Electrospun drug delivery and fast-dissolving membranes: dosage forms, structures, and research progress

01First distinguish between fast-dissolving membranes, sustained-release fibers, and local patches

Fibrous membranes for drug delivery do not constitute a fixed dosage form. Fast-dissolving membrane research focuses on disintegration, dissolution, and dose per unit area; sustained-release fiber research focuses on drug diffusion within the substrate and release persistence; adhesive patches must also maintain contact with moist, mobile tissue surfaces. They can use similar equipment but cannot share the same evaluation objectives.^1,2,3,4,5

A membrane that disappears quickly in water does not necessarily mean that all the drug has dissolved; rapid drug dissolution does not directly equate to improved in vivo absorption or therapeutic efficacy. Therefore, during development, membrane disintegration, drug release, and in vivo effects should be defined separately before determining the required structure.^1,2

02How polymer and fiber structures affect delivery

Hydrophilic fiber-forming materials such as polyvinylpyrrolidone (PVP) and pullulan are used for fast-dissolving membranes; systems such as ethyl cellulose and zein are used to explore slower drug release. Drug-polymer compatibility, drug-loading level, and solvent-removal processes all affect the final solid-state properties and dissolution performance.^1,2,3,4

Blended fibers focus on whether the drug is uniformly dispersed

Blended electrospinning can co-form fibers with the drug and polymer, but drug distribution and solid-state properties still need to be confirmed using content testing, thermal analysis, or diffraction methods. A continuous fiber appearance does not guarantee consistent dosing across different locations; the amorphous state also needs to be reconfirmed after storage.^1,4

Core-shell and bilayer structures focus on release pathways

A core-shell structure can allow the coating layer to control drug diffusion outward, whereas a bilayer patch can separate the adhesive and backing layers. The process advantage here lies in spatial partitioning; whether this truly alters release still needs to be demonstrated by test results from complete samples.^3,4,5

03How fast-dissolving fiber research links drug state to scale-up preparation

In 2021, Geng et al. studied PVP/ketoprofen fibers and increased the solution feed rate from 1 to 20 mL/h by adjusting the process and collection method, while comparing morphology, solid-state properties, and in vitro dissolution. Samples with lower drug loads disintegrated rapidly and showed improved dissolution under these conditions, but this advantage was no longer maintained when the drug load was increased. This indicates that the effects of fiber structure and hydrophilic substrates are formulation-dependent and that simply pursuing a higher drug proportion is not advisable.¹

In Ravasi and other 2023-year studies, water was used as the solvent and pullulan as the fiber-forming polymer to prepare oral fast-dissolving fibrous membranes containing sildenafil. The studies compared solution rheology, electrospinning conditions, drug content, and solid-state properties, and also compared disintegration with films prepared by other methods. This is a formulation feasibility study focused on oral dosage forms; although it addresses pediatric drug needs, it does not thereby constitute evidence of efficacy in pediatric patients.²

04Sustained-release fibers regulate release through coating layers and substrates

In Yu et al. (2013), an improved coaxial electrospinning method was used to form a drug-free thin layer on the surface of zein fibers containing ketoprofen. The study observed suppression of the initial burst release and achieved approximately 16 hours of near-linear release under in vitro conditions. This result reflects the effect of the surface coating layer; however, “in vitro linear release” should not be directly rewritten as constant-rate in vivo administration.³

In Geng and Williams (2023), cellulose ethyl fibers containing captopril were studied, comparing single-axis and coaxial structures and investigating scale-up preparation. Core-shell fibers exhibited weaker initial burst release in simulated gastric fluid and remained buoyant in this medium. Buoyancy observations are in vitro experiments; this result alone cannot establish improved gastric retention time or therapeutic efficacy in humans.⁴

These two studies jointly demonstrate that controlled release involves both polymer selection and the location of the drug. When comparing samples, the drug amount, medium, temperature, and sampling conditions should be fixed or recorded so that differences in release curves can be attributed to structural changes rather than summarizing all formulations with the label “slow release.”^3,4

05Adhesive patches combine local contact with a bilayer structure.

In Colley et al. (2018), electrospun bilayer adhesive patches were studied for delivering clobetasol propionate to oral mucosa. The research included material and cell evaluations, tissue-engineered oral mucosa, release studies on ex vivo porcine mucosa, and adhesion and delivery assessments in animal models; human feasibility observations regarding patch retention and acceptability were also conducted.⁵

This study suggests designing the patient-contact interface and the outer backing separately, rather than evaluating materials solely in static dissolution cups. Human acceptability addresses issues such as ease of use and duration of retention, which represent a different level of evidence from whether a drug-containing patch can improve disease outcomes.⁵

For local oral delivery, sample design should simultaneously consider the application site, salivary conditions, detachment caused by movement, and the direction of drug release. Different mucosal sites and usage scenarios require separate validation; results from oral patches cannot be directly generalized to transdermal, ocular, or implantable delivery.

06Clinical studies must correspond to specific drugs and dosage forms.

