The application of flow-through dissolution apparatus integrated with magnetic resonance imaging (MRI) system for discriminative evaluation of controlled release dosage forms with similar dissolution profiles was presented. Hydrodynamically balanced systems (HBS) containing l-dopa and various grades hydroxypropyl methylcelluloses were prepared. The dissolution studies of l-dopa were performed at high field (4.7 T) MR system with MR-compatible flow-through cell. MRI was done with 0.14 x 0.14 x 1-mm spatial resolution and temporal resolution of 10 min to record changes of HBS parameters during dissolution in 0.1 M HCl. Structural and geometrical changes were evaluated using the following parameters:
total
Selleck ARN-509 SC79 mouse area of HBS cross-section, its Feret’s diameter, perimeter and circularity, area of hydrogel layer, and “”dry core”" area. While the dissolution profiles of l-dopa were similar, the image analysis revealed differences in the structural and geometrical changes of the HBS. The mechanism of drug release from polymeric matrices is a result of synergy of several different phenomena occurring during dissolution and may differ between formulations, yet giving similar dissolution profiles. A multivariate analysis was performed to create a model taking into account dissolution data, data from MRI, information about chemical structure, and polymer viscosity. It provided a single model for all the formulations which was confirmed to be competent. The presented method has merit as a potential Process Analytical Technology tool.”
“Background: In 1997 the US Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) reported high proportions of drug-resistant Mycobacterium tuberculosis in three Mexican states: Sinaloa, Baja California, and Oaxaca. In 2006, we showed that resistance to anti-tuberculosis drugs remained frequent in Sinaloa.
Objectives: Adavosertib The objectives of this study were to describe drug-resistant tuberculosis (TB) trends and to investigate the probability that
patients acquire resistance to first-line anti-TB drugs on recurrence after treatment in Sinaloa.
Methods: Sputum specimens were collected from patients diagnosed with TB at all the health care institutions of Sinaloa during 1997-2005. Isolates were tested for susceptibility to first-line drugs.
Results: Among 671 isolates tested from 1997 to 2002, the overall resistance rate was 34.9% (95% confidence interval (CI) 31.2-38.4) with a 1.2% increase per year (Chi-square = 4.258, p = 0.03906). The prevalence of multi-drug resistance (MDR) was 17.9% (95% CI 14.9-20.7) with a 1.2% increase per year (Chi-square = 8.352, p = 0.00385). Of 50 patients registered twice between 1997 and 2005, 15 were fully susceptible at first registration, of whom six (40%) acquired drug resistance.