# Evidence: octanol-water partition coefficient

Parent: — · class: molecular interaction · names merged here: octanol-water partition coefficient; partition coefficient

9 papers measured or used it, 0 only mentioned it (of 207 kept papers). Papers in year order; each section heading ends with the paper's category / subcategory. Generated by tools/build_evidence.py from registry/concepts.csv and the cards; do not edit.

## 2013 Ilevbare — Impact of Polymers on Crystal Growth Rate of Structurally Diverse Compounds from Aqueous Solution · Dissolution / D. Crystallization from solution

[2013-ilevbare-polymers-crystal-growth-structurally-diverse-compounds](../../../cards/2013-ilevbare-polymers-crystal-growth-structurally-diverse-compounds/paper.html) · Dissolution / D. Crystallization from solution · used · as: octanol-water partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| M1 | material | efavirenz crystalline, used as received; Attix Corporation (Toronto, Ontario, Canada); seed crystals Form I, rod-like | pdf p.2, p.5 |
| M2 | material | ritonavir crystalline, used as received; Attix Corporation; seed crystals described in refs 27 and 41 | pdf p.2, p.5 |
| M3 | material | celecoxib crystalline, provided by Pfizer Inc. (Groton, MA); seed crystals Form III, plate-like | pdf p.2, p.5 |
| C10 | claim, assumption, authors: asserted | The lower the SP the more hydrophobic a compound; SP estimates cohesive interactions and relative polarity; on Log P and SP all three drugs are hydrophobic, ritonavir the most and celecoxib the least [rests on: M1, M2, M3; cited: ref 31] | pdf p.5 |

## 2013 Wegiel — Mid-infrared spectroscopy as a polymer selection tool for formulating amorphous solid dispersions · Solid state stability / Miscibility and drug-polymer interactions

[2013-wegiel-mid-ir-polymer-selection-polyphenol-asd-stability](../../../cards/2013-wegiel-mid-ir-polymer-selection-polyphenol-asd-stability/paper.html) · Solid state stability / Miscibility and drug-polymer interactions · used · as: octanol-water partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| C41 | claim, prior hypothesis, authors: "would be expected" | Being less hydrophobic than felodipine (log P in M1, M2, R14), naringenin- and quercetin-PVP dispersions would be expected to hold more water and to crystallize more readily than felodipine-PVP [rests on: R14; cited: refs 47, 48] | p.10 |
| R14 | record, cited | felodipine-PVP crystallization with moisture; felodipine log P — ref 46; ref 47 — the crystallization rate of felodipine from PVP dispersions increases dramatically in the presence of moisture; felodipine log P 4.5 | p.10 |
| M1 | material | naringenin (±)-naringenin, 95% purity; Sigma-Aldrich (St Louis, MO) | p.2 |
| M2 | material | quercetin quercetin dihydrate; Alfa Aesar (Ward Hill, MA) | p.2 |

## 2015 Purohit — Phase Separation Kinetics in Amorphous Solid Dispersions Upon Exposure to Water · Characterization methods / Solid-state methods

[2015-purohit-phase-separation-kinetics-asd-water](../../../cards/2015-purohit-phase-separation-kinetics-asd-water/paper.html) · Characterization methods / Solid-state methods · used · as: partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| R1 | record, measured | emission of four probes in single-component amorphous films — amorphous probucol and procaine films with probe (P2, P4) — sub-table below | Table 1, p.36; text p.9-10 |
| C5 | claim, conclusion, authors: "It is apparent" | Probes in amorphous probucol register a more hydrophobic environment than in amorphous procaine, reflecting the much higher log P of probucol (10 versus 1.3) [rests on: R1, R2] | p.10 |

## 2019 Saboo — Congruent release of drug and polymer: A “sweet spot” in the dissolution of amorphous solid dispersions · Dissolution / A. Release mechanism and LoC

