Table 2 Passive targeted drug delivery systems of norcantharidin

NCTD liposomes

Drug/lipids ratio = 1: 20, phospholipid/cholesterol ratio = 2: 1, pH = 6.8 (Film hydration method)

Size: 360 nm, EE: 47.5%

-

[56], 2005

NCTD proliposome

1.0 g soybean lecithin, 0.823 g cholesterol, 85 mL double distilled water, 2.5 g trehalose (Ultrasound-nanomachine method and freeze-drying method)

Size: 580 nm, EE: (38.3 ± 0.06) %, zeta potential: -44.23 mV, viscosity: 1.83 mPa·s, freezing point depression value: 0.64 ℃

LD₅₀: NCTD proliposome = 47.4 mg/kg, NCTD = 25.4 mg/kg;

H22 tumor inhibition rate: NCTD (3 mg/kg, ip., 1–7 day) = 37.6%, NCTD proliposome (10 mg/kg, ip., 1, 4 day) = 43.8%, NCTD proliposome (10 mg/kg, iv., 1, 4 day) = 48.4%

[57], 2006

NCTD proliposome

Drug/lipids = 0.346, cholesterol/ phospholipid = 0.038, 0.9% phospholipid, 0.8% NCTD (Ethanol injection method and freeze-drying method)

EE: 33.10%, pH: 7.8, repose angle: 30º

NCTD concentration in plasma, liver: NCTD proliposome > NCTD injection

[58], 2008

Disodium norcantharidate liposome

Drug/lipids ratio = 1: 20, phospholipid/cholesterol ratio = 8:1, water phase/oil phase = 1: 4 (Reverse evaporation method)

Size: 243.1 nm, zeta potential: -22.94 mV, pH: 7.54 ± 0.13, EE: (34.34 ± 1.21) %

Liposome/solution: t_1/2, V1/F, CL/F, AUC, MRT ↑; targeting efficiency in kidney ↓; relative uptake efficiency in heart, liver, spleen, lung, kidney, brain, stomach, intestine, uterus > 1

[59], 2009

NCTD liposome

Phospholipid/drug quality ratio = 10: 1, phosphatide/cholesterol mass ratio = 5: 1 (Reverse film evaporation technique)

Size: (90.50 ± 2.40) nm,

EE: (34.7 ± 1.3) %

-

[60], 2012

NCTD-loaded PEG-PLC diblock copolymer micelles

Drug/PEG-PLC diblock copolymer quality ratio = 0.0625: 1, solvent: tetrahydrofuran (Volatile dialysis method)

Size: (95.6 ± 10.1) nm, drug loading: (6.0 ± 0.3) %, EE: (79.1 ± 0.8) %

HepG2 cells (NCTD: IC₅₀ = 26.00 µg/mL, micelles: IC₅₀ = 22.13 µg/mL); A549 cells (NCTD: IC₅₀ = 27.27 µg/mL, micelles: IC₅₀ = 11.54 µg/mL); A2780 cells (NCTD: IC₅₀ = 26.40 µg/mL, micelles: IC₅₀ = 9.87 µg/mL);

S180 tumor inhibition rate (iv., 8 days): NCTD (2 mg/kg) = 47.5%, micelles (2, 4 mg/kg) = 61.36%, 77.63%

[62], 2012

NCTD-loaded poloxamer polymer micelles

200 mg poloxamer F127, 10 mg NCTD, solvent: absolute ethanol (Thin-film hydration method)

Size: 10.3 nm, EE: 98%, drug-loading coeffieient: 4.67%

-

[63], 2015

NCTD-loaded micelles

DSPE-PEG2000-MAL, NCTD, solvent: absolute ethanol

Size: (138.6 ± 45.8) nm, drug-loading rate: (2.82 ± 0.05) %, EE: (83.67 ± 1.78) %, zeta potential: -(12.75 ± 0.34) mV

A549 tumor inhibition rate (iv., 1 time/2 days, 8 weeks): NCTD (1 mg/kg) = 54.78%, micelles (1 mg/kg) = 64.35%

