Oral formulations of 5-fluorouracil (5-FU) with enhanced bioavailability were developed using microemulsion as a drug carrier system. The formulations were evaluated for drug content, physicochemical characteristics such as globule size, zeta potential, viscosity, stability and permeation characteristics. Ex vivo permeation studies were performed using non-everted rat intestinal sac technique. Results of the ex vivo permeation studies revealed that from aqueous solution only 25.08% drug was permeated, whereas, the optimized microemulsion formulation showed 97.5% drug permeation in 8 h, suggesting, approximately, four times enhancement in the drug permeability. Also a 7-fold increase in the flux of drug was observed from microemulsion formulation when compared with the aqueous solution. Further, in vivo pharmacodynamic studies were carried to check the therapeutic efficacy against benzo(a)pyrene [B(a)P]-induced stomach tumors in albino mice (Balb/C strain). The treatment of mice with 5-FU and microemulsion (5-FU II), after the last dose of B(a)P i.e. during the initiation period, resulted in 25% and 67% reduction in tumor incidence, respectively suggesting significant enhancement in the bioavailability and therapeutic efficacy of 5-FU when it was formulated as a microemulsion. These promising results suggest that microemulsion formulation of 5-FU may be used for the treatment of human cancers after pharmacokinetic and clinical evaluation.
Dendrimers represent a novel class of structurally controlled macromolecules derived from a branches-upon-branches structural motif. These consist of well defined, highly branched moieties that radiate from a central core and are synthesized through a stepwise, repetitive reaction sequence that guarantees complete shells for each generation, leading to formation of monodisperse polymers. The synthetic procedures developed for dendrimer preparation permit nearly complete control over the critical molecular design parameters, such as size, shape, surface/interior chemistry, flexibility, and topology by virtue of which these macromolecules offer diverse applications in drug delivery, solubility enhancement, gene therapy and diagnostic field. This article provides an insight into the structure, synthesis, properties, types and the applications of dendrimers in the bio-medical field.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.