Date Published: March 18, 2018
Publisher: Tabriz University of Medical Sciences
Author(s): Shahla Mirzaeei, Kaveh Berenjian, Rasol Khazaei.
Purpose: The poor bioavailability of drugs in the ocular delivery systems is an important issue and development of delivery systems with prolonged release profile could be in a major importance. This study aims to develop an ocular delivery system using electrospun nanofibers to be a candidate insert for delivery of triamcinolone acetonide.
Topical formulations of corticosteroids, including drops and ointments, are the most prescribed formulations for treatment of different ocular disorders. Eye drops are the most frequently used ophthalmic drugs, due to the ease of instill and topical administration.1 This type of administration of ophthalmic drugs affects the anterior segment of the eye and is associated by significant drawbacks; the poor bioavailability of drug (due to nasolacrimal drainage and dilution of drug by tear turnover), requirement of frequent administration, unpredictable and uncontrolled doses, blurred vision, messy and difficult dosing, and short residence time are some of these drawbacks.2-4
Chitosan and Zein were purchased from Sigma Aldrich (St. Louis, Missouri, USA). Eudragit S100 was procured from Evonik Industries, Parsippany, NJ, USA. Poly vinyl alcohol (PVA 13-23 kDa, 98% hydrolysis), poly vinyl pirolidine (PVP), and ethanol were procured from Merck (Germany). Triamcinolone acetonide was purchased from Crystal Pharma (Spain). All the other compounds were in analytical grade and were performed without further purification.
In order to study the release pattern of triamcinolone acetonide from different electrospun nanofibers, the concentration of drug in release medium at specified time intervals were determined using a UV-Vis spectrophotometer. The absorbance band of solutions was recorded and the concentration of drug was calculated using the standard calibration curve, which correlated the concentration of triamcinolone acetonide to the absorbance intensity. The calibration curve followed the below equation:
For the first time in the present study, hydrophilic chitosan-based ocular inserts were developed for delivery of triamcinolone acetonide by electrospinning method and the results were compared with a hydrophobic (Eudragit/ Zein) electrospun insert candidate. The prepared ophthalmic delivery system could achieve prolonged therapeutic drug concentrations and could be promising candidates as ocular inserts and it could be used in a single dose at longer time intervals. The Zero-order release profile indicated the prolonged, monotonic, and well-controlled release of drug from the suggested formulation, and consequently, limited systemic exposure and side effects and the possibility to improve the patient adherence to therapy could be taken into account as some of the advantages of the suggested formulation. The suggested formulation could be converted from solid to gel form after exposition into the ocular pH, and the muco-adhesive nature of the suggested formulation caused the longer period for control of lixiviation than other similar formulations. Based on the advantages of the suggested formulation, it could be performed for ocular delivery of other similar drugs.
The authors would like to acknowledge the Research Council of Kermanshah University of Medical Sciences (Grant number: 95416) for financial support of this work. Also faithfully thanks to Mr Komail Sadrjavadi and Miss Marziyeh Hajialyani for their assistances and valuable ideas.
The authors declared no conflict of interest for this study.