[64], 2017

NCTD-loaded PLGA nanoparticle

25 mg PLGA, 2.5–25 mg NCTD (Interfacial deposition method)

Size: about 150 nm, EE: 95%

LD₅₀: nanoparticle = 66.7 ± 3.9 mg/kg, NCTD = 25.4 ± 1.9 mg/kg;

H22-H tumor inhibition rate: NCTD (3 mg/kg, ip., 1–7 day) = 37.6%, nanoparticle (10 mg/kg, ip., 1, 4 day) = 43.8%, nanoparticle (10 mg/kg, iv., 1, 4 day) = 48.4%;

LA795 tumor inhibition rate: NCTD (6 mg/kg, ip., 1–7 day) = 36.3%, nanoparticle (16 mg/kg, ip., 1, 4, 7 day) = 47.4%

[66], 2009

NCTD-loaded PLA-PEG nanoparticle

0.04 g PLA-PEG, 0.06 g NCTD (Phase separation method)

Size: (97.4 ± 14.5) nm, EE: (51.7 ± 1. 32) %

Inhibition rate of GBC-SD cells at IC₅₀: NCTD = (23.14 ± 3.77) µg/mL, nanoparticle = (56.42 ± 9. 45) µg/mL

[68], 2007

NCTD-HPCS nanoparticle

NCTD: 2 mg/mL, HPCS: 1 mg/mL, tripolyphosphate: 1 mg/mL (Ionic crosslinking method)

Size: 95.15 ± 3.18 nm, EE: (23.68 ± 1.79) %, drug loading: (54.53 ± 2.61) %

BEL-7402 cells: NCTD: IC₅₀ = (283.72 ± 4.55) µg/mL, nanoparticle: IC₅₀ = (194.26 ± 3.69) µg/mL

[70], 2012

PVP-NCTD-NPs

0.1 g CS, 0.04 g NCTD, 7.5 mL of 1.2 mg/mL aqueous solution of TPP, 0.26 g PVP K₃₀ (Ionic gelation

between chitosan and sodium tripolyphosphate)

Size: (140.03 ± 6.23) nm; EE: (56.33 ± 1.41) %; drug-loading efficiency: (8.38 ± 0.56) %

PVP-NCTD-NP/NCTD (relative bioavailability): oral: 173.3%, iv.: 325.5%; targeted index (iv.): 1.168

[72], 2012

NCTD-SLN

Drug/stearic acid ratio = 0.3512, soybean lecithin: 125.10 mg/100 mL, poloxamer: 7.82 mg/mL, oil film/water phase volume ratio: 0.1286 (Thin film-ultrasonic dispersion method)

Size: (189 ± 6.0) nm, zeta potential: (-23.15 ± 0.17) mV, pH: 5.4-6.0, drug loading: 10.12%, EE: (55.4 ± 1.2) %

NCTD-SLN/NCTD solution in plasma: t_1/2, AUC, MRT ↑, V_d, CL ↓;

NCTD-SLN/NCTD solution in liver: relative uptake rate = 1.59, targeting efficiency = 1.45, peak concentration ratio = 1.36

[74], 2007

NCTD-NLC

NCTD-NE (W/O): 10.5 mg NCTD, 1.6511 g ethyl oleate, 0.6018 g cremophor, 0.4521 g PEG 400, 0.3 mL water;

NCTD-NLC: 1.0 mL NCTD-NE (W/O), 127.0 mg glyceryl monostearate, 102.1 mg lecithin, 51.0 mg glyceryl tripalmitate, 6.1 mg stearamide, 131.0 mg Tween-80, 20.0 mL dichloromethane, 5 mL water

-

NCTD concentration in liver and tumor (iv.): NCTD-NLC >

NCTD;

HepG2 cells: 100 µmol/L NCTD/NCTD-NLC (48 h), cell viability = 58.72%, 42.82%; cell apoptosis: 15.56%, 20.82%;

HepG2 tumor inhibition rate (32.6 mg/mouse, iv.): NCTD = 19.15%, NCTD-NLC = 27.48%

