Orodispersible films: Towards drug delivery in special populations

The dawning era of oral thin films for nutraceutical delivery: From laboratory to clinic

Oral thin films (OTFs) are innovative dosage forms that have gained tremendous attention for the delivery of nutraceuticals. They are ultra-thin, flexible sheets that can be easily placed on the tongue, sublingual or buccal mucosa (inner lining of the cheek). These thin films possess several advantages for nutraceutical delivery including ease of administration, rapid disintegration, fast absorption, rapid onset of action, bypass first-pass hepatic metabolism, accurate dosing, enhanced stability, portability, discreetness, dose flexibility and most importantly consumer acceptance. This review highlights the utilization OTFs for nutraceutical delivery, their composition, criteria for excipient selection, methods of development and quality-based design (QbD) approach to achieve quality product. We have also provided recent case studies representing OTFs as promising platform in delivery of nutraceuticals (plant extracts, bioactive molecules, vitamins, minerals and protein/peptides) and probiotics. Finally, we provided advancement in technologies, recent patents, market analysis, challenges and future perspectives associated with this unique dosage form.

The potential of three-dimensional printing for pediatric oral solid dosage forms

Pediatric patients often require individualized dosing of medicine due to their unique pharmacokinetic and developmental characteristics. Current methods for tailoring the dose of pediatric medications, such as tablet splitting or compounding liquid formulations, have limitations in terms of dosing accuracy and palatability. This paper explores the potential of 3D printing as a solution to address the challenges and provide tailored doses of medication for each pediatric patient. The technological overview of 3D printing is discussed, highlighting various 3D printing technologies and their suitability for pharmaceutical applications. Several individualization options with the potential to improve adherence are discussed, such as individualized dosage, custom release kinetics, tablet shape, and palatability. To integrate the preparation of 3D printed medication at the point of care, a decentralized manufacturing model is proposed. In this setup, pharmaceutical companies would routinely provide materials and instructions for 3D printing, while specialized compounding centers or hospital pharmacies perform the printing of medication. In addition, clinical opportunities of 3D printing for dose-finding trials are emphasized. On the other hand, current challenges in adequate dosing, regulatory compliance, adherence to quality standards, and maintenance of intellectual property need to be addressed for 3D printing to close the gap in personalized oral medication.

Unmet technological demands in orodispersible films for age-appropriate paediatric drug delivery

Age-appropriateness of a formulation is the ability to deliver variable but accurate doses to the paediatric population in a safe and acceptable manner to improve medical adherence and reduce medication errors. Paediatric drug delivery is a challenging area of formulation research due to the existing gap in knowledge. This includes the unknown safety of excipients in the paediatric population, the need for an age-appropriate formulation, the lack of an effective taste-masking method and the lack of paediatric pharmacokinetic data and patient acceptability. It is equally important to establish methods for predicting the biopharmaceutical performance of a paediatric formulation as a function of age. Overcoming the challenges of existing technologies and providing custom-made solutions for the development of age-appropriate formulation is, therefore, a daunting task. Orodispersible films (ODF) are promising as age-appropriate formulations, an unmet need in paediatric drug delivery. New technological improvements in taste masking, improving solubility and rate of dissolution of insoluble drugs, the flexibility of dosing and extemporaneous preparation of these films in a hospital good manufacturing practises (GMP) setup using 3D printing can increase its acceptance among clinicians, patients and caregivers. The current review discusses the problems and possibilities in ODF technology to address the outstanding issues of age-appropriateness, which is the hallmark of patient acceptance and medical adherence in paediatrics.

Factorial design of in situ gelling two-compartment systems containing chlorhexidine for the treatment of periodontitis

Periodontitis is one of the most widespread bacterial infectious oral diseases that affects a significant percentage of the population worldwide. Different bacterial strains are responsible for the chronic inflammation and subgingival plaque that could be effectively treated with prolonged exposure to therapeutic levels of antibiotics and antiseptics in the periodontal pockets. Medicated in situ gels of chlorhexidine (CHX), for extended drug release and long-lasting antiseptic effect in the targeted cavities, were prepared in a two-compartment system. One compartment was loaded with sodium alginate solution while other was filled with CHX and calcium solution. The mixing of the solutions during the application resulted in gelation. Two 33 full factorial designs were applied in this study in order to optimize the gel formulation. Initially, the effects of concentration of gelling agent, crosslinker, and pH of the system on the dependent variables such as gel formation and structure characteristics were investigated. Then, the concentration of the crosslinker was optimized. Afterwards, the effect of gelling agent, loading of the drug, and pH of the gel system were correlated with the gel characteristics through another factorial design. Optimized formulations were tested for mucoadhesion, in vitro drug release, and microbiological investigation. Based on the results of the factorial design, mucoadhesiveness, antimicrobial investigation, and drug release, a 4 % alginate composition can be considered optimal. Overall, the optimized in situ periodontal gel was found to be effective with prolonged retention time and desirable outcomes.

Oral disintegration films: applications and production methods

The use of orally disintegrating films (ODF) as a vehicle for the release of active compounds has drawn attention due to the advantages such as ease of swallowing, precise dosage, low thickness, flexibility, greater comfort and acceptability by the patient in relation to oral tablets, for do not require water for administration, it is ideal for people with difficulty in swallowing. In this review, recent advances in ODFs, their applications and production methods will be presented. The production of ODFs uses polymers, plasticizers and active compounds. Among the compounds added to the film that can affect its properties, the polymer used has a strong influence on the disintegration time and on the controlled release of active principles. Polymers used for the production of oral films must be non-toxic, have good wettability and spreadability, and may be of synthetic or natural origin. Regarding the methods used in the production of ODFs, those currently used are solvent evaporation and hot extrusion. However, one of the great challenges for the production of oral films is the scale up, from laboratory to industrial scale, as factors such as heating, mixing speed and temperatures can lead to changes in film quality. Recently, ODFs have been developed as carriers of natural compounds such as vitamins, phenolic compounds, antioxidant and antimicrobial activity. Thus, it was found that orally disintegrating films are an alternative for the release of active compounds, different from those already existing, which justifies the growing interest in this type of film.

