Inappropriate oral formulations and information in paediatric trials.

Previously, quality of formulations information provided for oral medications used in paediatric clinical trials published in 10 highly cited journals between 2002 and 2004 raised concerns. This short report explores if there was any subsequent improvement on how the formulations used in trials involving children <12 years reported in the same journals. Studies published between 2004 and 2008 were hand-searched and classified as containing adequate, some or no formulation information. Those involving solid dosage forms were further analysed. Only 31% (44/140) of publications provided adequate information, 5% less compared to 2002-2004 (28/76). There was a significant 12% rise (p<0.05) of no formulation information at all (37/140) and in tablets/capsules use (53/140), of which 3/4 gave no administration details, even for those under 6 years old, but a 12% decline in suitable paediatric formulations use (52/140 compared to 37/76). Contrary to expectations, overall quality of formulation information reported markedly deteriorated, jeopardising validity of clinical outcomes. The situation may reflect continued lack of awareness among investigators and other stakeholders of the importance of using suitable age-appropriate formulations.

Antibody and cytokine-associated immune responses to S. equi antigens entrapped in PLA nanospheres.

Strangles is an infectious disease caused by Streptococcus equi subspecies equi that affects the upper respiratory tract of the Equidae. The control of this disease seems to be dependent on its earlier detection and prevention, but prolonged animal protection without development of strong and severe side effects has not yet been achieved. Convalescent horses exhibit a protective immune response, mainly against SeM (58 kDa), an antiphagocytic and opsonogenic S. equi M-like protein, known as the major protective antigen against strangles. Purified recombinant SeM and S. equi protein extract-entrapped poly(lactic acid) (PLA) nanospheres were developed and their adjuvant potential was studied via the intramuscular route. The effect including molecules with adjuvant properties such as spermine, oleic acid, alginate and glycol-chitosan was also evaluated. Spherical nanometric particles <500 nm containing the protein antigen were prepared by the solvent evaporation method and protein structure was not affected throughout preparation. The humoral immune response induced by nanospheres was markedly higher than that elicited by soluble antigens, isolated or co-admixed with CpG. The IgG and IgG subtypes, along with cytokine titres, indicated that nanospheres composed by glycolchitosan developed a more balanced Th1/Th2 response for both purified SeM and S. equi enzymatic extract proteins, although those induced by the pure antigen-entrapped particles were higher than the S. equi tested vaccines composed by total antigens entrapped in polymeric nanospheres.

Enhancement of immune response of HBsAg loaded poly (L-lactic acid) microspheres against hepatitis B through incorporation of alum and chitosan.

PURPOSE: Poly (L-lactic acid) (PLA) microparticles encapsulating Hepatitis B surface antigen (HBsAg) with alum and chitosan were investigated for their potential as a vaccine delivery system. METHODS: The microparticles, prepared using a water-in-oil-in-water (w/o/w) double emulsion solvent evaporation method with polyvinyl alcohol (PVA) or chitosan as the external phase stabilising agent showed a significant increase in the encapsulation efficiency of the antigen. RESULTS: PLA-Alum and PLA-chitosan microparticles induced HBsAg serum specific IgG antibody responses significantly higher than PLA only microparticles and free antigen following subcutaneous administration. Chitosan not only imparted a positive charge to the surface of the microparticles but was also able to increase the serum specific IgG antibody responses significantly. CONCLUSIONS: The cytokine assays showed that the serum IgG antibody response induced is different according to the formulation, indicated by the differential levels of interleukin 4 (IL-4), interleukin 6 (IL-6) and interferon gamma (IFN-gamma). The microparticles eliciting the highest IgG antibody response did not necessarily elicit the highest levels of the cytokines IL-4, IL-6 and IFN-gamma.

Diphtheria toxoid loaded poly-(epsilon-caprolactone) nanoparticles as mucosal vaccine delivery systems.

Poly-(epsilon-caprolactone) (PCL), a poly(lactide-co-glycolide) (PLGA)-PCL blend and co-polymer nanoparticles encapsulating diphtheria toxoid (DT) were investigated for their potential as a mucosal vaccine delivery system. The nanoparticles, prepared using a water-in-oil-in-water (w/o/w) double emulsion solvent evaporation method, demonstrated release profiles which were dependent on the properties of the polymers. An in vitro experiment using Caco-2 cells showed significantly higher uptake of PCL nanoparticles in comparison to polymeric PLGA, the PLGA-PCL blend and co-polymer nanoparticles. The highest uptake mediated by the most hydrophobic nanoparticles using Caco-2 cells was mirrored in the in vivo studies following nasal administration. PCL nanoparticles induced DT serum specific IgG antibody responses significantly higher than PLGA. A significant positive correlation between hydrophobicity of the nanoparticles and the immune response was observed following intramuscular administration. The positive correlation between hydrophobicity of the nanoparticles and serum DT specific IgG antibody response was also observed after intranasal administration of the nanoparticles. The cytokine assays showed that the serum IgG antibody response induced is different according to the route of administration, indicated by the differential levels of IL-6 and IFN-gamma. The nanoparticles eliciting the highest IgG antibody response did not necessarily elicit the highest levels of the cytokines IL-6 and IFN-gamma.