Oral films: Current status and future perspectives

Acceptability of orodispersible films for delivery of medicines to infants and preschool children

Orodispersible films (ODFs) possess potential to facilitate oral drug delivery to children; however, documentation of their acceptability in this age group is lacking. This study is the first to explore the initial perceptions, acceptability and ease of use of ODFs for infants and preschool children, and their caregivers through observed administration of the type of dosage form. Placebo ODFs were administered to children stratified into aged 6 to 12 months, 1 year, 2 years, 3 years, 4 years and 5 years old and into those with an acute illness or long-term stable condition in hospital setting. Acceptability of the dosage form and end-user views were assessed by (a) direct observation of administration, (b) questionnaires to caregivers and nurses, and (c) age-adapted questionnaires for children aged 3 years and over. The majority of children (78%) aged 3 years and over gave the ODF a positive rating both on verbal and non-verbal scales. Despite little prior experience, 78% of caregivers expressed positive opinion about ODFs before administration. After the ODFs were taken, 79% of infant caregivers and 86% caregivers of preschool children positively rated their child's acceptance of the ODF. The intraclass correlation coefficient value was 0.92 showing good agreement between ratings of caregivers and nurses. ODFs showed a high degree of acceptability among young children and their caregivers. If drug loading permits, pharmaceutical companies should consider developing pediatric medicines in this format. The methodology described here is useful in assessing the acceptability of active ODF preparations and other dosage forms to children.

Incorporation of surface-modified dry micronized poorly water-soluble drug powders into polymer strip films

Recent work has established polymer strip films as a robust platform for delivery of poorly water-soluble drugs via slurry casting, in particular using stable drug nanosuspensions. Here, a simpler, robust method to directly incorporate dry micronized poorly water-soluble drug, fenofibrate (FNB), is introduced. As a major novelty, simultaneous surface modification using hydrophilic silica along with micronization was done using fluid energy mill (FEM) in order to reduce FNB hydrophobicity and powder agglomeration. It is hypothesized that silica coating promotes easy, uniform dispersion of micronized and coated FNB (MC-FNB) during direct mixing with aqueous hydroxypropyl methylcellulose (HPMC-E15LV) and glycerin solutions. Uniform dispersion leads to improved film critical quality attributes (CQAs) such as appearance, drug content uniformity and drug dissolution. The impact of polymer solution viscosity (low and high), mixer type (low versus high shear), and FNB surface modification on film CQAs were also assessed. Films with as-received FNB (AR-FNB) and micronized uncoated FNB (MU-FNB) were prepared as control. When MC-FNB powders were used, films exhibited improved appearance (thickness uniformity, visible lumps/agglomerates), better drug content uniformity (expressed as relative standard deviation), fast and immediate drug release, and enhanced mechanical properties (tensile strength, elongation percentage), regardless of the polymer solution viscosity or mixer type. These results compare favorably with those reported using nanosuspensions of FNB, establishing the feasibility of directly incorporating surface modified-micronized poorly water-soluble drug powders in film manufacturing.

New formulation and approach for mucoadhesive buccal film of rizatriptan benzoate

Mucoadhesive buccal film is developed as a promising dosage form, which has prominent advantages because of drug delivery through buccal mucosa. New formulation of buccal films containing rizatriptan benzoate (RB) was prepared by solvent casting method using various concentrations of hydroxypropyl methylcellulose (HPMC K4M), polyvinyl alcohol (PVA), polyethylene oxide (PEO), glycerol, stevia, and goat buccal mucosa used as a model membrane. In this work, the effect of polymers and plasticizer concentrations on drug release profile, disintegration and dissolution time, mechanical properties, and mucoadhesive characteristics of films was studied. Scanning electron microscopy analysis revealed uniform distribution of RB in film formulations. Chemical compounds and thermal analysis of the films were studied by Fourier transform infrared spectroscopy and differential scanning calorimetry, respectively. The buccal films produced were uniform in drug content and thickness. All formulations have in vitro release of 98–102% between 40 and 80 min. Also ex vivo mucoadhesion strength was in the range of 0.205 ± 0.035 to 0.790 ± 0.014 N for all formulations. A formulation consisting RB (50 mg), HPMC K4M, PVA, and PEO (63 mg), glycerol (1.5 ml), stevia (5 mg) was selected as our optimum composition. More satisfactory results were obtained in terms of disintegration and dissolution time, mechanical properties, and mucoadhesive characteristics. In addition, it showed about 99.89% RB released in 45 min. The results suggest that RB-loaded mucoadhesive buccal films could be a potential candidate to achieve optimum drug release for effective treatment of migraine.