Comparison of Hydroxypropyl Methylcellulose and Alginate Gel Films with Meloxicam as Fast Orodispersible Drug Delivery

The aim of the study was the preparation and comparison of two types of orodispersible gel films (ODF) by the solvent casting method. Natural polymers: sodium alginate (ALG) or hydroxypropyl methylcellulose (HPMC) were used as the gel film formers, and Kollidon or microcrystalline cellulose was used as the disintegrant. Meloxicam (MLX), the drug used to treat rheumatic diseases for children and adults, was proposed as the active pharmaceutical ingredient (API). The influence of the polymer and disintegrant on the properties of ODF was investigated. The evaluation of prepared gel films was based on appearance description, mass uniformity measurement, disintegration time, API content, film wettability, and water content. Also, the dissolution test was prepared in a basket apparatus using artificial salvia (pH = 6.8) as the medium. The obtained API release profiles were analyzed for the similarity factors (f2) with the DDSolver software. The results showed that independently of the polymer or disintegrant, using the solvent casting method, gel films have a similar appearance and active substance content close to the theoretical value and water content of less than 10%. Only the type of polymer influences the release profiles of MLX. However, the disintegration time was longer than 30 s, which makes the films non-fast-dissolving drug delivery systems. This means that for the ODF system, further evaluation is required, and some changes in the composition of the film have to be done.

Electrospinning of pullulan-based orodispersible films containing sildenafil

Feasibility of electrospinning in the manufacturing of sildenafil-containing orodispersible films (ODFs) intended to enhance oxygenation and to reduce pulmonary arterial pressure in pediatric patients was evaluated. Given the targeted subjects, the simplest and safest formulation was chosen, using water as the only solvent and pullulan, a natural polymer, as the sole fiber-forming agent. A systematic characterization in terms of shear and extensional viscosity as well as surface tension of solutions containing different amounts of pullulan and sildenafil was carried out. Accordingly, electrospinning parameters enabling the continuous production, at the highest possible rate, of defect-free fibers with uniform diameter in the nanometer range were assessed. Morphology, microstructure, drug content and relevant solid state as well as ability of the resulting non-woven films to interact with aqueous fluids were evaluated. To better define the role of the fibrous nanostructure on the performance of ODFs, analogous films were produced by spin- and blade-coating and tested. Interestingly, the disintegration process of electrospun products turned out to be the fastest (i.e. occurring within few s) and compliant with Ph. Eur. and USP limits, making relevant ODFs particularly promising for increasing sildenafil bioavailability, thus lowering its dosages.

3D printed mucoadhesive orodispersible films manufactured by direct powder extrusion for personalized clobetasol propionate based paediatric therapies

The aim of this work is the development and production by Direct Powder Extrusion (DPE) 3D printing technique of novel oral mucoadhesive films delivering Clobetasol propionate (CBS), useful in paediatric treatment of Oral Lichen Planus (OLP), a rare chronic disease. The DPE 3D printing of these dosage forms can allow the reduction of frequency regimen, the therapy personalization, and reduction of oral cavity administration discomfort. To obtain suitable mucoadhesive films, different polymeric materials, namely hydroxypropylmethylcellulose or polyethylene oxide blended with chitosan (CS), were tested and hydroxypropyl-β-cyclodextrin was added to increase the CBS solubility. The formulations were tested in terms of mechanical, physico-chemical, and in vitro biopharmaceutical properties. The film showed a tenacious structure, with drug chemical-physical characteristics enhancement due to its partial amorphization during the printing stage and owing to cyclodextrins multicomponent complex formation. The presence of CS enhanced the mucoadhesive properties leading to a significant increase of drug exposure time on the mucosa. Finally, the printed films permeation and retention studies through porcine mucosae showed a marked retention of the drug inside the epithelium, avoiding drug systemic absorption. Therefore, DPE-printed films could represent a suitable technique for the preparation of mucoadhesive film potentially usable for paediatric therapy including OLP.

Overview about Oral Films in Mental Disorders

Mental disorders are increasing worldwide, and efforts have been developed by multidisciplinary research groups to combine knowledge from different areas such as psychology, neuroscience, medicine, and biotechnology to develop strategies and products to promote the prevention of mental disorders. Excessive antipsychotic consumption is a public health problem, and innovative strategies must be devised. The development of innovative and, if possible, natural products is one of the strategies to combat this public health problem. Oral films are recent delivery systems that have been developed with several advantages that should be applied in this area. This review intends to draw attention to these new dosage forms of drugs and bioactive molecules pertinent to the field of mental health prevention and therapy and to the need for regulatory guidelines to ensure their quality and safety. This is a critical overview about strengths, weaknesses, opportunities, and threats related to oral film implementation in mental disorder treatment.

Orodispersible Film Based on Maltodextrin: A Convenient and Suitable Method for Iron Supplementation

Orodispersible film (ODF) is an innovative dosage form used to administer drugs and nutrients, designed to disintegrate or dissolve in the oral cavity without needing water. One of the advantages of ODF is that it is suitable for administration in older people and children who have difficulty swallowing because of psychological or physiological deficiencies. This article describes the development of an ODF based on maltodextrin, which is easy to administer, has a pleasant taste, and is suitable for iron supplementation. An ODF containing 30 mg of iron as pyrophosphate and 400 µg of folic acid (iron ODF) was developed and manufactured on an industrial scale. The kinetic profile for serum iron and folic acid upon consumption of ODF compared with a Sucrosomial^® iron capsule (known for its high bioavailability) was evaluated in a crossover clinical trial. The study was conducted in nine healthy women, and the serum iron profile (AUC_0-8, T_max, and C_max) of both formulations was defined. Results showed that the rate and extent of elemental iron absorption with iron ODF was comparable to that obtained using the Sucrosomial^® iron capsule. These data represent the first evidence of iron and folic acid absorption concerning the newly developed ODF. Iron ODF was proven to be a suitable product for oral iron supplementation.

