Nanoparticles represent drug delivery systems suitable for most administration routes. Over the years, a variety of natural and synthetic polymers have been explored for the preparation of nanoparticles, of which Poly(lactic acid) (PLA), Poly(glycolic acid) (PGA), and their copolymers (PLGA) have been extensively investigated because of their biocompatibility and biodegradability. Nanoparticles act as potential carries for several classes of drugs such as anticancer agents, antihypertensive agents, immunomodulators, and hormones; and macromolecules such as nucleic acids, proteins, peptides, and antibodies. The options available for preparation have increased with advances in traditional methods, and many novel techniques for preparation of drug-loaded nanoparticles are being developed and refined. The various methods used for preparation of nanoparticles with their advantages and limitations have been discussed. The crux of the problem is the stability of nanoparticles after preparation, which is being addressed by freeze-drying using different classes of lyoprotectants. Nanoparticles can be designed for the site-specific delivery of drugs. The targeting capability of nanoparticles is influenced by particle size, surface charge, surface modification, and hydrophobicity. Finally, the performance of nanoparticles in vivo is influenced by morphological characteristics, surface chemistry, and molecular weight. Careful design of these delivery systems with respect to target and route of administration may solve some of the problems faced by new classes of active molecules.

Chemistry, Pharmaceutical↗

PubMedDate not supplied

Comparison of ondansetron with ondansetron plus dexamethasone for antiemetic prophylaxis in children undergoing strabismus surgery.

BACKGROUND: Children undergoing strabismus surgery have a high incidence of postoperative nausea and vomiting. Ondansetron plus dexamethasone is effective in reducing its incidence in many surgical procedures. PURPOSE: To examine the efficacy of ondansetron plus dexamethasone in children undergoing strabismus surgery. PATIENTS AND METHODS: A randomized, placebo-controlled, double blind study of 100 children 2 to 12 years old, in American Society of Anesthesiologists classes I and II, and undergoing strabismus surgery with the use of general anesthesia was conducted. Children received normal saline (n = 31), an injection of 0.15 mg/kg of ondansetron (n = 39), or an injection of 0.15 mg/kg of ondansetron and 0.2 mg/kg of dexamethasone (n = 30). Postoperatively, children were monitored for the number of emetic episodes, Steward recovery score, and need for a rescue antiemetic. RESULTS: The incidence of vomiting was 64.5% in the group receiving saline, 33.3% in the group receiving ondansetron, and 10% in the group receiving ondansetron plus dexamethasone (P < .001). The incidence of early vomiting (0 to 4 hours) and the need for a rescue antiemetic were significantly lower in the groups receiving ondansetron (P < .01) and ondansetron plus dexamethasone (P < .001) compared with the group receiving saline; however, the former two groups were comparable in this regard. In the late postoperative period (4 to 24 hours), the incidence of vomiting and the need for a rescue antiemetic were not significantly different among the groups. Vomiting was significantly more severe in the group receiving saline compared with the groups receiving ondansetron and ondansetron plus dexamethasone at all times (P < .01 and P < .001, respectively). However, the latter two groups were comparable in this regard. CONCLUSION: Ondansetron and ondansetron plus dexamethasone were equally effective in preventing early nausea and vomiting in children following strabismus surgery. However, the efficacy of dexamethasone in late postoperative nausea and vomiting could not be demonstrated. Further studies with a large population and different doses of dexamethasone may be warranted.

Antiemetics↗