Allergy Therapeutics click here market aluminium-free SCIT products. “
“Conventional aluminium-containing adjuvants have been used in vaccine formulations for decades but promote poor induction of Th1 or cell-mediated immunity  and 
and require refrigeration during transportation and storage. Approximately 50% of vaccines are discarded globally, largely due to cold chain disruption  and . Therefore, a major objective of vaccine formulation t is to develop a safe, immunogenic composition which addresses the issues of immune bias and stability. Protein-coated microcrystals (PCMCs) are a recent advance in vaccine formulation  and have the potential to by-pass the cold chain. Originally developed to stabilise enzymes for
industrial applications , , ,  and , PCMCs are formed by rapid co-precipitation of protein(s) with an amino acid or sugar, producing particles with an inert core microcrystal coated with protein(s) ,  and . Vaccine antigens, loaded onto PCMCs, exhibited much higher resistance to heat stress compared to native antigens  and . These reports used PCMC formulations which were instantly soluble in aqueous buffer , , ,  and . In this study, novel sustained-release PCMCs have been used which are poorly soluble due to modification of their outer surface with sparingly soluble CaP. CaP served as an adjuvant in some early acellular vaccines  and , and is well-tolerated in man , , , ,  and . CaP also XL184 enhances Th1-biased immunity although this may be antigen-dependent ,  and . Here, the immunogenicity of CaP-modified PCMCs loaded with different model antigens was investigated. DT, a formaldehyde-toxoided antigen ,  and , and BSA have been used extensively as model antigens when validating new vaccine formulations , , of  and . The DT preparation was the 2nd international standard
for use in flocculation tests (02/176, NIBSC, UK). CyaA* was purified and characterised as described previously ,  and . BSA was from Sigma and BSA-FITC was from Life Technologies, UK. All reagents were of the highest grade available and were used at rt. The aqueous solution was prepared in endotoxin-free, sterile water (Sigma) and contained 30 mg/ml l-glutamine as the core component of the PCMCs, trehalose and the test antigens, sufficient to give final loadings of 10% and 0.2–0.4%, respectively, in the PCMC preparation. To precipitate PCMCs, 3 ml of the aqueous solution was added drop-wise to 60 ml of rapidly stirred isopropanol and stirring continued for 1 min at 1500 rpm. For CaP-modified PCMCs, the required concentration of NaH2PO4 was included in the aqueous solution and CaCl2 was included in the isopropanol at a 2-fold molar excess compared to NaH2PO4. PCMCs were collected by vacuum filtration onto PVDF hydrophilic 0.