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.

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.

Application of traditional Chinese medicine in film drug delivery system

Film drug delivery systems have the advantages of precise administration, simple process and easy portability, compared with other traditional drug delivery systems such as tablets, capsules, syrups, ointments, etc. The traditional Chinese medicine (TCM) are normally developed in four categories of film agent like patch film, coating, spray film and gel film, which are applied to the treatment of oral ulcers, chronic diseases of lower limbs, burns, scalds, gynecological disease and body care. So the TCM film has great research value and prominent market prospect. In this review, we summarized the research progress of the material composition, pharmaceutical production, clinical application and pharmacology mechanism of various TCM film agents. It may provide a comprehensive reference for further development and utilization of TCM film agents.

Orodispersible Film (ODF) Platform Based on Maltodextrin for Therapeutical Applications

Orodispersible film (ODF) is a new dosage form that disperses rapidly in the mouth without water or swallowing. The main ingredient of an ODF is a polymer that can be both of natural or synthetic origin. Maltodextrin is a natural polymer, mainly used in pharmaceutical and nutraceutical fields. This review aims to examine the literature regarding ODFs based on maltodextrin as the platform for developing new products for therapeutical application. ODFs based on maltodextrin contain plasticizers that enhance their flexibility and reduce their brittleness. Surfactants; fillers, such as homopolymer and copolymer of vinylacetate; flavour and sweetener were introduced to improve ODF characteristics. Both water-soluble and insoluble APIs were introduced up to 100 mg per dosage unit. The solvent casting method and hot-melt extrusion are the most useful techniques for preparing ODFs. In particular, the solvent casting method allows manufacturing processes to be developed from a lab scale to an industrial scale. ODFs based on maltodextrin are characterized in terms of mechanical properties, dissolution rate, taste and stability. ODFs made of maltodextrin, developed by IBSA, were tested in vivo to evaluate their bioequivalence and efficacy and were demonstrated to be a valid alternative to the marketed oral dosage forms.

Orally Dispersible Dosage Forms for Paediatric Use: Current Knowledge and Development of Nanostructure-Based Formulations

The paediatric population has always suffered from a lack of medicines tailored to their needs, especially in terms of accurate dosage, stability and acceptability. Orodispersible dosage forms have gone through a resurrection as an alternative to liquid formulations or fractioned solid formulations, although they are still subject to several inconveniences, among which the unpleasant taste and the low oral bioavailability of the API are the most significant hurdles in the way of achieving an optimal drug product. Nanostructures can address these inconveniences through their size and variety, owing to the plethora of materials that can be used in their manufacturing. Through the formation and functionalisation of nanostructures, followed by their inclusion in orodispersible dosage forms, safe, stable and acceptable medicines intended for paediatric use can be developed.

Incorporation of Ethylcellulose Microparticles Containing a Model Drug with a Bitter Taste into Nanofibrous Mats by the Electrospinning Technique—Preliminary Studies

Electrospinning is considered a simple and comprehensive technique to formulate ultrafine fibres by using an electric field. Polymeric nanofibers constitute promising materials in biomedical applications as drug delivery systems. For their preparation, both natural and synthetic polymers are utilised. Owing to the potential use of electrospun nanofibers as an orodispersible drug dosage form, ethylcellulose microparticles containing the antihistamine drug rupatadine fumarate, prepared by the spray drying technique to conceal the drug’s bitter taste, were incorporated into nanofibers. The obtained nanofibrous mats were evaluated for morphology, mechanical strength, disintegration time, the drug solid state and acceptability in terms of taste masking efficiency. Preliminary studies showed that hypromellose used as a single polymer was not a suitable substance for the manufacturing of nanofibers. Therefore, in order to facilitate the obtention of homogeneous nonwovens, different grades of polyethylene oxide (2,000,000–2M-Da and 4,000,000–4M-Da) were added, which improved the quality of the prepared mats. Nanofibers of the most satisfactory quality were obtained from hypromellose (6.5% w/v) and PEO (2M, 0.5% w/v). SEM image analysis has shown that the nanofibers were homogeneous and smooth and possessed a fast disintegration time (below 30 s) and an adequate drug content with a simultaneous taste-masking effect (as indicated by the in vivo and in vitro methods). However, further studies are necessary to refine their mechanical characteristics.

Modernising Orodispersible Film Characterisation to Improve Palatability and Acceptability Using a Toolbox of Techniques

Orodispersible films (ODFs) have been widely used in paediatric, geriatric and dysphagic patients due to ease of administration and precise and flexible dose adjustments. ODF fabrication has seen significant advancements with the move towards more technologically advanced production methods. The acceptability of ODFs is dependent upon film composition and process of formation, which affects disintegration, taste, texture and mouthfeel. There is currently a lack of testing to accurately assess ODFs for these important acceptability sensory perceptions. This study produced four ODFs formed of polyvinyl alcohol and sodium carboxymethylcellulose using 3D printing. These were assessed using three in vitro methods: Petri dish and oral cavity model (OCM) methods for disintegration and bio-tribology for disintegration and oral perception. Increasing polymer molecular weight (MW) exponentially increased disintegration time in the Petri dish and OCM methods. Higher MW films adhered to the OCM upper palate. Bio-tribology analysis showed that films of higher MW disintegrated quickest and had lower coefficient of friction, perhaps demonstrating good oral perception but also stickiness, with higher viscosity. These techniques, part of a toolbox, may enable formulators to design, test and reformulate ODFs that both disintegrate rapidly and may be better perceived when consumed, improving overall treatment acceptability.

