# Evidence: nanoconfinement

Parent: — · class: solid-state property · names merged here: nanoconfinement; nanoconfinement of amorphous drug

4 papers measured or used it, 1 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.

## 2019 Dening — Application of an adsorption isotherm to explain incomplete drug release from ordered mesoporous silica materials under supersaturating conditions · Mesoporous silica / Mesoporous silica

[2019-dening-adsorption-isotherm-incomplete-release-sba15](../../../cards/2019-dening-adsorption-isotherm-incomplete-release-sba15/paper.html) · Mesoporous silica / Mesoporous silica · used · as: nanoconfinement

| id | kind | content | locator |
|---|---|---|---|
| C45 | claim, mechanism, authors: can rationalize; are expected; we believe | The steep adsorption increase as concentration nears the amorphous solubility is believed to come from confinement: analogous to capillary condensation, melting point depression in mesopores stabilises the confined amorphous phase, so pores are expected to fill before bulk LLPS. [rests on: R2; cited: refs 7, 8, 62, 64, 65] | Section 5.1, pp. 195–196 |

## 2020 Hate — Interplay of Adsorption, Supersaturation and the Presence of an Absorptive Sink on Drug Release from Mesoporous Silica-Based Formulations · Mesoporous silica / Mesoporous silica

[2020-hate-atazanavir-mesoporous-silica-adsorption-absorptive-sink-release](../../../cards/2020-hate-atazanavir-mesoporous-silica-adsorption-absorptive-sink-release/paper.html) · Mesoporous silica / Mesoporous silica · measured · as: nanoconfinement

| id | kind | content | locator |
|---|---|---|---|
| R9 | record, measured | MDSC events, reversing heat flow, 10-220 °C at 2 °C/min — 1:1 w/w physical mixture of amorphous ATZ and SBA-15 (M9) and ATZ-MPS (P4) — sub-table below | Fig. 5, p.8; text p.7 |
| R11 | record, measured | TGA residual weight and DTG peak temperature — SBA-15, ATZ-MPS, pure ATZ (P5) — sub-table below; text: pure ATZ degradation at 340 °C; initial small weight drop for SBA-15; degradation temperature higher for 5 and 10% (p.8) or for 5, 10 and 20% (p.14) than for ATZ, decreasing towards that of ATZ as DL increases; 50% similar to bulk ATZ | Fig. 6, p.9; text p.7-8, p.14 |
| C4 | claim, mechanism, authors: abstract: "was suggested"; results: "suggest", "suggested"; discussion: "consistent with", "is expected" | At low DL the drug is nanoconfined in the mesopores and interacts with the pore walls: no thermal events (5-20%) and higher degradation temperature (5 and 10%, or 5-20%) than ATZ; the molecular environment changes with DL [rests on: R9, R11] | p.1, p.7-8, p.13-14 |

## 2020 Hate — Influence of Drug-Silica Electrostatic Interactions on Drug Release from Mesoporous Silica-Based Oral Delivery Systems · Mesoporous silica / Mesoporous silica

[2020-hate-drug-silica-electrostatic-interactions-mesoporous-release](../../../cards/2020-hate-drug-silica-electrostatic-interactions-mesoporous-release/paper.html) · Mesoporous silica / Mesoporous silica · used · as: nanoconfinement

| id | kind | content | locator |
|---|---|---|---|
| R6 | record, measured | solid state of the 20% DL formulations — KET-, CLZ-, ATZ-MPS (P1, P12, P13) — PXRD: broad halo with maximum ≈22-23° 2θ and no diffraction peaks for all three (Fig. S1); DSC reversing heat flow: no step change and no melting peak (KET to ≈165 °C, CLZ to ≈195 °C, ATZ to ≈210 °C), with a broad rise peaking near ≈100 °C in the CLZ and ATZ traces (Fig. S2); text: amorphous by PXRD, no crystallization or melting events in DSC | Figs. S1, S2, SI p.1-2; text p.13 |
| C2 | claim, prior hypothesis, authors: asserted | Loading drug into silica nanopores suppresses crystallization by confinement, giving an amorphous formulation with better physical stability, in particular for pores smaller than the critical nucleus [rests on: cited: refs 3-5] | p.4 |
| C15 | claim, conclusion, authors: main text: "suggesting"; SI caption: "suggests" | The 20% DL formulations are amorphous, and the absence of crystallization and melting events (and of a Tg) points to nanopore confinement [rests on: R6; cited: ref 41] | p.13; SI p.2 |

## 2020 Mccarthy — A Comparison of Drug Release and Adsorption Under Supersaturating Conditions for Ordered Mesoporous Silica with Indomethacin or Indomethacin Methyl Ester · Mesoporous silica / Mesoporous silica

[2020-mccarthy-indomethacin-indme-sba15-adsorption-release](../../../cards/2020-mccarthy-indomethacin-indme-sba15-adsorption-release/paper.html) · Mesoporous silica / Mesoporous silica · measured · as: nanoconfinement

| id | kind | content | locator |
|---|---|---|---|
| R19 | record, measured | PXRD of drug-loaded SBA-15 — IND and INDME at 25-150% theoretical monolayer (P12, P13) — text: both drugs X-ray amorphous at 25% and 50%; at 75% and above crystalline peaks "characteristic of the gamma polymorph"; distinct INDME crystalline peaks from 100%. Figure (read from Fig. 10): amorphous halo only at 25% and 50%; IND weak peaks at 75%, clearer at 100-150% (≈20.3, ≈22.8 and ≈26.2° 2θ; at 150% also ≈17.3 and ≈19.5°); INDME a small peak near ≈18.6° at 75%, distinct peaks from 100% (≈7.0, ≈9.3, ≈15.3, ≈18.6, ≈19.7° and others); no reference patterns shown | p.27; Fig. 10, p.28 |
| C1 | claim, prior hypothesis, authors: asserted | Drugs confined in mesoporous silica tend to be non-crystalline below a certain drug loading because of interactions with the pore walls [rests on: cited: ref 5] | p.3 |
| C33 | claim, conclusion, authors: asserted | Both drugs are X-ray amorphous on silica at 25% and 50% coverage; crystalline peaks characteristic of the gamma polymorph appear at 75% and above; distinct INDME crystalline peaks appear from 100% [rests on: R19] | p.27 |

## Mentioned only

- 2018 Dening — [2018-dening-ordered-mesoporous-silica-supersaturation-dissolution-flux](../../../cards/2018-dening-ordered-mesoporous-silica-supersaturation-dissolution-flux/paper.html) · Mesoporous silica / Mesoporous silica (ref 24)