Effects of formulation composition on the characteristics of mucoadhesive films prepared by hot-melt extrusion technology

Quality by design approach for fabrication of extended-release buccal films for xerostomia employing hot-melt extrusion technology

The study endeavors the fabrication of extended-release adipic acid (APA) buccal films employing a quality by design (QbD) approach. The films intended for the treatment of xerostomia were developed utilizing hot-melt extrusion technology. The patient-centered quality target product profile was created, and the critical quality attributes were identified accordingly. Three early-stage formulation development trials, complemented by risk assessment aligned the formulation and process parameters with the product quality standards. Employing a D-optimal mixture design, the formulations were systematically optimized by evaluating three formulation variables: amount of the release-controlling polymer Eudragit® (E RSPO), bioadhesive agent Carbopol® (CBP 971P), and pore forming agent polyethylene glycol (PEG 1500) as independent variables, and % APA release in 1, 4 and 8 h as responses. Using design of experiment software (Design-Expert®), a total of 16 experimental runs were computed and extruded using a Thermofisher ScientificTM twin screw extruder. All films exhibited acceptable content uniformity and extended-release profiles with the potential for releasing APA for at least 8 h. Films containing 30% E RSPO, 10% CBP 971P, and 20% PEG 1500 released 88.6% APA in 8 h. Increasing the CBP concentration enhanced adhesiveness and swelling capacities while decreasing E RSPO concentration yielded films with higher mechanical strength. The release kinetics fitted well into Higuchi and Krosmeyer-Peppas models indicating a Fickian diffusion release mechanism.

Development and evaluation of hot-melt-extruded diquafosol tetrasodium formulations for ophthalmic inserts: A design of experiments approach

This study aimed to develop, optimize, and evaluate hot-melt-extruded ophthalmic inserts capable of sustained release of diquafosol tetrasodium (DQS) via a design of experiments approach. DQS, a tear stimulant for dry eye management, faces challenges of frequent administration and low bioavailability. The developed insert uses biodegradable polymers in varied proportions to achieve sustained release. Optimized through mixture design, the insert completely dissolved within 24 h and maintained a stable drug content, thickness, and surface pH over three months at room temperature. In vitro corneal permeation studies on excised rabbit corneas demonstrated increased bioavailability, suggesting a reduced dosing frequency compared with conventional eye drops. Therefore, this insert has potential to enhance treatment outcomes by improving patient compliance and providing sustained drug effects.

Multiple Natural Polymers in Drug and Gene Delivery Systems

Natural polymers are organic compounds produced by living organisms. In nature, they exist in three main forms, including proteins, polysaccharides, and nucleic acids. In recent years, with the continuous research on drug and gene delivery systems, scholars have found that natural polymers have promising applications in drug and gene delivery systems due to their excellent properties such as biocompatibility, biodegradability, low immunogenicity, and easy modification. However, since the structure, physicochemical properties, pharmacological properties and biological characteristics of biopolymer molecules have not yet been entirely understood, further studies are required before large-scale clinical application. This review focuses on recent advances in the representative natural polymers such as proteins (albumin, collagen, elastin), polysaccharides (chitosan, alginate, cellulose) and nucleic acids. We introduce the characteristics of various types of natural polymers, and further outline the characterization methods and delivery forms of these natural polymers. Finally, we discuss possible challenges for natural polymers in subsequent experimental studies and clinical applications. It provides an important strategy for the clinical application of natural polymers in drug and gene delivery systems.

