# Evidence: monolayer coverage

Parent: — · class: thermodynamics · names merged here: BET monolayer coverage; monolayer coverage; monolayer surface coverage

6 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.

## 2018 Dening — Supersaturation Potential of Ordered Mesoporous Silica Delivery Systems. Part 1: Dissolution Performance and Drug Membrane Transport Rates · Mesoporous silica / Mesoporous silica

[2018-dening-ordered-mesoporous-silica-supersaturation-dissolution-flux](../../../cards/2018-dening-ordered-mesoporous-silica-supersaturation-dissolution-flux/paper.html) · Mesoporous silica / Mesoporous silica · measured · as: monolayer surface coverage

| id | kind | content | locator |
|---|---|---|---|
| E3 | equation | monolayer adsorption capacity (adapted from Azaïs et al.): X_m = (SSA adsorbent × 10^20 × MW adsorbate)/(S_c × N_A) | p.3492 |
| R4 | record, derived (E3) | contact surface area and theoretical monolayer coverage of ritonavir — P15; SSA 586 m²/g (M3); dimensions from Fig. 1 — Sc from the two largest dimensions, 18.2 and 15.2 Å (product not printed); Xm = 0.253 g/g, printed as "i.e., 25.3% w/w"; formulation loaded at 25% w/w for all dose experiments | p.3492; Fig. 1, p.3492 |
| R27 | record, measured | mass flow vs SBA-15 drug load — P12; formulations of the P4 sub-table each dosed at the amorphous solubility (S 7.8); reference amorphous ritonavir 9.20 ± 0.15 ng/min (R8.a); n = 3, mean ± SD — sub-table below; text: all six significantly below the reference (p < 0.05), 45−58% of its mass flow; 4.9, 8.8, 16.0 and 20.1% w/w gave 5.1 ± 0.2 to 5.4 ± 0.3 ng/min (≈56−58%), with no significant differences among them; 29.8 and 38.1% w/w gave 4.37 ± 0.06 and 4.10 ± 0.08 ng/min (45−48%), significantly lower | Fig. 11, p.3497; text p.3496-3497, p.3499 |
| C38 | claim, generalisation, authors: results: "Most interestingly"; "suggests"; discussion: "a clear trend is observed" | Flux differs significantly between loadings at or below and above theoretical monolayer coverage; the change at the calculated monolayer shows the calculation is reasonable and that surface coverage dictates release [rests on: R27, R4] | p.3497, p.3499 |

## 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 · measured · as: monolayer coverage

| id | kind | content | locator |
|---|---|---|---|
| R3 | record, cited (ref 6) | theoretical monolayer surface coverage of ritonavir in SBA-15 — calculated in ref 6 assuming the whole SSA accessible and an orientation maximising surface contact — 253 mg/g; isotherm points above it: Qa ≈262, ≈349, ≈423 mg/g (read from Fig. 1) | Section 4.2 and Fig. 1, p. 189; Section 5.1, p. 195 |
| R6 | record, derived (E4) | nonlinear liquid-phase BET fit (n = ∞) — R2 data; P12 — R² = 0.94; KS = 1.169 μg/mL⁻¹; KL = 0.031 μg/mL⁻¹ (units as printed); Qm = 103 mg/g; 1/KL = 32.7 μg/mL | Section 4.2 and Fig. 1, p. 189; Section 5.1, p. 196 |
| R16 | record, cited (ref 6) for % release; derived (relation not printed) for adsorbed amount | sequential-dilution release and ritonavir remaining adsorbed — P10; n = 2, mean ± range — sub-table R16 a–f (read from Fig. 8); text: release ≈40% at start, 60% after 75 min (theoretical S 2.6), no further change; remaining adsorbed ≈170 mg/g after 15 min, 100–110 mg/g from 75 min on; Qm line at 103 mg/g | Fig. 8 and Section 4.8, p. 193; Section 5.3, p. 197 |
| C41 | claim, mechanism, authors: it is feasible | Since silanols are the expected main binding sites, the BET Qm may reflect the number of specific drug binding sites in the presence of co-adsorbed water. [rests on: R6] | Section 5.1, p. 195 |
| C44 | claim, generalisation, authors: asserted ("Clearly") | Monolayer coverage by saturation of specific binding sites (silanols, with water) must be distinguished from monolayer coverage of the whole SSA; ritonavir adsorption exceeded both. [rests on: R2, R3, R6] | Section 5.1, p. 195 |

