In Vitro Release Kinetics and Bioavailability of Gastroretentive Cinnarizine Hydrochloride Tablet

An oral sustained release dosage form of cinnarizine HCl (CNZ) based on gastric floating matrix tablets was studied. The release of CNZ from different floating matrix formulations containing four viscosity grades of hydroxypropyl methylcellulose, sodium alginate or polyethylene oxide, and gas-forming agent (sodium bicarbonate or calcium carbonate) was studied in simulated gastric fluid (pH 1.2). CNZ release data from the matrix tablets were analyzed kinetically using Higuchi, Peppas, Weibull, and Vergnaud models. From water uptake, matrix erosion studies, and drug release data, the overall release mechanism can be explained as a result of rapid hydration of polymer on the surface of the floating tablet and formation of a gel layer surrounding the matrix that controls water penetration into its center. On the basis of in vitro release data, batch HP1 (CNZ, HPMC-K100LV, SBC, LTS, and MgS) was subjected to bioavailability studies in rabbits and was compared with CNZ suspension. It was concluded that the greater bioavailability of HP1 was due to its longer retention in the gastric environment of the test animal. Batch no. HP1 of floating tablet in rabbits demonstrated that the floating tablet CNZ could be a 24-h sustained release formulation

Alzheimer's disease related genes during primate evolution

During primate evolution, the neuronal and cognition-related genes have evolved rapidly. These genes seem to induce neurological illnesses such as Alzheimer's disease (AD). In this study, we analyzed genes APOE, TOMM40, and PICALM known as the risk factors of AD. We performed bioinformatics analyses in relation to evolution, phylogeny, and protein structure for those genes in humans, Neanderthals, chimpanzees, bonobos, gorillas, orangutans, crab-eating monkeys, and rhesus monkeys. Cholesterol-related genes showed relatively rapid evolution toward a lower risk of AD. Neanderthals showed relatively higher polymorphism in genes APOE, TOMM40, and PICALM than humans did. Phylogeny indicated different topologies in the trichotomy of humans, chimpanzees, and gorillas in terms of genes APOE, TOMM40, and PICALM. These results provide to hominin-specific patterns in three genes, and give clues to the modern human-specific traits of AD and shed light on further functional research helping to understand AD