[2019-saboo-congruent-drug-polymer-release-asd-sweet-spot](../../../cards/2019-saboo-congruent-drug-polymer-release-asd-sweet-spot/paper.html) · Dissolution / A. Release mechanism and LoC · measured · as: partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| M1 | material | nilvadipine (Nil) ChemShuttle (Jiangsu, China); solid form as received not stated | pdf p.6 |
| M2 | material | cilnidipine (Cil) Euroasia Chemicals Pvt. Ltd. (Mumbai, India); solid form as received not stated | pdf p.6 |
| A1 | scope item | drug (hydrophobicity) — nilvadipine (ClogP 3.04); cilnidipine (ClogP 5.54) — PVPVA; preparation (P7); 100 mM pH 6.8 phosphate buffer; 37 °C — drug and polymer release rates; LLPS; compact surface structure and composition |  |
| C6 | claim, prior hypothesis, authors: "we hypothesized" | Hypothesis 2: ASDs of the more hydrophobic drug show congruent release over a lower DL range, since a more hydrophobic drug lowers the hydrophilicity of the drug-polymer blend faster with composition [rests on: argument only] | pdf p.6, p.34 |
| C35 | claim, conclusion, authors: "we clearly see that our hypothesis is incorrect for the systems evaluated" | The log P hypothesis is incorrect for the systems evaluated: Nil and Cil switch above 10% and 15% w/w (~6-9 mol%) despite a log P difference of about 2.5 units [rests on: R5, R6, R7] | pdf p.34 |

## 2020 Saboo — Patterns of drug release as a function of drug loading from amorphous solid dispersions: A comparison of five different polymers. · Dissolution / A. Release mechanism and LoC

[2020-saboo-asd-drug-loading-polymer-hydrophobicity-release](../../../cards/2020-saboo-asd-drug-loading-polymer-hydrophobicity-release/paper.html) · Dissolution / A. Release mechanism and LoC · measured · as: octanol-water partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| R16 | record, derived (E3) | normalized drug and polymer release rates (mg/min/cm², mean ± SD, n = 3) — HPMCAS ASDs at 40 wt% DL with Nil (log P 4.06), Fel (4.46), Cil (5.40); P6 — sub-table below; Fig. 8 bars show the same values with a dashed guide line (labelled as a guide for the eye) | Table S3, SI p.8; Fig. 8, p.10 |
| C19 | claim, conclusion, authors: asserted | For Nil, Fel and Cil at 40% DL in HPMCAS release is congruent, both components are slower than neat polymer, and release decreases with drug hydrophobicity (Nil > Fel > Cil), with statistically significant differences [rests on: R16, R17, R13] | p.8 |
| C32 | claim, generalisation, authors: "substantiates the supposition"; "at least" | Because the three analogues differ in log P but have similar ability to interact with the polymer, the fall of both rates with log P substantiates the supposition that drug hydrophobicity influences component release, at least for congruently releasing systems at high DL [rests on: R16, R17] | p.11 |
| E5 | equation | octanol-water partition coefficient: log P = log([drug concentration]_octanol / [drug concentration]_aqueous buffer) | SI p.8 |

## 2020 Saboo — Congruent release of drug and polymer from amorphous solid dispersions: insights into the role of drug-polymer hydrogen bonding, surface crystallization and glass transition · Dissolution / A. Release mechanism and LoC

[2020-saboo-congruent-release-hbond-crystallization-tg-pvpva-asd](../../../cards/2020-saboo-congruent-release-hbond-crystallization-tg-pvpva-asd/paper.html) · Dissolution / A. Release mechanism and LoC · measured · as: octanol-water partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| M1 | material | IND (indomethacin) ChemShuttle (Jiangsu, China); molecular formula C19H16ClNO4 (p.21) | p.5, p.21 |
| M2 | material | INDester (indomethacin methyl ester) synthesized in-house: IND and anhydrous benzenesulfonic acid (1:2 molar) dissolved in methanol with heating (ca. 50 °C), crystals precipitated on cooling to room temperature, isolated and dried; 1H and 13C NMR signals of the methyl ester at δ 3.70 ppm and 52.11 ppm (CDCl3, 500 MHz, 298 K); purity >95% | p.5; SI p.2 |
| E4 | equation | octanol-water partition coefficient: logP = log([drug concentration]octanol/[drug concentration]aqueous buffer) | SI p.3 |
| C4 | claim, prior hypothesis, authors: "Somewhat counterintuitively" | In earlier work the LoC of two PVPVA ASDs was the same despite substantially different drug logP [rests on: cited: ref 7] | p.4 |

## 2020 Wilson — Amorphous solid dispersions of enzalutamide and novel polysaccharide derivatives: investigation of relationships between polymer structure and performance · Bioperformance / Bioperformance