[76], 2022

NCTD cubic liquid crystalline nanoparticle

Glyceryl monooleate/F127: 9: 1, 0.5 g NCTD, Glyceryl monooleate/water: 1: 500 (Emulsification method)

Size: 140 nm, zeta potential: -21 mV, EE: 45.33%

-

[78], 2017

NCTD-loaded mesoporous silica nanoparticle

NCTD, mesoporous silica nanoparticle (Midified Stober method and saturated solution adsorption method)

Size: about 140 nm (PDI < 0.3), zeta potential: about 35 mV, surface area: 1165.5 m²/g, cumulative pore volume: 2.16 cm³/g, pore size: 2.86 nm, drug loading rate: 12.88%

-

[80], 2018

Strontium/chitosan/hydroxyapatite/NCTD composite biomaterial

3 g CS, 42 g SrCl₂, 12 g Ca(OH)₂, 30 g KH₂PO₄, 5/6 g, 5/3 g, 5/2 g NCTD (Coprecipitation and freeze-drying method)

-

MG-63 cells (caspase-3 ↑, caspase-9 ↑, MMP-9 ↓); MC3T3-E1 cells (ALP ↓, runt-associated transcription factor 2 ↓, osteocalcin ↓, osteopontin ↑)

[84], 2020

DMCA-Zn1 NPs and DMCA-Zn2 NPs

DMCA-Zn1: NCTD (0.003 g, 0.0176 mmol), Zn(NO₃)₂·6H₂O (0.004 g, 0.012 mmol);

DMCA-Zn2: NCTD (0.006 g, 0.0356 mmol), Zn(NO₃)₂·6H₂O

(0.003 g, 0.010 mmol);

DMCA-Zn1 NPs: 2 mg DMCA-Zn1 crystals, 8 mg F127, 0.1 mL deionized water (A process of mechanical grinding, ultrasonic treatment and filtration)

Size: DMCA-Zn1 NPs: around 190 nm,

DMCA-Zn2 NPs: around 162 nm

Fluorescence intensity of Hep3B xenograft mice (iv.): liver and tumor: Nile red < DMCA-Zn1 NPs < DMCA-Zn2 NPs; kidneys: Nile red > DMCA-Zn2 NPs > DMCA-Zn1 NPs;

IC₅₀ of HepG2 and Hep3B cells: DMCA-Zn1 NPs and

DMCA-Zn2 NPs < NCTD; cytotoxicity to L929 normal cells: DMCA-Zn1 NPs and DMCA-Zn2 NPs < NCTD

Hep3B tumor inhibition rate: NCTD = (54.89 ± 5.84) %, DMCA-Zn1 NPs = (67.72 ± 2.18) %, DMCA-Zn2 NPs = (62.96 ± 6.94) %;

nanoparticle: no obvious liver and kidney injury (H&E and ALP, ALT, AST, BUN, UA)

[87], 2022

NCTD nanosuspension

22% hydroxypropyl cellulose-SL, 1% sodium dodecyl sulfate, 5 g NCTD (Wet media milling method)

Size: (325.4 ± 4.1) nm, PDI: 0.184 ± 0.009, zeta potential: (-32.5 ± 1.8) mV

-

[88], 2019

NCTD-loaded W/O microemulsion

7% water, 45% soybean lecithin/ethanol (2: 1), 48% ethyl oleate

Size: (44.5 ± 8.6) nm

NCTD microemulsion/injection in plasma: AUC, MRT, t_1/2 ↑, V_d, CL ↓;

NCTD microemulsion/injection in liver: overall targeting efficiency = 6.10 ± 0.15, 3.66 ± 0.14, targeting index = 3.55, relative overall targeting efficiency = 0.67; kidney: overall targeting efficiency = 0.03 ± 0.01, 0.06 ± 0.05

[90], 2005

NCTD-SNEDDS

50% Ethyl Oleate, 35% Cremophor EL, 15% ethylene glycol, 10 mg NCTD

Size: 36.31 nm, PDI: 0.05

-

[92], 2017

NCTD solid self-microemulsion

NCTD, polyoxyethylene hydrogenated castor oil, 1,2-propylene glycol, castor oil, 0.08% sodium dodecyl sulfate aqueous solution, ethyl cellulose, SiO₂ (Spherulite technology one-step curing method)

