A First-Order Derivative Spectrophotometric Method for the Quantification of Saquinavir in the Presence of Piperine in a Eutectic Mixture

Saquinavir is a drug used as an HIV treatment, with recent reports of new uses. It has poor aqueous solubility and very low oral bioavailability. However, when prepared in a eutectic mixture with the natural bioenhancer, piperine, it demonstrated improvements in these drawbacks. Therefore, considering that EMs can be easily produced and scaled-up, it could potentially be used in new pharmaceutical formulations. For this purpose, an analytical method capable of quantifying SQV in the presence of PIP is required for quality control purposes. In this context, UV–Vis equipment is simpler to use and cheaper than HPLC, and it is commonly available in most laboratories. Therefore, a derivative spectrophotometry method at 245 nm was developed and validated to quantify SQV. The method showed good linearity from 0.5 to 100.0 mg/L, with a limit of detection and limit of quantification of 0.331 mg/L and 0.468 mg/L, respectively. Furthermore, it was precise, accurate, and demonstrated good specificity up to a 1:4.3 SQV:PIP ratio. Consequently, the results demonstrate that the method can be employed for SQV quantification in the presence of PIP as an economical and simple technique. This contribution could be the basis for a quality control technique for these types of products.