Bilayered buccal films as child-appropriate dosage form for systemic administration of propranolol

Buccal mucosa has emerged as an attractive site for systemic administration of drug in paediatric patients. This route is simple and non-invasive, even if the saliva wash-out effect and the relative permeability of the mucosa can reduce drug absorption. Mucoadhesive polymers represent a common employed strategy to increase the contact time of the formulation at the application site and to improve drug absorption. Among the different mucoadhesive dosage forms, buccal films are particularly addressed for paediatric population since they are thin, adaptable to the mucosal surface and able to offer an exact and flexible dose. The objective of the present study was to develop bilayered buccal films for the release of propranolol hydrochloride. A primary polymeric layer was prepared by casting and drying of solutions of film-forming polymers, such as polyvinylpyrrolidone (PVP) or polyvinylalcohol (PVA), added with different weight ratios of gelatin (GEL) or chitosan (CH). In order to achieve unidirectional drug delivery towards buccal mucosa, a secondary ethylcellulose layer was applied onto the primary layer. Bilayered films were characterized for their physico-chemical (morphology, thickness, drug content and solid state) and functional (water uptake, mucoadhesion, drug release and permeation) properties. The inclusion of CH into PVP and PVA primary layer provided the best mucoadhesion ability. Films containing CH provided a lower drug release with respect to films containing GEL and increased the amount of permeated drug through buccal mucosa, thanks to its ability of interfering with the lipid organization. The secondary ethylcellulose layer did not interfere with drug permeation, but it could limit drug release in the buccal cavity.

Effect of storage on the physical stability of thin polymethacrylate-perphenazine films

We evaluated the physical stability of thin polymethacrylate-drug films under three different storage conditions by X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy, polarized light microscopy, and Fourier transform infrared spectroscopy. Mechanical properties i.e. elongation, mechanical strength, and in vitro drug release from the thin films were also determined during storage. The films consisted of ammonium methacrylate copolymer (RLPO)/dimethylaminoethyl methacrylate copolymer (EPO), polyvinylpyrroline (PVP)/polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus) and perphenazine (PPZ). PPZ remained fully amorphous in all RLPO- and EPO -films for up to 12months' storage at 4°C in dry conditions. Instead, in EPO+PVP+PPZ 15% -films, higher temperature induced recrystallization of PPZ within three months and higher humidity also at six months. Crystallization was also observed in EPO+Soluplus+PPZ 10% -films at high temperature at 12months. The amount of PPZ released was significantly lower from recrystallized PPZ films than from stable amorphous films. The better stability of RLPO -films was attributed to PPZ being molecularly dispersed and also because of strong drug-polymer interactions in the films, while increasing storage temperatures weakened the hydrogen bonding interactions in the EPO -films. In addition, the presence of hygroscopic PVP facilitated PPZ recrystallization in the EPO -films if they were stored in a highly humid environment.

Quality by Design approach for studying the impact of formulation and process variables on product quality of oral disintegrating films

The present investigation was carried out to understand the impact of formulation and process variables on the quality of oral disintegrating films (ODF) using Quality by Design (QbD) approach. Lamotrigine (LMT) was used as a model drug. Formulation variable was plasticizer to film former ratio and process variables were drying temperature, air flow rate in the drying chamber, drying time and wet coat thickness of the film. A Definitive Screening Design of Experiments (DoE) was used to identify and classify the critical formulation and process variables impacting critical quality attributes (CQA). A total of 14 laboratory-scale DoE formulations were prepared and evaluated for mechanical properties (%elongation at break, yield stress, Young's modulus, folding endurance) and other CQA (dry thickness, disintegration time, dissolution rate, moisture content, moisture uptake, drug assay and drug content uniformity). The main factors affecting mechanical properties were plasticizer to film former ratio and drying temperature. Dissolution rate was found to be sensitive to air flow rate during drying and plasticizer to film former ratio. Data were analyzed for elucidating interactions between different variables, rank ordering the critical materials attributes (CMA) and critical process parameters (CPP), and for providing a predictive model for the process. Results suggested that plasticizer to film former ratio and process controls on drying are critical to manufacture LMT ODF with the desired CQA.

