Physico-chemical characterization and in vitro/in vivo evaluation of loratadine:dimethyl-ß-cyclodextrin inclusion complexes.

A tricyclic, piperidine derivative of antihistamines, loratadine, which belongs in class II of the Biopharmaceutical Classification System, was investigated. It is an ionizable drug, whose solubility depends on the gastrointestinal pH, and the bioavailability is therefore very variable. Inclusion complexes were prepared by kneading method, containing loratadine (LOR) and dimethyl-ß-cyclodextrin (DIMEB) in two different molar ratios in an attempt to achieve better dissolution and therefore the better bioavailability of loratadine. The formation and physicochemical properties of the inclusion complexes were investigated by means of dissolution tests, pH-dependent solubility studies, electrospray ionization mass spectrometry and diffusion-ordered 1H NMR spectroscopy. The in vivo efficiency of the complexes was examined in rat animal experiments to confirm the better in vitro dissolution. The instrumental examinations proved the presence of total complexes in 1:1 ratio in both compositions. However, the in vitro pH-dependent solubility results, the in vivo blood levels and the greater pharmacological effect prove that excess DIMEB is needed to achieve the pH-independent and complete solubility of LOR, and therefore better and more consistent bioavailability.

In vitro and in vivo evaluation of drug release from semisolid dosage forms.

This study presents the in vitro and in vivo testing of anti-inflammatory drug containing creams, hydrogels and organogels for dermal use. In vitro penetration studies were performed with products by measuring the diffused drug amount through synthetic membranes soaked in isopropyl myristate (IPM). Our developed preparations were investigated under in vitro conditions together with two marketed medicinal products used as reference preparations. In vivo studies were carried out on anaesthetized male Wistar rats; the carrageenan-induced paw oedema decreasing effect of twelve different formulations and the reference products were measured in comparison with a control group. All - previously in vitro screened - selected products reduced paw oedema in rats. Significant differences were found among the developed products both in vitro and in vivo. Correlation between the in vitro penetration studies and in vivo results were found in the case of o/w creams, organogels and hydrogels.

In vitro and in vivo investigations on the binary meloxicam-mannitol system.

The objective of the study in rats was to investigate the anti-inflammatory effects of pure meloxicam (ME) with different particle sizes and of physical mixtures of the binary ME-mannitol system. The level of local inflammation was significantly decreased when the amount of mannitol was the highest and the particle size of ME was the lowest as well as the components had the interparticulate interaction. The same results were achieved in in vitro experiments.

Effect of Avemar--a fermented wheat germ extract--on rheumatoid arthritis. Preliminary data.

OBJECTIVE: To investigate the effect of the fermented wheat germ extract (Avemar)in patients with severe rheumatoid arthritis (RA). METHODS: Fifteen female RA (Steinbrocker II-III) patients, who had unsuccessfully tried two different DMARD treatments, were enrolled in an open-label, 1-year long, pilot clinical study. DMARD and steroid therapies were recorded and continued. All patients received Avemar as additional therapy. For measurement of efficacy the Ritchie Index, the Health Assessment Questionnaire (HAQ) and the assessment of morning stiffness were applied. Patients were evaluated at baseline, 6 and 12 months. For statistical analyses the Wilcoxon test was used. RESULTS: At both 6 and 12 months, Ritchie index, HAQ and morning stiffness showed significant improvements compared with the baseline values. Dosages of steroids could be reduced in about half of the patients. No side effects of Avemar were observed. CONCLUSION: Supplementation of standard therapies with a continuous administration of Avemar is beneficial for RA patients.

Topical absorption of piroxicam from organogels--in vitro and in vivo correlations.

