Figures & data
Figure 1 Absorption spectra of 5-fluorouracil (5-FU) in enzyme-free simulated gastric fluid (SGF) and enzyme-free simulated intestinal fluid (SIF).
![Figure 1 Absorption spectra of 5-fluorouracil (5-FU) in enzyme-free simulated gastric fluid (SGF) and enzyme-free simulated intestinal fluid (SIF).](/cms/asset/baa37392-fff9-40c0-8b90-18a0c00920f3/dddt_a_12182299_f0001_c.jpg)
Figure 2 Representative HPLC chromatograms of 5-fluorouracil (5-FU) in rabbit plasma: (A) blank plasma; (B) blank plasma spiked with 5-FU; and (C) plasma sample after oral administration of 5-FU hollow microspheres.
![Figure 2 Representative HPLC chromatograms of 5-fluorouracil (5-FU) in rabbit plasma: (A) blank plasma; (B) blank plasma spiked with 5-FU; and (C) plasma sample after oral administration of 5-FU hollow microspheres.](/cms/asset/302bd42a-349d-4cec-b660-aa6e17244d1a/dddt_a_12182299_f0002_b.jpg)
Figure 3 Representative HPLC chromatograms of 5-fluorouracil (5-FU) in tumor-bearing mice biosamples: (A) blank tumor; (B) blank tumor spiked with 5-FU; and (C) tumor sample after oral administration of 5-FU hollow microspheres.
![Figure 3 Representative HPLC chromatograms of 5-fluorouracil (5-FU) in tumor-bearing mice biosamples: (A) blank tumor; (B) blank tumor spiked with 5-FU; and (C) tumor sample after oral administration of 5-FU hollow microspheres.](/cms/asset/154c8df4-d48a-4b80-bba8-b6b5c850d236/dddt_a_12182299_f0003_b.jpg)
Table 1 The effect of Span 80 concentration in the liquid paraffin on particle size, drug loading amount, and production yield of 5-fluorouracil hollow microspheresTable Footnotea
Table 2 The effect of ether/ethanol volume ratio on particle size, drug loading amount, and production yield of 5-fluorouracil hollow microspheresTable Footnotea
Table 3 The effect of PVP/EC weight ratio on particle size, drug loading amount, and production yield of 5-fluorouracil hollow microspheresTable Footnotea
Figure 4 Effect of PVP/EC weight ratio on floating behavior of 5-fluorouracil hollow microspheres in simulated gastric fluid (A) and simulated intestinal fluid (B).
Abbreviations: EC, ethyl cellulose; PVP, polyvinyl pyrrolidone.
![Figure 4 Effect of PVP/EC weight ratio on floating behavior of 5-fluorouracil hollow microspheres in simulated gastric fluid (A) and simulated intestinal fluid (B).](/cms/asset/a75318a5-d73d-4f9d-af87-8b304b36d3c0/dddt_a_12182299_f0004_c.jpg)
Figure 5 Effect of PVP/EC weight ratio on in vitro release behavior of 5-fluorouracil hollow microspheres in simulated gastric fluid (A) and simulated intestinal fluid (B).
Abbreviations: EC, ethyl cellulose; PVP, polyvinyl pyrrolidone.
![Figure 5 Effect of PVP/EC weight ratio on in vitro release behavior of 5-fluorouracil hollow microspheres in simulated gastric fluid (A) and simulated intestinal fluid (B).](/cms/asset/81f2c909-4539-4540-91da-aed4929805bc/dddt_a_12182299_f0005_c.jpg)
Table 4 The particle size, drug loading amount, and production yield and floating efficiency of 5-fluorouracil hollow microspheresTable Footnotea
Figure 6 Scanning electron microscopy photographs of 5-fluorouracil hollow microspheres (batch: 20120401).
![Figure 6 Scanning electron microscopy photographs of 5-fluorouracil hollow microspheres (batch: 20120401).](/cms/asset/f7db286a-24d9-48f2-a4ad-ad366e714d6c/dddt_a_12182299_f0006_b.jpg)
Figure 7 Percentage cumulative release of three batches of 5-fluorouracil hollow microspheres in simulated gastric fluid (A) and simulated intestinal fluid (B).
![Figure 7 Percentage cumulative release of three batches of 5-fluorouracil hollow microspheres in simulated gastric fluid (A) and simulated intestinal fluid (B).](/cms/asset/88f11cd7-fc0c-4fb2-90d5-c89d5b398dfa/dddt_a_12182299_f0007_c.jpg)
Table 5 Pharmacokinetic parameters of 5-FU after oral administration of 5-FU hollow microspheres and its solid microspheres and powder to rabbits at a dose of 50 mg/kg body weightTable Footnotea
Figure 8 Plasma drug concentration–time curve after oral administration of 5-fluorouracil (5-FU) hollow microspheres and its solid microspheres and powder to rabbits at a dose of 50 mg/kg body weight.
![Figure 8 Plasma drug concentration–time curve after oral administration of 5-fluorouracil (5-FU) hollow microspheres and its solid microspheres and powder to rabbits at a dose of 50 mg/kg body weight.](/cms/asset/d8845298-e2f8-480f-8d7e-2ca6309a2d66/dddt_a_12182299_f0008_c.jpg)
Figure 9 Drug distribution in plasma, tumor, and main tissues including heart, liver, spleen, lung, kidney, and stomach in tumor-bearing mice after oral administration of 5-fluorouracil (5-FU) hollow microspheres as a test formulation and its solid microspheres and powder as controls in the sodium carboxymethyl cellulose suspension form at a dose of 72 mg/kg body weight.
Abbreviation: h, hours.
![Figure 9 Drug distribution in plasma, tumor, and main tissues including heart, liver, spleen, lung, kidney, and stomach in tumor-bearing mice after oral administration of 5-fluorouracil (5-FU) hollow microspheres as a test formulation and its solid microspheres and powder as controls in the sodium carboxymethyl cellulose suspension form at a dose of 72 mg/kg body weight.](/cms/asset/fab76d98-1967-413c-8b72-289ae035daed/dddt_a_12182299_f0009_c.jpg)