Orodispersible Films with Rupatadine Fumarate Enclosed in Ethylcellulose Microparticles as Drug Delivery Platform with Taste-Masking Effect

Orally disintegrating (orodispersible) films provide a versatile tool for drug administration, especially in the pediatric and geriatric population, since they reduce the risk of choking and do not necessitate drinking water during application. By considering their direct contact with the taste buds, palatability is an influential aspect related to patient compliance. The microparticles based on taste-masking polymers containing drugs enclosed inside effectively mask the unpleasant taste of medicines. Ethylcellulose is a hydrophobic polymer widely used as a taste-masking material. Rupatadine fumarate, a second-generation antihistamine drug, is characterised by an intense bitter taste; therefore, it is crucial to achieve a tolerable taste whilst developing orodispersible formulations with its content. The objective of this study was to develop orally disintegrating films with rupatadine fumarate in the form of ethylcellulose-based microparticles obtained from aqueous dispersions of ethylcellulose—Surelease^® or Aquacoat^® ECD. It was a technological challenge to achieve homogenous drug content per dosage unit and sufficient mechanical properties for film operating due to the necessity to suspend the microparticles in the casting solution. Although the process of obtaining films consisted of several steps (mixing, pouring, drying), the particles were homogeneously dispersed, and each film of the desired size contained the proper dose of the drug. The taste-masking effect was also maintained. This parameter was confirmed by three independent methods: in vivo by healthy volunteers, an electronic tongue and a dissolution test. The applied taste-evaluation techniques showed that the films containing Aquacoat^® ECD microparticles have the highest degree of bitter taste reduction, which confirms the results obtained in our previous studies.

Effects of Various Drying Times on the Properties of 3D Printed Orodispersible Films

Orodispersible films are an innovative dosage form. Their main advantages are the application comfort and the possibility of personalization. This work aimed to evaluate the influence of different drying times on the properties of orodispersible films of various thicknesses, prepared in two different semisolid extrusion 3D printing setups. In the first experiment, drying times were dependent on the overall print time of each batch. In the second setup, the drying time was set equal according to the longest one. The evaluated parameters were films’ weight uniformity, thickness, moisture content, surface pH, disintegration time, hardness, and tensile strength. Upon statistical comparison, significant differences in the moisture content were found, subsequently affecting the disintegration time. Moreover, statistically significant differences in films’ mechanical properties (hardness, tensile strength) were also described, proving that moisture content simultaneously affects film plasticity and related properties. In conclusion, a mutual comparison of the manufactured orodispersible films showed that the drying time affects their physical and mechanical properties. The in-process drying setup was proved to be sufficient while allowing quicker manufacturing.

Comparative Bioavailability Study of a New Vitamin D3 Orodispersible Film Versus a Marketed Oral Solution in Healthy Volunteers

BACKGROUND AND OBJECTIVE

An orally disintegrating film (ODF) formulation of vitamin D3 that dissolves rapidly in the mouth without drinking or chewing may be a worthwhile alternative to currently available drug products for therapeutic vitamin D supplementation. This study aimed to compare the bioavailability of a single dose of a vitamin D3 25000 I.U. ODF with those of a marketed oral vitamin D3 preparation in healthy subjects.

METHODS

This Phase 1, randomised, parallel-group, open-label study compared the pharmacokinetics of calcifediol [25(OH)D3], the precursor of bioactive vitamin D3, after a single dose of a new vitamin D3 25,000 I.U. ODF with those of a Reference formulation (vitamin D3 25000 I.U./2.5 mL oral solution) in healthy adult subjects using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. The primary objective was bioavailability under fed conditions, defined as maximum plasma concentration (C_max) of 25(OH)D3 and area under the concentration-time curve from time zero to time t, the last quantifiable concentration (AUC_0-t). The pharmacokinetics of 25(OH)D3 were also evaluated following the ODF administration under fasting conditions. Subjects were randomised to receive a single dose of the vitamin D3 25000 I.U. ODF or the Reference oral solution under fed conditions or the vitamin D3 ODF under fasting conditions.

RESULTS

Forty-eight healthy subjects were randomised and completed the study. Overall, the pharmacokinetic profile was very similar across the three treatment groups, and bioavailability did not significantly differ among treatments. Under fed conditions, mean 25(OH)D3 plasma values for C_max were 6.68 ± 2.03 versus 6.61 ± 2.62 ng/mL for the Test versus Reference formulations. Corresponding values for AUC_0-t were 2364.80 ± 1336.97 versus 2150.52 ± 1622.76 ng/mL × h. Mean C_max was slightly lower (6.68 ± 2.03 vs 7.23 ± 1.48 ng/mL) and the time to reach peak concentration was delayed (144 h [36-312] versus 42 h (2-480]) with the ODF under fed versus fasting conditions (p = 0.0371). The point estimates and 90 % CIs of the Test_fed/Reference_fed ratios of the geometric means showed that the bioavailability of exogenous 25(OH)D3 was, both in rate and extent of absorption, slightly higher with the vitamin D3 ODF than the vitamin D3 oral solution under the administration conditions recommended for the vitamin D3 oral solution. Palatability and ease of use of the ODF were satisfactory.

CONCLUSION

The new ODF 25000 I.U. formulation provided a valuable alternative to the marketed oral solution for therapeutic vitamin D supplementation, with a bioavailability that was slightly higher than that of the vitamin D3 oral solution administered under the same conditions.

TRIAL REGISTRATION

The study was retrospectively registered with the ISRCTN Registry (Registry code: ISRCTN13208948) on 27 November 2020.

