Critical Factors Involved in the Determination of the Optimal Concentration of Ophthalmic Anti-infective Compounded Drugs Publication History: Received: July 10, 2016 Accepted: December 26, 2016 Published: December 28, 2016 Keywords: Ophthalmic, Drug, Cyclodextrins, Macromolecules, Commentary Open Access Introduction Physiopathology characteristics of the eye make generally the treatment of the ocular surface illnesses diicult. In addition to the etiology, many times there is not any ocular commercial treatment available due to economical or stability issues. In this cases compounded drug are the alternative [1,2]. In ophthalmic pharmaceutical compounding, it is common to use parenteral formulations for the preparation of ophthalmic drugs by dissolution or dilution in eye compatible bufers. However, parenteral drugs are not designed for or adapted to ocular administration, so they can cause no desirable efects in the eye. On the other hand, we barely have ocular toxicity and dose-respond studies of these drugs. herefore, the concentrations utilised are chosen based on previous results and clinical experience gathered over the years [3]. Moreover, the poor adaptation to the route and the tendency of using simple formulations produce low eiciency systems, since they have a low permanence inthe surface eye owing to the efective precorneal clearance mechanisms [4]. In order to achieve therapeutic concentrations, ophthalmologists prescribe eye dropswith high doses of drugs, using very frequent instillations for extended periods of time. his may cause great discomfort among patients that oten results in a reduction in treatment adherence with the necessity of hospitalization in order to obtain correct compliance and recovery [5]. he manifestation of ocular toxic efects is quite common and can be caused by commercial medicines as well as by compounded drugs. his can occasionally imply the interruption of the treatment. here are tons of pharmacological groups of drugs for ocular route with well-known potential toxicity, like NSAIDs or prostaglandin analogues for glaucoma [6]. hese medicines, despite having gone through a strict control by the regulatory agencies, have sometimes signiicant toxicities. Another therapeutic group with well-known ocular toxicity are the compounded drugs named as reinforced eye drops of antibiotics. hese eye drops are used in the treatment of complex bacterial keratitis in which it is necessary topic antibiotics no commercially available or high concentrations of antibiotics which treble the commercial concentrations [7]. It is diicult to achieve efective concentrations of drugs on the ocular surface for long periods due tostrong precorneal clearance. Diferent technologies have been tested to increase ocular retention time, standing out the ones based onthe use of mucoadhesive polymers, smart hydrogels and nanotechnology [8]. Bioadhesive polymers increases the eye surface residence time by means unspeciic or speciic interactions with the ocular mucosae prolong the residence time [9]. In situ stimulus hydrogelsare utilised due to their ability of modifying their consistence and structure when they are exposed to external stimulus [9]. hese formulations gelled in the eye surface * Corresponding Author: Prof. Francisco Javier Otero Espinar, Pharmacy and Pharmaceutical Technology Department, Faculty of Pharmacy, University of Santiago de Compostela (USC), Spain, E-mail: francisco.otero@usc.es Citation: Fernández-Ferreiro A, González-Barcia M, Gil-Martínez M, Blanco- Méndez J, Luaces-Rodriguez A, et al. (2016) Critical Factors Involved in the Determination of the Optimal Concentration of Ophthalmic Anti-infective Compounded Drugs. Int J Clin Pharmacol Pharmacother 1: 122. doi: https://doi. org/10.15344/2016/2456-3501/122 Copyright: © 2016 Fernández-Ferreiro et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. International Journal of Clinical Pharmacology & Pharmacotherapy Anxo Fernández-Ferreiro 1,3,4* , Miguel González-Barcia 3,4 , Gil-Martínez M 5,6 , Blanco-Méndez J 1,2 , Luaces-Rodriguez A 1 , Victoria Díaz Tome 1 , Lamas MJ 3,4 and Otero-Espinar FJ 1,2 1 Pharmacy and Pharmaceutical Technology Department, Faculty of Pharmacy, University of Santiago de Compostela (USC), Spain 2 Instituto de Farmacia Industrial, Universidad de Santiago de Compostela (USC), Santiago de Compostela, España 3 Servicio de Farmacia. Xerencia de Xestión Integrada de Santiago de Compostela, SERGAS, Santiago de Compostela, España 4 Clinical Pharmacology Group, Health Research Institute of Santiago de Compostela (IDIS-ISCIII), Spain 5 Servicio Otalmología. Xerencia de Xestión Integrada de Santiago de Compostela, SERGAS, Santiago de Compostela, España 6 Instituto Otalmológico Gomez Ulla. Santiago de Compostela, España Int J Clin Pharmacol Pharmacother IJCPP, an open access journal ISSN: 2456-3501 Volume 1. 2016. 122 Fernández-Ferreiro et al., Int J Clin Pharmacol Pharmacother 2016, 1: 122 https://doi.org/10.15344/2016/2456-3501/122 by efect of a speciic stimulus forming a hydrogel ilm that releases the drug [10]. he ocular surface provides properties (i.e. tear ion concentration, pH or temperature) which facilitate the gelling of some stimuli-responsive polymers that otherwise are in sol forms which can easily be administered into the eye [8,11,12]. Finally the nanocarriers can enhance the bioavailability of ophthalmic formulations by means the improvement of the drug release properties, the surface permanence and the drug penetration into the eye tissues. On the other hand, poor aqueous solubility of some drugs complicates their ocular administration. Hence, a challenge in the ocular formulation is to achieve the incorporation olipophilic drugs in ocular systems for pathologies with not many or none available commercial alternatives. In order to reach that, it is indispensable to increase solubility in water [13]. Cyclodextrins technology, nanosuspensiones, polymeric micelles or the use of cosolvents or hydrophilic polymers are useful pharmaceutical tools that aid in the formulation of poorly aqueous soluble drugs [14]. he mentioned factors are just some of the ones thatmust be assessed when designing a new ophthalmic formulation. For instance, it is also necessary to determine optimal concentration of an anti- infective when designing a new formulation for ocular infections. Minimum Inhibitory Concentration in Ocular Opical Formulations Drug concentrations used in the current treatment of ocular infections that afect anterior chamber are in revision. Eiciency of