Disulfiram 3D printed film produced via hot-melt extrusion techniques as a potential anticervical cancer candidate

Cervical cancer is known globally as one of the most common health problems in women. Indeed, one of the most convenient approaches for its treatment is an appropriate bioadhesive vaginal film. This approach provides a local treatment modality, which inevitably decreases dosing frequency and improves patient compliance. Recently, disulfiram (DSF) has been investigated and demonstrated to possess anticervical cancer activity; therefore, it is employed in this work. The current study aimed to produce a novel, personalized three-dimensional (3D) printed DSF extended-release film using the hot-melt extrusion (HME) and 3D printing technologies. The optimization of the formulation composition and the HME and 3D printing processing temperatures was an important factor for overcoming the DSF heat-sensitivity issue. In addition, the 3D printing speed was specifically the most crucial parameter for alleviating heat-sensitivity concerns, which led to the production of films (F1 and F2) with an acceptable DSF content and good mechanical properties. The bioadhesion film study using sheep cervical tissue indicated a reasonable adhesive peak force (N) of 0.24 ± 0.08 for F1 and 0.40 ± 0.09 for F2, while the work of adhesion (N.mm) for F1 and F2 was 0.28 ± 0.14 and 0.54 ± 0.14, respectively. Moreover, the cumulative in vitro release data indicated that the printed films released DSF for up to 24 h. HME-coupled 3D printing successfully produced a patient-centric and personalized DSF extended-release vaginal film with a reduced dose and longer dosing interval.

Films composed of white angico gum and chitosan containing chlorhexidine as an antimicrobial agent

Anadenanthera colubrina, popularly known as white angico, is a species extensively cultivated in Brazil, mainly in the cerrado region, including the state of Piauí. This study examines the development of films composed of white angico gum (WAG) and chitosan (CHI) and containing chlorhexidine (CHX), an antimicrobial agent. The solvent casting method was used to prepare films. Different combinations and concentrations of WAG and CHI were used to obtain films with good physicochemical characteristics. Properties such as the in vitro swelling ratio, the disintegration time, folding endurance, and the drug content were determined. The selected formulations were characterised by scanning electron microscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction, and the CHX release time and antimicrobial activity were evaluated. CHX showed a homogenous distribution in all CHI/WAG film formulations. The optimised films showed good physicochemical properties with 80% CHX release over 26 h, which is considered promising for local treatment of severe lesions in the mouth. Cytotoxicity tests of the films did not show toxicity. The antimicrobial and antifungal effects were very effective against the tested microorganisms.

Three-Dimensional-Printed Oral Films Based on LCD: Influence Factors of the Film Printability and Received Qualities

As an oral mucosal drug delivery system, oral films have been of wide concern in recent years because of their advantages such as rapid absorption, being easy to swallow and avoiding the first-pass effect common for mucoadhesive oral films. However, the currently utilized manufacturing approaches including solvent casting have many limitations, such as solvent residue and difficulties in drying, and are not suitable for personalized customization. To solve these problems, the present study utilizes liquid crystal display (LCD), a photopolymerization-based 3D printing technique, to fabricate mucoadhesive films for oral mucosal drug delivery. The designed printing formulation includes PEGDA as the printing resin, TPO as the photoinitiator, tartrazine as the photoabsorber, PEG 300 as the additive and HPMC as the bioadhesive material. The influence of printing formulation and printing parameters on the printing formability of the oral films were elucidated in depth, and the results suggested that PEG 300 in the formulation not only provided the necessary flexibility of the printed oral films, but also improved drug release rate due to its role as pore former in the produced films. The presence of HPMC could greatly improve the adhesiveness of the 3D-printed oral films, but excessive HPMC increased the viscosity of the printing resin solution, which could strongly hinder the photo-crosslinking reaction and reduce printability. Based on the optimized printing formulation and printing parameters, the bilayer oral films containing a backing layer and an adhesive layer were successfully printed with stable dimensions, adequate mechanical properties, strong adhesion ability, desirable drug release and efficient in vivo therapeutic efficacy. All these results indicated that an LCD-based 3D printing technique is a promising alternative to precisely fabricate oral films for personalized medicine.