Development of buccal film formulations and their mucoadhesive performance in biomimetic models

When developing buccal films for oromucosal drug administration, adhesion is essential to ensure sufficient time for permeation of the active ingredient(s) through the oral mucosa and avoid the detachment and subsequent swallowing of the film. In this study, biomimetic materials were evaluated as a replacement for buccal mucosa in mucoadhesion testing and potential adhesives were compared regarding their suitability to increase the adhesion of hypromellose-based oromucosal films. Gelatin gels, as possible biomimetics, failed to mimic the buccal mucosa. Furthermore, esophageal tissue lead to a wider variance of adhesion data despite showing a good correlation with buccal tissue. A synthetic copolymer hydrogel based on hydroxyethylmethacrylate (HEMA) and N-acryloyl glucosamine (AGA) was able to mimic the buccal mucosa in these tests and reduced the variation in the data compared to animal tissue. Adding polyacrylic acid and polyvinylpyrrolidone to the film formulations at a concentration of 5% w/w approximately doubled the maximum detachment force and work of adhesion. Sodium alginate enhanced the adhesive properties moderately but adding chitosan did not significantly increase mucoadhesion. Polyvinylpyrrolidone and polyacrylic acid are rated as strong adhesion enhancers for buccal films and the HEMA/AGA hydrogel is considered as a suitable alternative for animal mucosa in mucoadhesion testing.

Orodispersible films: Conception to quality by design

Orodispersible films (ODFs) are ultra-thin, stamp-sized, elegant, portable and patient-centric pharmaceutical dosage forms that do not need water to be ingested. They are particularly useful for paediatric and geriatric patient populations with special needs such as dysphagia, Parkinson's disease, and oral cancer. Accordingly, they hold tremendous potential in gaining patient compliance, convenience and pharmacotherapy. In the present review, conception and evolution of ODFs as a product and its technology are discussed. The review continues by providing overview about the potential of ODFs as carriers for delivering drugs, herbal extracts, probiotics and vaccines. Besides, strategies employed in drug cargo loading, taste masking of bitter drugs and enhancing drug stability are discussed. Finally, the review concludes by providing a brief overview about quality by design (QbD) principles in development of ODFs.

Modular design principle based on compartmental drug delivery systems

The current manufacturing solutions for oral solid dosage forms are fundamentally based on technologies from the 19th century. This approach is well suited for mass production of one-size-fits-all products; however, it does not allow for a straight-forward personalization and mass customization of the pharmaceutical end-product. In order to provide better therapies to the patients, a need for innovative manufacturing concepts and product design principles has been rising. Additive manufacturing opens up a possibility for compartmentalization of drug products, including design of spatially separated multidrug and functional excipient compartments. This compartmentalized solution can be further expanded to modular design thinking. Modular design is referring to combination of building blocks containing a given amount of drug compound(s) and related functional excipients into a larger final product. Implementation of modular design principles is paving the way for implementing the emerging personalization potential within health sciences by designing compartmental and reactive product structures that can be manufactured based on the individual needs of each patient. This review will introduce the existing compartmentalized product design principles and discuss the integration of these into edible electronics allowing for innovative control of drug release.

Characterization of Hydrophilic Polymers as a Syringe Extrusion 3D Printing Material for Orodispersible Film

The application of hydrophilic polymers in designing and three-dimensional (3D) printing of pharmaceutical products in various dosage forms has recently been paid much attention. Use of hydrophilic polymers and syringe extrusion 3D printing technology in the fabrication of orodispersible films (ODFs) might hold great potential in rapid drug delivery, personalized medicine, and manufacturing time savings. In this study, the feasibility of 3D-printed ODFs fabrication through a syringe extrusion 3D printing technique and using five different hydrophilic polymers (e.g., hydroxypropyl methylcellulose E15, hydroxypropyl methylcellulose E50, high methoxyl pectin, sodium carboxymethylcellulose, and hydroxyethylcellulose) as film-forming polymers and printing materials has been investigated. Rheology properties and printability of printing gels and physicochemical and mechanical properties of 3D-printed ODFs were evaluated. Amongst the investigated hydrophilic polymers, sodium carboxymethylcellulose at a concentration of 5% w/v (SCMC-5) showed promising results with a good printing resolution and accurate dimensions of the 3D-printed ODFs. In addition, SCMC-5 3D-printed ODFs exhibited the fastest disintegration time within 3 s due to high wettability, roughness and porosity on the surface. However, the results of the mechanical properties study showed that SCMC-5 3D printed ODFs were rigid and brittle, thus requiring special packaging to prevent them from any damage before practical use.

"Success Depends on Your Backbone"-About the Use of Polymers as Essential Materials Forming Orodispersible Films

Polymers constitute a group of materials having a wide-ranging impact on modern pharmaceutical technology. Polymeric components provide the foundation for the advancement of novel drug delivery platforms, inter alia orodispersible films. Orodispersible films are thin, polymeric scraps intended to dissolve quickly when put on the tongue, allowing them to be easily swallowed without the necessity of drinking water, thus eliminating the risk of choking, which is of great importance in the case of pediatric and geriatric patients. Polymers are essential excipients in designing orodispersible films, as they constitute the backbone of these drug dosage form. The type of polymer is of significant importance in obtaining the formulation of the desired quality. The polymers employed to produce orodispersible films must meet particular requirements due to their oral administration and have to provide adequate surface texture, film thickness, mechanical attributes, tensile and folding strength as well as relevant disintegration time and drug release to obtain the final product characterized by optimal pharmaceutical features. A variety of natural and synthetic polymers currently utilized in manufacturing of orodispersible films might be used alone or in a blend. The goal of the present manuscript was to present a review about polymers utilized in designing oral-dissolving films.