Size: 22.76 nm, zeta potential: -2.77 mV, EE: 77.39%, yield: 84.5%

-

[93], 2017

NCTD-conjugated chitosan conjugates (NCTD-CSs)

1 g chitosan (6.2 mmol calculated as glucosamine units), 15 mL MeSO₃H, NCTD (1.0, 3.0 equiv/glucosamine units of chitosan) (Covalent attachment of NCTD to chitosan using the MeSO₃H as reaction solvent)

NCTD-CS1/ NCTD-CS2: DS = 60.2% and 97.9%, NCTD content = 38.4%, 48.4%, water solubility = 50.8, 74.2 mg/mL

MGC80-3 cells: NCTD/NCTD-CS1/ NCTD-CS2: IC₅₀ = 5.43, 28.2, 48.5 µg/mL;

early and late apoptotic cells (48 h): NCTD = (8.03 ± 0.16) %, (21.9 ± 1.01) %, NCTD/CS1 = (12.8 ± 0.18) %, (40.2 ± 5.3) %

[94], 2013

NCTD-CS

5.04 g NCTD, 1.61 g CS (Alcoholysis reaction)

The degrees of NCTD grafting of NCTD-CS (mol/monomer mol):

89.6%, NCTD

mass fractions: 48.0%

IC₅₀ of NCTD, NCTD-CS on ECA-109 cell (48 h): (9.4 ± 0.9), (168.8 ± 8.9) mg/mL, on EMT6 cell: (3.1 ± 0.3), (90.7 ± 8.1) mg/mL;

induce cell apoptosis and arrest cell cycle at the S phase; activate caspase-8 and caspase-3;

EMT6 tumor inhibition rate (iv.): NCTD (10 mg/kg, once daily, 8 days) = (35.87 ± 6.25) %, NCTD-CS [1 and 5 day, 83 mg/kg (40 mg/kg

NCTD-equivalent dose)] = (45.82 ± 12.12) %

[95], 2014

NCTD-conjugated hydroxypropyltrimethyl ammonium chloride chitosan derivatives (NCTD-HACCs)

1 g HACC, 15 mL MeSO₃H, NCTD (1.0, 2.0 equiv/glucosamine units of HACC)

NCTD-HACC1/ NCTD-HACC2: DS = 12.2%, 24.8%, NCTD content = 9.29%, 17.0%, water solubility = 18.8, 26.2 mg/mL

In vivo NIR fluorescence real-time imaging (iv.): tumor > heart, liver, spleen and lung (except kidney);

S180 tumor inhibition rate (one injection each day, 7 days): NCTD = 25.41%, HACC = 47.57%, NCTD-HACC2 = 42.70%

[97], 2013

NCTD-conjugated carboxymethyl chitosan conjugate (CNC)

1 g CMCS, NCTD (1.0 equiv., 0.7 g) (Chemical grafting technique)

DS = 30.10%, NCTD content = 20.05%

CNC/NCTD: AUC, t_1/2, MRT ↑, CL, V_d ↓; relative uptake efficiency: liver, spleen = 1.438, 1.585 (> 1); heart, kidney = 0.790, 0.714 (< 1);

BEL-7402 cells: CNC: enhance cytotoxicity compared with free NCTD, inhibit migration, induce apoptosis;

H22 tumor inhibition rate (ip., every other day for 12 days): NCTD (6.524 mg/kg) = 30.27%, CNC (32.62, 16.31 and 8.16 mg/kg) = 49.65%, 56.20%, 47.73%; TNF-α, IFN-γ ↑; heart, spleen, kidney toxicity ↓

[98], 2019

NCTD-conjugated carboxymethyl chitosan (CMCS-NCTD)

CMCS, NCTD (Chemical grafting technique)

