Due to the diversity of polymers as well as their complex behavior, research in this field is still widely developed. Because biodegradable polymers become decomposed in the human body after decomposition, they are more commonly used because surgery is not required to remove these polymers from the body after the drug is released. Understanding the mechanism, modeling and studies of drug release from homopolymers, copolymers and mixtures of this family of polyesters is the focus of this research. In this research, the release of drug from homo and biodegradable copolymer in pure form with drug and finally the mixture of the two with drug has been investigated to determine the differences. In the proposed model, the equations that represent the degradation of the polymer are used to be able to predict the degradation of the polymer. The drug used is paclitaxel, which is a very important drug for chemotherapy. Since this drug is administered every 3 weeks for 3 hours, it is necessary to use controlled systems. Therefore, the purpose of this study is to achieve a predictable model for controlled release of paclitaxel, so that this model responds to the release of paclitaxel at any time.

This study examines the controlled release behavior of both water-soluble (acetaminophen, caffeine, theophylline and salicylic acid) and water insoluble (indomethacin) drugs derived from Caesalpinia pulcherrima seed Gum isolated from Caesalpinia pulcherrima kernel powder. It further investigates the effect of incorporating diluents such as microcrystalline cellulose and lactose on caffeine release. In addition the effect the gum’s (polysaccharide) partial cross-linking had on release of acetaminophen was examined. Applying the exponential equation, the soluble drugs mechanism of release was found to be anomalous. The insoluble drugs showed a near case II or zero order release mechanism. The rate of release in descending order was caffeine, acetaminophen, theophylline, salicylic acid and indomethacin. An increase in the release kinetics of the drug was observed on blending with diluents. However, the rate of release varied with the type and amount of blend within the matrix. The mechanism of release due to effect of diluents was found to be anomalous. The rate of drug release decreased upon partial cross-linking and the mechanism of release was found to be of super case II.

In recent years, research in the field of pharmaceutical sciences has led to the design of drugs for various diseases. But for the treatment of some diseases, drugs with high side effects and low efficiency are used. Designing targeted drug release systems is one of the solutions to this problem. These systems can deliver a controlled amount of drug to the target cell or tissue. In this paper, drug release was simulated in a screw model designed in Comsol software for orthopedic applications. The purpose of this simulation is to investigate the distribution of the drug concentration on the screw in the surrounding chamber over time. To simulate drug release in a fluid, Navier-Stokes equations for incompressible fluid are used for fluid velocity and pressure, as well as mass transfer equations for the drug concentration distribution. A tetrahedral mesh is used for meshing the model. This simulation is performed in a time-dependent manner for 72 hours with time steps of 0. 1 hours. The equations have been solved directly with the PARDISO solver. The obtained results show that drug distribution changes exponentially. As can be seen, the first release of the drug was incremental to 50 hours, and after the release amount, it reached a constant and maximum value.

Gel dosage forms are successfully used as drug delivery systems considering their ability to control drug release and to protect medicaments from a hostile environment. The aim of this work was to investigate the properties of carbopol 934P polymeric system in water-misible co solvents such as glycerin and alcohol. Benzocaine is a local anesthetic and the mucosal gel formulation is applied in the treatment of dental pain. Samples were prepared by simply dispersing different amounts of Carbopols (0.5-3%) into the alcoholic solution at the room temperature and were kept at 4,25 and 40 C. All these systems were then characterized for distribution, bioadhesiveness on the mucosa, physical stability and drug release. The silastic membrane was employed. The membrane must not be a barrier for drug transport. Franz diffusion cell used to study in vitro drug release. The increase in carbopol concentration caused increased viscosity and bioadhesiveness. Neutralization of pH in various concentrations of carbopol gels showed resulted in increased viscosity. A relationship between the viscosity and bioadhesive strength was shown in the neutralized carbopol gels. On the other hand, the results indicated that increasing amount of alcohol and glycerin reduced drug release. In contrast, by increasing the amount of water, elasticity and release rate was increased. Vision-gel was used as a reference for comparison with the oromucosal gel formulation. The results showed that diffusion of benzocaine from oromucosal gel and commercial sample followed Higuchi law.

