Analytical Methodologies for Anti-Infective Orphan Drugs: A Comprehensive Review of FDA Approvals (2013-2023) Part 2

This review is part II of the series that aims to provide a comprehensive overview of analytical methodologies for anti-infective orphan drugs that received FDA market approval over a decade (2013-2023). While in Part I anti-infective orphan drugs were addressed except for antivirals, this part concerns antiviral orphan drugs against (i) HIV (ii) HCV (iii) HSV (iv) VARV and (v) CMV. Herein, we summarize the development of antiviral orphan drugs, challenges facing their R&D and incentives offered through the orphan drug act (ODA). The mechanism of action of each class of compounds, the rationale for orphan drug designation, and their use in clinical practice are briefly outlined. The review provides an expert opinion on the state of art in the field of analysis of these drugs in bulk, in different dosage forms, and in biological samples. Stability studies of these drugs are additionally described. A comparative analysis based on performance parameters is included. The methods developed for the determination of drugs from this class mostly include RP-HPLC, spectrophotometric and electrochemical conventional procedures. Current trends such as UHPLC-MS/MS are less used. Some of the published methods lack proper validation parameters and thus were considered insufficient.