Critical material attributes (CMAs) of strip films loaded with poorly water-soluble drug nanoparticles: III. Impact of drug nanoparticle loading

Polymer strip films have emerged as a robust platform for poorly water-soluble drug delivery. However, the common conception is that films cannot exceed low drug loadings, mainly due to poor drug stability, slow release, and film brittleness. This study explores the ability to achieve high loadings of poorly water-soluble drug nanoparticles in strip films while retaining good mechanical properties and enhanced dissolution rate. Aqueous suspensions containing up to 30wt% griseofulvin nanoparticles were prepared via wet stirred media milling and incorporated into hydroxypropyl methylcellulose (HPMC) films. Griseofulvin loading in films was adjusted to be between 9 and 49wt% in HPMC-E15 films and 30 and 73wt% in HPMC-E4M films by varying the mixing ratio of HPMC solution-to-griseofulvin suspension. All films exhibited good content uniformity and nanoparticle redispersibility up to 50wt% griseofulvin, while E4M films above 50wt% griseofulvin had slightly worse content uniformity and poor nanoparticle redispersibility. Increasing drug loading in films generally required more time to achieve 100% release during dissolution, although polymer-drug clusters dispersed from E4M films above 50wt% griseofulvin, resulting in similar dissolution profiles. While all films exhibited good tensile strength, a significant decrease in percent elongation was observed above 40-50wt% GF, resulting in brittle films.

Orodispersible films: Towards drug delivery in special populations

Orodispersible films (ODF) hold promise as a novel delivery method, with the potential to deliver tailored therapies to different patient populations. This article reviews the current strides of ODF technology and some of its unmet quality and manufacturing aspects. A topic highlights opportunities and limitations of inkjet printed ODF as a population-specific drug delivery. Overall, this article aims to stimulate further research to fill the current knowledge gap between manufacturing and administration requirements of ODF targeting specific patient subpopulations such as geriatrics.

Personalized Medicine in Pediatrics: The Clinical Potential of Orodispersible Films

Children frequently receive medicines that are designed for adults. The dose of commercially available products is adapted, mostly based on the child's bodyweight, thereby neglecting differences in pharmacokinetic and pharmacodynamics parameters. If commercial products are unsuitable for administration to children or are unavailable, extemporaneous pharmacy preparations are a good alternative. For this particular population, orodispersible films (ODFs) can be a highly attractive dosage form for the oral administration of drugs. ODFs are relatively easy to prepare in a hospital setting, create dose flexibility, and may suit an individual approach, especially for patients having difficulties in swallowing tablets or being fluid restricted. In this article, various aspects related to pharmacy preparations, clinical application, and preparation of ODFs for pediatric patients are highlighted and discussed.

Oromucosal multilayer films for tailor-made, controlled drug delivery

INTRODUCTION

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

Fish gelatin nanofibers prevent drug crystallization and enable ultrafast delivery

Eco-friendly and cost-effective electrospinning of aqueous fish gelatin could prevent the drug crystallization and exhibit the ultra-fast drug release behavior.

Critical material attributes (CMAs) of strip films loaded with poorly water-soluble drug nanoparticles: I. Impact of plasticizer on film properties and dissolution

Recent studies have demonstrated polymer films to be a promising platform for delivery of poorly water-soluble drug particles. However, the impact of critical material attributes, for example plasticizer, on the properties of and drug release from such films has yet to be investigated. In response, this study focuses on the impact of plasticizer and plasticizer concentration on properties and dissolution rate of polymer films loaded with poorly water-soluble drug nanoparticles. Glycerin, triacetin, and polyethylene glycol were selected as film plasticizers. Griseofulvin was used as a model Biopharmaceutics Classification System class II drug and hydroxypropyl methylcellulose was used as a film-forming polymer. Griseofulvin nanoparticles were prepared via wet stirred media milling in aqueous suspension. A depression in film glass transition temperature was observed with increasing plasticizer concentration, along with a decrease in film tensile strength and an increase in film elongation, as is typical of plasticizers. However, the type and amount of plasticizer necessary to produce strong yet flexible films had no significant impact on the dissolution rate of the films, suggesting that film mechanical properties can be effectively manipulated with minimal impact on drug release. Griseofulvin nanoparticles were successfully recovered upon redispersion in water regardless of plasticizer or content, even after up to 6months' storage at 40°C and 75% relative humidity, which contributed to similar consistency in dissolution rate after 6months' storage for all films. Good content uniformity (<4% R.S.D. for very small film sample size) was also maintained across all film formulations.

