Diclofenac sodium release

The dynamic neural networks are used to model the diclofenac sodium release from polyethylene oxide (PEO) hydrophilic matrix tablets [15]. 

Nakhare S, Vyas SP. 1996. Preparation and characterization of multiple emulsion based systems for controlled diclofenac sodium release. / Microencapsu 13(3) 281-292. 

Zupancic Bozic D, Vrecar F, Kozjek F. Optimization of diclofenac sodium dissolution from sustained release formulations using an artificial neural network. Eur... 

Schneeweis, A., and Mueller-Goymann, C.C., In vivo and in vitro diclofenac sodium evaluation after rectal application of soft gelatine capsules enabling application induced transformation (AIT) into a semisolid system of liquid crystals (SSLC) for controlled release, Pharm. Res., 14 1726-1729 (1997). 

Rheumatoid arthritis - 150 to 200 mg/day in divided doses (50 mg 3 or 4 times/day [diclofenac sodium or potassium] or 75 mg twice/day [diclofenac sodium]). Dosages greater than 225 mg/day of the delayed-release diclofenac sodium formulation and dosages greater than 200 mg/day of immediate-release diclofenac potassium formulation are not recommended. 

Table 11 contains the pertinent parameter estimates and the residual error for each release model. From these results and from Figs 4, 5 and 6 it can be concluded that the release of diclofenac sodium is fitted by the Weibull distribution. P>1 (P being the shape parameter) is characteristic for a slower initial rate (diclofenac sodium is insoluble at pH 1.2) followed by an acceleration to the final plateau (sigmoid). In the direct compression optimization, after infinite time, the fraction released (F.rJ is estimated to be only 90% [13]. 

From a minimum number of experiments, the Hadamard matrix gives the possibility of estimating the mean effects of four parameters. Among them, the particle size range had the most important effect in the release of diclofenac sodium. By interpreting data, a factorial design including only two parameters was applied from which an optimum formulation was found. 

The particle size range, when indicated in the model, demonstrated the most important effect on the liberation of diclofenac sodium. In the case of the separate compaction process, as the particle size range of the drag increased and the particle size range of PVC decreased, a prolonged release effect was observed [4]. 

The buccal permeability of the non-steroidal antiinflammatory drug, diclofenac sodium, has been evaluated in a dog model. The dog was selected because of the similarity of its buccal mucosa to that of man. Analysis of the buccal data indicated that diclofenac sodium permeability followed an essentially zero-order kinetic process with a minimal lag phase. Permeability of the drug was estimated to be 3 mg/cm2.h but significant differences were observed between animals. The absorption rate with the transbuccal delivery device decreased with time whereas the corresponding rate with a saturated solution was constant. This difference was attributed to the time dependency of drug delivery from the device and was modeled on the basis of release from a membrane-dispersed monolith combined with constant buccal permeability. The predictions of the model showed excellent agreement with the experimental data. 

The cumulative release profile for diclofenac sodium from the transbuccal delivery device exhibited a square root of time dependency over approximately 80% of the total release process (Figure 3). In view of the drug s solubility within the hydrogel ( 16 mg/cc) and the total loading (-420 mg/cc), dyjg2release was modelled as a dispersed monolith and a 3.19 x 10 cm /h diffusion coefficient was calculated. 

H. Velasco, M. V., Ford, J. L., Rowe, P., and Rajabi-Siahboomi,A. R. (1999), Influence of drug hydroxypropylmethylcellulose ratio, drug and polymer particle size and compression force on the release of diclofenac sodium from HPMC tablets, I. Controlled Release, 57, 75-85. 

Miyagawa, Y. Okabe, T. Yamaguchi, Y. Miyajima, M. Sato, H. Sunada, H. Controlled-Release of diclofenac sodium from wax matrix granule. Int. J. Pharm. 1996, 138, 215-224. 

Deakin M. Small bowel perforation associated with an excessive dose of slow release diclofenac sodium. BMJ 1988 297(6646) 488-9. 

Mirghani A, Idkaidek NM, Salem MS, Najib NM. Formulation and release behavior of diclofenac sodium in Compritol 888 matrix beads encapsulated in alginate. Drug Dev Ind Pharm 2000 26(7) 791-795. 

Gursoy A, Cevik S. Sustained release properties of alginate microspheres and tabletted microspheres of diclofenac sodium. ] Microencapsul 2000 17(5) 565-575. 

Sujja-areevath J, Munday DL, Cox PJ, Khan KA. Release characteristics of diclofenac sodium from encapsulated natural gum minimatrix formulations. Int Fharm 1996 139 53-62. 

Sabnis S, Rege P, Block LH. Use of chitosan in compressed tablets of diclofenac sodium inhibition of drug release in an acidic environment. Pharm Dev Technol 1997 2 243—255. 

Wang DP, Yang MC, Wong CY. Formulation development of oral controlled release pellets of diclofenac sodium. Drug Dev Ind Pharm 1997 23 1013-1017. 

Billa N, Yuen KH, Khader MA, Omar A. Gamma scintigraphic study of the gastrointestinal transit and in vivo dissolution of a controlled release diclofenac sodium formulation in xanthan gum matrices. Int J Pharm 2000 201 109—120. 

Bravo S, Lamas MC, Salomon CJ. Swellablc matrices for the controlled-release of diclofenac sodium Formulation and in vitro. studies. Pharm Dev Tech 2004 9(l) 75-83. 

Diclofenac Potassium and Sodium. Diclofenac. sodium. sodium [o-(2.6-dichluroanilino)phenyl acetate (Vul-taren). is indicated for short- and long-term treatment of RA. OA, and ankylo.sing spondylitis. The potassium salt (Ca-taflam). which is faster acting, is indicated fur the management of acute pain and PD. The sodium salt is available as delayed-release tablets (25. 50. 75. and 100 mg), with a recommended daily dose of l(X) to 2(X) mg in divided doses. The potassium salt is available as a tablet (50 mg), with a reeommended duse of 50 mg 3 times daily. 

Figure 11.2 shows the influence of drug solubility on release profiles for chlorpheniramine maleate, diclofenac sodium and theophylline from a Methocel K4M CR matrix formulation, keeping all other matrix composition and properties constant [46], As aqueous solubility of the drug decreased, drug release rate also... 

Another example of assay testing involves diclofenac sodium, which is a synthetic analgesic and an anti-inflammatory drug available as delayed release tablets (Fig. 8). ... 

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