Linear Drug Release Research Articles

Preparation and characterization of magnetic microgels with linear thermosensitivity over a wide temperature range

Abstract Hybrid nanogels that are both thermosensitive and superparamagnetic, and have good biocompatibility are expected to have applications in the biomedical field. In this article, a linearly thermosensitive magnetic microgel was prepared by a radical copolymerization reaction in aqueous dispersion. In this reaction, poly(ethylene glycol) diacrylate was used as a crosslinker, polyvinylpyrrolidone was used as a stabilizer, and 2-methoxyethyl acrylate, poly(ethylene glycol)methyl ether acrylate, and 2-(methacryloyloxy)ethyl acetoacetate were used as copolymer monomers. The thermosensitive magnetic microgel displays a linear volume phase transition in water upon heating over a wide range of temperatures. Transmission electron microscopy, scanning electron microscopy, and dynamic light scattering were used to characterize the morphology and dimensions of the thermosensitive magnetic microgel. This material is expected to be used in magnetically targeted drug delivery systems that require linear drug release.

Polymer based dual drug delivery system for targeted treatment of fluoroquinolone resistant Staphylococcus aureus mediated infections

The present study attempts to treat S. aureus-induced soft skin infections using a combinatorial therapy with an antibiotic, Ciprofloxacin (CIP), and an efflux pump inhibitor 5-Nitro-2-(3-phenylpropoxy) pyridine (5-NPPP) through a smart hydrogel delivery system. The study aims to reduce the increasing rates of infections and antimicrobial resistance; therefore, an efflux pump inhibitor molecule is synthesized and delivered along with an antibiotic to re-sensitize the pathogen towards antibiotics and treat the infections. CIP-loaded polyvinyl alcohol (PVA) hydrogels at varying concentrations were fabricated and optimized by a chemical cross-linking process, which exhibited sustained drug release for 5 days. The compound 5-NPPP loaded hydrogels provided linear drug release for 2 days, necessitating the need for the development of polymeric nanoparticles to alter the release drug pattern. 5-NPPP loaded Eudragit RSPO nanoparticles were prepared by modified nanoprecipitation—solvent evaporation method, which showed optimum average particle size of 230–280 nm with > 90% drug entrapment efficiency. The 5-NPPP polymeric nanoparticles loaded PVA hydrogels were fabricated to provide a predetermined sustained release of the compound to provide a synergistic effect. The selected 7% PVA hydrogels loaded with the dual drugs were evaluated using Balb/c mice models induced with S. aureus soft skin infections. The results of in vivo studies were evidence that the dual drugs loaded hydrogels were non-toxic and reduced the bacterial load causing re-sensitization towards antibiotics, which could initiate re-epithelization. The research concluded that the PVA hydrogels loaded with CIP and 5-NPPP nanoparticles could be an ideal and promising drug delivery system for treating S. aureus-induced skin infections.

A dual functional chondro-inductive chitosan thermogel with high shear modulus and sustained drug release for cartilage tissue engineering.

We report a chitosan-based nanocomposite thermogel with superior shear modulus resembling that of cartilage and dual pro-chondrogenic and anti-inflammatory functions. Two therapeutic agents, kartogenin (KGN) and diclofenac sodium (DS), are employed to promote chondrogenesis of stem cells and suppress inflammation, respectively. To extend the release time in a controlled manner, KGN is encapsulated in the uniform-sized starch microspheres and DS is loaded into the halloysite nanotubes. Both drug carriers are doped into the maleimide-modified chitosan hydrogel to produce a shear modulus of 167±5kPa that is comparable to that of articular cartilage (50-250kPa). Owing to the hydrogel injectability and relatively suitable gelation time (5±0.5min) at 37°C, this system potentially constitutes a manageable platform for clinical practice. Moreover, sustained linear drug release for over a month boosts chondro-differentiation of stem cells to eliminate the necessity for multiple administrations. Considering virtues such as thermogel strength and ability to co-deliver anti-inflammatory and chondro-inductive biomolecules continuously, the materials and strategy have promising potential in functional cartilage tissue engineering.

