(116aj) Development of NIR Spectroscopy Method for Drug Concentration in a Novel Gel Strip Formulation

The objective of this study was to determine the drug content of in a novel gel strip. Gel strips are being developed as an approach to deliver poorly soluble drugs, as nanoparticles and by preventing their possible agglomeration. The distribution of the nanoparticles of drugs is important in order to improve solubility. Gel strips samples are composed of the following materials: griseofulvin (poorly soluble active ingredient), hydroxypropyl methylcellulose (HPMC), glycerin, and Sodium Lauryl Sulfate (SLS) as the excipients. The API ingredient ranged in drug concentration from 0-10% w/w and the concentration of the excipients varies as well, and have a thickness of about 100 µm. Spectra were obtained using a Multipurpose Analyzer (MPA) Fourier transform Near Infrared (FT-NIR) spectrometer (Bruker Optics) equipped with a lead sulfide detector, an integrating sphere (sphere macrosample) and with a beam size of 15 mm diameter. Since these are novel formulations, there is no established way to obtain their spectra. The research includes several approaches to obtaining the spectra, and these will be discussed. The method repeatability is being evaluated by taking 9 spectra at the same spot. The variation of the gel strip is being evaluated by taking spectra at different sections of the gel strip. The drug content in several areas of the gel strip was measured with the NIR method. The standard deviation for the areas was about 0.21%. Results demonstrated that the NIR system is able to discriminate between gel strips of different compositions. The method repeatability (measurements under identical conditions) is about 0.01 %. Future plans include the full method validation, its use for determining the drug content of gel strips, and efforts to improve their manufacturing process.