Eudragit-coated pectin microspheres of 5-fluorouracil for colon targeting

Abstract

An objective of the present investigation was to prepare and evaluate Eudragit-coated pectin microspheres for colon targeting of 5-fluorouracil (FU). Pectin microspheres were prepared by emulsion dehydration method using different ratios of FU and pectin (1:3 to 1:6), stirring speeds (500-2000 rpm) and emulsifier concentrations (0.75%-1.5% wt/vol). The yield of preparation and the encapsulation efficiencies were high for all pectin microspheres. Microspheres prepared by using drug:polymer ratio 1:4, stirring speed 1000 rpm, and 1.25% wt/vol concentration of emulsifying agent were selected as an optimized formulation. Eudragit-coating of pectin microspheres was performed by oil-in-oil solvent evaporation method using coat:core ratio (5:1). Pectin microspheres and Eudragit-coated pectin microspheres were evaluated for surface morphology, particle size and size distribution, swellability, percentage drug entrapment, and in vitro drug release in simulated gastrointestinal fluids (SGF). The in vitro drug release study of optimized formulation was also performed in simulated colonic fluid in the presence of 2% rat cecal content. Organ distribution study in albino rats was performed to establish the targeting potential of optimized formulation in the colon. The release profile of FU from Eudragit-coated pectin microspheres was pH dependent. In acidic medium, the release rate was much slower; however, the drug was released quickly at pH 7.4. It is concluded from the present investigation that Eudragit-coated pectin microspheres are promising controlled release carriers for colon-targeted delivery of FU.

Microparticles for cell encapsulation and colonic delivery produced by membrane emulsification

“…Simulation of the gastro-intestinal transit conditions was obtained varying the pH of the dissolution medium over time: the acidic stomach fluid was reproduced using a pH 1.2 for 2 hours, afterwards a pH 7 (or pH 8) medium was used to mimic the intestinal-colon area for a maximum period of time of 3 hours (or up to complete particle dissolution) [18]. The dissolution medium was prepared from a phosphate buffer saline (PBS, Sigma Aldrich, UK) solution (pH 7), adjusting the pH with hydrochloric acid (Sigma Aldrich, UK), or sodium hydroxide (Sigma Aldrich, UK).…”

“…After a time of 30 minutes, the gelatin particles were completely dissolved and the content released in the surrounding medium. The pure gelatin microparticles did not meet the requirements for a gastro-resistant formulation: they did not protect the yeast cells from the acidic environment of the stomach for a period of at least 2 hours [18]. Therefore, the Edudragit S100 coating was added to the gelatin particles to preserve the gelatin polymer during the residence at pH 1.2; allowing dissolution of the particles only in a neutral, or basic, environment (pH between 7 and 8) typical of the intestinal-colonic area [17].…”

“…The pH dependent polymer Eudragit S100 is used in drug delivery for the production of colonic delivery systems [17]; it is an anionic copolymer based on methacrylic acid and methyl methacrylate which dissolves above pH 7. Eudragit coated microparticles were produced for the colonic release of therapeutics [16,18] or proteins [19], but it has not yet been applied for the coating of encapsulated cells. A variety of materials have been tested for the encapsulation of living cells; alginate [4,6,8,12,15,[20][21][22][23] is the most common and versatile, chitosan [9,23], gelatin [22,24], cellulose [23,25], agarose [23,26], dextran [1], carrageenan [9,12,27], poly(lactide-co-glycolide) (PLGA) [1,23], Poly (Ethylene Glycol) [23,28] all have been used individually, and in blends [1,27].…”

Evaluation of liposomes coated with a pH responsive polymer

“…The polymer Eudragit S100 was chosen as the coating material as it is widely used in both commercially available and experimental formulations for colonic targeting e.g. tablets (Khan et al, 1999 and2000), microspheres (Paharia et al, 2007) and capsules (Kraeling and Ritschel, 1992).…”

Lung-targeted delivery system of curcumin loaded gelatin microspheres

“…1), and the drug loading (DL) was obtained from the ratio of the amount of curcumin loaded in microspheres to the amount of C-GMS (Eq. 2) (Paharia et al, 2007).…”