## 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: monolayer coverage

| id | kind | content | locator |
|---|---|---|---|
| R1 | record, derived (E2) | theoretical geometric monolayer coverage of ATZ on SBA-15 — SSA 586 m²/g; contact area 17.53 Å × 14.07 Å (P15) — 278 mg/g or ~28% w/w | p.5 |
| R3 | record, derived (E1) | BET monolayer coverage Qm — fit of R2 (P16) — 4.5 mg/g; K_BET not printed; Langmuir and Freundlich fits poor (not shown) | p.6-7 |
| C22 | claim, conclusion, authors: asserted ("significantly less") | Overall adsorption with 300 µg/mL SBA-15 was significantly less than the geometric monolayer estimate, with a maximum of 25 mg/g at the amorphous solubility [rests on: R1, R2] | p.6 |
| C25 | claim, conclusion, authors: "This also suggested"; "possibly" | The BET monolayer coverage of 4.5 mg/g is much lower than the geometric estimate, and beyond it there was possibly multilayer adsorption [rests on: R3, R1] | p.7 |

## 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 · measured · as: BET monolayer coverage

| id | kind | content | locator |
|---|---|---|---|
| R21 | record, derived (E2) | BET monolayer coverage Qm (unit printed "mg/mol") — fits of the Fig. 3 isotherms (P14) — sub-table below (transcribed in full) | Table S1, SI p.4; text p.22 |
| E2 | equation | BET adsorption isotherm:  | p.22; SI p.4 |
| P14 | method | BET isotherm fitting | p.22; SI p.4 |
| C42 | claim, conclusion, authors: "suggests" | BET monolayer coverage at pH 6.8 ranks CLZ > KET > ATZ; Qm of CLZ rises with pH, pointing to more adsorption sites from silica ionization; Qm of ATZ falls with pH [rests on: R21] | p.22 |

## 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 · used · as: monolayer coverage

| id | kind | content | locator |
|---|---|---|---|
| E3 | equation | theoretical monolayer loading from molecular cross-section: Xm = SSA adsorbent × 10^20 × MWadsorbate / (Sc × NA) (printed with a trailing "#") | p.11 |
| R16 | record, derived (E3) | theoretical monolayer coverage — SBA-15 SSA 586 m²/g (M3); dimensions from Fig. 1 (M1, M2; P11) — IND 0.287 g/g ("28.7 % w/w"); INDME 0.269 g/g ("26.9 %w/w") | p.26 |
| R17 | record, derived (E3) for theoretical load; measured (P12) for actual load, mean ± SD, n = 3 | drug load of SBA-15 formulations (% w/w) — incipient wetness loading from ethanol (P12) — sub-table below | Table 4, p.27 |
| C18 | claim, conclusion, authors: asserted | Both drugs adsorb significantly onto silica, increasingly as supersaturation rises, and adsorption begins to exceed theoretical monolayer coverage at the highest initial concentration [rests on: R7, R8, R9] | p.20-21 |

## 2022 Soto — Impact of Surfactants on the Performance of Clopidogrel-Copovidone Amorphous Solid Dispersions: Increased Drug Loading and Stabilization of Nanodroplets · Dissolution / A. Release mechanism and LoC

[2022-correa-soto-surfactants-clopidogrel-copovidone-asd-nanodroplets](../../../cards/2022-correa-soto-surfactants-clopidogrel-copovidone-asd-nanodroplets/paper.html) · Dissolution / A. Release mechanism and LoC · used · as: monolayer surface coverage

| id | kind | content | locator |
|---|---|---|---|
| E2 | equation | monolayer surface coverage estimate: stated in words: minimum surfactant concentration needed to cover the nanodroplet surface, from droplet surface area (estimated from the hydrodynamic radius RH by DLS and NTA) and the literature molecular surface area of the surfactant | p.182 |
| R24 | record, cited (SA); derived (monolayer coverage, E2); measured (minimum effective concentration) | surfactant molecular surface area, calculated monolayer coverage of the nanodroplets and experimentally observed minimum concentration that prevented droplet coarsening — CPD nanodroplets in PB at 37 °C (P6); calculation in SI — sub-table below; text p.173: 50 μg/ml SDS needed, ≤5 μg/ml TPGS and TWN sufficient, CTAB unstable | Table IV, p.183; text p.173, p.182 |
| C41 | claim, conclusion, authors: "reasonable agreement" | For the non-ionic surfactants the calculated monolayer coverage agrees reasonably with the effective concentration; CTAB fails even above its theoretical minimum [rests on: R24] | p.182 |