Multi-compartment linear circulation mathematical model for targeted drug delivery systems was established on the bases of compartment theory and mass conservation theory. The function formulas of drug concentration-time in blood and target organ were established. According to this model, the drug concentration-time curve for the target organ can be plotted with reference to the data on blood. Based on the target organ drug concentration-time curve,the pharmacokinetics parameters of the target organ can also be calculated by the statistical moment. We further detected the practicability of the models by using the experimental data of drug concentration-time curve in blood and target organ of microspheres. The drug concentration-time curve in blood and in target organ predicted by mathematical model was agreed with that observed.
Albumins ; administration & dosage ; Drug Delivery Systems ; Humans ; Microspheres ; Models, Theoretical ; Pharmacokinetics

AIMTo develop a method for direct determination of perfluoropropane in canine whole blood and to study its pharmacokinetics after a suspension of perfluoropropane-containing albumin microcapsules was administered intravenously.

METHODSPerfluoropropane-containing albumin microcapsule suspension was administered intravenously to anesthetized canines at the dosage of 0.6 mL x kg(-1). Whole blood samples were collected and added directly into the purging glass tube in Tekmar 3000 Purge and Trap Concentrator coupled with a GC-MS for the determination of perfluoropropane. The pharmacokinetic parameters of perfluoropropane were calculated by non-compartment model statistics.

RESULTSThe linear range was 0.0168-4.03 mg x L(-1). The main pharmacokinetic parameters of perfluoropropane was obtained as follows: mean residence time (MRT) was (63 +/- 5) s, T1/2 was (44 +/- 4) s, Tmax was 30 s, Cmax was (2.20 +/- 0.20) mg x L(-1), AUC0-infinity was (96 +/- 11) mg x s x L(-1).

CONCLUSIONThe method is sensitive, specific and simple. It can be used to determine fluorocarbon contained in microcapsule ultrasound contrast agents for studying its pharmacokinetics.

Albumins ; Animals ; Area Under Curve ; Capsules ; Dogs ; Fluorocarbons ; administration & dosage ; blood ; pharmacokinetics ; Gas Chromatography-Mass Spectrometry ; methods ; Injections, Intravenous

OBJECTIVETo observe the change in albumin concentration in the subeschar tissue fluid of rabbits in early stage after burn, and to analyze its regular pattern.

METHODSThirty-four adult male New Zealand rabbits were divided into control group and experiment group according to the random number table, with 17 rabbits in each group. Rabbits in experiment group were subjected to 8% TBSA full-thickness scald on the back and were injected with human serum albumin in subeschar tissue serving as tracing albumin. 1.5 mL blood sample was collected at post scald hour (PSH) 2, 4, 8, 16, 24, 48, 72 respectively. Rabbits in control group were dealt with the above-mentioned procedures except for scald. The concentration of tracing albumin was measured with the enzyme-linked immunosorbent assay kit. The concentration of the serum albumin of rabbits were determined with biochemical analyzer. Pharmacokinetics parameters of tracing albumin were calculated with fitting model of 3P97 practical pharmacokinetics calculating program.

RESULTS(1) Concentration of tracing albumin of rabbits in experiment group was respectively higher than that in control group (P < 0.01) at each time point, and it peaked at PSH 8 [(421 +/- 10) microg/L]. (2) The concentration of serum albumin of rabbits in experiment group decreased in the beginning and increased later, while no significant change was observed in control group. (3) The distribution phase half-life of tracing albumin of rabbits in experiment group (4.0271 h) was about 1/3 of that of the control group (12.0907 h); while the area under the curve in the experiment group (22 336.38 microg.h.mL(-1)) was about 4 times of that in the control group (5827.77 microg.h.mL(-1)).

CONCLUSIONSThe albumin in the subcutaneous tissue could be absorbed into blood circulation in normal conditions. The resorption occurs earlier and faster and more when obvious inflammation occurs (such as deep burn). Exudation and resorption of albumin co-exist in the early stage after burn.

Albumins ; pharmacokinetics ; therapeutic use ; Animals ; Burns ; metabolism ; therapy ; Edema ; metabolism ; Fluid Therapy ; Male ; Rabbits ; Subcutaneous Tissue ; metabolism

OBJECTIVETo develop a method for quantitative collection of exhaled gas in anesthetized dogs at given time following intravenous administration of octafluoropropane (OFP)-containing human albumin micropheres for assessing the gas kinetics of OFP.

