Indomethacin emulsion

Emulsions have been used for centuries for the oral administration of medical oils and vitamins and as dermatological vehicles. Recently, their application has been extended as drug carriers in the delivery and targeting of ophthalmic drags. An indomethacin emulsion has been reported to increase ocular bioavailability and efficacy compared to commercially available formulation in rabbits. 0.4% indomethacin emulsion showed 2.2 fold increase in the area under the anterior aqueous drag concentration/time curve compared to a 1% indomethacin suspension. The emulsion formulation also reduced ocular surface irritation caused by indomethacin Similar advantages have been shown for a pilocarpine emulsion which produced a prolonged therapeutic effect in comparison with pilocarpine hydrochloride eyedrops in man. It can be administered only twice a day, rather than four times daily for conventional formulation. 

Nanospheres of PLGA were prepared by emulsion-evaporation by employing homogenization and a solvent system consisting of acetone in which both the drug and polymer were dissolved [95], The encapsulation of 5FU in these nanospheres was low compared to the more hydrophobic drug, indomethacin. It was reported that the hydrophilic 5FU leaked to the aqueous phase. PGL nanoparticles were prepared by aldol condensation loading 5FU with an efficiency of 14.32% [50]. 

Klang, S., M. Abdulrazik, and S. Benita. 2000. Influence of emulsion droplet surface charge on indomethacin ocular tissue distribution. Pharm Dev Technol 5 521. 

Muchtar, S., Abdulrazik, M., Frucht-Pery, J., and Benita, S. (1997), Ex-vivo permeation study of indomethacin from a submicron emulsion through albino rabbit cornea, /. Controlled Release, 44(1), 55-64. 

Several studies have reported on the enhanced bioavailability of cutaneous drugs using o/w and w/o MEs compared to conventional emulsions, gels or solutions, mesophases, micellar and inverse micellar systems, and vesicles [93], Moreover, a diverse range of drug molecules such as ketoprofen, apomorphine, estradiol, lido-caine [94-97], indomethacin and diclofenac [98], prostaglandin Ei [99], aceclofenac... 

When compared to either saline or anionic emulsions, the nanosized cationic emulsions were shown to enhance the ocular bioavailability of indomethacin [108], piroxicam [178], and cyclosporin A [106,179] following one single-drop dose instillation into the rabbit eye (Figure 4). A significant drug reservoir effect was noted in the cornea and conjunctiva even for more than 8 h following the instillation [106],... 

Alkaline hydrolysis of forskolin is inhibited in a lipid emulsion.550 Indomethacin in an oil-water gel is solubilized in the surfactant aggregates and stabilized against acid- and base-catalyzed hydrolysis.551... 

The topic of ocular bioavailability of indomethacin administered in a sub-micrometer emulsion was al.so examined by the research group led by M, J. Alon.so at the University of Santiago de Compo-stela, Spain (32). These workers tested several carriers in vivo in rabbits nanopaiticles, nanocapsules, microparticles, and a submicrometer emulsion. The latter, prepared by the method of Yu et al. (33) with poloxamer 188 and soybean lecithin and containing 0.1% w/v indomethacin, had particles of diameter 0.21 0.02 im. The submicrometer systems (nanoparticles, nanocapsules, and emulsion) increased by more than three-fold the indomethacin concentration in the cornea, aqueous humor, and iris-ciliary body at 0.S and 1.0 h post instillation. Furthermore, an increased indomethacin bioavailability of 300% was observed in comparison with the value obtained for an aqueous commercial solution. Confocal laser scanning microscopy studies indicated (hat the submtcion particles penetrated into the comeal epithelium cells by endocyiosis (he audiors further suggested that the vehicle components (lecithin in the case of emulsions) may act as penetration enhancers or as endocytotic stimulators. 

Emulsion/ PLA, PLGA, Indomethacin Simple and easy to Only applicable for [61,62,... 

A better result was reported with indomethacin, an anti-inflammatory agent used to reduce postoperative inflammation after cataract smgery. The incorporation of this drug of low water solubility into a submicrometer emulsion stabilized by a combination of phospholipids and small amoimts of amphoteric surfactant resulted in higher bioavailability and higher comeal permeability of the drug [31,135,136]. 

---