Objective: The aim of this study was to develop and validate two HPLC methods for the quantification of meloxicam and tenoxicam from transdermal therapeutic systems. Methods: Based on 1.0% hydroxypropyl methylcellulose 15000, transdermal patches containing meloxicam or tenoxicam were prepared by solvent evaporation technique. Analytical performances of the HPLC methods for the quantification of meloxicam and tenoxicam from such systems were assessed in terms of specificity, linearity, detection limit, quantification limit, recovery and precision. Results and discussion: The linearity of the method was assessed through a calibration curve in the 1.0 -75.0 μg•mL-¹ concentration range, with a regression coefficient higher than 0.999. The detection limit and the quantification limit were found to be 0.46 μg•mL-¹ and 1.39 μg•mL-¹, for meloxicam; and 0.88 μg•mL-¹, respectively 2.64 μg•mL-¹ for tenoxicam. According to the European Pharmacopeia 5.0 the mean recovery was found to be between 75% and 125%. As performance criteria for precision was used the RSD% which were lower than 2.0% for both methods. Conclusions: The proposed liquid chromatography methods provide selective, linear and precise results for the quantification of meloxicam and tenoxicam from transdermal therapeutic systems. The presence of a single peak in the chromatograms of the analyzed transdermal patches with meloxicam or tenoxicam, certify the successful determination of the active pharmaceutical ingredient in the prepared patches.

Attention-deficit–hyperactivity disorder (ADHD) is a common neuropsychiatric disorder that impairs academic, social and occupational functioning in children, adolescents and adults. It is characterized by excessive activity, restlessness, and nervousness. The disease occurs in general at children before the age of 7 and usually is not easy to be detected, due to various symptoms. When the diagnosis is established the physician can prescribe two types of drugs, stimulants: amphetamine, dexamphetamine, lisdexamphetamine, methylphenidate, and non-stimulants such as: guanfacine, atomoxetine, and clonidine. So what can be done for a person who has ADHD, and wants to be an elite athlete? Due to the rules established by the World Anti-Doping Agency the stimulant drugs are prohibited in competition and if traces of a prohibited substance are detected in the sample of blood of the athlete his access to competition can be blocked from 2-4 years, from that date of the incident. Fortunately for some athletes the disease was acute in childhood but as they grew up the symptoms were reminiscent and they could concentrate at the sporting task that was supposed to be achieved. What about those athletes that still have the symptoms? Well, they can be treated with the non-stimulant drugs, but their doctor must monthly verify if the list of prohibited drugs has been changed. In conclusion we can say that ADHD can be an impediment, but with the help of parents, teachers, and physicians the athlete can achieve very good performances.

Sibutramine is a chiral anti-obesity drug which decreases food intake and increases energy expenditure. In therapy it is used as a racemic mixture; however both pharmacokinetic and pharmacodynamic data have revealed enantioselective behavior of sibutramine and its major active metabolites. Several chromatographic and electrophoretic analytical methods have been published so far for the chiral determination of sibutramine from pharmaceutical preparations and biological samples. The current paper aims to provide a systematic review of the stereochemical aspects and analytical methods used for the enantiodetermination of sibutramine and its active enantiomers covering the last 15 years.