Formulation development and in Vitro-Ex vivo characterization of hot-melt extruded ciprofloxacin hydrochloride inserts for ocular applications: Part I

This study developed, optimized, characterized, and evaluated bioadhesive, hot-melt extruded (HME), extended-release ocular inserts containing ciprofloxacin hydrochloride (CIP-HCL) to improve the therapeutic outcomes of ocular bacterial infections. The inserts were fabricated with FDA-approved biocompatible, biodegradable, and bioadhesive polymers that were tuned in different ratios to achieve a sustained release profile. The results revealed an inverse relationship between the Klucel™ hydroxypropyl cellulose (HPC, 140,000 Da) concentration and drug release and extended-release profile over 24 h. The CIP-HCL-HME inserts presented stable drug content, thermal behavior, surface pH, and release profiles over three months of room-temperature storage and demonstrated adequate mucoadhesive strength. SEM micrographs revealed a smooth surface. Bacterial growth was not observed on the samples during the in vitro release experiment (0.5-24 h), indicating that a minimum inhibitory concentration (MIC) of 90 against Pseudomonas aeruginosa was achieved. Ex vivo transcorneal permeation studies using excised rabbit corneas revealed that the prepared ocular inserts prolonged the transcorneal flux of the drug compared to commercial eye drops and immediate-release inserts and could reduce the administration frequency to once daily. Therefore, the inserts could increase patient compliance and exhibited prolonged antibacterial activity and thus could provide better therapeutic outcomes against ocular bacterial infections.

Polymeric Biomaterials for Topical Drug Delivery in the Oral Cavity: Advances on Devices and Manufacturing Technologies

There are several routes of drug administration, and each one has advantages and limitations. In the case of the topical application in the oral cavity, comprising the buccal, sublingual, palatal, and gingival regions, the advantage is that it is painless, non-invasive, allows easy application of the formulation, and it is capable of avoiding the need of drug swallowing by the patient, a matter of relevance for children and the elderly. Another advantage is the high permeability of the oral mucosa, which may deliver very high amounts of medication rapidly to the bloodstream without significant damage to the stomach. This route also allows the local treatment of lesions that affect the oral cavity, as an alternative to systemic approaches involving injection-based methods and oral medications that require drug swallowing. Thus, this drug delivery route has been arousing great interest in the pharmaceutical industry. This review aims to condense information on the types of biomaterials and polymers used for this functionality, as well as on production methods and market perspectives of this topical drug delivery route.

Novel linezolid loaded bio-composite films as dressings for effective wound healing: experimental design, development, optimization, and antimicrobial activity

Biphasic release bio-composite films of the low water-soluble drug, linezolid (LNZ), were formulated using the solvent casting technique. Different polymers and plasticizers (gelatin, Tween 80, polyethylene glycol 400, and glycerol) were assessed for the preparation of bio-composite films. An I-optimal design was applied for the optimization and to study the impact of polymer concentration (X₁), plasticizer concentration (X₂), polymer type (X₃), and plasticizer type (X₄) on different LNZ-loaded bio-composite films. The film thickness, moisture content, mechanical properties, swelling index, and percentage of drug release at fixed times opted as dependent variables. Results demonstrated a significant effect of all independent variables on the drug release from the prepared bio-composite films. The plasticizer concentration significantly increased the thickness, moisture content, elongation at break, swelling index, and in vitro drug release and significantly reduced the tensile strength. The optimized LNZ-loaded bio-composite film comprised of 15% Tween 80 and 30% PEG 400 was highly swellable, elastic, acceptable tensile properties, safe, maintained a moist environment, and indicated great antimicrobial activity against both Staphylococcus aureus (ATCC^® 25922) and methicillin-resistant Staphylococcus aureus (MRSA), which are common wound infectious bacteria. The present study concludes that the optimized LNZ-loaded bio-composite film was successfully designed with fast drug release kinetics and it could be regarded as a promising novel antimicrobial wound dressing formulation.