Near-Infrared Hyperspectral Imaging as a Monitoring Tool for On-Demand Manufacturing of Inkjet-Printed Formulations

This study evaluates the potential use of near-infrared hyperspectral imaging (NIR-HSI) for quantitative determination of the drug amount in inkjet-printed dosage forms. We chose metformin hydrochloride as a model active pharmaceutical ingredient (API) and printed it onto gelatin films using a piezoelectric inkjet printing system. An industry-ready NIR-HSI sensor combined with a motorized movable linear stage was applied for spectral acquisition. Initial API-substrate screening revealed best printing results for gelatin films with TiO₂ filling. For calibration of the NIR-HSI system, escalating drug doses were printed on the substrate. After spectral pre-treatments, including standard normal variate (SNV) and Savitzky-Golay filtering for noise reduction and enhancement of spectral features, principal component analysis (PCA) and partial least squares (PLS) regression were applied to create predictive models for the quantification of independent printed metformin hydrochloride samples. It could be shown that the concentration distribution maps provided by the developed HSI models were capable of clustering and predicting the drug dose in the formulations. HSI model prediction showed significant better correlation to the reference (HPLC) compared to on-board monitoring of dispensed volume of the printer. Overall, the results emphasize the capability of NIR-HSI as a fast and non-destructive method for the quantification and quality control of the deposited API in drug-printing applications.

The Impact of the Preparation Method on the Properties of Orodispersible Films with Aripiprazole: Electrospinning vs. Casting and 3D Printing Methods

Orodispersible films (ODFs) address the needs of pediatric and geriatric patients and people with swallowing difficulties due to fast disintegration in the mouth. Typically, they are obtained using the solvent casting method, but other techniques such as 3D printing and electrospinning have already been investigated. The decision on the manufacturing method is of crucial importance because it affects film properties. This study aimed to compare electrospun ODFs containing aripiprazole and polyvinyl alcohol with films prepared using casting and 3D printing methods. Characterization of films included DSC and XRD analysis, microscopic analysis, the assessment of mechanical parameters, disintegration, and dissolution tests. Simplified stability studies were performed after one month of storage. All prepared films met acceptance criteria for mechanical properties. Electrospun ODFs disintegrated in 1.0 s, which was much less than in the case of other films. Stability studies have shown the sensitivity of electrospun films to the storage condition resulting in partial recrystallization of ARP. These changes negatively affected the dissolution rate, but mechanical properties and disintegration time remained at a desirable level. The results demonstrated that electrospun fibers are promising solutions that can be used in the future for the treatment of patients with swallowing problems.

Recent advances of oral film as platform for drug delivery

Orally drug delivery film has received extensive interest duo to a distinct set of its advantageous properties compared to the traditional orally administered dosages, including faster rate of drug absorption, higher bioavailability and better patient compliance for children and elders with swallowing deficiencies. In particular, its potential capacity of delivering proteins and peptides has further attracted great attention. Lately, tremendous advances have been made in designing and developing both novel mucoadhesive films and orodispersible films to fulfill specific accomplishments of drug delivery. This review aims to summarize those newly developed oral films, discussing their formulation strategies, manufacturing methods as well as advantages and limitations thereof. Conclusions and future perspectives are also provided in brief.

Neonatal and pediatric oral drug delivery: Hopes and hurdles

The neonatal and pediatric populations have long been neglected concerning the development of oral dosage forms. For close to two decades, caregivers have had to adjust the doses of the off-label medicines and drugs for adults to suit the neonatal and pediatric needs. This is due to the lack of rules and regulations regarding neonates and pediatrics clinical trials while pharmaceutical industries see this as a non-lucrative approach. Despite such limitations, the administration of solid and liquid dosage forms to neonates and pediatrics necessitates the development of new technologies and even new strategies to meet the needs. Current approaches have not only focused on the development of suitable dosage forms but also the advancement of devices to enhance drug administration to pediatrics and neonates. Though current approaches have significantly added to the number of pediatric and neonatal oral dosage formulations on the market, there is still more room for improvement(s). While novel dosage forms including multiparticulates, orodispersible tablets/films, and chewable tablets have extensively been researched, some administration devices (e.g., nipple shield, pill swallowing cup, and solid dosage pen) have also been explored. Although a few of these products are in the market, the concerted efforts of regulation administrative bodies, pharmaceutical industry settings, and scientists in academia have been oriented to address all issues and advance the neonatal and pediatric-centric pharmaceutical products.

Pressure-assisted microsyringe 3D printing of oral films based on pullulan and hydroxypropyl methylcellulose

Oral films (OFs) continue to attract attention as drug delivery systems, particularly for pedatric and geriatric needs. However, immiscibility between different polymers limits the full potential of OFs from being explored. One example is pullulan (PUL), a novel biopolymer which often has to be blended with other polymers to reduce cost and alter its mechanical properties. In this study, the state-of-the-art in fabrication techniques, three-dimensional (3D) printing was used to produce hybrid film structures of PUL and hydroxypropyl methylcellulose (HPMC), which were loaded with caffeine as a model drug. 3D printing was used to control the spatial deposition of films. HPMC was found to increase the mean mechanical properties of PUL films, where the tensile strength, elastic modulus and elongation break increased from 8.9 to 14.5 MPa, 1.17 to 1.56 GPa and from 1.48% to 1.77%, respectively. In addition, the spatial orientation of the hybrid films was also explored to determine which orientation could maximize the mechanical properties of the hybrid films. The results revealed that 3D printing could modify the mechanical properties of PUL whilst circumventing the issues associated with immiscibility.

Applications of polymer blends in drug delivery

Background

Polymers are essential components of many drug delivery systems and biomedical products. Despite the utility of many currently available polymers, there exists a demand for materials with improved characteristics and functionality. Due to the extensive safety testing required for new excipient approval, the introduction and use of new polymers is considerably limited. The blending of currently approved polymers provides a valuable solution by which the limitations of individual polymers can be addressed.

Main body

Polymer blends combine two or more polymers resulting in improved, augmented, or customized properties and functionality which can result in significant advantages in drug delivery applications. This review discusses the rationale for the use of polymer blends and blend polymer-polymer interactions. It provides examples of their use in commercially marketed products and drug delivery systems. Examples of polymer blends in amorphous solid dispersions and biodegradable systems are also discussed. A classification scheme for polymer blends based on the level of material processing and interaction is presented.