In Brennan et al. (2022), a phase II randomized, double-blind, placebo-controlled study of clobetasol-containing adhesive patches for erosive oral lichen planus was published, enrolling 138 patients across Europe, Canada, and the United States. The bilayer patch described in the paper was based on the technical literature of earlier work by Colley et al. The study examined changes in total ulcer area and pain-related indicators over 4 weeks and reported improvements in specific dose groups relative to placebo.^5,6

This provides an example of human research in a specific adhesive delivery direction but cannot serve as proof of efficacy for all drug-loaded electrospun membranes, nor can it be used to infer current marketing or sales status. In vitro dissolution of orally disintegrating membranes, acceptability of blank patches, and patient outcomes with drug-containing patches should be presented separately in literature reviews and sample designs.^1,2,5,6

07From formulation exploration to reproducible drug-loaded membrane samples.

First define dose and sample units.

When developing thin films, the evaluation unit—whether per unit area, per patch, or per dose—should be clearly defined, and film thickness, surface density, and drug content should be linked to actual drug measurements. Sampling at different locations can help assess deposition uniformity, and the dose after cutting must be confirmed separately.

Select fluid supply and collection methods based on release objectives.

Rapidly wetting blended membranes and core-shell slow-release fibers have different requirements for fluid supply, collection, and drying. Coaxial structures require separate control of core and shell flow rates, while bilayer patches require recording the deposition sequence and backing treatment. Equipment discussions should begin with these structural objectives rather than specifying a particular nozzle first.^1,3,4,5

Compare performance before and after scale-up under the same conditions.

After increasing fluid supply or web width, fiber morphology, solid-state properties, content distribution, residual solvents, disintegration, and release should be re-evaluated. Packaging moisture protection, crystallization during storage, and changes in release also need to be included in formulation studies. Equipment provides process control and sample-preparation capabilities but cannot replace pharmaceutical quality and clinical evaluation.^1,2,4

08Common issues in drug delivery and orally disintegrating membrane development.

Are orally disintegrating membranes and oral adhesive patches made of the same material?

The two can have different purposes. The former typically focuses on rapid disintegration and drug release, whereas the latter emphasizes local retention and delivery pathways; structure and testing should be selected according to the intended use.^2,5

Does an amorphous drug form necessarily provide better dissolution?

Judgment cannot rely solely on solid-state properties. Drug loading, polymer, medium, and storage conditions all affect results; the PVP/ ketoprofen study demonstrated differences resulting from variations in drug loading.¹

Does a fluid supply rate of 20 mL per hour mean that large-scale production has already been achieved?

This indicates that scale-up studies of fluid supply for a specific system still require confirmation of solid content, effective collection, cutting yield, quality consistency, and continuous operation to establish production capacity.^1,4

References

The following are the original studies used in this document. TONGLI independently summarizes the literature and does not reproduce original figures or tables; the listed authors and institutions are not presented as TONGLI client cases. The scope and validation stage of each conclusion should be understood according to the main text and original publications.

Bibliographic records retain the original publication language for accurate lookup.

1. Geng Y, Zhou F, Williams GR. Developing and scaling up fast-dissolving electrospun formulations based on poly(vinylpyrrolidone) and ketoprofen. Journal of Drug Delivery Science and Technology, 2021, 61:102138.

   DOI：10.1016/j.jddst.2020.102138 ↗

   Scope of review: full-text extraction of the local original PDF, including the homepage, conclusions, and previously verified records.

2. Ravasi E, Melocchi A, Arrigoni A, et al. Electrospinning of pullulan-based orodispersible films containing sildenafil. International Journal of Pharmaceutics, 2023, 643:123258.

   DOI：10.1016/j.ijpharm.2023.123258 ↗

   Scope of review: homepage and abstract of the local original PDF; verification against the publisher’s abstract.

3. Yu DG, Chian W, Wang X, et al. Linear drug release membrane prepared by a modified coaxial electrospinning process. Journal of Membrane Science, 2013, 428:150–156.

   DOI：10.1016/j.memsci.2012.09.062 ↗

   Scope of review: homepage and abstract of the local original PDF; online publication in 2012 and published issue 2013.

4. Geng Y, Williams GR. Developing and scaling up captopril-loaded electrospun ethyl cellulose fibers for sustained-release floating drug delivery. International Journal of Pharmaceutics, 2023, 648:123557.

   DOI：10.1016/j.ijpharm.2023.123557 ↗

   Scope of review: homepage and abstract of the local original PDF.

5. Colley HE, Said Z, Santocildes-Romero ME, et al. Pre-clinical evaluation of novel mucoadhesive bilayer patches for local delivery of clobetasol-17-propionate to the oral mucosa. Biomaterials, 2018, 178:134–146.

   DOI：10.1016/j.biomaterials.2018.06.009 ↗

   Scope of review: abstract and bibliographic information of the original PubMed study; publicly accessible full text provided by the author’s institution.

6. Brennan MT, Madsen LS, Saunders DP, et al. Efficacy and safety of a novel mucoadhesive clobetasol patch for treatment of erosive oral lichen planus: A phase 2 randomized clinical trial. Journal of Oral Pathology & Medicine, 2022, 51(1):86–97.

   DOI：10.1111/jop.13270 ↗

   Scope of review: publisher’s original abstract, introduction, and methods; earlier technical literature cited as reference 14; official publication year 2022.