Zero-order Drug Release Research Articles

Prolonged Delivery of Ciprofloxacin and Diclofenac Sodium from a Polymeric Fibre Device for the Treatment of Peridontal Disease

In vitro analysis of drug release and antimicrobial activity of the coblended crosslinked polymeric fibre device (PFD) were investigated. The fibre loaded with ciprofloxacin and diclofenac sodium was comprised of alginate and glycerol crosslinked with barium cations. The pH dependent drug release was evident with ciprofloxacin and diclofenac sodium diffusing from the fibre at pH 4.0 compared to pH 6.8, where the fibre swelled and eroded resulting in zero-order drug release. Agar diffusion studies followed by minimum inhibitory assays were conducted to determine the antimicrobial activity of the device against Escherichia coli, Enterococcus faecalis, and Streptococcus mutans. The antimicrobial activity of the PFD was confirmed in both test assays against all test pathogens. The MIC ranges at pH 4.0 for E. coli, E. faecalis, and S. mutans were 0.5–0.8, 0.4–1.1, and 0.7–2.1 μg/mL, respectively. At pH 6.8, similar efficacies (0.3–0.5 μg/mL for E. coli and E. faecalis and 0.6–1.0 μg/mL for S. mutans) were observed. The effect of varying the plasticizer and crosslinking ion concentration on drug release profile of the fibers was further elucidated and conceptualized using molecular mechanics energy relationships (MMER) and by exploring the spatial disposition of geometrically minimized molecular conformations.

Compression of coated drug beads for sustained release tablet of glipizide: formulation, and dissolution

A promising glipizide formulation comprising compression of four-layer coated beads into tablets was prepared. The tablet offered the advantages of: a two-hour lag time before drug release, retaining sustained release characteristics and providing approximately zero-order drug release. Drug release was nearly independent of paddle speeds of 50 and 100 rpm releasing 80% over 14 h similar to the commercial glipizide osmotic pump tablet during dissolution testing while keeping the benefits of multiparticular dosage forms. The tablets contain beads with four layers: (1) the innermost layer consists of 2.5 g glipizide and 3.75 g solid ethylcellulose (Surelease®) coated onto 71.25 g of sugar beads; (2) next a hardening layer of 5 g of hypromellose; (3) the controlled release layer of 7.5 g of Surelease®:lactose at a solids ratio of 100:7 and (4) an outermost layer of 20 g of lactose:sodium starch glycolate (Explotab®) at a 2:1 ratio. Then, beads were compressed into tablets containing 11 mg of glipizide using 1500 lbs of compression pressure. The dissolution test similarity factor (f2) was above 50 for all test conditions for formulation F13 and Glucotrol® with a high of 69.9. The two Surelease® layers both aid controlling drug release, with the Surelease®-drug layer affecting drug release to a greater extent.

Studies on losartan novel extrudates design and evaluation to treat hypertension

Mini matrices containing Losartan potassium as a model drug were prepared by extrusion method using Hydroxy propyl methyl cellulose as matrix materials with or without xanthan gum and carbopol, and combination of xanthan gum and carbopol and propylene glycol as plasticizer. The prepared mini matrices were further evaluated for surface texture, uniformity of diameter, thickness, weight, moisture content, drug content uniformity, drug-excipients interaction, relative swelling, mucoadhesive test, in vitro drug release pattern. All the HPMC mini matrices showed good swelling which is proportional to concentration of polymer. The In vitro release of drug was in the range of 64.83% to 93.66%. Formulation H1 prepared with a drug-polymer ratio of 1:0.5 (LSP:HPMC) and 5% propylene glycol by weight of polymer as plasticizer showed promising results as a controlled release dosage form and released approximately 93.66% of the drug in 12 h. This study proves that extrusion method can be used for designing controlled release drug delivery systems providing nearly zero-order drug release over a period of 12 h.

