Pharmacological studies on taurohyodeoxycholic acid.

In this study we investigated the anticholelithogenic and choleretic activities and the general pharmacological action of taurohyodeoxycholic acid (THDCA, Io, Praxis, CAS 2958-04-5), a new biliary acid advocated for use as anticholelithogenic agent. THDCA had no significant activity on the CNS (spontaneous locomotor activity, body temperature, coordinated movement, respiration); it also had no significant anticonvulsant or central anticholinergic actions. With regard to the action on the cardiovascular system, THDCA administration did not give rise to significant changes in blood pressure or ECG. Investigation of its action on the gastrointestinal system revealed no significant changes in the intestinal transport of charcoal after treatment. However, biliary flow and biliary solids content were increased by THDCA intraduodenal doses of 300 mg/kg b.w. In mice fed with lithogenic diet THDCA administration (230 and 450 mg/kg b.w. for 8 weeks) significantly decreased gallstone and steatosis incidence.

Chronic toxicity of taurohyodeoxycholic acid in rats.

Fifty-two-week oral toxicity and 24-week intraperitoneal toxicity of a new synthetized biliary acid, taurohyodeoxycholic acid (Io, Praxis, CAS 2958-04-5), were investigated in rats. Taurohyodeoxycholic acid was orally administered at dose levels up to 500 mg/kg/d and intraperitoneally administered at dose levels up to 200 mg/kg/d. The treated animals showed no deviations from normality in mortality, physical appearance and general behavior. Food and water consumption and body weight gain of the treated groups did not differ from those of the control. No treatment-related changes were observed in hematology, serum biochemistry, urinalysis, organ weights and post-mortem macroscopic or histopathological examinations. No dose- or sex-related differences were observed. The no-effect dose level was estimated to be 500 mg/kg/d in the chronic oral toxicity study and 200 mg/kg/d in the intraperitoneal study.

Pharmacokinetic studies in healthy volunteers on a new gastroprotective pharmaceutic form of diclofenac.

The pharmacokinetic properties of a new gastroprotective pharmaceutical formulation of diclofenac (CAS 15307-79-6) were investigated in twelve healthy volunteers. In this new form the diclofenac is the nucleus of sequential sucralfate-covered tablets. The experimental design was an open, random, two period balanced cross-over study. All the subjects received a single oral dose of 50 mg diclofenac contained in the new formulation or in the reference enteric-coated tablets. Plasma concentrations of diclofenac were determined at 0.5, 1, 2, 4, 6, and 8 h after drug administration using HPLC method. After administration of a diclofenac-sucralfate association diclofenac was quickly absorbed and the peak plasma concentration (0.773 +/- 0.08 microgram/ml) was achieved in about 1 h. AUC(0-infinity) value was about 1.8 micrograms/ml/h and the mean elimination half-life was 1.20 +/- 0.12 h. The pharmacokinetic profile of diclofenac-sucralfate association is similar to the values reported in previous papers for enteric-coated forms; anyway an early occurrence of the peak plasma concentration was observed for the new formulation. The new diclofenac-sucralfate association shows a different rate of absorption (namely an early and greater peak plasma concentration of diclofenac) and a similar extent of absorption (AUC(0-infinity) being not statistically different) as compared to the reference enteric-coated tablets of 50 mg diclofenac. These results could be related to the delaying and protective effect of sucralfate whose action is different from the one carried by the coat of the enteric-coated tablets.

Chronic toxicity study on a new glucan extracted from Candida albicans in rats.

Fifty-two-week oral toxicity of a new glucan (Glucanil, Gluimmun) extracted from Candida albicans ATCC 20955 was investigated in rats. The glucan was orally administered in dose levels up to 200 mg/kg/d and was well tolerated. No deviation from normality was observed in mortality, physical appearance and general behaviour of the treated animals. Food and water consumption and body weight gain of glucan-fed groups did not differ from those of control animals. In these groups no alteration of the weight of the main organs was also observed. Hematology, blood chemistry, urinalysis and autopsy findings were within normal ranges in every group of rats treated. No sex difference was noted. In the 200 mg/kg group soft stools or diarrhoea and cecal enlargement with variable hyperplasia of the colon mucosa were observed. These symptoms are typical of exposure to substances which are absorbed incompletely in the small intestine and subjected to microbial metabolism in the cecum and colon. Diarrhoea, cecal enlargement and mucosal hyperplasia are reversible. The no-effect dose level was estimated to be 100 mg/kg/d under these conditions.

[Intranasal absorption of various calcitonin spray preparations]. / Assorbimento intranasale di preparazioni diverse di calcitonina spray.

In a cross-over study performed on 10 patients the intranasal absorption of calcitonin contained in three formulation spray was evaluated. One of them contained biliary acid (sodium taurocholate) as the absorption promoting factor while the other two drugs did not. The dosage of calcitonin in blood was effected by means of radioimmunoassay using salmon calcitonin marked with I126 in competition to the one present in the sample for a limited quantity of specific antibodies for salmon calcitonin. The minimum measurable quantity of calcitonin is 10 pg and the response is linear including values between 20% and 80%. It is observed that the plasmatic concentration of calcitonin dosed in different times after administration of the drug containing sodium taurocholate are always significantly higher (Student "t" test for unpaired data, p less than 0.005) than the measurements after administration of the other two drugs. They are about 8 times higher at the first half an hour, about 6 times after an hour and again double at the second hour. The AUC calculated for sodium taurocholate containing drug (1629 pg/ml/h) results significantly higher in relation to the other two drugs (1133 and 926 pg/ml/h) indicating a better bio-availability of calcitonin contained in that spray. The relative bioavailability between calcitonin spray with sodium taurocholate and the other two drugs in reference resulted to 144% and 176%. The presence of a transmucosal absorption promoting factor at the level of a nasal mucosa, represented in this case by sodium taurocholate, enhances significantly the absorption and the bioavailability of calcitonin present in the formulation spray.

Effects of topical treatment with piroxicam on prostaglandin synthesis in experimental uveitis.

We have assessed the efficacy of 0.5% piroxicam collyrium applied for 15 days to the eyes of rabbits in which uveitis had been experimentally induced. The results demonstrate the capability of the drug to easily overcome the ocular barrier. On the 30th day, a clear regression of the uveitis symptoms was observed, the hyperaemia having completely disappeared. By means of radioimmunological assay (RIA), it was found that the increased PGF2 alpha concentration in the aqueous humour had returned to normal levels.