5-fluorouracil loaded guar gum microspheres for colon delivery: preparation, characterization and in vitro release / 药学学报

The present investigation is aimed to develop a new formulation containing chemically crosslinked guar gum microspheres loaded with 5-fluorouracil for targeting colorectal cancer. The emulsification polymerization method involving the dispersion of aqueous phase of guar gum in castor oil was used to prepare spherical microspheres. Various processing parameters were studied in order to optimize the formulation. Particle size and surface morphology of the microspheres were determined using optical microscopy and scanning electron microscopy. The in vitro drug release studies performed in simulated gastric fluid (SGF) for 2 h followed by intestinal fluid for 3 h, revealed the retention of the drug inside the microspheres from which only (15.27 +/- 0.56) % of the drug was released in 5 h. In vitro release rate studies were also carried out in simulated colonic fluid (SCF) in the presence of rat caecal contents, which showed improved drug release. The drug release from the formulation was found to be (41.6 +/- 3.5) % with 2% (w/v) caecal matter in 24 h as compared to control study where (25.2 +/- 3.5) % of drug was released. The drug release from the formulation with 2% and 4% rat caecal contents medium after 2 days of enzyme induction was found to be (56.3 +/- 4.1) % and (78.9 +/- 2.8) % in 24 h respectively. Similarly, (61.3 +/- 5.4) % and (90.2 +/- 2.9) % drug was released respectively with 2% and 4% rat caecal matter after 4 days of enzyme induction and (72.1 +/- 2.9) % and (90.2 +/- 3.2) % after 6 days of enzyme induction. In this way, 5-fluorouracil loaded guar gum microspheres have shown promising results in the management of colorectal cancer, warranting thorough in vivo study for scale up technology.

Effect of ciprofloxacin and chloramphenicol on humoral immune response elicited by bovine albumin encapsulated in niosomes / 药学学报

The aim is to evaluate the effect of ciprofloxacin and chloramphenicol on anti-BSA antibody production triggered by bovine albumin encapsulated in non-ionic surfactant vesicle, niosomes. Reverse phase evaporation method was adopted to entrap the antigen in colloidal carrier composed of Span 80 and Span 85 followed by simultaneous characterization for particle size, entrapment efficiency and in vitro release. The protein content was determined by Bradford method using UV Visible Spectrophotometer at 595 nm. Humoral immune response was measured in terms of systemic IgG antibody titre by ELISA method. Experimental data indicated that 7 : 3 molar ratio of Span 80 and cholesterol based niosomal formulation possessed maximum (39.8 +/- 2.9)% of soluble protein. Ciprofloxacin markedly (P < 0.05) decreased the antibody titre. In contrast, chloramphenicol did not reduce the antibody titre significantly in comparison to control group (P > 0.05). It is necessary to explore the effect of a vaccine antigen when a candidate is medicated with a therapeutic agent, which might help in programming a new drug management and vaccination programme.