Osmotic Pellet System Comprising Osmotic Core and In-Process Amorphized Drug in Polymer–Surfactant Layer for Controlled Delivery of Poorly Water-Soluble Drug

The aim of the present investigation was to develop controlled porosity osmotic system for poorly water-soluble drug based on drug in polymer-surfactant layer technology. A poorly water-soluble drug, glipizide (GZ), was selected as the model drug. The technology involved core of the pellets containing osmotic agent coated with drug dispersed in polymer and surfactant layer, finally coated with release-retardant layer with pore former. The optimized drug-layer-coated pellets were evaluated for solubility of GZ at different pH conditions and characterized for amorphous nature of the drug by differential scanning calorimetry and X-ray powder diffractometry. The optimized release-retardant layer pellets were evaluated for in vitro drug release at different pH, hydrodynamic, and osmolality conditions. The optimized drug layer showed improvement in solubility (10 times in pH 1.2, 11 times in pH 4.5, and 21 times in pH 6.8), whereas pellets coated with cellulose acetate (15.0%, w/w, weight gain) with pore former triethyl citrate (10.0%, w/w, of polymer) demonstrated zero-order drug release for 24 h at different pH conditions; moreover, retardation of drug release was observed with increment of osmolality. This system could be a platform technology for controlled delivery of poorly water-soluble drugs.

DEVELOPMENT AND EVALUATION OF ORAL ELEMENTARY OSMOTIC PUMP TABLETS FOR ROPINIROLE HYDROCHLORIDE

The objective of the present study was to develop a sustained release once a day oral elementary osmotic tablet for ropinirole hydrochloride and evaluate its in vivo performance. The core of elementary osmotic tablet of ropinirole hydrochloride was prepared by compression of mixture consisting of drug,different concentrations of osmogens, and other tablet material. Core tablets were then coated with different concentrations of cellulose acetate and PEG-400. FTIR was used to identify if the excipients are compatible with the drug. All the tablets that were prepared were evaluated for drug release and based on the results an optimum and ideal osmotic pump composition with a zero-order drug release extended for 24 h was proposed and this was considered the optimized formulation. Surface morphology of coated formulation was studied by scanning electron microscopy. The drug release was determined in different pH media and different agitation speeds. The pharmacokinetics of the drug after oral administration of optimized osmotic pump was investigated in rabbits and the data were compared with that of a conventional tablet. In vitro in vivo correlation was determined for the optimized formulation. A suitable and simple sustained release elementary osmotic pump for ropinirole hydrochloride was developed. The release rate was independent of the pH of the dissolution medium and the agitation speeds. In vivo studies with optimized osmotic tablet formulation demonstrated that drug concentration in plasma was maintained for prolonged period and minimized fluctuation. A better in vitro in vivo correlation was achieved with the osmotic tablet. A simple once a day elementary osmotic tablet is feasible for ropinirole hydrochloride.

Modified coaxial electrospinning for the preparation of high-quality ketoprofen-loaded cellulose acetate nanofibers

This study investigates the use of a modified coaxial electrospinning process in the production of drug-loaded cellulose acetate (CA) nanofibers. With CA employed as a filament-forming matrix and ketoprofen (KET) as an active pharmaceutical ingredient, modified coaxial processes using sheath fluids comprising only mixed solvents were undertaken. With a sheath-to-core flow rate ratio of 0.2:1, the nanofibers prepared from the coaxial process had a smaller average diameter, narrower size distribution, more uniform structures, and smoother surface morphologies than those generated from single fluid electrospinning. In addition, the coaxial fibers provided a better zero-order drug release profile. The use of a sheath solvent means that the core jet is subjected to electrical drawing for a longer period, facilitating homogeneous core jet solidification and retarding the formation of wrinkles on the surface of the nanofibers. This modified coaxial electrospinning protocol allows the systematic fabrication of functional polymer nanofibers with improved quality.

Characterization of internal structure, polymer erosion and drug release mechanisms of biodegradable poly(ester anhydride)s by X-ray microtomography

Surface-eroding biodegradable polymers can provide many advantages in drug delivery, such as controllable and zero-order drug release. Photocrosslinkable poly(ester anhydride)s are a recently developed family of surface-eroding polymers with readily modifiable oligomer chemistry allowing tailoring of polymer properties. For example, in vivo release rate of peptide from photocrosslinked poly(ester anhydride)s can be controlled by oligomer hydrophobicity. In this study, X-ray microtomography (micro-CT) was used to gain a deeper understanding on internal structure, polymer erosion and drug release mechanisms of photocrosslinked poly(ester anhydride)s. Micro-CT is non-destructive and able to provide quantitative and qualitative information on the 3D structure of the sample in micrometer resolution. Photocrosslinked poly(ester anhydride) samples with varying drug loading degrees (propranolol HCl 0%, 10% and 60% w/w) and hydrophobicity (with and without 12-carbon alkenyl chain) were prepared. The samples, both freshly prepared and exposed to buffer solution for varying durations were characterized by micro-CT. The results showed that drug release from photocrosslinked poly(ester anhydride)s was primarily controlled by the surface erosion. However, drug diffusion had also a significant role in drug release from less hydrophobic samples with very high (60% w/w) drug loading degrees. In conclusion, micro-CT is a valuable tool in the characterization of surface-eroding polymers.

