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.

Development of sericin/alginate particles by ionic gelation technique for the controlled release of diclofenac sodium

“…The drug entrapment efficiency (DEE) was calculated by eq. . All determinations were carried out in triplicate.…”

Probing insulin bioactivity in oral nanoparticles produced by ultrasonication-assisted emulsification/internal gelation

“…20 Furthermore, cosurfactant addition has been shown to make particles smoother and slightly porous in previous studies. 73 Insulin retention/release studies Insulin release from nanoparticles was studied as a function of time in enzyme-free simulated digestive fluids as illustrated in Figure 6. Insulin-loaded nanoparticles showed the protective effect of biopolymers at the beginning in simulated gastric fluid during the first 2 hours.…”

PsychrotrophicStreptomycesspp. cells immobilisation in alginate microspheres produced by emulsification–internal gelation

“…Microspheres were recovered from the oily phase by Vacuum Filtration Equipment (Agilent Technologies, Inc., Santa Clara, CA) and successively washed with 0.2 M acetate buffer at pH 4.5 until no more oil was detected by optical microscope observation (Silva et al, 2006;Ahmed et al, 2013). Microspheres were dried for 48 h at room temperatures in a desiccator and stored there for further experiment (Ahmed et al, 2013). The moisture content of microspheres was determined using the gravimetric method (AOAC, 1980).…”

“…Microspheres having 5100 mm can be produced by this technique by dispersing an alginate solution containing insoluble calcium salt into an oil. Gelation is achieved by gentle acidification with an oil-soluble acid that causes calcium ion release (Silva et al, 2006;Ahmed et al, 2013). One of the most suitable carriers for cell immobilisation is entrapment in calcium alginate, because this technique is simple and cheap (Anisha and Prema, 2008).…”