METHODSOFP-containing albumin micropheres were administered intravenously at 0.4, 0.8 and 1.2 ml/kg, respectively, in anesthetized and ventilated dogs. The exhaled air samples were analyzed by gas chromatography-tandem mass spectrometry (GC-MS-MS).

RESULTSThe correlation curve between the area under curve (AUC) and administered dose was roughly linear (Y=1162.5X-417.38, r square=0.949 9). The total recovery rate was (119.49-/+27.62)% which was not significantly different from the rate of 100% (P>0.05). GC-MS-MS was accurate, sensitive, precise and applicable for OFP determination.

CONCLUSIONThe sampling method is useful for characterizing OFP pharmacokinetics in dogs, and also applicable for studying the pharmacokinetics of other gas-containing drugs.

Albumins ; administration & dosage ; analysis ; pharmacokinetics ; Animals ; Dogs ; Exhalation ; Female ; Fluorocarbons ; administration & dosage ; analysis ; pharmacokinetics ; Gas Chromatography-Mass Spectrometry ; methods ; Humans ; Injections, Intravenous ; Male ; Microspheres ; Reproducibility of Results

OBJECTIVETo prepare carbon nanoparticle-paclitaxel suspension(CNPS) and to study the pharmacokinetics of intraperitoneal chemotherapy with CNPS.

METHODSSaturated absorption capacity of carbon nanoparticle suspension (CNS) and paclitaxel were detected by high performance liquid chromatography in order to prepare the above suspension. Wistar rats were randomly divided into the experimental group (A) and the control group (B), to which intraperitoneal injections of CNPS and paclitaxel were given respectively. At different time points, measure the blood samples, mesenteric lymph nodes, and intraperitoneal lavage fluid were collected to measure the concentration of paclitaxel.

RESULTSOne ml CNS could absorb 7 mg paclitaxel by maximum. The ratio of area under the curve (AUC) in the plasma of group A to group B was 0.63. The ratio of AUC in lymph nodes of group A to group B was 0.75 and that in intraperitoneal lavage fluid was 1.25. The metabolic half-life (t1/2) of paclitaxel in the plasma of group A was 1.61 times as long as that of group B. The t1/2 of paclitaxel in intraperitoneal lavage fluid of group A was 0.88 as long as that of Group B. The t1/2 of paclitaxel in lymph nodes of group A was 1.10 as long as that of Group B.

CONCLUSIONSCNS has a high absorption capacity with paclitaxel. Intraperitoneal chemotherapy by CNPS is characterized by low drug concentration in the blood, high drug concentration in the peritoneal cavity and high safety. However, the targeting and lymphatic retention effect are not significant. The mechanism warrants further investigation.

Albumin-Bound Paclitaxel ; Albumins ; chemistry ; pharmacokinetics ; Animals ; Area Under Curve ; Carbon ; chemistry ; Injections, Intraperitoneal ; Lymph Nodes ; Nanoparticles ; administration & dosage ; Paclitaxel ; chemistry ; pharmacokinetics ; Rats ; Rats, Wistar

To observe the pharmacokinetic and tissue-distribution characters of 5-flourouracil magnetic albumin deuto-microsphere (5-Fu-MAD) in normal and tumor-bearing mice, HPLC method for the determination of 5-Fu in plasma and tissues was established and applied to determine 5-Fu in mouse plasma and tissue samples. A Flame atomic absorption spectrometer was used to detect the iron concentration in mouse tissue. Plasma concentration-time curves of free 5-Fu, 5-Fu-MAD and 5-Fu-MAD plus the magnetic frame (MF) conformed to two compartment model of first order absorption and they had C(max) of 34.9, 7.95 and 5.97 mg x L(-1); T1/2 (Ke) of 22.26, 76.0 and 124.6 min, V(d) of 3.28, 30.7 and 66.1 L x kg; AUC(0-t), of 233.9, 78.3 and 50.2 mg x min x L(-1); AUC(0-infinity) of 237.2, 89.3 and 68.1 mg x min x L(-1), respectively. The distribution of 5-Fu and iron was the highest in the plenty blood perfusion organs like the liver, tumor, spleen and lung, while lower in the kidney and heart and lowest in brain and muscle. The tissue distribution of muscle and tumor increased significantly when a magnetic frame was inserted there. The pharmacokinetics and tissue distribution of 5-Fu-MAD exhibited sustained-release and target characteristics.
Albumins ; chemistry ; Animals ; Antimetabolites, Antineoplastic ; administration & dosage ; pharmacokinetics ; Area Under Curve ; Cell Line, Tumor ; Delayed-Action Preparations ; Female ; Fluorouracil ; administration & dosage ; pharmacokinetics ; Liver ; metabolism ; pathology ; Liver Neoplasms, Experimental ; metabolism ; pathology ; prevention & control ; Magnetics ; Male ; Mice ; Microspheres ; Random Allocation ; Tissue Distribution