Development of drug loaded cardiovascular prosthesis for thrombosis prevention using 3D printing

Cardiovascular disease (CVD) is a general term for conditions which are the leading cause of death in the world. Quick restoration of tissue perfusion is a key factor to combat these diseases and improve the quality and duration of patients' life. Revascularization techniques include angioplasty, placement of a stent, or surgical bypass grafting. For the latter technique, autologous vessels remain the best clinical option; however, many patients lack suitable autogenous due to previous operations and they are often unsuitable. Therefore, synthetic vascular grafts providing antithrombosis, neointimal hyperplasia inhibition and fast endothelialization are still needed. To address these limitations, 3D printed dipyridamole (DIP) loaded biodegradable vascular grafts were developed. Polycaprolactone (PCL) and DIP were successfully mixed without solvents and then vascular grafts were 3D printed. A mixture of high and low molecular weight PCL was used to better ensure the integration of DIP, which would offer the biological functions required above. Moreover, 3D printing technology provides the ability to fabricate structures of precise geometries from a 3D model, enabling to customize the vascular grafts' shape or size. The produced vascular grafts were fully characterized through multiple techniques and the last step was to evaluate their drug release, antiplatelet effect and cytocompatibility. The results suggested that DIP was properly mixed and integrated within the PCL matrix. Moreover, these materials can provide a sustained and linear drug release without any obvious burst release, or any faster initial release rates for 30 days. Compared to PCL alone, a clear reduced platelet deposition in all the DIP-loaded vascular grafts was evidenced. The hemolysis percentage of both materials PCL alone and PCL containing 20% DIP were lower than 4%. Moreover, PCL and 20% DIP loaded grafts were able to provide a supportive environment for cellular attachment, viability, and growth.

Fabrication of pH-Responsive Polyimide Polyacrylic Acid Smart Gating Membranes: Ultrafast Method Using 248 nm Krypton Fluoride Excimer Laser.

pH-responsive smart gating membranes were developed using a two-step fabricating process. In the first step, a porous polyimide (PI) support membrane with ordered, regular, and well-defined pores was obtained with a 248 nm KrF excimer laser using a lithography technique. The porous membranes were then grafted with poly(acrylic acid) (PAAc) hydrogel by free radical polymerization using the same excimer laser. The number of pulses and frequency could be varied to obtain a range of water permeabilities. Permeability of membrane changed significantly due to swelling and deswelling of PAAc inside the pores at pH 7 and pH 3, respectively. These hydrogel networks were firmly grafted inside pores and remained mechanically intact even after using high pressure during permeability studies. PAAc grafting was confirmed using ATR-FTIR. PAAc hydrogel distribution inside membrane pores was analyzed using SEM and fluorescence microscopy. To quantify the amount of polymer grafted, TGA studies were carried out. Diffusion studies were also carried out using caffeine as a drug molecule to evaluate the application of membrane in drug delivery devices. The linear drug release profile obtained from the study confirmed the potential application of membrane for drug delivery purposes. Results obtained also suggest that the fabrication method developed is fast, efficient, solvent-free, and economical.

HA particles as resourceful cancer, steroidal and antibiotic drug delivery device with sustainable and multiple drug release capability

Hyaluronic acid (HA) particles with divinyl sulfone (DVS) crosslinking at 10% mole ratio (HA macromolecule repeating units) were prepared and demonstrated as versatile drug carriers with sustainable and long-term release capabilities for cancer drugs, corticosteroid, and antibiotics. Two different methods were chosen in drug loading process; encapsulation for cancer drugs, 5-fluorouracil (5FU), mitomycin C (MMC), and doxorubicin (Dox), and dual drug conjugation for anti-inflammatory glucocorticoid dexamethasone (Dex) and antibiotic ciprofloxacin (Cipro) drugs, respectively. It was demonstrated that HA particles prepared during drug encapsulation were attained smaller sizes with 833 ± 46, 867 ± 50, 728 ± 41 nm for 5FU, MMC, and Dox, respectively. Bare and drug loaded HA particles were shown to be blood compatible with the highest hemolytic ratio of 3.1 ± 0.12% for HA-Dex-Cipro conjugates and fairly good blood clotting index with minimum 71.7 ± 6.0% for MMC encapsulated HA particles. Drug release studies from HA particles indicated that depending on the types of cancer drugs, it is possible to gradually release the drug in long-term up to 300 h in linear fashions with the highest release of 9.34 ± 2.25 mg/g for 5FU. Similarly, drug conjugated HA-Dex-Cipro particles were also showed linear dual drug release up to 100 h at physiological conditions, pH 7.4 and 37.5 °C.

Preparation of hyaluronic acid and copolymeric hyaluronic acid: sucrose particles as tunable antibiotic carriers

Hyaluronic acid (HA) and copolymeric HA:Sucrose (HA:Suc) particles were synthesis with two different crosslinkers (Xs), divinyl sulfone (DVS) and glycerol diglycidyl ether (GDE) in 0.5–20 μm size range. The sustenance potential of HA:Suc particles in bacterial growth media was examined with time, up to 72 h incubation time in the cultivation of various gram-negative (GN) and gram-positive (GP) bacterial strains. Furthermore, ciprofloxacin, model drug was loaded into HA and HA:Suc particles few times by chemical conjugations; e.g., 1st and 2nd chemical conjugations and named as 1C and 2C, respectively. To increase the drug loading amount into HA-based particles, 2C particles was placed in drug solution for physical adsorption (2C + A). Therefore, drug carrier capacity of HA-based particles was enhanced almost 6.5-fold with the highest ciprofloxacin release from HA particles was 43.47 ± 2.36 mg/g within 120 h. The antimicrobial susceptibility studies revealed that ciprofloxacin-loaded copolymeric HA:Suc particles with 2C + A loading process has the highest antimicrobial effects. The minimum inhibition concentration (MIC) against E. coli, P. aeruginosa, S. aureus, and B. subtilis strains were found to range between 0.25–1 mg/mL, and an increasing inhibition trend was observed by increasing the incubation time up to 72 h due to linear drug release profile from HA particles.

Design and In-vitro evaluation of gastro retentive drug delivery systems of metoprolol succinate

Gastro retentive drug delivery is a special approach that remains in the stomach for a prolonged period which helps to increase gastric residence time along with site specific drug delivery especially in the upper gastrointestinal tract (GIT) for local or systemic effects. Metoprolol succinate is a beta1-selective adrenergic receptor antagonist used to treat hypertension, angina and arrhythmia. It has a t1/2 of 3-7hrs and is mainly absorbed from the upper parts of GIT with good stability in the acidic environment. The main objective of the present study was to design a floating formulation having Metoprolol succinate as a model drug by using the polymers like HPMC K100M, HPMC K15M, HPMC K4M, Kollidon SR to increase the bioavailability of drug and reduce the dosing frequency. FTIR studies proved that there was no incompatability in the optimized formulations. All the formulations remained buoyant without any disintegration. The formulations F4, F8, F12 and F15 showed similar drug release to that of marketed formulation for a period of 12 hours. To ascertain the mechanism of drug release, in-vitro data was fitted into various release kinetic models like zero order, first order, Higuchi and Peppas. The values indicated, the non fickian diffusion with slow erosion of polymer matrix followed by drug diffusion and resulted in linear drug release profile over a prolonged period of time.

Development and evaluation of dipyridamole sustained release tablets containing micro-environmental pH modifiers

The objective of the present study is to develop sustained release of dipyridamole, a poorly soluble weakly basic compound. The solubility of dipyridamole is the limit step of its bioavailability. To improve this, direct compressed tablets were formulated containing organic acids as pH modifiers to regulate micro-environmental pH on drug release from hydrophilic polymer matrix. Based on preliminary results from differential scanning calorimetry, fourier transform infrared spectroscopy, powder x-ray diffraction of dipyridamole with various polymer and pH modifier mixtures as well as tablet properties and drug release kinetics of dipyridamole tablets, HPMC K15 M and fumaric acid were selected as tablet matrix forming polymer and acidic micro-environmental pH modifier. Thereafter, tablets formulated with various concentrations of HPMC K15 M and fumaric acid were further evaluated. Among all the tablets fabricated, the tablet formulation containing 20% HPMC K15 M and 20% fumaric acid was observed to be the best formulation due to its near linear drug release profile in phosphate buffer medium (pH 6.8). Furthermore, under simulated gastrointestinal tract conditions, sustained drug release of approximately entire drug content from the tablets was achieved. This formulation has potential to improve dipyridamole bioavailability as well as therapeutic effect.

Fine-Tuning the Linear Release Rate of Paclitaxel-Bearing Supramolecular Filament Hydrogels through Molecular Engineering.

One key design feature in the development of any local drug delivery system is the controlled release of therapeutic agents over a certain period of time. In this context, we report the characteristic feature of a supramolecular filament hydrogel system that enables a linear and sustainable drug release over the period of several months. Through covalent linkage with a short peptide sequence, we are able to convert an anticancer drug, paclitaxel (PTX), to a class of prodrug hydrogelators with varying critical gelation concentrations. These self-assembling PTX prodrugs associate into filamentous nanostructures in aqueous conditions and consequently percolate into a supramolecular filament network in the presence of appropriate counterions. The intriguing linear drug release profile is rooted in the supramolecular nature of the self-assembling filaments which maintain a constant monomer concentration at the gelation conditions. We found that molecular engineering of the prodrug design, such as varying the number of oppositely charged amino acids or through the incorporation of hydrophobic segments, allows for the fine-tuning of the PTX linear release rate. In cell studies, these PTX prodrugs can exert effective cytotoxicity against glioblastoma cell lines and also primary brain cancer cells derived from patients and show enhanced tumor penetration in a cancer spheroid model. We believe this drug-bearing hydrogel platform offers an exciting opportunity for the local treatment of human diseases.

Microgels Derived from Different Forms of Carrageenans, Kappa, Iota, and Lambda for Biomedical Applications

ABSTRACTKappa (k-), iota (ɩ-), and lambda (λ-) Carrageenan (Car) microparticles were synthesized by crosslinking corresponding natural polymers with divinyl sulfone (DVS) via microemulsion polymerization/crosslinking methods for potential biomedical applications. Negatively charged e.g., -44 mV of Car particles were modified with diethylenetriamine (DETA) to generate positively charged modified (M-) ᴋ-Car particles with +23 mV zeta potential values. Cationic M-Car-DETA particles were found to be effectively antimicrobial material against gram negative bacteria, and some fungi species. Moreover, upon protonation of M-Car-DETA particles with HCl the effectiveness against all types of microorganisms are significantly increased. All types of Car based particles can be applicable for blood contacting material as low hemolysis ratio, 2.56% and high blood clotting capability, 86% were obtained. Furthermore, Car based particles found biocompatible against L929 fibroblast cells, and can induce necrotic cell death at 12.5 μg/mL concentration against DLD-1 colon cancer cells. M-ᴋ-Car-DETA particles were also demonstrated to be useful rending long term and linear drug release profiles using Rosmarinic Acid (RA) as a model drug.

Applications of PLGA microcarriers prepared using geometrically passive breakup on microfluidic chip

We present geometrically passive T-junction breakup as a high-throughput preparation method for polymer microcarriers. In passive T-junction breakup, an alternative method that can satisfy requirements for uniform size distribution and high production, a polymer solution droplet is split into numerous smaller droplets as it passes T-junctions, and is then polymerized into particles as solvents evaporate. Microparticles generated from poly(lactic-co-glycolic acid) (PLGA) were used to demonstrate the applicability of this method. The proposed method of droplet fission, controlled by microfluidic flow, allowed for preparation of biopolymer particles at 8000 Hz and size distribution of CV < 5%. Feasibility of the prepared PLGA microparticles was verified as microcarriers for functional materials: lidocaine, carbon nanotubes (CNTs), and 3T3 cells. The prepared microparticles showed a slower and more linear drug release profile compared to those generated using the conventional evaporation method. Highly porous microparticles were also prepared successfully using gelatin as a porogen in the T-junction breakup device.

In silico mechanistic disposition and in vivo evaluation of zero-order drug release from a novel triple-layered tablet matrix

Objectives: The purpose of this study was to formulate novel triple-layered tablet (TLT) matrices employing modified polyamide 6,10 (mPA6,10) and salted-out poly(lactic-co-glycolic acid) (s-PLGA) in an attempt to achieve stratified zero-order drug release.Methods: mPA6,10 and s-PLGA were employed as the outer drug-carrier matrices, whereas poly(ethylene oxide) (PEO) was used as the middle-layer drug matrix. Diphenhydramine HCl, ranitidine HCl and promethazine were selected as model drugs to pre-optimize the TLT, whereas atenolol, acetylsalicylic acid and simvastatin were employed as a comparable fixed dose combination to test the TLT prototype in vitro and in vivo (Large White Pig model). A total of 17 formulations that varied in terms of polymer stoichiometry, salt addition and polymer–polymer ratios were generated using a Box-Behnken experimental design.Results: The in vitro drug release analysis revealed that release from the mPA6,10 layer was relatively linear with a burst release, which upon addition of sodium sulfate was reduced. Furthermore, formulations with higher quantities of mPA6,10 provided more controlled zero-order drug release and increased the matrix hardness. The addition of PEO to the s-PLGA layer significantly reduced the initial burst release that occurred when s-PLGA was used alone.Conclusions: The formulation with a lower s-PLGA:PEO ratio displayed superior zero-order release. Relatively, linear drug release was achieved from the middle-layer. The in vivo results proved the applicability of optimized TLT formulation in a therapeutic cardiovascular drug treatment regimen.

Cross-linked vegetable oil with covalently loaded dexamethasone: linear drug release for osteogenic induction of hBMSCs in vitro

A novel covalently dexamethasone-conjugated drug release system based on cross-linked vegetable oil (DEX-CVs) was designed and prepared by simple curing reaction of modified vegetable oil and dexamethasone phosphomonoester (DEX-P) without any toxic catalyst and initiator. UV and HPLC analysis confirmed that the dexamethasone (DEX) drug could be released linearly with high purity by adjusting the component ratios. The analysis of the model reaction indicated that DEX-P in the optimized DEX-CV (A4) was mainly covalently conjugated in the cross-linked vegetable oil network by cyclic phosphotriester bond, and the selective hydrolysis induced the pure release of dexamethasone drug. Finally, the low cytotoxicity and successful osteogenic differentiation effect of A4 on human bone marrow mesenchymal stem cells (hBMSCs) was corroborated by the detection of MTT analysis, ALP activity, staining experiments and some gene expressions, which provided the promising applications in drug release areas and bone tissue engineering.

Linear drug release membrane prepared by a modified coaxial electrospinning process

This study investigated a novel type of drug-delivery membrane prepared by a modified coaxial electrospinning process. Using 1% (w/v) unspinnable zein solution as sheath fluid, the coaxial electrospinning process can be smoothly conducted to generate ketoprofen (KET)-loaded zein nanofibers coated with a thin layer of blank zein. Scanning electron microscopy and transmission electron microscopy images demonstrated that the nanofibers had a ribbon morphology with a smooth surface, as well as average diameters of 860±210nm (coating thickness of ca. 20nm) and 680±140nm (coating thickness of ca. 30nm) at sheath-to-core flow rate ratios of 0.11 and 0.25, respectively. X-ray diffraction and differential scanning calorimetry verified that KET presented an amorphous state in all nanofibers. Attenuated total reflectance Fourier transform infrared spectroscopy demonstrated that zein had good compatibility with KET because of hydrogen bonding. In vitro dissolution tests showed that the nanofibers coated with blank zein did not exert any initial burst release effect, and can enable linear drug release over a period of 16h via a diffusion mechanism. The modified coaxial electrospinning process can provide new approaches to the development of nanofiber membranes with improved structural characteristics and performance.

5-Fluorouracil encapsulated HA/PLGA composite microspheres for cancer therapy

5-Fluorouracil (5FU) was successfully entrapped within poly(lactide-co-glycolide) (PLGA) and hydroyapatite (HA) composite microspheres using the emulsification/solvent extraction technique. The effects of HA to PLGA ratio, solvent ratio as well as polymer inherent viscosity (IV) on encapsulation efficiency were investigated. The degradation and drug release rates of the microspheres were studied for 5 weeks in vitro in phosphate buffered solution of pH 7.4 at 37 °C. The drug release profile followed a biphasic pattern with a small initial burst followed by a zero-order release for up to 35 days. The initial burst release decreased with increasing HA content. The potential of HA in limiting the initial burst release makes the incorporation of HA into PLGA microspheres advantageous since it reduces the risk of drug overdose from high initial bursts. The linear sustained drug release profile over the course of 5 weeks makes these 5-FU-loaded HA/PLGA composite microparticles a promising delivery system for the controlled release of chemotherapy drugs in the treatment of cancer.

Enhanced neurotrophin-3 bioactivity and release from a nanoparticle-loaded composite hydrogel