DS = 30.81%, NCTD content = 20.05%

H22 tumor: CMCS-NCTD (3.12, 6.25, 12.5 mg/kg, ip., every other day for 12 days): liver index ↓; TNF-α, IFN-γ, TIMP-1, E-cadherin ↑; ALT, AST, VEGF, MMP-9 ↓; SOD, GSH-Px ↑

[99], 2017

CMCS-NCTD

1.0 equiv./glucosamine units of CMCS, NCTD (Chemical grafting technique)

DS = 30.10%, NCTD content = 20.05%

A549 cells: CMCS-NCTD: obvious cytotoxicity, inhibit migration;

Lewis lung carcinoma metastasis model, tumor inhibition rate (ip., every other day for 14 days): NCTD (6.524 mg/kg) = 35.39%, CMCS-NCTD (32.62, 16.31 and 8.16 mg/kg) = 64.58%, 50.57%, 47.71%; median survival time: NCTD = 30 days, CMCS-NCTD (32.62 mg/kg) = 39 days; VEGF, MMP-9 ↓, TIMP-1 ↑

[100], 2019

CNC

0.2 g CMCS, NCTD (1.0 equiv.) (Amidation reaction)

NCTD content = 20.05%

SGC-7901 cells: CNC: inhibit proliferation, anti-angiogenesis effect, induce apoptosis;

SGC-7901 tumor inhibition rate (iv., every other day for 24 days): NCTD (6.524 mg/kg) = 40.46%, CMCS-NCTD (32.62, 16.31 mg/kg) = 59.57%, 50.64%; the density of positive microvessels in NCTD, high and low dose of CNC group were decreased by 13.27%, 26.39% and 20.51%, compared with that of control group; TNF-α, Bax, Caspase-3 ↑, CD34, VEGF, MMP-2, MMP-9, Bcl-2 ↓

[101], 2019

NCTD-PVA

5.04 g NCTD, 1.76 g PVA (Alcoholysis reaction)

The degrees of NCTD grafting of NCTD-CS (mol/monomer mol):

10.4%, NCTD

mass fractions: 38.8%

IC₅₀ of NCTD, NCTD-CS on ECA-109 cell (48 h): (9.4 ± 0.9), (55.3 ± 3.0) mg/mL, on EMT6 cell: (3.1 ± 0.3), (30.5 ± 5.4) mg/mL;

induce cell apoptosis and arrest cell cycle at the S phase; activate caspase-8 and caspase-3;

EMT6 tumor inhibition rate (iv.): NCTD (10 mg/kg, once daily, 8 days) = (35.87 ± 6.25) %, NCTD-PVA [1, 3 5 and 7 day, 52 mg/kg (20 mg/kg NCTD-equivalent dose)] = (56.17 ± 11.34) %

[95], 2014

NCTD-loaded lipid microsphere

A mixture of soybean oil and MCT 10 g; lecithin 1.2 g;

Tween 80 20 mg, glycerol 2.5 g, DL-α-tocopherol 300 mg, sodium oleate 30 mg; EDTA 20 mg, NCTD 200 mg, doubly distilled water, qs 100.0 g (High-pressure homogenization process)

2 mg/mL NCTD, zeta potential: about − 38 mV

-

[45], 2006

NCTD-loaded lipid microsphere

Medium-chain triglyceride oil (MCT) (7.5%, w/v), Long-chain triglyceride (LCT) (2.5%, w/v),

Egg phospholipids PL-100 M (3.6%, w/v), NCTD (0.2%, w/v);

Poloxamer 188 (Pluronic F68) (0.4%, w/v), glycerin (2.5%, w/v), sodium oleate (0.03%, w/v) (Homogenization method)

Size: 167.4 ± 63.1 nm, zeta potential: -31.6 mV, EE: 84.9%

Microsphere/injection: no significant differences in

pharmacokinetic parameters; the content and AUC of NCTD in heart: microsphere < injection;

