Hepatic tissue distribution of doxorubicin-loaded nanoparticles after i.v. administration in reticulosarcoma M 5076 metastasis-bearing mice.

In our previous studies, doxorubicin-loaded polyisohexylcyanoacrylate nanoparticles have been proven to increase dramatically the antitumoral activity of the cytotoxic agent in metastasis-bearing mice. The experimental model consisted of metastases induced by i.v. inoculation of reticulosarcoma M 5076 cell suspension to C57BL/6 mice. The improved efficacy of the drug was noted in terms of either metastasis count or survival. Therefore, tissue-distribution studies of this drug delivery system within the metastatic liver after i.v. administration were undertaken to gain more insight into the mechanism of action. Doxorubicin measurements in healthy hepatic or neoplastic tissue were carried out together with histological examinations using transmission electron microscopy. These results demonstrated the hepatic tissue to be an efficient reservoir of the drug when it was injected associated with nanoparticles. Accumulation of biodegradable nanoparticles with associated doxorubicin in Kupffer cells created a gradient of drug concentration for a massive and prolonged diffusion of the free drug towards the neoplastic tissue.

Pharmacokinetics of perindopril and its metabolites in healthy volunteers.

Perindopril, an angiotensin converting enzyme (ACE) inhibitor, is converted in vivo to its active diacid metabolite, perindoprilat and to a perindoprilat glucuronide. The pharmacokinetic parameters of perindopril, perindoprilat and perindoprilat glucuronide were evaluated after single administration to healthy volunteers (N = 12) of 8 mg of perindopril tert-butylamine salt by oral route (treatment A), by intravenous route (bolus in 5 min, treatment B) and of an equimolar dose of perindoprilat (6.1 mg) by intravenous route (infusion over 2 h, treatment C). The treatments were administered as a randomised 3-way cross-over design. Plasma samples were collected up to 96 h and urines up to 120 h. Perindopril is rapidly absorbed with an oral bioavailability of 95% and is mainly eliminated by metabolic processes. The formation of perindoprilat is slow and about 20% of the available parent drug is transformed into this metabolite. Elimination profile of perindoprilat is biphasic, with a rapid renal excretion of the free fraction and a long terminal half-life of the fraction bound to ACE. Perindoprilat glucuronide is mainly obtained from perindopril by a pre-systemic first pass metabolism.

In vitro release kinetic pattern of indomethacin from poly(D,L-lactide) nanocapsules.

Indomethacin nanocapsules were prepared by interfacial deposition of poly(D,L-lactide) polymer following displacement of acetone from a lipophilic phase to an aqueous phase. Highly solvated bilayers of phospholipids in excess in the formulation were formed and easily detected by TEM. In vitro release kinetic analysis of indomethacin from pure nanocapsules prepared with poloxamer as sole emulsifier, mixed colloidal suspension (nanocapsules and liposomal vesicules), and multiamellar phospholipidic bilayers revealed that drug release in phosphate buffer sink solution was drastically delayed and incomplete as a result of the high indomethacin solubility in the oily core, poloxamer micelles, and phospholipidic bilayers, respectively. The release process was thus dependent on drug partition from the colloidal suspension phases to the external sink solution. However, addition of albumin to the sink solution markedly enhanced the indomethacin release due to protein binding affinity. A kinetic model equation dealing with biphasic systems in which a drug is dissolved or partitioned between the lipophilic and hydrophilic phases of a dispersed system is proposed and found suitable for the description of indomethacin release from the mixed colloidal suspension only.

Effect on cerebral blood flow of orally administered indomethacin-loaded poly(isobutylcyanoacrylate) and poly(DL-lactide) nanocapsules.

