Evaluation of Specific Administering Devices for Antineoplastic Drugs Compounded in Syringes in Paediatry: Methodology Proposal

Purpose The aims of this study were to propose a simple methodology to assess the rinsing volume of syringe extension sets and to compare several marketed devices. Methods A UV-spectrophotometry assay using quinine hydrochloride as drug substitute was developed. Quinine concentration ranged from 20 to 200 µg/ml. The assay was validated with the accuracy profile method and tested on five different assemblies (device+extension sets) with different dead-space volumes (1.28–2.80 ml) and at two different quinine concentrations (0.3 and 8.0 mg/ml). Rinsing was performed stepwise with water for injection until reaching an undetectable quinine concentration. After fitting the data with a Weibull model, assemblies were compared with an ANOVA performed on ranks (GraphPad, La Jolla, USA). Results The within-day and between-day precision ranges were 0.39–0.81 and 0.48–0.84%, respectively. The lower limit of quantification was 4.26 µg/ml. The volume required to completely rinse the infusion line was different according to the initial drug concentration and to the device assessed: from 6 to 10 ml for a low quinine concentration and from 7 to 17 ml for a high quinine concentration. Conclusion This study shows that a simple, cheap and easy-to-use methodology may be used to assess the rinsing volume of syringe extension sets. The rinsing volume is different according to the tested device.

Relationship between plasma and red blood cell concentrations of quinine in Brazilian children with uncomplicated Plasmodium falciparummalaria on oral therapy

We determined the relationship between plasma and red blood cell concentrations of quinine in children with uncomplicated falciparum malaria from an endemic area of Amazonian region. Quinine was determined by high performance liquid chromatography with ultraviolet detection. In the steady state the ratio between plasma and red blood cell quinine concentration was 1.89 ± 1.25 ranging from 1.05 to 2.34. This result demonstrated that quinine do not concentrate in red blood cell of Brazilian children and characterize the absence of interracial difference in this relationship.

Influence of Bitter Taste on Mastication Pattern

Mastication is a rhythmic activity that can be modified by peripheral information generated in the mouth. To study whether taste cognition could influence the way in which a food is broken down in the mouth, subjects masticated firm, sugar-based gelatine gels with differing concentrations of quinine, up to 1500 μmol/kg, while electromyography (EMG) of masticatory muscles was recorded. Taste intensity and composition of saliva were measured. With increasing quinine concentration, the average number of chews for nine subjects decreased from 30 to 22, and their average clearance time increased from 7 to 14 sec. Quinine concentration had no effect on chewing frequency (1.3 Hz) or on the rate of salivation (5.5 g/min). Bitterness increased, while acceptability and sweetness decreased, with increasing concentration of quinine in the gel and in saliva. Taste cognition could therefore modify food breakdown in the mouth.