An Updated Overview of the Emerging Role of Patch and Film-Based Buccal Delivery Systems

Buccal mucosal membrane offers an attractive drug-delivery route to enhance both systemic and local therapy. This review discusses the benefits and drawbacks of buccal drug delivery, anatomical and physiological aspects of oral mucosa, and various in vitro techniques frequently used for examining buccal drug-delivery systems. The role of mucoadhesive polymers, penetration enhancers, and enzyme inhibitors to circumvent the formulation challenges particularly due to salivary renovation cycle, masticatory effect, and limited absorption area are summarized. Biocompatible mucoadhesive films and patches are favored dosage forms for buccal administration because of flexibility, comfort, lightness, acceptability, capacity to withstand mechanical stress, and customized size. Preparation methods, scale-up process and manufacturing of buccal films are briefed. Ongoing and completed clinical trials of buccal film formulations designed for systemic delivery are tabulated. Polymeric or lipid nanocarriers incorporated in buccal film to resolve potential formulation and drug-delivery issues are reviewed. Vaccine-enabled buccal films have the potential ability to produce both antibodies mediated and cell mediated immunity. Advent of novel 3D printing technologies with built-in flexibility would allow multiple drug combinations as well as compartmentalization to separate incompatible drugs. Exploring new functional excipients with potential capacity for permeation enhancement of particularly large-molecular-weight hydrophilic drugs and unstable proteins, oligonucleotides are the need of the hour for rapid advancement in the exciting field of buccal drug delivery.

Hot-Melt Extrusion: a Roadmap for Product Development

Hot-melt extrusion has found extensive application as a feasible pharmaceutical technological option over recent years. HME applications include solubility enhancement, taste masking, and sustained drug release. As bioavailability enhancement is a hot topic of today's science, one of the main applications of HME is centered on amorphous solid dispersions. This review describes the most significant aspects of HME technology and its use to prepare solid dispersions as a drug formulation strategy to enhance the solubility of poorly soluble drugs. It also addresses molecular and thermodynamic features critical for the physicochemical properties of these systems, mainly in what concerns miscibility and physical stability. Moreover, the importance of applying the Quality by Design philosophy in drug development is also discussed, as well as process analytical technologies in pharmaceutical HME monitoring, under the current standards of product development and regulatory guidance. Graphical Abstract.

Mucoadhesive Delivery System: A Smart Way to Improve Bioavailability of Nutraceuticals

The conventional oral administration of many nutraceuticals exhibits poor oral bioavailability due to the harsh gastric conditions and first-pass metabolism. Oral mucosa has been recognized as a potential site for the delivery of therapeutic compounds. The mucoadhesive formulation can adhere to the mucosal membrane through various interaction mechanisms and enhance the retention and permeability of bioactive compounds. Absorption of bioactive compounds from the mucosa can improve bioavailability, as this route bypasses the hepatic first-pass metabolism and transit through the gastrointestinal tract. The mucosal administration is convenient, simple to access, and reported for increasing the bioactive concentration in plasma. Many mucoadhesive polymers, emulsifiers, thickeners used for the pharmaceutical formulation are accepted in the food sector. Introducing mucoadhesive formulations specific to the nutraceutical sector will be a game-changer as we are still looking for different ways to improve the bioavailability of many bioactive compounds. This article describes the overview of buccal mucosa, the concept of mucoadhesion and related theories, and different techniques of mucoadhesive formulations. Finally, the classification of mucoadhesive polymers and the mucoadhesive systems designed for the effective delivery of bioactive compounds are presented.

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.

Development and optimization of hot-melt extruded moxifloxacin hydrochloride inserts, for ocular applications, using the design of experiments

The current study sought to formulate sustained-release hot-melt extruded (HME) ocular inserts of moxifloxacin hydrochloride (MOX; MOX-HME) for the treatment of bacterial keratitis. The concentration of Eudragit™ FS-100 (FS) and propylene glycol (PG) used as polymer and plasticizer, respectively, in the inserts were optimized using the central composite design (CCD) to achieve sustained release. The inserts were characterized for weight, thickness, surface characteristics, pH, and in vitro release profile. The crystalline characteristics of MOX and surface morphology of the inserts were evaluated using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Furthermore, ex vivo permeation through rabbit cornea and stability of the optimized MOX-HME insert was investigated. The results demonstrate an inverse correlation between FS concentration and MOX release from the MOX-HME inserts, and a potential 24 h release. The optimized MOX-HME inserts were found to be stable at room temperature for four months, showing no significant change in drug content, pH and release profile. MOX converted into an amorphous form in the MOX-HME inserts and did not recrystallize during the study period. SEM analysis confirmed the smooth surface of the MOX-HME insert. The ex vivo studies revealed that the MOX-HME inserts provided a much prolonged transcorneal MOX flux as compared to the commercial ophthalmic solution and the immediate-release MOX-HME insert. The results indicate that MOX-HME inserts could potentially provide a once-a-day application, consequently reducing the dosing frequency and acting as an alternative delivery system in the management of bacterial infections.

