In vitro release of new designs of modified-release tramadol hydrochloride included in a polymer matrix

Tramadol reaches therapeutic plasma concentrations in a time interval of 0.5 to 1.7 hours, so it is necessary to dose 4 times/day, which reduces compliance with the dose and the effectiveness of the treatment. Design formulations of tramadol that allow the release time to be prolonged, surpassing those obtained with the commercial product and tramadol without excipients. Several formulations of 5% tramadol hydrochloride were designed in a matrix system based on poloxamer 407 at different concentrations (10%, 14%, 17%, and 20%). In vitro release studies were performed, using a spectrophotometer at a wavelength of 273.15 nm; were compared the results with tramadol without polymeric supplements and with the commercial formulation samples were taken in a period of time from 0.25 to 72 hours, and also compared the use or absence of dialysis membrane with a porosity of 50 kilodaltons was. With the use of the membrane, the designed formulations had a release of 98%, 50%, 23%, 16% at 72 hours, respectively, different from the commercial product and the tramadol formulation without excipients released the 24 hours. Without using dialysis membranes, a 90-100% release was achieved in the 10% and 14% formulation at 36 hours. The 17% and 20% formulation at 48 hours and the commercial formulation and tramadol without excipient were released within 2 hours. Modified release formulations were obtained, which retain and prolong the release of tramadol compared to the commercial product. Therefore, we propose to conduct further in vivo model experiments to confirm our conclusion.

Evaluación de dos fuentes suplementarias de clorhidrato de zilpaterol sobre la calidad de la carne y los rasgos de la canal de toros Bos indicus cruzados en los trópicos

It was studied the effect of two zilpaterol hydrochloride (ZH) brands on carcass and meat quality traits of crossbred Bos indicus young bulls under tropical conditions. The patented ZH formulation (Zilmax®, ZHp) and a generic brand (Zipamix®, ZHg) were added to the feed (6 ppm) for 30 d before slaughter. Animals (n= 288) were randomly assigned to 1 of 3 diets, with 32 animals per pen and 3 replicates, for a total of 96 bulls per treatment: 1) basal diet without ZH (Control), 2) basal diet supplemented with Zipamix® at 6 ppm in the diet, as fed-basis (ZHg), and 3) basal diet supplemented with Zilmax® at the same concentration in the feed (ZHp). Carcass yield traits were significantly improved by ZH supplementation. Carcasses of ZH-treated bulls were 6-9 kg heavier (P=0.0023) and produced about 8-10 kg more of lean tissue (P<0.0001) as compared to the Control group. Carcass quality traits were less affected by ZH supplementation. Among meat quality attributes, ultimate pH of ZHg (5.81) and ZHp (5.89) was higher (P=0.0022) than that of the Control (5.78). Results showed both ZH brands, when administered for 30 d before slaughter, as recommended by the manufacturer, improve most carcass yield traits without compromising carcass or meat quality attributes. Hence, tropical beef producers may use the ZH formulation of lowest cost to improve their productivity.