Formulation and drug-content assay of microencapsulated antisense oligonucleotide to NF-κB using ATR-FTIR

Antisense oligonucleotide to NF-kappa B sequence: 5'-GGA AAC ACA TCC TCC ATG-3', was microencapsulated in an albumin matrix by the method of spray drying (TM). Spectral analysis was performed on varying drug loading formulations of both drugs by mid-IR attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). An out of plane O-H bending vibration at 948 cm(-1), unique to both the native and microencapsulated drugs was identified. The calculated peak areas corresponded to the drug loadings in the microsphere formulations. A standard curve could then be used to determine the drug content of an unknown microsphere formulation. Accuracy and precision were determined to be comparable to other analytical techniques such as HPLC.