# Formula: polynomial calibration curve

Parent: — · class: spectroscopy and calibration · names as written: ATR-FTIR peak-ratio calibration (second-order polynomial); empirical quadratic infrared standard curve (PHPH ASDs); second-degree polynomial calibration of PVPVA absorbance at 220 nm

3 instances in 3 papers (of 207 kept papers). Each section heading ends with the paper's category / subcategory. Generated by tools/build_evidence.py from registry/formulas.csv; do not edit.

## 2018 Bhardwaj · E7 · second-degree polynomial calibration of PVPVA absorbance at 220 nm · Dissolution / A. Release mechanism and LoC

[2018-bhardwaj-surface-area-normalized-dissolution-itraconazole-pvpva-asd](../../../cards/2018-bhardwaj-surface-area-normalized-dissolution-itraconazole-pvpva-asd/paper.html) · Dissolution / A. Release mechanism and LoC

- expression: 
- symbols and units: absorbance; concentration 2-140 µg/mL; R² = 1.000; coefficients not printed
- assumptions stated: ITZ contribution at 220 nm removed with the A253/A220 ratio ~0.68; the quadratic solved for concentration
- used for: R8, R9, R14
- status: named only · recomputed: named only
- locator: p.6-7

## 2023 Deac · E3 · empirical quadratic infrared standard curve (PHPH ASDs) · Dissolution / A. Release mechanism and LoC

[2023-deac-asd-drug-load-molecular-interactions-loc](../../../cards/2023-deac-asd-drug-load-molecular-interactions-loc/paper.html) · Dissolution / A. Release mechanism and LoC

- expression: y = 5.1445x² − 0.2064x + 4.1749; R² = 0.9967
- symbols and units: y drug load (%); x inverse of the normalized intensity of the PVPVA peak (1491 cm⁻¹ in the caption, 1492 cm⁻¹ in the text) after normalization to the PHPH peak at 1513 cm⁻¹
- assumptions stated: standards measured in triplicate (5-50% DL)
- used for: R6, R13
- status: printed, checked against page image · recomputed: reproduces (x ≈1.79 read for the 20% standard gives y = 20.3%; x ≈1.39 for the 15% standard gives 13.8%)
- locator: SI p.7 (Fig. S7a); p.726

## 2023 Yang · E3 · ATR-FTIR peak-ratio calibration (second-order polynomial) · Dissolution / A. Release mechanism and LoC

[2023-yang-surfactant-containing-asd-release-enhancement](../../../cards/2023-yang-surfactant-containing-asd-release-enhancement/paper.html) · Dissolution / A. Release mechanism and LoC

- expression: peak ratio (1522 cm⁻¹ / 1369 cm⁻¹) vs DL fitted with a second-order polynomial; coefficients not printed
- symbols and units: 1522 cm⁻¹ RTV-specific band; 1369 cm⁻¹ PVPVA-specific band; DL RTV wt% on RTV+PVPVA basis
- assumptions stated: SDS has no peaks in this region, so the curve applies regardless of SDS content
- used for: R18, R19
- status: printed in words · recomputed: inputs not printed (polynomial coefficients absent)
- locator: Fig. 13a, p.2839; Results, p.2833