In view of their good skin tolerability, glyceryl fatty acid esters were used as organogelators, and their effects in the topical penetration of piroxicam (Px) were investigated. The in vivo skin penetration was evaluated by measuring the anti-inflammatory effect in rats, where we found that Px incorporated into glyceryl fatty acid ester organogels exhibited a significantly greater inhibition of oedema than that of the placebo control either when applied locally (p < 0.001), or via transdermal absorption (p < 0.01 and < 0.05, respectively). As the Px concentration was increased, the extent of oedema inhibition rose in accordance with a power law. Comparisons with traditional galenic organogels and a marketed product revealed that the relative biological availability of Px was better from glyceryl fatty acid ester organogels, except when calculated for D1 versus T2 and T3. In order to predict the extent of in vivo skin absorption, we measured the penetration coefficient and the in vitro penetration. In accordance with theory, the extent of in vivo oedema inhibition increased as P(oct/w) increased, and maximum inhibition was observed at logP = 2.0211. However, the in vitro penetration through a synthetic membrane did not correlate with the in vivo results, the reason for which might be the different natures of the model barriers.

In vitro and in vivo percutaneous absorption of topical dosage forms: case studies.

This article evaluated the influence of vehicle compositions on topical drug availability. In vitro drug release and in vivo experiments were performed in case of the hydrophilic ketamine hydrochloride and the lipophilic piroxicam. Ketamine hydrochloride is a NMDA receptor antagonist that has been useful for anesthesia and analgesia. The study of transdermal ketamine delivery is a novelty, because nobody has investigated the hypnotic effects of ketamine after this administration route. In vitro measurements gave a good basis for screening among the developed products. The physiological changes after ketamine administration showed, that there were significant differences among the parameters tested (breathing rate, duration of sleep) from the developed products (hydrogel, lyotropic liquid crystal and o/w cream) compared to the reference product (Carbopol gel). The in vivo feedback for piroxicam was the measurement of the anti-inflammatory activity by edema inhibition percentage. Significant differences were measured in case of the developed systems compared to the reference.

Pycnogenol accelerates wound healing and reduces scar formation.

Pycnogenol was applied topically to experimental wounds inflicted on healthy rats by means of a branding iron. The wound-healing time was taken as the number of days required for 50% of the scabs to separate spontaneously from the animals. Application of a gel formulation containing 1% Pycnogenol significantly shortened the wound healing time, by 1.6 days compared with the group treated with gel only (15.4 days). The application of 2% Pycnogenol decreased the healing time by almost 3 days, while 5% Pycnogenol further accelerated the wound-healing process. In parallel, Pycnogenol gels reduced the diameter of the scars remaining following complete scab loss in a concentration-dependent manner. In conclusion, Pycnogenol is a potent active ingredient for the treatment of minor injuries.

Jatrophane diterpenoids from Euphorbia peplus.

From the pro-inflammatory active extract of Euphorbia peplus, a new diterpene polyester (1) based on the jatrophane skeleton was isolated together with the known compounds 2-5. The irritant activities of some jatrophane diterpenes (2, 3 and 6-9) were also investigated: only compound 2 was found to exert a weak pro-inflammatory activity on mouse ear.

Effects of cinnarizine on different experimentally induced oedemas.

Experiments with male mice (28-32 g) of the CFLP strain showed that cinnarizine in doses of 2.5, 5.0 or 10.0 mg kg-1 significantly inhibited the extent of ear oedema induced by croton oil, capsaicin or dithranol, in a dose-dependent manner. In rats of the Wistar strain, oedema was induced in the hind paw by subplantar injection of carrageenin, and simultaneously by the application of croton oil to the inner surface of the ear. Preliminary cinnarizine treatment (5, 10 or 20 mg kg-1) inhibited the development of both types of oedema, to a statistically significant extent, in a dose-dependent manner.

Antiinflammatory activities of procyanidin-containing extracts from Pinus pinaster Ait. after oral and cutaneous application.