Dual-function membranes based on alginate/methyl cellulose composite for control drug release and proliferation enhancement of fibroblast cells

Membranes based on natural polymers are highly promising therapies for skin damaged sites as they can mimic its biological microstructure to support the fibroblasts cells survival and proliferation. In addition, these membranes could be loaded with active molecules that help in skin regeneration and eliminate the potential bacterial infection. This research aims to formulate novel medicated membranes for controlled release and cytocompatibility elevation of fibroblast cells for engineering of soft tissue. Pre-formulation researches have been conducted for membranes of sodium alginate (Alg)/methyl cellulose (MC) that used loaded with undoped, Bi doped and Bi, Cu co-doped SrTiO₃ using solvent casting technique. In addition, another group of these membranes were loaded with DOXycycline antibiotic (DOX) as model drug as well as for eliminating the potential bacterial infections. The prepared membranes were evaluated by XRD, SEM-EDX, FTIR, Zetasizer, and swelling behaviour was also tested. Profiles of the released drug were determined using phosphate-buffered saline (PBS) (pH 7.4) at 37 °C for 30 days. The investigation of the cytocompatibility and proliferation of fibroblast cells with the prepared membranes were conducted. The XRD, FTIR and SEM data recognised the possible interaction that takes place among Alg and MC, through presence of hydrogen bonds. Existence of the nano-particles within the membrane polymer matrix enhanced the membrane stability and enhanced the drug release rate (from 20 to 45%). Medication release mechanism elucidated that DOX was released from all the fabricated membranes through the relaxation of polymer matrix that takes place after swelling. The filler type and/or dopant type possess no remarkable influence on the cytotoxicity of the membranes against the investigated cells when compared to their individual influence on the same cells. Cells attachments results have revealed an impressive effect for DOX-loaded membranes on the cells affinity and growth. These membranes are recommended for treatments of skin infections.

Unidirectional drug release from 3D printed mucoadhesive buccal films using FDM technology: In vitro and ex vivo evaluation

Oromucosal delivery of active pharmaceutical ingredients provides an attractive alternative route of administration, due to avoidance of the first pass effect and improved patient compliance. In the current work, fused deposition modelling (FDM) 3D printing was investigated as an additive manufacturing approach for poly(vinyl alcohol)-based mucoadhesive films, enabling unidirectional drug release. For this purpose, chitosan was incorporated as a permeation and mucoadhesion enhancer whereas ethylcellulose and commercial wafer sheets were evaluated as backing layers. The formulated films were initially assessed for structural integrity and dose uniformity. Solid-state characterization of the films, including thermal methods (DSC, TGA), diffraction (XRPD) and Raman spectroscopy, was implemented to characterize the physicochemical properties of the produced polymeric filaments and buccal films. The mechanical properties of the products were investigated by instrumented indentation and tensile tests. Evaluation of buccal films was assessed in vitro, to study the effect of backing-layer type on hydration capacity of the films, diffusion of the drug throughout the restricting layer and release profiles in simulated saliva. The ex vivo performance of the manufactured products, associated with the presence of chitosan, was investigated by textural analysis for mucoadhesion properties, whereas permeation studies and histological studies were performed across porcine buccal epithelium. The results demonstrated that FDM printing is a timesaving and versatile approach in the context of manufacturing multi-layered mucoadhesive buccal films, providing unidirectional release properties.