Background: The purpose of this in vitro study was to investigate drug release kinetics and cytotoxicity of a novel drug delivery system for treatment of periodontitis. Materials and Methods: This in vitro study addresses the fabrication of a polycaprolactone/ alginic acid‑, based polymeric film loaded with metronidazole, as a basic drug in the treatment of periodontal diseases. Films were prepared by solvent casting technique. Four formulations with different percentages of drug by weight (3%, 5%, 9%, and 13%) were prepared. Drug release kinetics were investigated using ultraviolet–, visible spectroscopy during (one week). Data were analyzed using repeated measures ANOVA. Cytotoxicity of drug‑, loaded system extracts was evaluated by 3‑, (4, 5‑, dimethylthiazol‑, 2‑, yl)‑, 2, 5‑, diphenyltetrazolium bromide (MTT) assay using L929 cells after 24‑, h incubation. The results were evaluated according to ISO standard 10993‑, 5 and assessed using ANOVA and Tukey’, s tests at a significance level of P < 0. 05. Results: All polymeric films showed a burst drug release followed by a gradual release. Drug release data were fitted well with the first‑, order kinetic model in all drug‑, containing formulations indicating that drug release is a fraction of remaining drug in the matrix. Drug release is mainly driven by diffusion of medium into the composite matrix. 3%wt metronidazole‑, containing formulation exhibited the best MTT result. Conclusion: The findings of this study supported the synthesis of drug‑, loaded periodontal films with 3% metronidazole due to better biological properties along with the ability of acceptable drug release to eradicate anaerobic periodontal bacteria.

Purpose: The main objective of the present study was to develop the colonic delivery system for 5-aminosalicylic acid (5-ASA) as an anti-inflammatory drug. Methods: Matrix pellets containing various proportions of alginate, calcium and Eudragit® RS were prepared by extrusion-spheronization technique. Thermal treatment was used to investigate the effect of the curing process on the surface morphology, mechanical and physicochemical properties and in vitro drug release profile of pellets. Based on the obtained results optimal formulations were selected to coating by the Eudragit® RS and subjected to a subsequent continuous dissolution test. Results: Image analysis and also scanning electron microscopy results proved acceptable morphology of the pellets. The fourier transform infrared spectroscopy and differential scanning calorimetry studies ruled out any interactions between the formulation’ s components. Curing process did not alter the mechanical properties of pellets. The release rate of the drug from matrices was prolonged due to the decreased porosity of cured pellets. Furthermore, selected cured pellets which coated with Eudragit® RS, prevented undesired premature drug release. Conclusion: Formulation containing 17. 5% calcium, 17. 5% alginate, and a coating level of 10% demonstrated enhanced drug release so that provided resistance to acidic conditions, allowing complete drug release in alkaline pH, mimicking colonic environment. The slow and consistent drug release from this formulation could be used for treatment of a broader range of Inflammatory bowel disease (IBD) patients especially in whom colonic pH levels have been measured at lower than pH 7. 0.

Objectives: Kinetic study of drug dissolution and release is of importance from different points of view including quality control, comparison, bioavailability of drug dosage forms and delivery systems. Thus, in the present work different kinetic models available in many scientific sources are reviewed analytically. Methods: Several equations and laws of dissolution and release were gathered from many sources. The models then were categorized into two general groups of applied to pure solids and conventional dosage forms as well as controlled release systems. Each group was further classified into subgroups for analytical purposes. Results: The analytical review indicates that the models are essentially based on theoretical, semi-theoretical and empirical principles. Also some of the models are applicable for all forms i.e. pure solids, conventional forms and controlled release systems. Conclusion: Depending on the processes involved, the drug dissolution and release kinetic models are versatile. The prominent mechanisms of the processes which determine the kind of suitable kinetic model are diffusion, dissolution, osmosis and combination of these phenomena.