Simultaneous determination of pseudoephdrine, pheniramine, guaifenisin, pyrilamine, chlorpheniramine and dextromethorphan in cough and cold medicines by high performance liquid chromatography.

A new simple, rapid and sensitive liquid chromatographic method has been developed and validated for the simultaneous determination of pseudoephdrine, pheniramine, guaifenisin, pyrilamine, chlorpheniramine and dextromethorphan in cough and cold pharmaceuticals. The separation of these compounds was achieved within 13 min on a Kromasil C18 column using an isocratic mobile phase consisting of methanol-dihydrogenphosphate buffer at pH 3 (45:55, v/v). The analysis was performed at a flow rate of 1 mL min(-1) and at a detection wavelength of 220 nm. The selectivity, linearity of calibration, accuracy, within and between-days precision and recovery were examined as parts of the method validation. The concentration-response relationship was linear over a concentration range of 5-50 microg mL(-1) for pseudoephdrine, pheniramine, chlorpheniramine and 50-600 microg mL(-1) for guaifenisin, pyrilamine, dextromethorphan, methylparaben and sodium benzoate with correlation coefficients better than 0.998. The standard deviations of the intraday and interday were all less than 2%. The proposed liquid chromatographic method was successfully applied for the routine analysis of these compounds in different cough and cold pharmaceutical preparations such as syrups, capsules, tablets and sachets. The presence of preservatives (sodium benzoate and methylparaben) and other excipients did not show any significant interference on the determination of these compounds.

[Fixed drug eruption induced by sulfaguanidine]. / Erythème pigmenté fixe à la sulfaguanidine.

INTRODUCTION: Fixed drug eruption is a lesion induced by drugs. The family of drugs usually incriminated are sulfonamides, tetracyclines and pyrazols. We describe nine cases of fixed drug eruption induced by sulfaguanidine, a sulfonamide with local action. CASE REPORTS: All the patients presented one or more fixed drug eruption reactivation lesions induced by sulfaguanidine as self-medication for diarrhea. The number of lesions increased in 7 cases after reactivation. The delay in occurrence of the fixed drug eruption decreased during the different episodes. The lesions predominated on the hands in 8 cases of 9. DISCUSSION: The sulfaguanidine must be added to the list of drug-induced fixed drug eruptions with limited absorption from the gastrointestinal tract.

[Are sigma receptors implicated in ischemic injury?]. / Les récepteurs sigma sont-ils impliqués dans les lésions d'ischémie?

Sigma receptors are present in many organs and several functions are allotted to them but the specificity of their effect remains to be established. Indeed, all the molecules known to interact with these receptors also have affinities for other receptors. Recently, sigma-1 receptors were implied in the processes of cellular protection, several of their ligands showing a neuroprotector effect in various models of cerebral ischaemia. S-16950, a trimetazidine derivative, is a powerful anti-ischaemic drug on a hepatic model of ischaemia-reperfusion. It is structurally closely related to SA4503, a sigma receptor ligand showing also an anti-ischaemic action. Our study shows that S-16950 inhibits the binding of [3H]pentazocine, a selective sigma-1 receptor radioligand, to rat brain membranes with a high affinity (IC50 = 7 nM). This affinity is equivalent to the most potent sigma ligand such as haloperidol. Its affinity is 170 times higher for the sigma-1 subtype than for the sigma-2 subtype. The effect of Gpp[NH]p on S-16950 inhibition of [3H]pentazocine binding and the potentiation of the convulsivant effect of cocaine under the action of S-16950 suggest that this molecule may act as an agonist. These results indicate that S-16950 is a new sigma ligand and reinforce the assumption of a link between sigma receptors and a cytoprotective activity.