title: Emulsification/internal gelation as a method for preparation of diclofenac sodium-sodium alginate microparticles.
abstract: Emulsification/internal gelation has been suggested as an alternative to extrusion/external gelation in the encapsulation of several compounds including non-steroidal anti-inflammatory drugs such as diclofenac sodium. The objective of the present study was a trial to formulate diclofenac sodium as controlled release microparticles that might be administered once or twice daily. This could be achieved via emulsification/internal gelation technique applying Box-Behnken design to choose these formulae. Box-Behnken design determined fifteen formulae containing specified amounts of the independent variables, which included stirring speed in rpm (X1), drug:polymer ratio (X2) and the surfactant span 80% (X3). The dependent variables studied were cumulative percent release after two hours (Y1), four hours (Y2) and eight hours (Y3). The prepared microparticles were characterized for their production yield, sizes, shapes and morphology, entrapment efficiency and Diclofenac sodium in vitro release as well. The results showed that the production yield of the prepared diclofenac sodium microparticles was found to be between 79.55% and 97.41%. The formulated microparticles exhibited acceptable drug content values that lie in the range 66.20-96.36%. Also, the data obtained revealed that increasing the mixing speed (X1) generally resulted in decreased microparticle size. In addition, scanning electron microscope images of the microparticles illustrated that the formula contains lower span concentration (1%) in combination with lower stirring speed (200 rpm) which showed wrinkled, but smooth surfaces. However, by increasing surfactant concentration, microspheres' surfaces become smoother and slightly porous. Kinetic treatment of the in vitro release from drug-loaded microparticles indicated that the zero order is the drug release mechanism for the most formulae.
authors: Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut, Egypt.
authors: Mahmoud M
authors: MM
authors: Ahmed
authors: Saleh Abd
authors: SA
authors: El-Rasoul
authors: Sayed H
authors: SH
authors: Auda
authors: Mohamed A
authors: MA
authors: Ibrahim
keywords: Box–Behnken design; Diclofinac sodium; Internal gelation; Microparticles; Sodium alginate
references: Colloids Surf B Biointerfaces. 2010 Dec 1;81(2):521-9
references: 20732796
references: Int J Pharm. 2007 Aug 16;341(1-2):230-7
references: 17507189
references: Int J Pharm. 2002 Jun 4;239(1-2):81-91
references: 12052693
references: Eur J Pharm Biopharm. 2000 Mar;49(2):103-9
references: 10704892
references: Int J Pharm. 2001 May 7;218(1-2):1-11
references: 11337145
references: Eur J Pharm Biopharm. 2007 Mar;65(3):354-62
references: 17150342
references: Int J Pharm. 2006 Mar 27;311(1-2):1-10
references: 16442757
references: Int J Pharm. 2002 Aug 21;242(1-2):259-62
references: 12176259
references: Adv Drug Deliv Rev. 2001 Dec 31;53(3):321-39
references: 11744175
references: Eur J Pharm Sci. 2003 Mar;18(3-4):221-9
references: 12659933
references: J Microencapsul. 2006 May;23(3):245-57
references: 16801237
references: J Pharm Sci. 1963 Feb;52:162-4
references: 13954439
references: Eur J Pharm Biopharm. 2001 Mar;51(2):111-8
references: 11226817
references: Int J Pharm. 2003 Apr 30;256(1-2):43-52
references: 12695010
references: Res Pharm Sci. 2010 Jan;5(1):29-39
references: 21589766