Design and evaluation of rectal drug delivery systems of non-steroidal anti-inflammatory drug

The aim of the present study was to design and evaluate the suppositories of aceclofenac a non-steroidal anti inflammatory drug (NSAID). Aceclofenac, rectal suppositories were developed by employing various hydrophilic and hydrophobic polymeric bases like gelatin, PEG-400 and hydrogenated vegetable oil using propylene glycol as plasticizer and beeswax as hardening agent. The in-vitro release rate data was evaluated statistically and was found that from all the formulations the drug release is by diffusion mechanism (r = 0.9547 to 0.9967) according to Higuchi’s equation. All the prepared formulations have shown zero-order release kinetics except those prepared by utilizing 15% and 20 % of PEG-400. The formulation prepared using 7.5% beeswax in hydrogenated vegetable oil has displayed zero-order drug release (r = 0.9927) and has released 99.18% of the aceclofenac within 4h, hence, this formulation is considered as a promising formulation. The stability study on the promising formulation was conducted over a period of 6 months and found that there are no significant changes in the drug content and in-vitro drug release rate (p<0.05). The result suggests that the suppositories can be prepared by employing hydrophilic and hydrophobic polymers.DOI: http://dx.doi.org/10.3329/icpj.v1i7.10810International Current Pharmaceutical Journal 2012, 1(7): 165-170

Low molecular mass chitosan as carrier for a hydrodynamically balanced system for sustained delivery of ciprofloxacin hydrochloride

Chitosan has become a focus of major interest in recent years due to its excellent biocompatibility, biodegradability and non-toxicity. Although this material has already been extensively investigated in the design of different types of drug delivery systems, it is still little explored for stomach specific drug delivery systems. The objective of the present investigation was to explore the potential of low molecular mass chitosan (LMCH) as carrier for a hydrodynamically balanced system (HBS) for sustained delivery of water soluble drug ciprofloxacin hydrochloride (CP). Various formulations were prepared by physical blending of drug and polymer(s) in varying ratios followed by encapsulation into hard gelatin capsules. All the formulations remained buoyant in 0.1 mol L⁻¹ HCl (pH 1.2) throughout the experiment. Effect of addition of xanthan gum (XG) or ethyl cellulose (EC) on drug release was also investigated. Zero order drug release was obtained from the formulations containing LMCH alone or in combination with XG, and in one instance also with EC. Our results suggest that LMCH alone or in combination with XG is an excellent material for stomach specific sustained delivery of CP from hydrodynamically balanced single unit capsules.

Development of Platform Technology for Oral Controlled Delivery of Highly Water Soluble Drugs Using Milnacipran HCl as a Model Drug

The present study was aimed towards development of porosity controlled osmotic pump as a platform technology for delivering highly water soluble drugs using Milnacipran HCl as a model drug. Theoretical zero order drug release profile (5 mg/hr) was targeted to achieve for fulfilling desired plasma concentration up to 24 hrs. Novel ethyl cellulose based coating system, Aquarius EKX 19102 SRX-2, was employed in the development of osmotic pump. Influences of media pH, agitation intensity and osmotic pressure on drug release rate were investigated. Statistical approaches including mean dissolution time, dissolution efficiency, similarity factor and SeDeM diagram were applied to translate dissolution profile in to a single value. The Aquarius EKX 19102 SRX-2 coating system at 7% weight gain exhibited zero order drug release. Scanning electron microscopy confirmed the microporous structure of the film. The results obtained from stability study, Fourier Transform Infra Red spectra and Differential Scanning Calorimetry study of optimized formulation confirmed stable characteristics. This platform technology was further validated using Diltiazem HCl and satisfactory results were obtained. FORTRAN language based software was applied to assess drug release kinetics and it was found to be zero order. Keywords: Aquarius EKX 19102 SRX-2, FORTRAN, Milnacipran HCl, Platform technology, SeDeM diagram, FORTRAN, gastrointestinal tract, neurotransmitter receptor, Agitation, Drug-Release Kinetics

Development of Platform Technology for Oral Controlled Delivery of Highly Water Soluble Drugs Using Milnacipran HCl as a Model Drug

