Release Rate Of Indomethacin Research Articles

Design and release kinetic pattern evaluation of indomethacin microspheres intended for oral administration

Indomethacin has been incorporated into either ethylcellulose (EC) or Eudragit RL microspheres by a solvent-evaporation process. Production variables have been tested in an attempt to produce indomethacin microspheres having adequate oral controlled-release properties. In spite of high drug content in the ethylcellulose microspheres, the indomethacin release rate was too slow and incomplete. Although the addition of an hydrophilic polymer, polyethylene glycol), to the EC polymer enhanced the indomethacin release rate, it was not possible to reach release profiles suitable for oral use. Therefore, indomethacin was incorporated into a more permeable polymer, Eudragit RL. While incorporation efficiency decreased with increasing initial concentration of indomethacin, adequate oral-release profiles were achieved. It was found that all the global-release profiles yielded by the indomethacin-loaded Eudragit RL microspheres conformed to the Higuchi diffusional model of dispersed drug particles in spherical micromatrices and not to the desorption kinetic model of a dissolved drug from a monolithic spherical device.

市販インドメタシン坐剤の放出特性と家兎における直腸吸収

The release rates of indomethacin from 5 kinds of commercially available suppositories were compared by using three different methods, i.e., dialysis cell, membrane diffusion, and cylindrical filter paper.The release from each fatty base by the method of membrane diffusion was about 30% for labeled amount after 120min, and that from each macrogol base was 23%.By dialysis cell method, indomethacin released from macrogol base was about 80% after 120min, whereas that from fatty base was 26-37%. The maximum plasma concentrations of indomethacin after rectal administration of both products A and B composed of macrogol base to rabbits was 31.8μg/ml, and those of products C, D, and E of fatty base were 21.4, 15.0, and 34.7μg/ml, respectively.The in vitro release rate was not concerned in the plasma concentration of indomethacin.It was found that the volume of suppository markedly influenced the rectal absorption, because correlation coefficient between the maximum plasma concentration of indomethacin and the volume of suppository was 0.932.

透析チューブ法によるレクタルカプセル剤からの薬物放出試験

The release of indomethacin from 3 kinds of rectal capsules was investigated by 2 different dialysis tubing methods, i.e., stationary method and up-and-down motion method. In the case of stationary method, any release rate of indomethacin from rectal capsules was much slower than that from suppositories, and the amount of the release during 2 hrs was within 8% of the labeled amount. The release of the drug from rectal capsule was not improved by the addition of water into the dialysis tubing, or by sinking deeply the dialysis tubing to spread out the contents in rectal capsule. However, by the up-and-down motion of dialysis tubing using disintegration test apparatus, the release rate was 2-3 times higher than that by the stationary method.The data from this experimental condition was well reproducible. The technique could be applied to test the release of drug from both rectal capsule and suppository.

Sustained-release and intragastric-floating granules of indomethacin using chitosan in rabbits.

The release rate of indomethacin from chitosan granules was compared with that of conventional commercial indomethacin capsules and a sustained-release capsule. In contrast with the rapid release of a commercial conventional capsule form, sustained release from the chitosan granules was observed. Furthermore, the release rate could be controlled by changing the mixing ratio of drug and chitosan.The potential of chitosan granules as an oral sustained-release dosage form of indomethacin was investigated in rabbits. When a conventional commercial capsule was administered orally to rabbits, the plasma concentration reached the maximum level 1 h after administration. In the case of the granules with a 1: 2 mixture of drug and chitosan, the chitosan granules did not give a sharp peak of plasma concentration, but produced a sustained plateau level of indomethacin. The area under the plasma concentration curve (AUC)(0-8 h) value of chitosan granules showed a slightly higher value than that of commercial capsules. This may be due to the slow rate of release from the chitosan granules and the longer residence time in the stomach.Thus, in terms of decrease in the peak of plasma concentration and maintenance of indomethacin concentration in plasma, the chitosan granules were superior to the conventional commercial capsules. Indomethacin granule preparations using chitosan may be practically useful as oral preparations with reduced side effects and with prolonged action.

Release Rate of Indomethacin from Coated Granules

The purpose of this investigation was a study on sustained release coated granules manufactured by means of the air-suspension coating technique. The smoothed 12/20-mesh fractions of indomethacin granulation containing povidone as a binder were coated in a modified air-suspension coater with film of ethylcellulose-glyceryl monostea-rate mixture at various percents by weight of coat. The kinetics of drug release was determined and appears to conform to the first-order fashion. The relationship between the coating weight and the first-order release rate constant was developed and found to be in the form of exponential function.

