title: Effect of Percent Relative Humidity, Moisture Content, and Compression Force on Light-Induced Fluorescence (LIF) Response as a Process Analytical Tool.
abstract: The effect of percent relative humidity (16-84% RH), moisture content (4.2-6.5% w/w MC), and compression force (4.9-44.1 kN CF) on the light-induced fluorescence (LIF) response of 10% w/w active pharmaceutical ingredient (API) compacts is reported. The fluorescent response was evaluated using two separate central composite designs of experiments. The effect of % RH and CF on the LIF signal was highly significant with an adjusted R (2)  = 0.9436 and p < 0.0001. Percent relative humidity (p = 0.0022), CF (p < 0.0001), and % RH(2) (p = 0.0237) were statistically significant factors affecting the LIF response. The effects of MC and CF on LIF response were also statistically significant with a p value <0.0001 and adjusted R (2) value of 0.9874. The LIF response was highly impacted by MC (p < 0.0001), CF (p < 0.0001), and MC(2) (p = 0022). At 10% w/w API, increased % RH, MC, and CF led to a nonlinear decrease in LIF response. The derived quadratic model equations explained more than 94% of the data. Awareness of these effects on LIF response is critical when implementing LIF as a process analytical tool.
authors.affiliation: Department of Pharmaceutical Sciences, Campbell University College of Pharmacy & Health Sciences, Buies Creek, North Carolina, USA.|Data and Clinical Programming Department, PRA Health Sciences, Blue Bell, Pennsylvania, USA.
authors.forename: Ishan G
authors.initials: IG
authors.lastname: Shah
authors.affiliation: Department of Pharmaceutical Sciences, Campbell University College of Pharmacy & Health Sciences, Buies Creek, North Carolina, USA. bcstagner@gmail.com.
authors.forename: William C
authors.initials: WC
authors.lastname: Stagner
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D005453:Fluorescence; D006813:Humidity; D008027:Light; D055595:Mechanical Phenomena; D008962:Models, Theoretical; D011312:Pressure; D013678:Technology, Pharmaceutical / Q000379:methods*
keywords: design of experiments (DOE); fluorescence quenching; light-induced fluorescence (LIF); moisture; process analytical technology (PAT)