The present study was aimed towards development of porosity controlled osmotic pump as a platform technology for delivering highly water soluble drugs using Milnacipran HCl as a model drug. Theoretical zero order drug release profile (5 mg/hr) was targeted to achieve for fulfilling desired plasma concentration up to 24 hrs. Novel ethyl cellulose based coating system, Aquarius EKX 19102 SRX-2, was employed in the development of osmotic pump. Influences of media pH, agitation intensity and osmotic pressure on drug release rate were investigated. Statistical approaches including mean dissolution time, dissolution efficiency, similarity factor and SeDeM diagram were applied to translate dissolution profile in to a single value. The Aquarius EKX 19102 SRX-2 coating system at 7% weight gain exhibited zero order drug release. Scanning electron microscopy confirmed the microporous structure of the film. The results obtained from stability study, Fourier Transform Infra Red spectra and Differential Scanning Calorimetry study of optimized formulation confirmed stable characteristics. This platform technology was further validated using Diltiazem HCl and satisfactory results were obtained. FORTRAN language based software was applied to assess drug release kinetics and it was found to be zero order. Keywords: Aquarius EKX 19102 SRX-2, FORTRAN, Milnacipran HCl, Platform technology, SeDeM diagram, FORTRAN, gastrointestinal tract, neurotransmitter receptor, Agitation, Drug-Release Kinetics

Pharmacokinetic Studies on Metoprolol - Eudragit Matrix Tablets and Bioequivalence Consideration with Mepressor<sup>®</sup>

Purpose: To investigate the pharmacokinetics of of a developed metoprolol and a reference standard (Mepressor®).Methods: Metoprolol tartrate-loaded Eudragit® FS microparticles were formulated and compressed into tablets. The tablets were tested for their physicochemical properties according to United States Pharmacopoeia (USP) criteria. In vivo studies of the formulations were carried out in 28 young healthy fasting male volunteers based on a randomized open label 4×4 crossover study design with a washout period of 7 days.Results: In vitro tests showed that the developed and reference standard of metoprolol tablets met compendia (USP) requirements. Zero order release of drug was observed from all the tablets. In vivo data demonstrated that there were significant (p < 0.05) differences in tmax, Cmax, MRT, AUC0−t, and AUC0–∞ between the reference and test (developed) formulations. However, the 90 % class interval for the mean ratios of the ln-transformed Cmax, AUC0-t and AUC0-α for the reference, T1, T2, and T3 lied in the bioequivalence range (80 to 125 %) indicating bioequivalence between the compared formulations.                  Conclusion: It can be concluded from this single-dose study that the reference and test (developed) formulations met the predetermined criteria for bioequivalence in young healthy fasting male human subjects as the bioequivalence factor lie in the pre-determined limits for bioequivalence. Thus, the two formulations can be considered bioequivalent.Keywords: Metoprolol tartrate, Eudragit® FS, Microparticles, Bioavailability, Pharmacokinetics.

Preparation and characterization of controlled release matrices based on novel seaweed interpolyelectrolyte complexes

Novel interpolyelectrolyte complexes (IPECs) between naturally sulfated polysaccharides of the seaweed Polysiphonia nigrescens (PN) and cationized agaroses (CAG) and Eudragit E (EE) were prepared using an organic solvent free process, characterized, and explored for controlled drug release. Tablets containing model drug ibuprofen and IPECs were prepared by direct compression. Drug release in acid medium was low owing to the low solubility of ibuprofen in that condition and to the matrix action. Zero order drug release was determined in the buffer stage (pH=6.8), with Fickian diffusion predominating over relaxation during the initial phases. Relaxation appears to increase along the release process and even overcomes diffusion for some systems. Drug release profiles could be controlled by varying the content of IPECs in the tablets. Also, the change in molecular weight and the degree of substitution of the components allowed altering the release profiles.

Development of photostable gastro retentive formulation for nifedipine using low-density polypropylene microporous particles

The aim of this study was to develop photostable gastro retentive formulation for nifedipine loading into low-density polypropylene microporous particles (Accurel MP 1000®) by a solvent evaporation technique using the 32 factorial design. Yield, drug loading, surface topography, thermal properties, crystal characteristics, photostability and in vitro drug release were studied. Optimized microparticles formulated into a capsule were evaluated for the dissolution study and compared with marketed formulation. Higher values of T50%, time required for 50% degradation of drug with threefold and 1.5-fold decrease in degradation rate constant (K) under UV and fluorescent lamp were observed for the microparticles, respectively, as compared to pure nifedipine indicated remarkable improved photostability. Microparticles showed good floating ability in 0.1N HCl with initial burst release (16–29%) followed by the zero-order drug release up to 8 h. The capsule formulation followed the ideal modified release pattern.

