Microemulsion: New Insights into the Ocular Drug Delivery (original) (raw)
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Development of microemulsions for ocular delivery
Therapeutic Delivery, 2017
Microemulsions (MEs) are thermodynamic stable dispersion of oily phase and aqueous phase stabilized by surfactants and co-surfactants, and are a small droplet size of less than 100 nm. MEs are appropriate systems for ocular drug delivery because they improve ocular drug retention, extended duration of action, high ocular absorption, permeation of loaded drugs and effortlessness of preparation and administration. This review is an effort to summarize the recent development in the area of MEs, self-emulsifying drug delivery systems, which are examined in relation to their uses in ocular drug delivery. The noteworthy patent, toxicity and stability issues related to these ME systems are also explored here.
NEW TECHNOLOGY RELATED TO DRUG DELIVERY OF MICROEMULSION FOR OCULAR DRUG DELIVERY
Pawan Bhandari*, Ashutosh Badola
Delivery of drugs into eyes using conventional dosage form or conventional drugs eg.solutions is a complicated and considerable challenges to the scientist for the treatment of ocular diseases. In Ocular drug delivery system the scientist faced many challenges due to unique structure, anatomy and physiology of eye. The aim of the present study was to develop Erythromycin Microemulsion for Ocular drug delivery. Micro emulsions (ME) are thermodynamically stable and clear mixtures of oil, surfactants, and water sometimes also available in combination with co surfactants. Erythromycin belongs to the class of Macrolide antibiotics & drug delivery through microemulsion via ocular enhaned bioavailability. The main objective of the present investigation was to formulate and characterise microemulsion for ocular drug delivery. 70% of the ophthalmic preparations are conventional dosage forms, extensive pre corneal loss caused by rapid drainage and high tear liquid are the main drawbacks associated with these systems, only 1 to 5% of the total drug penetrates into cornea and reaches to the intraocular tissue, to overcome these problems, microemulsion based systems are developed. The microemulsion was prepared by using different ingredients are as follows: oleic acid as an oil phase, tween 80 as surfactant, ethanol as co surfactant and 0.5 N NAOH as aqueous phase. The optimization and formulation chart was carried out using 23 factorial design. The prepared microemulsion was evaluated by using various evaluation parameters such as PH, Particle Size and Zeta potential etc. Keywords: Microemulsion, Conventional dosage form, Thermodynamically, Surfactant, Co-surfactant, Isotropic, Bioavailability, Amphiphile, Patent, Evaluation of Microemulsion.
Asian Pacific Journal of Health Sciences
Drug administration through ocular route is associated to treat the ophthalmic diseases; glaucoma, conjunctivitis, retinal disorder, and diabetic eye problems. Various ophthalmic formulations as nanoparticles, nanoemulsion, microemulsion, nanosphere, microsphere, and nanosuspension have been developed. Such novel formulations have ability to prolonged the contact time of dosage form on ocular surface and reduce the drug elimination. Microemulsion is the thermodynamically stable and clear dispersion of oil and aqueous phase stabilized by surfactant and cosurfactant with target droplet size up to100 nm. Self-microemulsifying drug delivery system (SMEDDS) approach is generally adopted to enhance bioavailability of poorly water-soluble drugs. SMEDDS is the appropriate system for ocular drug delivery as it improves the ocular drug retention, high ocular absorption, and extended duration of action. The surfactant/cosurfactant combination used in SMEDDS has capacity to improve drug permeat...
Purpose: Moxifloxacin (MXN) is widely prescribed for the treatment of bacterial keratitis. The conventional MXN solution has several limitations, including short precorneal residence time and poor intrastromal bioavailability, requiring frequent instillation of the drug to achieve the desired therapeutic effect. To circumvent this problem, the W/O (water-in-oil) microemulsion (ME) system was utilized for sustained release and improved precorneal retention. Methods: The pseudo-ternary phase diagrams were developed and various MEs were prepared using two nonionic surfactants, Tween 80 and Span 20, with isopropyl myristate and acetate buffer. Physicochemical parameters, in vitro drug release and in vitro antibacterial activity were studied. The in vivo antimicrobial efficacy of optimized microemulsion (ME 10) was studied in an experiment on bacterial keratitis in rabbit eyes and compared with that of the marketed eye drops. Results: The optimized microemulsion (ME 10) displays as an average globule size of <40 nm. The developed MEs showed acceptable physico-chemical behaviour, good stability for 3 months and exhibited sustained drug release. Greater efficacy in experimental bacterial keratitis in rabbit eyes was also observed in comparison with marketed drug solution. Conclusions: The developed MEs are a viable alternative to conventional eye drops, because of its ability to enhance bioavailability through its longer precorneal residence time and its ability to sustain the release of the drug.
Novel Ofloxacin-Loaded Microemulsion Formulations for Ocular Delivery
Purpose: The aim of this study was to prepare a novel oil-in-water microemulsion of ofloxacin (OFX) for topical ocular application. Methods: Pseudo-ternary phase diagrams were constructed for combination of oleic acid as oil phase, Tween 80 as surfactant, ethanol as co-surfactant, and 0.5N NaOH solutions as aqueous phase. The optimum microemulsion was modified with 0.75% chitosan oligosaccharide lactate (COL). The properties of microemulsions in the absence or presence of OFX (0.3%) were measured, such as electrical conductivity, droplet size, viscosity, and pH. The in vitro release study was carried out using the dialysis bag method. Ex vivo permeability studies were performed with rabbit cornea in Franz-diffusion cells. Sterility, minimum inhibition concentration (MIC), and antibacterial activity studies were conducted microbiologically. The preocular residence time and efficacy against bacterial keratitis was compared with a commercial (C) solution via in vivo studies. Results: M2OFX modified with 0.75% COL showed slower release than M1OFX, which does not contain COL. The permeation rate of OFX from M1OFX was significantly higher than M2OFX and the C solution. The formulations were sterile and MIC values were the same for both. M2OFX, which contains 0.75% COL, performed higher antibacterial activity than M1OFX. The preocular residence time was improved by microemulsion in comparison to solution; the addition of COL did not make a significant difference. In total, 8 rabbits gave better results with M1OFX, whereas 4 gave similar scores to commercial solution-applied rabbits. Conclusion: