Core Tablets Research Articles

ВАЛІДАЦІЯ ВИРОБНИЦТВА ТАБЛЕТОК «УРОНЕФРОН»

Мета роботи. Надати документальні докази, які підтвердять, що процес виробництва препарату «Уронефрон» у формі таблеток, вкритих плівковою оболонкою, приводить до отримання продукту встановленої якості.Матеріали і методи. Валідаційні дослідження проводили на 3 серіях препарату.Валідація процесу виробництва таблеток «Уронефрон» проведена на всіх стадіях технологічного процесу з визначенням критичних параметрів, а саме: підготовка сировини, отримання маси для таблетування, зберігання таблетмаси, таблетування, нанесення плівкової оболонки на таблетки-ядра.Результати й обговорення. Для визначених критичних параметрів технологічного процесу отримання продукту проводили валідаційні випробування, які дозволяють визначити допустимі межі відхилення цих параметрів.Результати проведення валідаційних випробувань на кожній стадії технологічного процесу виготовлення таблеток «Уронефрон» відповідають критеріям прийнятності.Висновки. Валідація процесу виробництва таблеток «Уронефрон» підтвердила кваліфікацію виробничого персоналу і дотримання ним прописаних параметрів; показала, що технологічне обладнання ділянки в змозі забезпечити відтворюваність параметрів технологічного процесу виробництва, що призводить до очікуваного рівня якості напівпродукту і готової продукції; продемонструвала відтворюваність і стандартність показників якості напівпродукту і готової продукції відповідно до нормативної документації.

In Vitro Evaluation of Cocoa Pod Husk Pectin as a Carrier for Chronodelivery of Hydrocortisone Intended for Adrenal Insufficiency.

This study evaluated the in vitro potential of cocoa pod husk (CPH) pectin as a carrier for chronodelivery of hydrocortisone intended for adrenal insufficiency. FTIR studies found no drug-CPH pectin interactions, and chemometric analysis showed that pure hydrocortisone bears closer similarity to hydrocortisone in hot water soluble pectin (HWSP) than hydrocortisone in citric acid soluble pectin (CASP). CPH pectin-based hydrocortisone matrix tablets (~300 mg) were prepared by direct compression and wet granulation techniques, and the tablet cores were film-coated with a 15% HPMC formulation for timed release, followed by a 12.5% Eudragit® S100 formulation for acid resistance. In vitro drug release studies of the uncoated and coated matrix tablets in simulated gastrointestinal conditions showed that wet granulation tablets exhibit greater retardation of drug release in aqueous medium than directly compressed tablets. CASP showed greater suppression of drug release in aqueous medium than HWSP. Wet granulation HWSP-based matrix tablets coated to a final coat weight gain of ~25% w/w were optimized for chronodelivery of hydrocortisone in the colon. The optimized tablets exhibited a lag phase of ~6 h followed by accelerated drug release in the colonic region and have potential to control night time cortisol levels in patients with adrenal insufficiency.

Characterization of the coating and tablet core roughness by means of 3D optical coherence tomography

This study demonstrates the use of optical coherence tomography (OCT) to simultaneously characterize the roughness of the tablet core and coating of pharmaceutical tablets. OCT is a high resolution non-destructive and contactless imaging methodology to characterize structural properties of solid dosage forms. Besides measuring the coating thickness, it also facilitates the analysis of the tablet core and coating roughness. An automated data evaluation algorithm extracts information about coating thickness, as well as tablet core and coating roughness. Samples removed periodically from a pan coating process were investigated, on the basis of thickness and profile maps of the tablet core and coating computed from about 480,000 depth measurements (i.e., 3D data) per sample. This data enables the calculation of the root mean square deviation, the skewness and the kurtosis of the assessed profiles. Analyzing these roughness parameters revealed that, for the given coating formulation, small valleys in the tablet core are filled with coating, whereas coarse features of the tablet core are still visible on the final film-coated tablet. Moreover, the impact of the tablet core roughness on the coating thickness is analyzed by correlating the tablet core profile and the coating thickness map. The presented measurement method and processing could be in the future transferred to in-line OCT measurements, to investigate core and coating roughness during the production of film-coated tablets.

The Impact of Amorphisation and Spheronization Techniques on the Improved in Vitro & in Vivo Performance of Glimepiride Tablets.

Purpose: Triple solid dispersion adsorbates (TSDads) and spherical agglomerates (SA) present new techniques that extensively enhance dissolution of poorly soluble drugs. The aim of the present study is to hasten the onset of hypoglycemic effect of glimepiride through enhancing its rate of release from tablet formulation prepared from either technique.Methods: Drug release from TSDads or SA tablets with different added excipients was explored. Scanning electron microscopy (SEM) and effect of compression on dissolution were illustrated. Pharmacodynamic evaluation was performed on optimized tablets.Results: TSDads & SA tablets with Cross Povidone showed least disintegration times of 1.48 and 0.5 min. respectively. Kinetics of drug release recorded least half-lives (54.13 and 59.83min for both techniques respectively). Cross section in tablets displayed an organized interconnected matrix under SEM, accounting for the rapid access of dissolution media to the tablet core. Components of tablets filled into capsules showed a similar release profile to that of tablets after compression as indicated by similarity factor. The onset time of maximum reduction in blood glucose in male albino rabbits was hastened to 2h instead of 3h for commercial tablets.Conclusion: After optimization of tablet excipients that interacted differently with respect to their effect on drug release, we could conclude that both amorphisation and spheronization were equally successful in promoting in vitro dissolution enhancement as well as providing a more rapid onset time for drug action in vivo.

Chronomodulated drug delivery system of Irbesartan: Formulation and development using Desing of Experiment (DoE)

The work is based on pulsatile principles to deliver a programmed dose of Irbesartan, an angiotensin-II receptor antagonist for chronotherapy of hypertension induced by excessive secretion of aldosterone, thereby lower the blood pressure at early morning. Solid dispersion of Irbesartan, a BCS class II drug, was prepared by using Poloxamer-188 by melt method in ratio of 1:1 to increase the dissolution properties of drug. Compressed coated pulsatile tablets included a core layer consisting of Kyron T-134 as a super-disintegrant and pulsatile layer comprising of HPMC K4M and Eudragit RLPO. The prepared core tablets were evaluated for weight variation, hardness, thickness, friability, drug content, disintegration time and In vitro dissolution studies. Final core tablet (C8) was selected on the basis of disintegration time (23.33 ± 2.08 s). For optimization Face centred central composite design was employed to study the effect of independent variables viz. Weight ratio of HPMC K4M: Eudragit RLPO (X1) and Total weight of coating (X2) on dependent variables viz. Drug release lag time (Y1) and Drug release after lag time within 15 min (D15) (Y2). Results revealed positive influence of independent factors on responses. The data were statistically analyzed using ANOVA and were found to be statistically significant (P < .05). Mathematical modeling for kinetic studies revealed that the release profile after lag time followed first order kinetics. Accelerated stability studies for one month at 40 ± 2 °C/75 ± 5% RH showed no remarkable changes concluding that a successful pulsatile drug delivery system of Irbesartan was developed.

Совместимость субстанции рамиприла и лерканидипина в одной твердой лекарственной форме

Для выбора необходимых условий при разработке технологии получения твердой лекарственной формы изучены химические свойства фармацевтических субстанций рамиприла и лерканидипина. Для исследования химической совместимости субстанций, а также их совместимости с вспомогательными веществами наработаны и поставлены на хранение смеси, содержащие 2 или 3 ингредиента. Анализ данных смесей показал возможную совместимость субстанций в одной лекарственной форме. С целью изучения технологических факторов наработаны, поставлены на хранение и проанализированы образцы полупродуктов (смеси, грануляты, массы для таблетирования, таблетки-ядра) и готового продукта (таблеток, покрытых пленочной оболочкой). Доказано, что процесс таблетирования, а также совместное нахождение рамиприла и лерканидипина в любых видах полупродуктов, значительно влияет на рост примесей. Обоснована необходимость использования технологии двухслойных таблеток.

Demonstration of pharmaceutical tablet coating process by injection molding technology

We demonstrate the coating of tablets using an injection molding (IM) process that has advantage of being solvent free and can provide precision coat features. The selected core tablets comprising 10% w/w griseofulvin were prepared by an integrated hot melt extrusion-injection molding (HME-IM) process. Coating trials were conducted on a vertical injection mold machine. Polyethylene glycol and polyethylene oxide based hot melt extruded coat compositions were used. Tablet coating process feasibility was successfully demonstrated using different coating mold designs (with both overlapping and non-overlapping coatings at the weld) and coat thicknesses of 150 and 300 μm. The resultant coated tablets had acceptable appearance, seal at the weld, and immediate drug release profile (with an acceptable lag time). Since IM is a continuous process, this study opens opportunities to develop HME-IM continuous processes for transforming powder to coated tablets.

Bilayer tablets of Paliperidone for Extended release osmotic drug delivery

The purpose of this study is to develop and optimize the formulation of paliperidone bilayer tablet core and coating which should meet in vitro performance of trilayered Innovator sample Invega. Optimization of core formulations prepared by different ratio of polyox grades and optimization of coating of (i) sub-coating build-up with hydroxy ethyl cellulose (HEC) and (ii).enteric coating build-up with cellulose acetate (CA). Some important influence factors such as different core tablet compositions and different coating solution ingredients involved in the formulation procedure were investigated. The optimization of formulation and process was conducted by comparing different in vitro release behaviours of Paliperidone. In vitro dissolution studies of Innovator sample (Invega) with formulations of different release rate which ever close release pattern during the whole 24 h test is finalized.

An Investigation into Formulation and Processing Strategies to Drive Gastroretention of Gabapentin Tablets

The aim of the present work was to develop gastroretentive drug delivery system of gabapentin from different matrices prepared by hot melt or conventional wet granulation, which may enhance drug bioavailability. The influence of core type, granulation process, and coating level on the drug release rates was investigated. Tablet cores were prepared from hydrophilic system of hypermellose, carboxy melthyl celloulse, and Avicel or hydrophobic system of ethyl cellulose, alginic acid, and stearic acid. The tablets were coated by Eudragit RL with triethyl citrate and compressed directly. These tablets were evaluated according to their in vitro dissolution profiles and release mechanisms. Hydrophobic matrices allowed the control of drug release. Hot melt granulation was an effective tool over wet granulation or coating for slowing release rates from hydrophobic tablets. Both hydrophobic polymer ratio and coating level influenced the drug release mechanism. The drug release of samples with minor proportion of ethyl cellulose and stearic acid or low Eudragit RL level was driven by anomalous transport and the increase of their proportions contributed to the erosion of the matrix. Hydrophobic core tablet prepared from hot melt granulation and coated by Eudragit RL has shown to be a promising formulation intended to gastroretentive gabapentin delivery system.

Development and bioequivalence study of potassium chloride extended release tablets

The purposes of this study are to prepare the generic extended release tablet of potassium chloride (PC) 600 mg and to compare the absorption of potassium ion from the experimental tablets to that of Kaleorid® LP 600 mg (Leo Pharmaceutical Products, Denmark). Carnauba wax was used as retardant in the matrix core tablets. The core tablets were coated with blends of ethyl cellulose (EC) and hydroxypropyl methyl cellulose (HPMC) to modulate the drug release. Results of a selective two-level, three-factor experiment design revealed that a blend of 41.75% of EC and 58.25% of HPMC at 4.5% weight gained could produce the coated tablets having dissolution profiles similar to those of Kaleorid®. A two-treatment, two-period, two-sequence crossover bioequivalence study was carried out on 24 healthy volunteers to compare the absorption of potassium ion from experimental tablets to that from Kaleorid®. The potassium ion in the urine was measured by a selective electrode of the ADVIA 1650 system (Bayer) and used to calculate cumulative urinary excretion and urinary excretion rate. Results of 90 percent confidence interval analysis showed that the limits for natural log-transformed cumulative urinary potassium excretion (Ln Ae0-24) of test product were in the range of 3.73–3.79 mEq, corresponding to 99.08%–100.92% of Kaleorid®, respectively, and the limits for natural log-transformed maximal potassium excretion rate (Rmax) of test product were in the range of 1.72–1.82 mEq/h, corresponding to 97.34%–102.66% of reference product, respectively. Both of them fell within the bioequivalence interval (80%–125%) of reference product, proving that experimental product is bioequivalent to Kaleorid®.

Study of controlled-release floating tablets of dipyridamole using the dry-coated method

Dipyridamole (DIP), having a short biological half-life, has a narrow absorption window and is primarily absorbed in the stomach. So, the purpose of this study was to prepare controlled-release floating (CRF) tablets of dipyridamole by the dry-coated method. The influence of agents with different viscosity, hydroxypropylmethylcellulose (HPMC) and polyvinylpyrollidon K30 (PVP K30) in the core tablet and low-viscosity HPMC and PVP K30 in the coating layer on drug release, were investigated. Then, a study with a three-factor, three-level orthogonal experimental design was used to optimize the formulation of the CRF tablets. After data processing, the optimized formulation was found to be: 80 mg HPMC K4M in the core tablet, 80 mg HPMC E15 in core tablet and 40 mg PVP K30 in the coating layer. Moreover, an in vitro buoyancy study showed that the optimized formulation had an excellent floating ability and could immediately float without a lag time and this lasted more than 12 h. Furthermore, an in vivo gamma scintigraphic study showed that the gastric residence time of the CRF tablet was about 8 h.

Tablets of paliperidone using compression-coated technology for controlled ascending release

The aim of this work was to prepare ascending release compression-coated (CC) tablets with paliperidone (PAL) using a simple manufacturing technique and short manufacturing process. The release behavior and mechanisms in vitro of the final tablets was investigated and evaluated. The PAL CC tablets were comprised of a core layer of high viscosity hydroxypropyl cellulose (HPC-H) and a coating layer of high viscosity hydroxypropyl methylcellulose (HPMC-K100M). Several factors such as materials and core tablet compositions were studied for their influence in the formulation procedure. The drug release mechanism was studied using gravimetric analysis. The data could be fitted to the Peppas model. The ascending drug release results were expressed in terms of the slope of the release curve at different time points. Results showed that the formulation could achieve a good ascending drug release when the weight ratio of PAL was 5:1 (core:layer). The fraction of HPC and HPMC was 33 %, and the combination of Eudragit RL-PO was 10%. The ascending release mechanism was due to solvent penetration into the PAL CC tablets, and subsequent drug dissolution from the gelatinous HPC and HPMC matrix erosion. The release mechanism was therefore a combination of diffusion and erosion. This work demonstrated that the compression-coated tablets could achieve controlled ascending release over 24 h for the oral administration systems.

Design and Evaluation of Chronomodulated Drug Delivery of Tramadol Hydrochloride.

Rheumatoid arthritis is an auto immune disease which requires chronotherapy as it occurs during early morning. Tramadol hydrochloride (TH) is an analgesic drug, used to treat rheumatoid arthritis. The aim of the present investigation was to develop chronomodulated drug delivery system of tramadol hydrochloride such that it releases the drug early in the morning, during which the symptoms of rheumatoid arthritis worsen. To develop chronomodulated drug delivery system of TH, initially core tablets of TH were prepared using three different supradisintegrants followed by coating with pH dependent polymer of Eudragit S100. The prepared core tablets are evaluated for physical parameters and an optimal system was identified. Further, coating composition of Eudragit S100 was optimized and coating tablets of TH was prepared. The prepared coated tablets were evaluated for weight variation, hardness, drug content and in vitro release studies in 0.1N HCl, pH 6.8 phosphate buffer and pH 7.4 phosphate buffer. Formulation with 7.5% of coating solution (ES2) had shown a significant drug release after a lag time of 3 h (in pH 6.8 medium), 6 h (in pH 6.8 medium) and 8 h (in pH 7.4 medium), respectively. DSC studies revealed that no interaction between core and coated materials with drug was observed. Thus, chronomodulated drug delivery system of TH was formulated and assuming that if a tablet is administered around 9 pm to 10 pm, the drug release starts after a lag time of 6 h i. e., around 3am to 4 am.

FORMULATION DEVELOPMENT AND EVALUATION OF ELEMENTARY OSMOTIC TABLET OF LISINOPRIL DIHYDRATE

Objective: Lisinopril Dihydrate is one of the antihypertensive drug used to control the high blood pressure. Osmotically Controlled release tablet of Lisinopril Dihydrate was performed for reducing dosing frequency and patient compliance.Methods: Elementary osmotic tablets of Lisinopril Dihydrate were developed using Sodium chloride as a key ingredient which gives osmogent property which provides driving force inside the core tablet and which leads to release of the drug. Microcrystalline cellulose used as a release retardant material in the present work. Different formulations were prepared by varying the concentrations using 32 factorial designs. It was applied to see the effect of variables Sodium chloride (X1) and MCC (X2) on the response percentage drug release as a dependent variable. These formulations were evaluated for, Hardness, Flow property, Thickness, Friability, Drug content and In vitro drug release. Tablets were coated with a semipermeable membrane using 5% w/v cellulose acetate(CA) in acetone and PEG 400(1%) used as Plasticizer. Coated Elementary osmotic tablets were drilled for delivery orifice using a standard micro drill of diameter size 0.8 mm.Results: Drug release rate was increased as the increase in the concentration of sodium chloride and release rate decreased on increasing the concentration of MCC. Drug release rate was directly proportional to delivery orifice size. SEM Study carried out for detection of diameter size of the delivery orifice. The FTIR studies demonstrate that there was no interaction between polymer and drug.Conclusion: The optimized formulation was stable for 3 mo of accelerated stability study

Mathematical modelling of water absorption and evaporation in a pharmaceutical tablet during film coating

It is well understood that during the pharmaceutical aqueous film coating process the amount of liquid water that interacts with the porous tablet core can affect the quality of the final product. Therefore, understanding and simulating the mechanisms of water droplet spreading, absorption and evaporation is crucial for controlling the process and optimising the shelf-life of the tablets. The purpose of the work presented in this paper is to define and describe the spreading, absorption and evaporation phenomena after droplet impingement on a tablet. We divided the droplet behaviour into three phases of different dynamics and duration: the kinematic, capillary and evaporation phases. To model the kinematic phase, we combined and modified 1-D spreading models from the literature which solve the kinetic energy balance equation for the first milliseconds of spreading. For the capillary phase, we simplified and solved the continuity and Navier-Stokes equations using the lubrication approximation theory. Finally, for the evaporation phase, we adopted a modelling approach for the second drying stage of slurry droplets inside a spray dryer. During this stage, one can no longer describe the droplet as a liquid system containing solids, having to regard it as a wet particle with a dry crust and a wet core. In our work, we represented in a novel way the crust as the dry surface of the tablet and the wet core as the wetted area inside the porous matrix. We implemented the mathematical model presented in this work in gPROMS, employing the Modelbuilder platform. Our numerical results (droplet height and spreading, wetting, evaporation front profiles) are in good agreement with recent experimental data that we found in the literature.

DEVELOPMENT AND EVALUATION OF CONTROLLED RELEASE FORMULATION OF LAMIVUDINE BASED ON MICROPOROUS OSMOTIC TABLET TECHNOLOGY USING FRUCTOSE AS OSMOGEN

The present study was undertaken to develop controlled release osmotic pump tablets of lamivudine a nucleoside reverse transcriptase inhibitor for the treatment of acquired immune deficiency syndrome (AIDS).The tablets were prepared by wet granulation method using controlled release polymer hydroxyl propyl methyl cellulose (HPMCE5 LV), MCC as diluent, starch as binder and fructose as osmogen. The coating solution of core tablets were prepared by using cellulose acetate,poly ethylene glycol 400,600,4000,6000 and acetone to quantity sufficient with sorbitol for different batches. The prepared tablets were evaluated for pre compression parameters, post compression parameters, in vitro drug release study and scanning electron microscopy study. Among the prepared formulations LF4 batch show 97.78% drug release in 12hrs.The in vitro release kinetics were analyzed for different batches by different pharmacokinetic models such as zero order, first order,Higuchi,Korsmeyer Peppas and Hixon Crowell model. Short term stability study at 40±2oC/75±5% RH for three months on the best formulation was performed showing no significant changes in thickness, hardness, friability, drug content and in vitro drug release.

A photochemical kinetic model for solid dosage forms

Photochemical kinetic models to describe the solution phase degradation of pharmaceutical compounds have been extensively reported, but formalisms applicable to the solid phase under polychromatic light have not received as much attention. The objective of this study was to develop a mathematical model to describe the solid state photodegradation of pharmaceutical powder materials under different area/volumetric scales and light exposure conditions. The model considered the previous formalism presented for photodegradation kinetics in solution phase with important elements applied to static powder material being irradiated with a polychromatic light source. The model also included the influence of optical phenomena (i.e. reflectance, scattering factors, etc.) by applying Beer-Lambert law to light attenuation, including effects of powder density. Drug substance and drug product intermediates (blends and tablet cores) were exposed to different light sources and intensities. The model reasonably predicted the photodegradation levels of powder beds of drug substance and drug product intermediates under white and yellow lights with intensities around 5–11kLux. Importantly, the model estimates demonstrated that the reciprocity law for photoreactions was held. Further model evaluation showed that, due to light attenuation, the powder bed is in virtual darkness at cake depths greater than 500μm. At 100μm, the photodegradation of the investigated compound is expected to be close to 100% in 10days under white fluorescent halophosphate light at 9.5kLux. For tablets, defining the volume over exposed surface area ratio is more challenging. Nevertheless, the model can consider a bracket between worst and best cases to provide a reasonable photodegradation estimate. This tool can be significantly leveraged to simulate different light exposure scenarios while assessing photostability risk in order to define appropriate control strategy in manufacturing.

