Читать книгу Oil-in-Water Nanosized Emulsions for Drug Delivery and Targeting - Tamilvanan Shunmugaperumal - Страница 45

The principles of factor sparsity are applied for the factor screening studies in which only a few of the factors among the numerous ones are identified to explain the major proportion of the experimental variation in the final product (Negi et al. 2015). Whereas the active or influential variables were responsible for the major variability, remaining all other factors were termed as inactive, less influential, or simply the noise variables. Based on Eq. (2.1), the CMAs/CPPs that produced high RPN values were finally subjected to factor screening studies to quantitatively estimate the risk associated with the formulation and process variables of topical ophthalmic emulsions. A 7‐factor 8‐run Taguchi design was employed for screening the formulation and process variables of the ophthalmic emulsions. The design matrix was prepared using Design‐Expert^® (version 11.1.0.1, Stat‐Ease Inc., Minneapolis, MN, USA) software. Table 2.5 enlists the Taguchi design matrix selected for the preparation of topical ophthalmic emulsions along with the description of their respective low and high levels. A total of eight trial formulations were thus prepared as per the screening design and evaluated for the identified/selected CQAs [mean particle size (MPS), polydispersity index (PDI), and zeta potential (ZP)]. The analysis of the design‐generated data was performed by fitting it to the first‐order linear model obviating the interaction effect(s), while analyzing coefficients for each of the factors. The Half‐normal and Pareto charts were used for quantitatively identifying the effect of each MAs/PPs on the selected CQAs for screening.

TABLE 2.4. Selective List of Various Designs Used for Optimization and Screening of CPPs of O/W Nanosized Emulsion [As Per Design‐Expert® (version 11.1.0.1, Stat‐Ease Inc., Minneapolis, MN, USA) Software]