Conclusion

The use of polymer blends represents a valuable and under-utilized resource in addressing a diverse range of drug delivery challenges. It is anticipated that new drug molecule development challenges such as bioavailability enhancement and the demand for enabling excipients will lead to increased applications of polymer blends in pharmaceutical products.

Graphical abstract

Development and Characterization of an Orodispersible Film for Vitamin D3 Supplementation

Vitamin D plays a crucial and very well-known role in regulation of calcium homeostasis and bone metabolism and mineralization. However, a huge and more recent body of evidence supports the positive influence of vitamin D on the regulation of immune response, ranging from protection against respiratory tract infections to prevention and management of asthma. Nevertheless, vitamin D deficiency is a very common condition and there is an increasing need for suitable products for proper supplementation, allowing good compliance also in specific populations. Orally disintegrating tablets (ODT) were first developed to overcome the difficulty experienced by pediatric and geriatric patients of swallowing traditional oral dosage forms and, recently, orodispersible films (ODF) are gaining popularity as novel dosage form for assuming active pharmaceutical ingredients, vitamins, and ingredients for food supplements. This study describes a 2000 IU Vitamin D3 ODF for daily intake, consisting of hydrophilic polymers and suitable excipients, manufactured by film-casting process. Elongation-at-break (E%), Young’s modulus (Y), and tensile strength (TS) were investigated using a dynamometer. Chemical stability was evaluated assaying the vitamin D3 in the films stored at different environmental conditions. In addition, in vitro disintegration and dissolution studies were performed. Correlation existed between the mechanical properties of the film and the residual water, acting as plasticizer. The stability study showed that vitamin D3 assay was ≥90% also after 3 months at 40 °C. The film disintegrated in less than 1 min and the vitamin D3 released was ≥75% after 15 min. An ODF with suitable properties can be manufactured and used as innovative dosage form for vitamin D3 food supplements.

The potential of Streptococcus salivarius oral films in the management of dental caries: An inkjet printing approach

The use of probiotics, which can be administered in oro-dispersible films (ODFs) and have prolonged activity in the mouth, was explored. ODFs made of xylitol and containing Streptococcus salivarius were formulated using inkjet printing and tested against Streptococcus mutans - a causative organism of dental caries. The testing of the prepared ODFs involved co-incubating an ink-jetted formulation of S. salivarius and xylitol with S. mutans and monitoring the microbial growth kinetics in real-time using isothermal microcalorimetry and colony plate counts. Cell-free supernatants (CFS) of S. salivarius were also tested against S. mutans. The phosphate solubilisation potential of S. salivarius was also determined and found to be negative, an indication that the species will not deplete phosphate from teeth. From the tests, it was observed that the formulation reduced the S. mutans population from 7.9 to 5.04 Log CFU/mL post-calorimetry (approximately 3 Log reduction) which was comparable to the 99.9% reduction expected during antimicrobial activity testing. A gradual decrease in S. mutans population was also observed with increasing of CFS of S. salivarius volumes indicative of pathogen suppression. This study demonstrates that S. salivarius can be useful in managing dental caries and ODFs of S. salivarius can be formulated easily using ink-jetting for such management.

Human mouthfeel panel investigating the acceptability of electrospun and solvent cast orodispersible films

A human panel study was performed to investigate the acceptability of orodispersible electrospun and solvent cast films. 50 healthy volunteers took two drug-free samples of polyvinyl alcohol films prepared by the two methods. On a 5-point hedonic scale, the volunteers assessed the films' perceived size, stickiness, thickness, disintegration time, thickening effect on saliva, and handling. The films manufactured by both methods were similar in their end-user acceptability. The modal values of perceived size, thickness, disintegration time, saliva thickening effect, and handling were high (4 or 5). However, for both, the stickiness mode was 2 (strongly sticky) and the only negative attribute. Both films were reported to take approximately 30 s to disintegrate completely in the mouth. Electrospun films scored similarly high to solvent cast orodispersible films in most attributes of end-user acceptability. Electrospun films were marginally preferred, with 27 out of 50 participants picking electrospinning when presented with a forced choice test of both fabrication methods. This is the first study to show that electrospinning enables the fabrication of orodispersible films that are acceptable to adult human participants in terms of handling and mouthfeel and suggests that the potential for clinical translation of such formulations is high.

Orodispersible films as a personalized dosage form for nursing home residents, an exploratory study

Background A frequent problem in ageing patients, and thus in nursing home residents, is dysphagia, affecting the ability to swallow solid dosage forms. A promising and personalized drug delivery system for this patient group is the orodispersible film. Orodispersible films could be prepared extemporaneously in a (hospital) pharmacy setting or in specialty compounding community pharmacies using the solvent casting method. Little has been done to systematically investigate which medications should be chosen for orodispersible film formulation development. Objective In this study, the medication use of nursing home residents was examined to identify medications that are suitable for orodispersible film formulation development. Setting Nursing homes of three Northern provinces of Netherlands. Method Medication intake data from 427 nursing home residents from nine nursing homes from the three northern provinces of the Netherlands were used to identify candidates for orodispersible film formulation development. A stepwise approach, with exclusion steps, was used. Selection criteria included systemic use with a maximum amount of 100 mg per dose unit, no commercially available suitable dosage forms for administration in dysphagia, indication for diseases associated with dysphagia. Furthermore, the characteristics of the active pharmaceutical ingredient needed for the orodispersible film formulation development, such as water solubility and taste, were reviewed. Main outcome measure Active pharmaceutical ingredients suitable for orodispersible film formulation development. Results The nursing home residents used three hundred forty one different medications. Of those, 34 active pharmaceutical ingredients from six therapeutic groups were considered as candidates for orodispersible film formulation development. Most of these active pharmaceutical ingredients have a bitter taste and poor water solubility, which is a challenge for orodispersible film production. Conclusions The most suitable active pharmaceutical ingredient candidates for manufacturing of orodispersible films for the ageing patient population may be the combination of levodopa and carbidopa used to treat the symptoms of Parkinson’s disease, and baclofen used to treat spasticity.