Effect of the molecular weight of polyethylene glycol on the bioavailability of indomethacin sustained-release suppositories prepared with solid dispersions.

Conventional suppositories were prepared by using polyethylene glycol (PEG) alone, and sustained-release suppositories were prepared by using hydroxypropylmethylcellulose phthalate (HP55) -PEG 1000, 2000 and 4000 matrices. The effect of the molecular weight of PEG on the in vitro release characteristic and bioavailability in rabbits of indomethacin (IM) in those suppositories was investigated. The release rate of IM from the conventional and matrix suppositories decreased slightly with increase of the molecular weight of PEG. The bioavailability of the conventional suppositories was independent of the molecular weight of PEG, but the bioavailability of the matrix suppositories decreased with increase of the molecular weight of PEG.

Preparation and in Vitro Evaluation of Controlled Release Dosage form of Indomethacin

AbstractA controlled release oral drug delivery system of Indomethacin was developed using gelatin as the matrix system, which was rigidized with different concentrations of formalin, without using alcohol. The proportion of drug and gelatin as well as the concentration of formalin had the pronounced effect on the Indomethacin release rate and the patterns of which depicted that they correlated with Lang primary requirements for drug release from controlled release dosage forms. All the types of formulations showed release rate patterns that could best be described by First Order Kinetics, indicating that First Order release was mainly operative.

Medicament Release from Ointment Bases: I. Indomethacin. In Vitro and in Vivo Release Studies

The in vitro release of indomethacin from 1%, 3%, and 5% indomethacin ointments and its in vivo absorption through the skin of rabbits was investigated. The in vitro release of indomethacin followed zero-order kinetics and was better from an absorption base ointment. No significant differences (F=3.047 and P=0.079 for the absorption base) and (F=2.15 and P=0.14 for the hydrophilic base) in the release rate of indomethacin in 1%, 3%, and 5% indomethacin ointments were observed. Indomethacin was most effectively absorbed from absorption ointment bases. A correlation between the in vitro release and the in vivo absorption was found; also, a correlation between the in vivo release pattern of the bases used and the in vivo data reported in the literature was observed.

Release Test of Indomethacin Suppository from Macrogol Bases

Release of indomethacin from 6 kinds of commercially available macrogol suppositories (products A to F) was studied. The release profile of indomethacin from products A to E was similar. The amount released from each product during 150 min was more than 95%. However, the release of product F was considerably slow as compared with products A to E, and the release rate was 81% in 150 min. Indomethacin suppositories, prepared in different proportion of macrogols, were compared with products A to F. When the base was prepared with two macrogols, the release rate of indomethacin decreased with an increase of the content of macrogol 4000 or 6000. For the base composed of macrogol 6000 alone, indomethacin was released slowly. For macrogol suppositories studied, linear relations were found between the amount released and the square root of time. The values of lag time and release rate were obtained from each linear equation. These values were important to evaluate the release profile of drug from suppositories.

Development of Indomethacin Sustained Release Microcapsules using Ethyl Cellulose and Hydroxy Propyl Methyl Cellulose Phthalate by O/W Emulsification

Indomethacin (IM) sustained release microcapsules were successfully prepared using ethyl cellulose (EC) and hydroxy propyl methyl cellulose phthalate (HPMCP) by o/w emulsification-solvent evaporation technique. The prepared microcapsules were evaluated for size, shape, drug content and in vitro drug release. The microcapsules show sustained release curves at pH 7.2 phosphate buffer for up to 6 h. The data obtained from the dissolution profiles were compared in the light of different kinetics models and the regression coefficients were compared. The in vitro dissolution study confirmed the Higuchi-order release pattern. Particle size and release data analysis from five consecutive batches prepared in the laboratory indicated suitable reproducibility of the solvent evaporation process. The release rate increased exponentially with the addition of HPMCP in EC. IM release rate was observed highest with the highest concentration of HPMCP (3:7 ratio of EC:HPMCP), used in the present studies. On the other hand, IM release rate was lowest when EC and HPMCP combination was used at the ratio of 10:0. When percent of HPMCP was increased, the particle size of microcapsules was decreased. Key words: Indomethacin, sustained release, microcapsule, HPMCP, EC, Higuchi-order  DOI = 10.3329/dujps.v7i1.1223 Dhaka Univ. J. Pharm. Sci. 7(1): 83-88, 2008 (June)