Effect of excipients on product characteristics and structure of lyophilized lasota vaccine

The research was aimed to minimize product defects and lyophilization-induced denaturation of lasota vaccine. Sugars alone produced coherent cake but failed to protect virus during lyophilization. Maillard cake browning due to denaturation was evident in N,Z amine products. Polymers, PF-127 and PVP K-90 were able to produce porous cake structure and thus showed efficient water removal. DSC curves reveal endothermic melting corresponding to partial crystallization of PEG6000 and PF-127, while remaining plugs were amorphous. The X-ray diffraction confirms the DSC findings. Aqueous IR of harvest revealed symmetrical α-helix of virus. Loss of alpha helix in lasota products is indicated by the decreased absorbance of 1654 cm band. The qualitative comparisons of α-helix region in aqueous IR spectra are in correlation with antibody titer. Trehalose with most excipients gave better titer than sucrose. The stable glass matrix with arrested molecular mobility prevented unfolding of lasota. PF-127 was better stabilizer than PEG-6000 but both crystallized during freezing. Trehalse-PVP K-90 showed optimum product characteristics and maximum protection to antigen.