Objective Injured tubular reabsorption is highlighted as one of the causes of increased albuminuria in the early stage of diabetic nephropathy; however, the underlying mechanism has not been fully elucidated. In this study, we aimed to explore whether reducing inflammation and remodeling the insulin signaling pathway could improve albumin uptake of renal tubules. Methods 8-week-old male db/db mice (n=8), a type 2 diabetic nephropathy model, administered with nuclear factor kappa-B (NF-κB) inhibitor parthenolide (PTN, 1 mg/kg) intraperitoneally every other day for 8 weeks, were as the treatment group. Meanwhile, the age-matched male db/m mice (n=5) and db/db mice (n=8) were treated with saline as the control group and type 2 diabetic nephropathy group. When the mice were sacrificed, blood and urine were collected to examine homeostasis model assessment of insulin resistance (HOMA-IR) and urine albumin creatinine ratio, and kidney samples were used to analyze histopathologic changes with periodic acid-Schiff (PAS) staining, NF-κB p65, phosphorylation of AKT (p-AKT), amnionless and cubilin expressions with immunohistochemistry as well as western blot, and the albumin uptake of renal tubules by using immunofluorescence. In addition, HKC cells were divided into the insulin group treated with insulin alone, the TNF-α group treated with insulin and tumor necrosis factor (TNF-α), and the TNF-α+PTN group exposed to PTN, insulin and TNF-α. The levels of albumin uptake and expression levels of NF-κB p65, p-IRS-1/IRS-1, p-AKT/AKT, amnionless and cubilin in HKC cells were measured. Results Compared with the db/db group, the db/db+PTN group demonstrated decreased levels of HOMA-IR (36.83±14.09 vs. 31.07±28.05) and urine albumin creatinine ratio (190.3±7.3 vs. 143.0±97.6 mg/mmol); however, the differences were not statistically significant (P>0.05). Periodic acid-Schiff staining showed PTN could alleviate the glomerular hypertrophy and reduce the matrix in mesangial areas of db/db mice. The renal expression of NF-κB p65 was increased and p-AKT (s473) decreased in the db/db group compared with the db/m group (P<0.05). PTN significantly reduced the renal expression of NF-κB p65 and ameliorated the decline of p-AKT (s473) compared with the db/db group (P<0.05). Compared with the db/m group, the expression of amnionless and cubilin decreased and albumin uptake in tubules were reduced in the db/db group (P<0.05), and PTN could significantly increase the expression of cubilin (P<0.05), and improve albumin uptake in tubules. Insulin promoted albumin uptake and the expression of amnionless and cubilin in HKC cells (P<0.05). TNF-α stimulated the expression of NF-κB p65, increased p-IRS-1 (s307) and reduced p-AKT (s473) in HKC cells (P<0.05). In the TNF-α+PTN group, the expression of NF-κB p65 declined and p-IRS-1 (s307) and p-AKT (s473) were restored, compared with the TNF-α group (P<0.05). The expression of amnionless and cubilin decreased in the TNF-α group (P<0.05), and PTN could significantly increase the expression of cubilin (P<0.05). Conclusions Inflammation caused damage to insulin signaling, which reduced amnionless-cubilin expression and albumin uptake. PTN could reduce inflammation and remodel the impaired insulin signaling pathway, which promoted the expression of cubilin and albumin uptake. Our study can shed light on the role of inflammation in the reduction of albumin uptake of renal tubules in type 2 diabetic nephropathy.
Albumins/pharmacokinetics* ; Albuminuria/urine* ; Animals ; Anti-Inflammatory Agents, Non-Steroidal/pharmacology* ; Cell Line ; Creatinine/urine* ; Diabetes Mellitus, Type 2/complications* ; Diabetic Nephropathies/metabolism* ; Humans ; Insulin Resistance ; Kidney Tubules, Proximal/metabolism* ; Male ; Mice ; NF-kappa B/metabolism* ; Receptors, Cell Surface/metabolism* ; Sesquiterpenes/pharmacology*