Nanocapsules, containing indomethacin, were prepared either by interfacial polymerization of isobutylcyanoacrylate monomers or by interfacial deposition of a performed (DL-lactide) polymer. In-vitro release of indomethacin from nanocapsules was dependent on the pH of the sink solution and was enhanced by addition of albumin. A decrease in cerebral blood flow was noted 15 min after oral administration to rats of indomethacin nanocapsules (5 mg kg-1) and lasted over 3 h. Empty nanocapsules had no effect. Since release of indomethacin from nanocapsules is unlikely to occur in the lumen of the stomach, due to unsuitable pH conditions, and nanocapsules have been previously shown to be able to cross the intestinal barrier, to reach the villi vessels intact and to protect against the ulcerating effect of the free drug, it is suggested that the rapid onset of the pharmacological effect was sufficiently induced by free indomethacin released in the plasma following absorption of the intact nanocapsules.

Validation of the Multiple Sclerosis International Quality of Life questionnaire.

This study aims to validate the Multiple Sclerosis (MS) International Quality of Life (MusiQoL) questionnaire, a multi-dimensional, self-administered questionnaire, available in 14 languages, as a disease-specific quality of life scale that can be applied internationally. A total of 1992 patients with different types and severities of MS from 15 countries were recruited. At baseline and day 21 +/- 7, each patient completed the MusiQoL, a symptom checklist and the short-form (SF)-36 QoL questionnaire. Neurologists also collected socio-demographic, MS history and outcome data. The database was randomly divided into two subgroups and analysed according to different patient characteristics. For each model, psychometric properties were tested and the number of items was reduced by various statistical methods. Construct validity, internal consistency, reproducibility and external consistency were also tested. Nine dimensions, explaining 71% of the total variance, were isolated. Internal consistency and reproducibility were satisfactory for all the dimensions. External validity testing revealed that dimension scores correlated significantly with all SF-36 scores, but showed discriminant validity by gender, socio-economic and health status. Significant correlations were found between activity in daily life scores and clinical indices. These results demonstrate the validity and reliability of the MusiQoL as an international scale to evaluate QoL in patients with MS.

Jejunal absorption, pharmacological activity, and pharmacokinetic evaluation of indomethacin-loaded poly(d,l-lactide) and poly(isobutyl-cyanoacrylate) nanocapsules in rats.

The jejunal absorption of indomethacin nanocapsules was studied using an in vivo infusion technique. Jejunal absorption of indomethacin from the nanocapsules was slightly delayed as compared to a commercial indomethacin solution. The plasma and jejunal mucosa indomethacin concentrations were similar in both cases. However, the nanocapsules protected the rat jejunum from the ulcerating effect of indomethacin, probably by avoiding direct contact of the free drug with the surface of the mucosa. The pharmacokinetic profile of indomethacin nanocapsule formulations was compared to a solution of free drug following oral administration of 5 mg/kg in rats; no difference in the mean concentration-time profiles of the drug was observed. Blood levels of thromboxane showed a sustained biological activity, over a period of 24 hr, of indomethacin-loaded nanocapsules, relative to the drug in solution, following oral administration.

Serum concentrations of albumin, C-reactive protein, alpha 2-macroglobulin, prealbumin, fibronectin, fibrinogen, transferrin, and retinol binding protein in 55 patients with hepatic glycogen storage diseases.

Hepatic glycogen storage diseases are hereditary metabolic disorders involving the metabolism of glycogen. This study was designed to investigate the serum protein status in such diseases. Fifty-five patients with glycogen storage disease types I, III, VI, and IX, whose ages ranged from 1 month to 27 years, were included in this work. C-reactive protein, fibrinogen, alpha 2-macroglobulin, albumin, transferrin, fibronectin, retinol binding protein, and prealbumin serum concentrations were measured in each patient. In patients affected with type I glycogen storage disease, serum concentrations of alpha 2-macroglobulin, fibrinogen, C-reactive protein, and transferrin were significantly increased. In patients with types III, VI, and IX glycogen storage diseases, the concentration of alpha 2-macroglobulin was the only one that was significantly increased. Thus, even though this study raises more questions than it answers, it seems likely that the hepatic synthesis of some proteins may be increased in patients affected by hepatic glycogen storage diseases. This may indicate some degree of mild hepatic dysfunction in such metabolic disorders. However, further investigations are required to elucidate the discrepancies observed among the different types of diseases.