<p>Challenges to medication administration arise in children when pediatric-friendly (PF) formulations are lacking. This study examines the extent to which PF formulations were developed for use in pediatric trials of drugs awarded 6-months of patent extension under a written request (WR). Publicly accessible and proprietary data were aggregated to characterize the formulations used in studies submitted to the U.S. FDA in support of pediatric labeling for WRs issued through September 2025. From 1998–2025, exclusivity was awarded to 321 unique sponsor:drug pairs satisfying the requirements of a WR. A majority, (235/321), received a new or updated pediatric indication and nearly all (310/321) resulted in pediatric labeling. Drugs intended for oral administration (<i>n</i> = 213) were supported by 304 studies. The majority (173/304) exclusively studied adult solid dosage forms (SDF), a minority (129/304) used at least one PF dosage form, and 2 accomplished labeling without the conduct of clinical trials. SDF were exclusively used in 26.3%, 44.9%, 85.1%, and 94.1% of studies in children &lt; 2&#xa0;yr, 2–5&#xa0;yr, 6–12&#xa0;yr and &gt; 12&#xa0;yr, respectively. Of trials employing an oral PF formulation, 85% were associated with a marketed PF product at labeling. Marketed oral PF formulations were also associated with 8% of cases where studies relied exclusively on a s SDF. Nearly all non-enteral drug studies were supported by existing commercial formulations with only investigational inhalation formulations making their way to market. Legislative provisions enacted to incentivize pediatric drug development incompletely extend to pediatric reformulation efforts despite the associated financial gains.</p> Graphical Abstract <p></p>