheep buccal mucosa indicated significant enhancement in penetration of VDF from bilosomal buccal sponge compared to plain VDF gel. Pharmacokinetic study in Albino rats showed ~5 fold increase in relative bioavailability with bilosomal buccal sponge, compared to VDF suspension. In addition, VDF-loaded bilosomal buccal sponge triggered higher serum levels of cGMP, a biomarker of VDF in vivo efficacy, compared to oral VDF suspension. To sum up, bilosomes might represent a potential nanocarrier for buccal delivery of VDF, enhancing its oral bioavailability and therapeutic efficacy.

Oral transmucosal delivery of eletriptan for neurological diseases

Migraine is a highly prevalent neurological disease affecting circa 1 billion patients worldwide with severe incapacitating symptoms, which significantly diminishes the quality of life. As self-medication practice, oral administration of triptans is the most common option, despite its relatively slow therapeutic onset and low drug bioavailability. To overcome these issues, here we present, to the best of our knowledge, the first study on the possibility of oral transmucosal delivery of one of the safest triptans, namely eletriptan hydrobromide (EB). Based on a comprehensive set of in vitro and ex vivo experiments, we highlight the conditions required for oral transmucosal delivery, potentially giving rise to similar, or even higher, drug plasma concentrations expected from conventional oral administration. With histology and tissue integrity studies, we conclude that EB neither induces morphological changes nor impairs the integrity of the mucosal barrier following 4 h of exposure. On a cellular level, EB is internalized in human oral keratinocytes within the first 5 min without inducing toxicity at the relevant concentrations for transmucosal delivery. Considering that the pK_a of EB falls within the physiologically range, we systematically investigated the effect of pH on both solubility and transmucosal permeation. When the pH is increased from 6.8 to 10.4, the drug solubility decreases drastically from 14.7 to 0.07 mg/mL. At pH 6.8, EB gave rise to the highest drug flux and total permeated amount across mucosa, while at pH 10.4 EB shows greater permeability coefficient and thus higher ratio of permeated drug versus applied drug. Permeation experiments with model membranes confirmed the pH dependent permeation profile of EB. The distribution of EB in different cellular compartments of keratinocytes is pH dependent. In brief, high drug ionization leads to higher association with the cell membrane, suggesting ionic interactions between EB and the phospholipid head groups. Moreover, we show that the chemical permeation enhancer DMSO can be used to enhance the drug permeation significantly (i.e., 12 to 36-fold increase). Taken together, this study presents important findings on transmucosal delivery of eletriptan via the oral cavity and paves the way for clinical investigations for a fast and safe migraine treatment.

Advances in the Application of Electrospun Drug-Loaded Nanofibers in the Treatment of Oral Ulcers

Oral ulcers affect oral and systemic health and have high prevalence in the population. There are significant individual differences in the etiology and extent of the disease among patients. In the treatment of oral ulcers, nanofiber films can control the drug-release rate and enable long-term local administration. Compared to other drug-delivery methods, nanofiber films avoid the disadvantages of frequent administration and certain side effects. Electrospinning is a simple and effective method for preparing nanofiber films. Currently, electrospinning technology has made significant breakthroughs in energy-saving and large-scale production. This paper summarizes the polymers that enable oral mucosal adhesion and the active pharmaceutical ingredients used for oral ulcers. Moreover, the therapeutic effects of currently available electrospun nanofiber films on oral ulcers in animal experiments and clinical trials are investigated. In addition, solvent casting and cross-linking methods can be used in conjunction with electrospinning techniques. Based on the literature, more administration systems with different polymers and loading components can be inspired. These administration systems are expected to have synergistic effects and achieve better therapeutic effects. This not only provides new possibilities for drug-loaded nanofibers but also brings new hope for the treatment of oral ulcers.

Stability, Permeability and Cytotoxicity of Buccal Films in Allergy Treatment

Oral mucoadhesive systems, such as polymer films, are among innovative pharmaceutical products. These systems can be applied in swallowing problems and can also be used in geriatrics and paediatrics. In our earlier work, we successfully formulated buccal mucoadhesive polymer films, which contained cetirizine-hydrochloride (CTZ) as the API. The present study focused on investigating the stability and permeability of the prepared films. The stability of the films was studied with an accelerated stability test. During the stability test, thickness, breaking hardness and in vitro mucoadhesivity were analysed. Furthermore, the interactions were studied with FT-IR spectroscopy, and the changes in the amount of the API were also monitored. Cytotoxicity and cell line permeability studies were carried out on TR 146 buccal cells. Compositions that can preserve more than 85% of the API after 6 months were found. Most of the compositions had a high cell viability of more than 50%. Citric acid (CA) decreased the stability and reduced every physical parameter of the films. However, cell line studies showed that the permeability of the films was enhanced. In our work, we successfully formulated CTZ-containing buccal films with adequate stability, high cell viability and appropriate absorption properties.

Composite dissolvable microneedle patch for therapy of oral mucosal diseases

A composite microneedle patch (MN patch) is developed for oral transmucosal administration. To improve the oral transmucosal drug delivery efficiency, the composite MN patch is designed to consist of an array of 100 dissolvable microneedles (MNs) with drug-loaded tips and a backing layer. The MNs are composed of two parts, the hyaluronic acid (HA) tip part and the polyvinylpyrrolidone (PVP) base part. Due to the small size and sufficient mechanical strength, the HA-PVP MNs can painlessly penetrate the oral mucosa barrier and deliver drugs directly to the basal layer or submucosa. Betamethasone sodium phosphate (BSP), as the model drug, is concentrated in the HA tip parts to avoid the drug waste caused by mucosa elasticity. Considering the special moist environment and saliva flow in the mouth, a double-layer backing layer composed of a poly(vinyl alcohol) (PVA) adhesive layer and an ethyl cellulose (EC) waterproof layer is designed and constructed, which could reduce the saliva flow effects. The in vitro and in vivo results demonstrate that the MN patch could achieve rapid and efficient BSP release in oral mucosa due to the rapid dissolution of HA. The proposed MN patch provides a novel strategy for the therapy of oral mucosal diseases.