Atomic layer deposition—A novel method for the ultrathin coating of minitablets

We introduce atomic layer deposition (ALD) as a novel method for the ultrathin coating (nanolayering) of minitablets. The effects of ALD coating on the tablet characteristics and taste masking were investigated and compared with the established coating method. Minitablets containing bitter tasting denatonium benzoate were coated by ALD using three different TiO2 nanolayer thicknesses (number of deposition cycles). The established coating of minitablets was performed in a laboratory-scale fluidized-bed apparatus using four concentration levels of aqueous Eudragit® E coating polymer. The coated minitablets were studied with respect to the surface morphology, taste masking capacity, in vitro disintegration and dissolution, mechanical properties, and uniformity of content. The ALD thin coating resulted in minimal increase in the dimensions and weight of minitablets in comparison to original tablet cores. Surprisingly, ALD coating with TiO2 nanolayers decreased the mechanical strength, and accelerated the in vitro disintegration of minitablets. Unlike previous studies, the studied levels of TiO2 nanolayers on tablets were also inadequate for effective taste masking. In summary, ALD permits a simple and rapid method for the ultrathin coating (nanolayering) of minitablets, and provides nanoscale-range TiO2 coatings on porous minitablets. More research, however, is needed to clarify its potential in tablet taste masking applications.

Bioenhanced advanced third generation solid dispersion of tadalafil: Repurposing with improved therapy in pyelonephritis

Tadalafil (TDL) a BCS-II drug is recently reported for repurposing nephroprotective effect in Pyelonephritis (PN). However, poor water solubility and dissolution rate limited oral bioavailability pose serious challenges in its therapeutic applications. We present an advanced third generation Solid Dispersion (SD) of TDL comprising a polymer in combination with a Self Micro-emulsifying Composition (SMEC) to achieve high drug loading, improved stability and rapid dissolution of TDL for enhancing bioavailability and efficacy in PN. TDL-SMEC-SD was coated onto rapidly disintegrating inert tablet cores which disintegrated rapidly in water to release SD as a film. TDL-SMEC-SD was evaluated for in-vivo oral bioavailability and in-vivo efficacy in lipopolysaccharide-induced PN in rats. TDL exhibited high solubility (45.6 mg/ml) in the SMEC. TDL-SMEC-SD exhibited remarkably high TDL loading (45%w/w), exceptionally low contact angle (9°), rapid in-vitro release (t50 7.3 min), microemulsion formation (globule size ~100 nm) in aqueous dispersion, and stability as per ICH guidelines. SEM, DSC, and XRD confirmed high physical stability. A relative bioavailability of 350% and 150% compared to TDL and TDL-SD without SMEC respectively, established the superiority of TDL-SMEC-SD. A significant reduction in serum creatinine, blood urea nitrogen and nitric oxide levels in the lipopolysaccharide-induced PN confirmed the benefit of the TDL-SMEC-SD. The advanced third generation SMEC SDs presents the possibility of platform technology for bioenhancement of poorly water soluble drugs.

Comparative Evaluation and Optimization of Film Coating Formulation Variables and Delayed Release Properties of Three Enteric Polymers on Diclofenac Sodium Core Tablets

Enteric coatings present surfaces that have low permeability in the low pH environments of the stomach and release drug from the underlying core when they reach more neutral to alkaline environments of the intestinal milieu. However, the degree of ester substitution in the polymers, resulting in varied pH/dissolution behaviour, affects the rate and extent of drug release, the suitability of methods to be used and the overall cost of medication. In this study, hydroxypropyl methylcellulose phthalate (HPMCP) and two polymethacrylates, Wangit L30D-55® and Wangit L-100® were investigated for their enteric coating properties using diclofenac sodium tablets as core. Both polymers showed acid protective effect at the weight gain of 6%. Polymethacrylate based coatings showed somewhat better surface characteristics and drug release properties than HPMCP. The coating performance of the polymers was found to be better with lower and medium concentration of plasticizer to polymer ratio. The in vitro drug release profiles of the polymethacrylates showed cumulative drug release of 1.72% and 1.69% in 0.1 N HCl over 2 h of release study and 79.5% and 76.1% over 45 min in phosphate buffer pH 6.8, respectively. According to f2 test, the Wangit L30D-55® and Wangit L-100® coated tablets were similar to the two most commonly marketed products of diclofenac sodium 50 mg with f2 values of 66.66 and 70.88, respectively, for Marketed Product-1 (DilcoDenk®) and 59.9 and 58.74 for Marketed Product-2 (Remethan®). The results of the study showed that the polymethacrylates provide better tablet coating properties.Keywords: enteric coating, hydroxypropyl methylcellulose phthalate, polymethacrylates, diclofenac sodium, optimization