Embramine

Relative Efficacy of Seven Common H1 Receptor Antagonist Antihistamines in Chronic Idiopathic Urticaria

The order of clinical potency of seven Hi receptor antagonist antihistamines in usual therapeutic doses was evaluated in 30 patients of chronic idiopathic urticaria by a double blind, placebo controlled trial utilizing a self-assessment method. The analysis of mean whealing and, itching scores established a potency sequence in the -decreasing order of cyproheptidine, hydroxyzine, chlorpheniramine, embramine, promethazine, dimeth'mdene and dexchlorpheniramme. The differences between the first five antihistamines were not statistically significant, though these were superior to ddxchlorpheniralmine and placebo. Dexchlorpheniramine was statistically better than placebo.

Content uniformity test of tablets by nonaqueous titration method

For the Content uniformity test (CUT) of tablets where the active drug behaves in a nonaqueous medium as a base a very simple method was developed. This method is based on the extraction of the active drug from the tablet into anhydrous acetic acid and direct titration of the solute with HClO4 (0.1 or 0.05 mol/l solution in anhydrous acetic acid). The course of the titration is followed potentiometrically with a glass and calomel electrode coupled and recorded automatically with a suitable registration potentiometer. The method was successfully applied to samples of commercial tablets containing the following drugs: codeine phosphate, embramine, ephedrine, ethylmorphine, pyridoxine, thiamine and tolazoline, all as hydrochlorides. It can be used also for several other drugs.

H(1)- antihistamines and activated blood platelets

Cationic amphiphilic drugs and platelet phospholipase A(2) (cPLA(2))

The aim of the study was to verify and compare the effect of cationic amphiphilic drugs (CAD) from different pharmacological groups on activation of platelet phospholipase A2 (PLA2)--the essential enzyme of arachidonic pathway in blood platelets. Beta-adrenoceptor-blocking (BAB) drugs inhibited platelet aggregation in the rank order of potency: propranolol>alprenolol>metipranolol>atenolol. The higher the inhibition of arachidonic acid (AA) liberation by BAB drugs, the higher the inhibition of aggregation. Similarly did the H1-histamine antagonists bromadryl (BRO) and dithiaden (DIT) as well as the antimalarial chloroquine (CQ) show antiplatelet effect in vitro in the rank order of potency: DIT>BRO>CQ. Dose-dependent inhibition of aggregation was followed by the inhibition of AA liberation from membrane phospholipids of platelets stimulated either at the receptor site (thrombin) or by a stimulus bypassing membrane receptors (Ca2+ ionophore A23187). The rank order potency for inhibition of stimulated 3H-AA liberation from membrane phospholipids was: (a) for BAB drugs: propranolol>alprenolol>metipranolol, (b) for other drugs: DIT>BRO>CQ. The investigated drugs' interference with stimulated liberation of AA showed nonspecific inhibition of platelet cytosolic PLA2 (cPLA2) by these drugs at intracellular level. The results revealed that besides the inhibition of cyclooxygenase pathway and receptors for adenosine diphosphate (ADP) and glycoproteins Gp IIbIIIa, the interaction of drugs with cPLA2 may represent a further site for antiplatelet action.

Vitrification of mouse oocytes using a nylon loop

Cryopreservation of mouse oocytes was improved by the use of ultra-rapid vitrification using a nylon loop of 0.5 mm diameter. Oocytes that were vitrified using the loop survived at high rates and were fertilized following a small hole being made in the zona pellucida (69.8%) and developed to the blastocyst stage in culture (67.4%) at similar rates to that of oocytes that were not cryopreserved. Blastocysts resulting from oocytes vitrified using the nylon loop had similar development of the inner cell mass and trophectoderm as blastocysts from non-cryopreserved oocytes. In contrast, oocytes that were cryopreserved using a slow-freezing protocol where most of the Na+ is replaced with choline had lower rates of fertilization (39.5%), reduced development to the blastocyst stage (25.7%), and blastocysts had reduced development of the inner cell mass. Blastocysts derived from oocytes that were vitrified with the nylon loop were able to implant (88.0%) and develop into fetuses (56.5%) at significantly higher rates compared to blastocysts derived from oocytes that were slow-frozen (52.4 and 26.2%, respectively). Vitrification of mouse oocytes using the nylon loop results in the retention of viability of the oocytes and subsequent embryos.