[Acute diarrhea in children less than 3 years of age: Enteropathogens isolated in patient's stools, compared with a control group]

Submission of Rifaximin to Different Techniques: Characterization, Solubility Study, and Microbiological Evaluation

Rifaximin, an oral antimicrobial drug, is marketed as 200-mg tablets. The daily dose ranges from 600 mg (1 tablet 3 times a day) to 800 mg (2 tablets twice a day). It is used for a wide range of ages, from adults to children, since it is indicated for the treatment of hepatic encephalopathy, travelers' diarrhea, irritable bowel syndrome, Clostridium difficile, ulcerative colitis, and acute diarrhea. The success of pharmacotherapy will depend on correct fulfillment of drug administration; however, it becomes difficult when the tablets are large and the doses are frequent. Rifaximin belongs to class IV according to the Biopharmaceutic Classification System (BCS), meaning that it is both poorly soluble and poorly permeable. Thus, in this study, solubility of rifaximin was improved by its complexation to β-cyclodextrin by (i) phase solubility diagram, (ii) malaxation, and (iii) decreasing particle size by wet milling. Improved solubility provides lower doses and facilitates compliance with pharmacotherapy. The products formed were analyzed by spectrophotometry in the infrared region (FT-IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Also, their solubility and microbiological activity were determined. The products obtained in all techniques were more soluble than the free drug; they presented higher thermal stability and antimicrobial potency was approximately 100% with all the formulations. It is important to highlight that the treatment failure not only affects the quality of life of the patients, but also contributes significantly to the economic burden of the health system. Therefore, these findings are extremely interesting, both from a technological and financial point of view.

Rotavirus type A and other enteric pathogens in stool samples from children with acute diarrhea on the Colombian northern coast

The present study, conducted from March 1998 to July 2000, determined the etiology of acute diarrhea in 253 young children and infants from Cartagena and Sincelejo, Colombia. In 253 stool samples, the following enteric pathogens were recovered: rotavirus type A (36.6%) as the major agent, Salmonella spp (9.0%), Shigella spp (8.0%), enteric pathogenic Escherichia coli (6.0%), enteric hemorragic Esc. coli (2.8%), Providencia alcalifaciens (2.8%), Aeromonas hydrophila (2.0%), Yersinia enterocolitica (0.8%), Entamoeba hystolitica (10%), Giardia lamblia (4%), Endolimax nana (3.2%), Ascaris lumbricoides (2.8%), Ent. coli (1.2%), Balantidium coli (0.8%), Blastocystis hominis (0.8%), Dypilidium caninum (0.4%) and hook worm sp. (0.4%). Infection with more than one pathogen occurred in 96 (37.9%) patients. Rotavirus and enteric pathogenic Esc. coli were frequent. Concurrent infection by more than one parasite occurred in 18.6% of the infants. Most rotavirus infections (76.7%) occurred in infants under 12 months. Vomiting, severe dehydration and fever were frequent in children with rotavirus infection. At least one fecal marker of inflammatory diarrhea was registered in patients with bacterial infection. To our knowledge, this is first report of P. alcalifaciens associated with infantile diarrhea in Colombia and the first description of Esc. coli O157:H7 and Y. enterocolitica in our region.