A549, BEL7402, BCAP-37 tumor inhibition rate (iv., once a week): A549: injection (2.5 mg/kg) = 68.7%, microsphere (1.25, 2.5, 5.0 mg/kg) = 39.2%, 65.6%, 73.1%; BEL7402: injection (2.5 mg/kg) = 65.9%, microsphere (1.25, 2.5, 5.0 mg/kg) = 58.9%, 64.2%, 70.4%; BCAP-37: injection (2.5 mg/kg) = 65.9%, microsphere (1.25, 2.5, 5.0 mg/kg) = 56.3%, 57.3%, 70.7%;

LD₅₀ and 95% confidence limit for female mice and male mice: injection = 10.10 (8.33–13.10), 8.93 (6.92–11.77) mg/kg; microsphere = 15.67 (13.61–17.58), 16.64 (15.14–18.25) mg/kg;

white blood cell count (WBC): microsphere = (18.5 ± 3.4 × 10⁹ L^− 1), injection = (15.6 ± 2.4 × 10⁹ L^− 1), NCTD = (11.8 ± 2.4 × 10⁹ L^− 1);

cardiac and renal toxicity: injection = 66.7% (20/30),

73.3% (22/30), microsphere = no obvious damage to the heart,

33.3% (10/30); no hemolysis or erythrocyte agglutination; no obvious intravenous irritation; no hypersensitivity reactions

[103], 2012

NCTD-loaded lipid microsphere (NPCLM)

NCTD-phospholipid complex (NPC): phospholipids (E80), cholesterol, NCTD; MCT 10% (w/v), oleic acid 0.06% (w/v), 2.5% (w/v) glycerol, 0.4% (w/v) F-68, 0.04% (w/v) EDTA, 0.8% (w/v) PL-100 M (Concentrated homogenization method and phospholipid complex method)

Size: (173.2 ± 41.6) nm, zeta potential: -34.54 mV, EE: (84.6 ± 0.62) %,

pH: 7.69, content: (99.53 ± 0.11) %

Relative tissue exposure in liver, spleen, lung and kidney: NPCLM/injection = 1.67, 1.49, 1.06 and 0.96

[104], 2014

NCTD encapsulated albumin microspheres

about 30 mg NCTD, 2.5 mL diethyl ether, castor oil (25 mL) containing a surfactant (0.25 g span-80), 25% glutaraldehyde solution, 1 mL aqueous mannitol (20%, w/v) (Emulsion cross-linking method)

Size: (13.3 ± 0.4) µm, EE: (54.3 ± 4.18) %, PDI: 0.129 ± 0.039, zeta potential: -(12.1 ± 0.8) mV

Pharmacokinetic parameters: microsphere/injection: AUC, t_1/2, MRT ↑, CL ↓; target index: liver, spleen = 3.49, 1.03 (> 1); heart, kidney = 0.79, 0.92 (< 1); no histological change occurred to the rat liver

[106], 2015

NCTD-loaded chitosan microsphere

Liquid paraffin, Span-80, formaldehyde, chitosan, NCTD (Emulsification cross-linking process)

Size: (25 ± 10) µm, drug-loading rate: (15.08 ± 2.85) %, EE: (57.80 ± 1.35) %

-

[107], 2008

NCTD loaded-emulsion-hybrid nanoparticle (NLEH)

NCTD phospholipid complexes [phospholipids (E80), cholesterol and NCTD (10:2.5:1)], MCT, oleic acid, glycerol, Poloxamer 188 and PL-100 M (High-pressure homogenization method)

Size: (163.8 ± 1.082) nm, PDI: 0.084, zeta potential: -(38.0 ± 7.11) mV, EE: 89.3%, drug loading: 2 mg/mL, pH: about 7.40

Cellular uptake ↑; inhibit H22 cell proliferation, induce cell apoptosis ↑; NLEH/NCTD solution in plasma: AUC, t_1/2 ↑, CL ↓; NLEH/NCTD solution: targeting efficiency in tumor, liver and spleen = 1.19, 1.40, 1.21 > 1, targeting efficiency in kidneys, heart = 0.77, 0.73 < 1; enhance tumor penetration; H22 tumor inhibition rate (iv., twice a week, 3 weeks, 2.7 mg/kg): NLEH > NCTD solution; improve immunity: the leukogenic effect, the spleen index ↑

[108], 2022