Orally in liquid diet administered procyanidin-containing extracts from Pinus pinaster Ait. decreased the croton oil-induced ear edema in mice or the compound 48/80-induced hind paw edema in rats to a statistically significant extent. Most effective were the extracts containing mainly oligomeric procyanidins with chain lengths greater then 4 units (extracts A or B). Further, the different extracts incorporated in various concentrations (1.0, 3.0 or 0.1%) in 5% hydroxyethylcellulose gel and applied topically on the shaved back of rats, inhibited significantly the ultraviolet radiation-induced increased capillary permeability. In these experiments, normalisation of capillary permeability was not correlated with the content of the extracts on higher oligomeric procyanidins.

Evaluation of the anti-oedematous effects of some H1-receptor antagonists and methysergide in rats.

A combined method was used for a comparative study of some H1 and H2 antagonists and methysergide. In male rats of the Wistar strain weighing 130 +/- 5 g, oedema was induced in the hind paw by the subplantar injection of zymosan, and simultaneously in the ear by the application of croton oil to the inner surface of the ear. Intraperitoneally orally administered H1 antagonists (dimethindene, clemastine, cyproheptadine, astemizole, cetirizine, loratadine and terfenadine) inhibited the oedema to a statistically significant extent, in a dose-dependent manner. Outstanding inhibition was observed after simultaneous administration of the antiserotonin methysergide with dimethindene, clemastine, loratadine or cetirizine.

[Effects of drugs on re-excitability of synapses of isolated frog ganglia]. / Farmakonok hatása a béka izolált ganglion szinapszisának újraingerelhetóségére.

Effects of different pharmacons on the non-excitable period (NEP) and on the relative excitable period (REP) was studied in the sympathetic ganglionic synapses of the frog (Rana esculenta). Using paired stimulation we demonstrated that hexamethonium, magnesium, pempidine, tetraethylammonium (TEA) and d-tubocurarine chlorides significantly prolonged both NEP and REP at ganglion blocking threshold concentrations. Their maximum effect occurred within 30-60 min after the start of the exposition. Hemicholine and neostigmine prolonged only NEP but not REP while lidocaine influenced neither period applying continuous repeated stimulation at low frequencies (0.1-12.5 Hz). TEA showed no effect, however, at higher frequencies (14.3-20.0 Hz) it exerted a frequency-dependent depressant effect on the amplitude of the compound action potential.

[Effects pf captopril and D-penicillamine on kinins-mediated and chronic inflammation]. / Kaptopril és d-penicillamin hatása a kinin mediált, illetve krónikus gyulladásra.

In our study the effects of angiotension converting enzyme inhibitor captopril and immunosuppressant agent d-penicillamine were investigated on inflammations mediated by kinins and on adjuvant arthritis in rat paw oedema tests. Kinins mediated inflammations were increased by small doses of captopril (0.04-5 mg/kg per os) in a dose dependent manner. However this effect of captopril was reduced at higher doses of the drug (5-400 mg/kg). In the case of d-penicillamine there was exerted an inflammation increasing effect similarly to captopril. Maximum value of this action could be measured at dose 100 mg/kg per os. After administration higher doses of d-penicillamine were not revealed any depression in inflammation increasing effect. In capillary resistance studies we have shown capillary resistance increasing action of captopril that was dose depend. However this effect was not found in the case of d-penicillamine. According to these finding kinins mediated inflammation increasing effects of captopril and d-penicillamine are suggested as a results of their ability inhibit angiotensin converting enzyme. Maximum depression at higher doses of captopril may be caused by its capillary resistance elevating action. In chronic inflammations studies we have shown developments of secondary symptoms of adjuvant arthritis inhibiting effects of captopril and d-penicillamine in a dose dependent manner. We assume that immunosuppressive action of both drug are responsible for reduction of chronic inflammations. Our study strengthens the argument that captopril can be used in therapy of rheumatoid arthritis. Further clinicopharmacological studies of captopril may clarify the role of this drug in therapy of rheumatoid diseases.

Effects of prostaglandin antagonist phloretin derivatives on mouse ear edema induced with different skin irritants.