PULSATILE: A TOOL FOR CIRCARDIAN RHYTHM - A REVIEW

In the field of modified release, this review covers the detail aspect of a novel pulsatile drug delivery systems (PDDS) by oral administration that aims to release drugs on a programmed pattern at specific time and specific site as per the pathophysiological need of the disease, resulting in improved patient therapeutic efficacy and compliance. In particular, the recent literature reports on a variety of pulsatile release systems intended for the oral route, which have been recognised as potentially beneficial to the chronotherapy of widespread diseases. Asthma, peptic or deodenal ulcer, diabetes, neurological disorder, hypertension, cardiovascular diseases, arthritis, attention deficit syndrome in children, and hypercholesterolemia these kind of diseases are promising by pulsatile drug delivery. Technically, This system is designed for chronopharmacotherapy which is based on circadian rhythm and beneficial for the drugs having chronopharmacological behavior where night time dosing is required and for the drugs having high first-pass effect and specific site of absorption in gastrointestinal tract. This controlled–release system can maintain the drug concentration within the therapeutic window with a single dose, which lowers the systemic drug level and also preserves medication that rapidly destroyed by the body. Pulsatile drug delivery system is time related or site-specific related to drug released at the desired site within the intestinal tract (e.g., the colon). Pulsatile drug delivery systems are formulated when zero order drug release is not desired. Based on these premises, the aim of this review is to outline the rational and prominent design strategies behind oral pulsatile delivery. Capsular systems, osmotic systems, soluble or erodible polymer coating and rupturable membranes etc. are summarized in this pulse article. Various marketed technologies on pulsatile drug delivery like OROS, PULSINCAP, GEOCLOCK, SODAS, CODAS, etc., were launched by pharmaceutical companies.

Relationship between Diffusivity of Water Molecules Inside Hydrating Tablets and Their Drug Release Behavior Elucidated by Magnetic Resonance Imaging

We reported previously that sustained release matrix tablets showed zero-order drug release without being affected by pH change. To understand drug release mechanisms more fully, we monitored the swelling and erosion of hydrating tablets using magnetic resonance imaging (MRI). Three different types of tablets comprised of polyion complex-forming materials and a hydroxypropyl methylcellulose (HPMC) were used. Proton density- and diffusion-weighted images of the hydrating tablets were acquired at intervals. Furthermore, apparent self-diffusion coefficient maps were generated from diffusion-weighted imaging to evaluate the state of hydrating tablets. Our findings indicated that water penetration into polyion complex tablets was faster than that into HPMC matrix tablets. In polyion complex tablets, water molecules were dispersed homogeneously and their diffusivity was relatively high, whereas in HPMC matrix tablets, water molecule movement was tightly restricted within the gel. An optimal tablet formulation determined in a previous study had water molecule penetration and diffusivity properties that appeared intermediate to those of polyion complex and HPMC matrix tablets; water molecules were capable of penetrating throughout the tablets and relatively high diffusivity was similar to that in the polyion complex tablet, whereas like the HPMC matrix tablet, it was well swollen. This study succeeded in characterizing the tablet hydration process. MRI provides profound insight into the state of water molecules in hydrating tablets; thus, it is a useful tool for understanding drug release mechanisms at a molecular level.

Oral drug delivery systems comprising altered geometric configurations for controlled drug delivery.

Recent pharmaceutical research has focused on controlled drug delivery having an advantage over conventional methods. Adequate controlled plasma drug levels, reduced side effects as well as improved patient compliance are some of the benefits that these systems may offer. Controlled delivery systems that can provide zero-order drug delivery have the potential for maximizing efficacy while minimizing dose frequency and toxicity. Thus, zero-order drug release is ideal in a large area of drug delivery which has therefore led to the development of various technologies with such drug release patterns. Systems such as multilayered tablets and other geometrically altered devices have been created to perform this function. One of the principles of multilayered tablets involves creating a constant surface area for release. Polymeric materials play an important role in the functioning of these systems. Technologies developed to date include among others: Geomatrix® multilayered tablets, which utilizes specific polymers that may act as barriers to control drug release; Procise®, which has a core with an aperture that can be modified to achieve various types of drug release; core-in-cup tablets, where the core matrix is coated on one surface while the circumference forms a cup around it; donut-shaped devices, which possess a centrally-placed aperture hole and Dome Matrix® as well as “release modules assemblage”, which can offer alternating drug release patterns. This review discusses the novel altered geometric system technologies that have been developed to provide controlled drug release, also focusing on polymers that have been employed in such developments.