A Focus Group Study about Oral Drug Administration Practices at Hospital Wards-Aspects to Consider in Drug Development of Age-Appropriate Formulations for Children

Oral drug administration to pediatric patients is characterized by a lack of age-appropriate drug products and the off-label use of medicines. However, drug administration practices at hospital wards is a scarcely studied subject. The aim of this study was to explore the oral drug administration practices at pediatric hospital wards, with a focus on experiences and challenges faced, methods used to mitigate existing problems, drug manipulation habits, perceptions about oral dosage forms and future needs of oral dosage forms for children. This was a qualitative study consisting of focus group discussions with physicians, nurses and clinical pharmacists in a tertiary university hospital with the objective of bringing forward a holistic view on this research topic. These healthcare professionals recognized different administration challenges that were classified as either dosage form-related or patient-related ones. A lack of depot formulations developed especially for children as well as oral pediatric dosage forms of drug substances currently available as intravenous dosage forms was recognized. The preferred oral dosage forms were oral liquids and orodispersible tablets. Patient-centered drug administration practices including factors facilitating drug administration both at hospital wards and at home after patient discharge were identified. Among all healthcare professionals, the efficient cooperation in drug prescribing and administration as well as in educating the child’s caregivers in correct administration techniques before discharge and improving the overall discharge process of patients was emphasized. This study complements the prevalent understanding that new dosage forms for children of varying ages and stages of development are still needed. It also brings a holistic view on different aspects of oral drug administration to pediatric patients and overall patient-centered drug administration practices.

Patient Centric Pharmaceutical Drug Product Design-The Impact on Medication Adherence

Medication adherence is a growing concern for public health and poor adherence to therapy has been associated with poor health outcomes and higher costs for patients. Interventions for improving adherence need to consider the characteristics of the individual therapeutic regimens according to the needs of the patients. In particular, geriatric and paediatric populations as well as dermatological patients have special needs/preferences that should be considered when designing drug products. Patient Centric Drug Product Pharmaceutical Design (PCDPD) offers the opportunity to meet the needs and preferences of patients. Packaging, orodispersible formulations, fixed dose combinations products, multiparticulate formulations, topical formulations and 3D printing are of particular relevance in a PCDPD process. These will be addressed in this review as well as their impact on medication adherence.

Orodispersible films containing ball milled aripiprazole-poloxamer®407 solid dispersions

This research aimed at developing ODFs containing an antipsychotic drug - aripiprazole (ARP). ARP, as a BCS II class molecule, requires enhancing its water solubility prior to formulating. Therefore, a solid dispersion of ARP - Poloxamer® 407 was prepared by ball milling, then incorporated into the films. It was found that co-processing led to an over 100-fold increase in drug solubility in comparison with pure drug. Moreover, ODFs with solid dispersion showed faster drug release (>95% below 15 min) and disintegration (<30 s), compared with raw ARP films. These results are believed to be due to the solubilization effect of poloxamer and enhanced wettability of the film. Films containing solid dispersions were found to possess smoother film surfaces and favorable mechanical properties - flexibility and strength. The ODF formulations, prepared by a casting method, were based on three different polymers (Kollicoat® IR, Kollicoat® Protect or PVA). It was found that not only the form of the incorporated drug, but also the type of film-forming polymer had an impact on the analyzed parameters. The use of PVA was beneficial in the film formulation with aripiprazole in comparison to other tested film-forming polymers.

3D printing of multilayered orodispersible films with in-process drying

The aim of this study was to prepare benzydamine hydrochloride loaded orodispersible films using modified semisolid extrusion 3D printing method. An innovative approach was developed where thin layer of drug loaded dispersion is printed and dried before printing of subsequent layers. Layer-by-layer drying as the in process step improves mechanical properties of films, uniformity of drug content and allows faster preparation of films in compounding settings due to shortening of drying time. Orodispersible films consisted of film forming maltodextrin, sorbitol as a plasticizer and hydroxyethylcellulose as a thickening agent. The height of the digital model showed excellent correlation with the disintegration time, weight, thickness and mechanical properties of prepared films. Drug content, predefined by volume of digital model and concentration of drug in print dispersion, showed excellent uniformity. The modified printing method shows great promise in a compounding production of personalized film dosage forms, and brings in possibilities such as one step preparation of films with compartmented drugs and incorporation of taste masking or release control layers.

Towards Printed Pediatric Medicines in Hospital Pharmacies: Comparison of 2D and 3D-Printed Orodispersible Warfarin Films with Conventional Oral Powders in Unit Dose Sachets

To date, the lack of age-appropriate medicines for many indications results in dose manipulation of commercially available dosage forms, commonly resulting in inaccurate doses. Various printing technologies have recently been explored in the pharmaceutical field due to the flexible and precise nature of the techniques. The aim of this study was, therefore, to compare the currently used method to produce patient-tailored warfarin doses at HUS Pharmacy in Finland with two innovative printing techniques. Dosage forms of various strengths (0.1, 0.5, 1, and 2 mg) were prepared utilizing semisolid extrusion 3D printing, inkjet printing and the established compounding procedure for oral powders in unit dose sachets (OPSs). Orodispersible films (ODFs) drug-loaded with warfarin were prepared by means of printing using hydroxypropylcellulose as a film-forming agent. The OPSs consisted of commercially available warfarin tablets and lactose monohydrate as a filler. The ODFs resulted in thin and flexible films showing acceptable ODF properties. Moreover, the printed ODFs displayed improved drug content compared to the established OPSs. All dosage forms were found to be stable over the one-month stability study and suitable for administration through a naso-gastric tube, thus, enabling administration to all possible patient groups in a hospital ward. This work demonstrates the potential of utilizing printing technologies for the production of on-demand patient-specific doses and further discusses the advantages and limitations of each method.