Design and evaluation of mucoadhesive oral films containing sodium hyaluronate using multivariate data analysis

CONTEXT

Mucoadhesive oral films, with their prolonged residence time at the site of application, offer a promising approach for protection of the oral lesion surface. The addition of sodium hyaluronate of different molecular weights as a second mucoadhesive polymer into the film matrix could positively influence the physico-mechanical and mucoadhesive properties of films.

OBJECTIVE

The aim of this study was to investigate the formulation of a monolayered film matrix containing varying amounts of sodium hyaluronate and to test the properties of such matrices by applying different characterization methods.

MATERIALS AND METHODS

Film matrix was composed of two mucoadhesive polymers, carmellose sodium and sodium hyaluronate, plasticized with glycerol. Resulting films were characterized with regard to their viscosity and physico-mechanical properties.

RESULTS AND DISCUSSION

Multivariate data analysis was employed to evaluate the influence of varying amounts of mucoadhesive polymers on the main mucoadhesive oral films' properties. The lower content of sodium hyaluronate caused improvements in mechanical properties and residence time on the artificial oral mucosa, both of which are the main characteristics that determine the quality of the final product.

CONCLUSIONS

The best results were obtained by samples containing carmellose sodium with a small amount of sodium hyaluronate (about 0.5% in casting dispersion).

Preparation and characterization of fast dissolving pullulan films containing BCS class II drug nanoparticles for bioavailability enhancement

The aim of this study is to assess pullulan as a novel steric stabilizer during the wet-stirred media milling (WSMM) of griseofulvin, a model poorly water-soluble drug, and as a film-former in the preparation of strip films via casting-drying the wet-milled drug suspensions for dissolution and bioavailability enhancement. To this end, pullulan films, with xanthan gum (XG) as thickening agent and glycerin as plasticizer, were loaded with griseofulvin nanoparticles prepared by WSMM using pullulan in combination with sodium dodecyl sulfate (SDS) as an ionic stabilizer. The effects of drug loading and milling time on the particle size and suspension stability were investigated, as well as XG concentration and casting thickness on film properties and dissolution rate. The nanosuspensions prepared with pullulan-SDS combination were relatively stable over 7 days; hence, this combination was used for the film preparation. All pullulan-based strip films exhibited excellent content uniformity (most <3% RSD) despite containing only 0.3-1.3 mg drug, which was ensured by the use of precursor suspensions with >5000 cP viscosity. USP IV dissolution tests revealed fast/immediate drug release (t80 < 30 min) from films <120 μm thick. Thinner films, films with lower XG loading, or smaller drug particles led to faster drug dissolution, while drug loading had no discernible effect. Overall, these results suggest that pullulan may serve as an acceptable stabilizer for media milling in combination with surfactant as well as a fast-dissolving film former for the fast release of poorly water-soluble drug nanoparticles.

Mucoadhesive oral films: The potential for unmet needs

Oral drug delivery is the most common route of drug administration. Nevertheless, there are some important limitations that reinforce the need for developing new drug delivery systems. Mucoadhesive oral films (MOF) are promising dosage forms that adhere to the oral mucosa and deliver the drug through it, which present several advantages. These include: bypassing the hepatic first pass effect, fast onset of action, ease of transportation and handling. The use of such dosage form is beneficial for drugs that have poor oral bioavailability and also for drugs that need to be rapidly absorbed. In spite of the known benefits, the number of marketed MOF is still quite small. This review explores the products under development and corresponding clinical trials in respect to their status, therapeutic indication, companies involved and technologies. In this way, it was possible to identify the preferred therapeutic indications, new research and market trends as well as future prospects of MOF. Moreover, it is reasonable to expect an increase in the number of products on the market due to their great potential to satisfy unmet medical needs.