Neurotrophin-3 (NT-3) has shown promise in regenerative strategies after spinal cord injury; however, sustained local delivery is difficult to achieve by conventional methods. Controlled release from poly(lactic-co-glycolic acid) (PLGA) nanoparticles has been studied for numerous proteins, yet achieving sustained release of bioactive proteins remains a challenge. To address these issues, we designed a composite drug delivery system comprised of NT-3 encapsulated in PLGA nanoparticles dispersed in an injectable hydrogel of hyaluronan and methyl cellulose (HAMC). A continuum model was used to fit the in vitro release kinetics of an NT-3 analog from a nanoparticle formulation. Interestingly, the model suggested that the linear drug release observed from composite HAMC was due to a diffusion-limiting layer of methyl cellulose on the particle surface. We then studied the effects of processing parameters and excipient selection on NT-3 release, stability, and bioactivity. Trehalose was shown to be the most effective additive for stabilizing NT-3 during sonication and lyophilization and PLGA itself was shown to stabilize NT-3 during these processes. Of four excipients tested, 400g/mol poly(ethylene glycol) was the most effective during nanoparticle fabrication, with 74% of NT-3 detected by ELISA. Conversely, co-encapsulation of magnesium carbonate with NT-3 was the most effective in maintaining NT-3 bioactivity over 28days according to a cell-based axonal outgrowth assay. Together, the modeling and optimized processing parameters provide insight critical to designing a controlled bioactive release formulation for ultimate testing in vivo.

Porous and modified HA particles as potential drug delivery systems

Composite silica-hyaluronic acid (Si-HA) micro particles were synthesized, employing tetraethyl orthosilicate (TEOS) in the presence of linear HA and a crosslinker, divinyl sulfone (DVS) via a water-in-oil microemulsion polymerization technique. Porous HA (PHA) hydrogel particles were generated after removal of silica particles upon treatment of HA composites with hydrofluoric acid (HF). Furthermore, HA particles were quaternized (QHA) by chemical modification using 3-chloro-2-hydroxypropyl trimethyl ammonium chloride as a quarternization agent. The size of HA based particles were ranged between 1.26 and 2.95μm. The PHA particles have a surface area of 2.7m2/g confirmed by the surface area measurements. Modified HA particles were used in the absorption and release studies of two model drugs in PBS, trimethoprim (TMP) and sodium diclofenac (SDF) which are acidic and basic in nature, respectively. The ability to control the size, charge and porosity of the HA particles which showed almost linear drug release profiles.

Numerical modeling of a novel degradable drug delivery system with microholes

Based on UV-LIGA technology, a novel drug delivery microsystem is proposed to eliminate the time lag in initial drug release. With proper microholes in bonding membrane, the drug release rate can be controlled at a stable level in the whole release process. This microsystem is fabricated by degradable polymer and suitable for subcutaneous implants. As a significant parameter, the demarcation time of polymer absorption/erosion is estimated by comparing the experimental results of polymer erosion and in vitro release. By considering diffusion, swelling and erosion mechanisms simultaneously, a numerical drug releasing model is developed to investigate the effect of microholes on drug release and impact factors of linear drug releasing. The simulation results show that the microholes are beneficial to eliminate the time lag, and furthermore, the area of microholes and the initial drug loading have great impact on the release time and the linear drug release rate.

Design and Development of an &amp;lt;i&amp;gt;in Vitro&amp;lt;/i&amp;gt; Assay for Evaluation of Solid Vaginal Dosage Forms

Vaginal dosage forms are seen as a viable option for empowering women to protect themselves from the risk of HIV transmission. Because of limited research in the field, there is a lack of suitable dissolution methods established for determination of drug release from vaginal formulations inside the vaginal tract. The main aim of this study was to develop a simple, reliable and reproducible in vitro release method for evaluation of solid vaginal dosage forms (VDFs) which was hoped to exhibit a close in vitro-in vivo correlation. Dapivirine, a drug being developed as a microbicide and a well established marketed anti fungal drug, Clotrimazole were used as model drugs. Two doses (0.5 mg and 1.25 mg) of Dapivirine were prepared as novel rapidly disintegrating, bioadhesive tablets. Clotrimazole 100 mg, prepared in house as conventional release tablets and commercially available Canesten (Clotrimazole tablet 100 mg) were used. The in vitro drug release testing of these tablets was carried out using a designed system which consisted of modified USP dissolution Apparatus II in conjunction with Enhancer cell (as sample holder) in 150 ml capacity flasks instead of the standard 900 ml flasks. The suitability of the system was investigated for variable parameters such as formulation types, drug concentration, stirring speeds, media volume and comparison of in house product with marketed product. The method was successfully optimized at a volume of 100 ml and a low speed of 25 rpm at pH 4 and was found sensitive enough to distinguish between formulations and evaluate products of different strengths. A linear drug release profile (R2 = 0.99) was obtained in case of Dapivirine, indicating that drug release is controlled by diffusion. The developed dissolution system has a potential to exhibit a good in vitro-in vivo correlation in addition to carrying out routine dissolution tests for solid VDFs.