Edema was induced in one ear of male mice of the CFLP strain with solutions of different skin irritants (croton oil 10 microL/35 micrograms, dithranol 10 microL/30 micrograms, capsaicin 10 microL/40 micrograms or arachidonic acid to 10 microL/2 mg per ear). Edema, determined by the edema-disk gravimetric technique, was inhibited in a dose-dependent manner by the intraperitoneally administered prostaglandin antagonists polyphloretin phosphate (PPP) or di-4-phloretin phosphate (DPP). With croton oil-induced mouse ear edema, DPP 10 mg/kg caused a 38% inhibition, PPP 25 mg/kg a 33% inhibition. With dithranol-induced edema DPP 0.5 mg/kg caused a 57% inhibition, while PPP 25 mg/kg was needed to exert a similar effect. Doses of DPP and PPP needed to cause a > 40% inhibition of edema were 10 mg/kg and 25 mg/kg, respectively, for capsaicin, and 25 mg/kg and 100 mg/kg for arachidonic acid. The inhibition of the ear edema by the phloretin derivatives was: dithranol > croton oil > capsaicin > arachidonic acid. This probably reflects the different contributions of prostaglandins to the inflammation.

[Effects of calcium channel blockers on electrical and mechanical responses of rat phrenic nerve-diaphragm preparations]. / Kalcium-csatorna blokkolók hatása patkány nervus phrenicus-diaphragma preparátum elektromos és mechanikus válaszára.

The effects of diltiazem, prenylamine and verapamil on the electrical and mechanical responses of a rat phrenic nerve-diaphragm preparation were investigated as a function of the indirect stimulating frequency. The amplitude of the muscle compound action potential was depressed by all three drugs with stimulation between 3 and 50 Hz. The contractile force of the diaphragm was increased by these drugs in concentrations of 3 x 10(-8)-3 x 10(-5) mol/l at low frequency (3-10 Hz), but the contractility was decreased at higher concentrations (above 3 x 10(-5) mol/l). In contrast, a facilitating effect was not observed at a higher stimulating frequency (above 20 Hz), but a concentration depressant effect did develop above 1 x 10(-6) mol/l. The literature data and our results suggest that low concentrations of calcium channel blocking agents can not influence the trigger calcium current at low frequency (under 15 Hz), but calcium liberation and the contractile force are increased by these drugs. The intracellular calcium liberation triggered by the calcium current or the muscle force was inhibited by these drugs at higher concentrations. Above 15 Hz, the liberated intracellular calcium is insufficient for the contraction, so an adequate quantity of calcium is obtained from the extracellular space. It is suggested that an adequate calcium uptake is inhibited at low concentrations of these drugs at higher frequency, and the contractility is thereby inhibited.

Anti-oedematous action of some H1-receptor antagonists.

The oedema disk technique was used to study the effects of orally administered H1-receptor antagonists (cetirizine, chloropyramine, clemastine, cyproheptadine, dimethindene, loratadine, mequitazine and terfenadine) on the inflammation induced with capsaicin or croton oil in the mouse ear, and the effect of topically applied dimethindene maleate gel on the inflammation induced with croton oil in the mouse ear. In rats of the Wistar strain, oedema was induced in the hind paw by the subplantar injection of dextran or compound 48/80. Preliminary antihistamine treatment inhibited the development of oedema in the mouse ear, and of oedema in the rat paw, to statistically significant extents, in a dose-dependent manner. In all experiments, the most potent drugs were loratadine and cyproheptadine.

Influence of 0-(beta-hydroxyethyl)-rutin on the oedema-inhibiting effect of indomethacin.

An experimental investigation was made of the influence of 0-(beta-hydroxyethyl)-rutin (HR) on the effect of indomethacin (1, 2 or 4 mg/kg i.p.) in inhibiting rat paw oedema. HR was given once daily during a 6-day pretreatment, with the final dose 90 minutes before the inflammatory reaction was induced. In the group of HR-pretreated rats which also received indomethacin in a dose of 2 or 4 mg/kg, the extent of the carrageenin-oedema was diminished significantly in comparison to that in experimental animals treated merely with indomethacin.