Floating Elementary Osmotic Pump Tablet (FEOPT) for Controlled Delivery of Diethylcarbamazine Citrate: a Water-Soluble Drug

The present work investigates the feasibility of the design of a novel floating elementary osmotic pump tablet (FEOPT) to prolong the gastric residence of a highly water-soluble drug. Diethylcarbamazine citrate (DEC) was chosen as a model drug. The FEOPT consisted of an osmotic core (DEC, mannitol, and hydrophilic polymers) coated with a semipermeable layer (cellulose acetate) and a gas-generating gelling layer (sodium bicarbonate, hydrophilic polymers) followed by a polymeric film (Eudragit RL 30D). The effect of formulation variables such as concentration of polymers, types of diluent, and coat thickness of semipermeable membrane was evaluated in terms of physical parameters, floating lag time, duration of floatation, and in vitro drug release. The Fourier transform infrared and X-ray diffraction analysis were carried out to study the physicochemical changes in the drug excipients powder blend. The integrity of the orifice and polymeric film layer was confirmed from scanning electron microscopy image. All the developed FEOPT showed floating lag time of less than 8 min and floating duration of 24 h. A zero-order drug release could be attained for DEC. The formulations were found to be stable up to 3 months of stability testing at 40°C/75% relative humidity.

Formulation and Optimization of Mucoadhesive Nanodrug Delivery System of Acyclovir

Acyclovir is an antiviral drug used for the treatment of herpes simplex virus infections, with an oral bioavailability of only 10–20% [limiting absorption in gastrointestinal tract to duodenum and jejunum] and half-life of about 3 h, and is soluble only at acidic pH (pKa 2.27). Mucoadhesive polymeric nanodrug delivery systems of acyclovir have been designed and optimized using 23 full factorial design. Poly (lactic-co-glycolic acid) (PLGA) (50:50) was used as the polymer along with polycarbophil (Noveon AA-1) as the mucoadhesive polymer and pluronic F68 as the stabilizer. From the preliminary trials, the constraints for independent variables X1 (amount of PLGA), X2 (amount of pluronic F68) and X3 (amount of polycarbophil) have been fixed. The dependent variables that were selected for study were particle size (Y1), % drug entrapment (Y2) and % drug release in 12 h (Y3). The derived polynomial equations were verified by check point formulation. The application of factorial design gave a statistically systematic approach for the formulation and optimization of nanoparticles with the desired particle size, % drug release and high entrapment efficiency. Drug: Polymer ratio and concentration of stabilizer were found to influence the particle size and entrapment efficiency of acyclovir-loaded PLGA nanoparticles. The release was found to follow Fickian as well as non-Fickian diffusion mechanism with zero-order drug release for all batches. In vitro intestinal mucoadhesion of nanoparticles increased with increasing concentration of polycarbophil. These preliminary results indicate that acyclovir-loaded mucoadhesive PLGA nanoparticles could be effective in sustaining drug release for a prolonged period.

Zero-order release of 5-fluorouracil from PCL-based films featuring trilayered structures for stent application

A trilayered Poly( ε-caprolactone) (PCL)-based film with a coating layer (CL), a drug-storing layer (DSL) loaded with antitumor drug 5-Fluorouracil (5-FU) and a backing layer (BL) are presented for film-based stent application in malignant stricture or stenosis. V-C diffusion cells were used to investigate the drug permeability of the CL, while scanning electron microscopy (SEM) was employed for observing the microscopic architectures and morphologies. Drug release from the trilayered films exhibited a zero-order pattern, and the release process followed an ‘outer-to-inner’ pattern. The formation mechanism and influencing factors of the zero-order drug release pattern were in-depth elucidated, and factors affecting the drug release were also investigated. The reduction of initial drug loading in DSL slowed the drug release and diminished the zero-order release pattern. Drug permeability of the CL depended significantly on CL thickness, but not significantly on PCL molecular weight. Besides, the addition of PEG porogen in the CL accelerated the drug release by elevation of the drug permeability of CL, and the action mechanism of PEG was revealed by the PEG release test and SEM. The loading of 5-FU in the CL could lead to a two-phased release profile. This study revealed the potential of the trilayered film in controlled drug delivery to intraluminal tumor due to its highly tunable zero-order drug release.