[2020-wilson-enzalutamide-polysaccharide-asd-polymer-performance](../../../cards/2020-wilson-enzalutamide-polysaccharide-asd-polymer-performance/paper.html) · Bioperformance / Bioperformance · measured · as: partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| M1 | material | enzalutamide ChemShuttle (Hayward, California); crystalline form used for SEDDS and crystalline slurry | p.2, p.7 |
| C18 | claim, conclusion, authors: asserted | Enzalutamide is more hydrophobic than any of the polymers, based on the total solubility parameter and the calculated log P of 4.75 [rests on: M1-M4] | p.4 |

## 2021 Yang — Drug Release and Nanodroplet Formation from Amorphous Solid Dispersions: Insight into the Roles of Drug Physicochemical Properties and Polymer Selection · Dissolution / A. Release mechanism and LoC

[2021-yang-asd-nanodroplet-release-drug-properties-polymer-selection](../../../cards/2021-yang-asd-nanodroplet-release-drug-properties-polymer-selection/paper.html) · Dissolution / A. Release mechanism and LoC · measured · as: octanol-water partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| M1 | material | loratadine Attix Pharmaceuticals (Toronto, ON, Canada) | Materials, p.2068; Table 1, p.2070 |
| M2 | material | miconazole ChemShuttle (Jiangsu, China); base or salt form not stated | Materials, p.2068; Table 1, p.2070 |
| M3 | material | danazol Euroasia Chemicals (Mumbai, India) | Materials, p.2068; Table 1, p.2070 |
| M4 | material | elbasvir provided by Merck & Co., Inc (Kenilworth, NJ) | Materials, p.2068; Table 1, p.2070 |
| C19 | claim, conclusion, authors: discussion: asserted; conclusions: "somewhat counterintuitively" | Drug log P did not correlate with release vs DL or with nanodroplet yield: miconazole, elbasvir and ivacaftor share similar log P but drop off at very different DLs with PVPVA, while elbasvir and danazol differ in log P but drop off at similar low DL [rests on: R7–R12; M1–M6] | Discussion p.2076; Conclusions p.2079 |
| C42 | claim, generalisation, authors: asserted ("A useful conclusion") | Taken with the literature, API log P gives little indication of ASD performance, so the ASD formulation space is not limited by log P [rests on: C19; R26] | Discussion p.2079 |

## 2022 Ueda — Variable-Temperature NMR Analysis of the Thermodynamics of Polymer Partitioning between Aqueous and Drug-Rich Phases and Its Significance for Amorphous Formulations · Dissolution / C. Amorphous solubility and LLPS

[2022-ueda-polymer-partitioning-ibuprofen-drug-rich-phase-nmr](../../../cards/2022-ueda-polymer-partitioning-ibuprofen-drug-rich-phase-nmr/paper.html) · Dissolution / C. Amorphous solubility and LLPS · measured · as: partition coefficient

| id | kind | content | locator |
|---|---|---|---|
| R20 | record, derived (E5) | linear van't Hoff fits of ln K IBP-rich/aqueous against 1/T (n = 3, mean ± SD points) — P12 — HPMC: ln K = −4.23 × 10^3(1/T) + 1.99 × 10, R2 = 0.962; PVP−VA: ln K = −1.79 × 10^3(1/T) + 1.22 × 10, R2 = 0.961; PVP: ln K = −1.44 × 10^3(1/T) + 1.05 × 10, R2 = 0.817 (text: R2 > 0.95 for HPMC and PVP−VA, 0.817 for PVP) | Fig. S4, SI p.6; text p.109 |
| R21 | record, derived (P12, E3, E6) | ln K IBP-rich/aqueous of each polymer versus 1/T (n = 3, mean ± SD) with polynomial fits — P12 — HPMC: ln K = −6.59 × 10^6(1/T)^2 + 3.87 × 10^4(1/T) − 4.98 × 10, R2 = 0.996; PVP−VA: ln K = −2.52 × 10^6(1/T)^2 + 1.45 × 10^4(1/T) − 1.42 × 10, R2 = 0.994; PVP: ln K = −4.74 × 10^6(1/T)^2 + 2.92 × 10^4(1/T) − 3.90 × 10, R2 = 0.971 (text: all R2 > 0.97); data points in sub-table below | Fig. 12, p.110; text p.109 |
| E3 | equation | partition coefficient: K_p/q = C_p/C_q | p.109 |