# Evidence: steric stabilization

Parent: colloidal stability · class: solution behaviour · names merged here: steric stabilization

3 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.

## 2020 Ueda — Polymer type impacts amorphous solubility and drug-rich phase colloidal stability: A mechanistic study using nuclear magnetic resonance spectroscopy · Dissolution / C. Amorphous solubility and LLPS

[2020-ueda-polymer-type-amorphous-solubility-drug-rich-phase-colloidal-stability](../../../cards/2020-ueda-polymer-type-amorphous-solubility-drug-rich-phase-colloidal-stability/paper.html) · Dissolution / C. Amorphous solubility and LLPS · used · as: steric stabilization

| id | kind | content | locator |
|---|---|---|---|
| C50 | claim, mechanism, authors: discussion: "proved to be ineffective"; "Clearly"; abstract: "relatively poor" | PVP-VA proved ineffective at preventing coarsening and creaming compared with HPMC and EUD-E, although it suppressed initial Ostwald ripening: being uncharged, adsorbed PVP-VA gives no charge repulsion, and it also does not give sufficient steric repulsion [rests on: R6.c, R7.c, R7.g, R15.g] | p.3, p.39 |
| C51 | claim, mechanism, authors: discussion: "Hence" asserted; abstract: asserted ("effectively suppressed by the steric repulsion"); conclusion: asserted ("effectively stabilized") | HPMC is the most effective polymer for stabilizing the IBP-rich phase, through the combined effects of Ostwald ripening inhibition from HPMC mixing with the droplet phase and coalescence inhibition by steric repulsion of HPMC adsorbed at the droplet surface, as HPMC is reported to stabilize emulsions sterically [rests on: R5.d-f, R7.b, R7.f, R15.f; cited: refs 59, 60] | p.3, p.39-40 |
| X3 | extractor note | claim-data gap — Steric stabilization by HPMC adsorbed at the droplet surface (C51) is not measured here: the zeta potential in HPMC (0.12 mV) is close to buffer (−1.92 mV), no adsorption or interfacial measurement was made, and the steric mechanism rests on refs 59 and 60 — C51, R6.a-b — treat HPMC adsorption and steric repulsion as a cited mechanism not shown in this paper |  |

## 2022 Indulkar — Role of Surfactants on Release Performance of Amorphous Solid Dispersions of Ritonavir and Copovidone · Dissolution / A. Release mechanism and LoC

[2022-indulkar-surfactants-ritonavir-copovidone-asd-release-performance](../../../cards/2022-indulkar-surfactants-ritonavir-copovidone-asd-release-performance/paper.html) · Dissolution / A. Release mechanism and LoC · used · as: steric stabilization

| id | kind | content | locator |
|---|---|---|---|
| C50 | claim, mechanism, authors: "may" | Alternatively, Span 20 and Span 85 may inhibit coalescence by steric repulsion [rests on: R11] | p.395 |

## 2024 Deac — Dissolution mechanisms of amorphous solid dispersions: Role of polymer molecular weight and identification of a new failure mode · Dissolution / A. Release mechanism and LoC

[2024-deac-asd-polymer-molecular-weight-failure-mode-loc](../../../cards/2024-deac-asd-polymer-molecular-weight-failure-mode-loc/paper.html) · Dissolution / A. Release mechanism and LoC · measured · as: steric stabilization

| id | kind | content | locator |
|---|---|---|---|
| R5 | record, measured | droplet diameter in dilute suspension versus time (DLS) — 100 µL of 10 mg/mL clotrimazole in ethanol into 10 mL medium at 37 °C, without PVP or with 1 mg/mL PVP K12 or K29/32 (P11); total monitoring time not stated — text: without PVP initial diameter ~540 nm, grew to ~1 µm; with PVP K12 ~340 nm, grew to ~610 nm; with PVP K29/32 ~290 nm, grew to ~630 nm; initial diameter larger without polymer and not sensitive to polymer grade (Fig. S6a); normalized diameter grew at a similar rate in all three media (Fig. S6b) | p.5-6; Fig. S6 (not supplied) |
| C44 | claim, mechanism, authors: "we expect"; "not the likely mechanism" | Steric stabilization by polymer adsorbed on the droplets (stronger for longer chains) was considered, but since neither K29/32 nor K12 changed droplet growth rate in dilute solution, steric repulsion is not the likely reason for stable droplets in the gel layer of K29/32 or higher grades [rests on: R5; cited: refs 45-47] | p.9-10 |