I’m weighing whether DSC or isothermal microcalorimetry gives a better early read on API–excipient interactions before we lock a tablet design. Our TA DSC 25 flags Tg shifts, but the TAM IV has caught low-level Maillard heat with lactose in 24 h at 40°C/75% RH that DSC missed — what’s your go-to for weakly basic APIs trending amorphous?
I’d lean TAM IV for these weakly basic, amorphous-leaning cases, but if you’re seeing “24 h at 40°C/75% RH” heat, precondition that same blend at 40/75 then run MDSC on the TA DSC 25 with a 60‑min isothermal hold at 40°C in hermetic pans (tiny pinhole) before a 1 °C/min ramp — this has pulled out nonreversing shifts near Tg that the standard scan missed for me. Small caveat: sample mass homogeneity matters a lot at these signals. Do you have MDSC enabled on the 25?
Precondition the blend 24 h at 40/75, then load and crimp into Tzero hermetic pans inside a 75% RH bag and run MDSC at 1°C/min with ±0.5°C/60 s — those settings pulled out tiny Tg shifts and weak exotherms for my amine–lactose cases that standard scans missed. Building on @nick_ramos84, tack on a 40°C isothermal hold for about 30–45 min right after; keep mass about 8–[redacted] and well-mixed — can you set up in-pan RH handling?
I’ve found the TAM IV really shines for those subtle heat signals, especially with lactose. Have you considered trying a different humidity level for your preconditioning?