Drug loading optimization and extended drug delivery of corticoids from pHEMA based soft contact lenses hydrogels via chemical and microstructural modifications

2015 ◽  
Vol 487 (1-2) ◽  
pp. 260-269 ◽  
Author(s):  
Eva García-Millán ◽  
Sandra Koprivnik ◽  
Francisco Javier Otero-Espinar
2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaohong Hu ◽  
Lingyun Hao ◽  
Huaiqing Wang ◽  
Xiaoli Yang ◽  
Guojun Zhang ◽  
...  

Soft contact lenses can improve the bioavailability and prolong the residence time of drugs and, therefore, are ideal drug carriers for ophthalmic drug delivery. Hydrogels are the leading materials of soft contact lenses because of their biocompatibility and transparent characteristic. In order to increase the amount of load drug and to control their release at the expected intervals, many strategies are developed to modify the conventional contact lens as well as the novel hydrogel contact lenses that include (i) polymeric hydrogels with controlled hydrophilic/hydrophobic copolymer ratio; (ii) hydrogels for inclusion of drugs in a colloidal structure dispersed in the contact lenses; (iii) ligand-containing hydrogels; (iv) molecularly imprinted polymeric hydrogels; (v) hydrogel with the surface containing multilayer structure for drugs loading and releasing. The advantages and disadvantages of these strategies in modifying or designing hydrogel contact lenses for extended ophthalmic drug delivery are analyzed in this paper.


2014 ◽  
Vol 679 ◽  
pp. 118-127 ◽  
Author(s):  
Deirdre M. McElroy ◽  
Luke M. Geever ◽  
Clement L. Higginbotham ◽  
Sinead M. Devery

Hydrogel soft contact lenses have been investigated as delivery systems for ophthalmic drug products in response to the need for more efficient ophthalmic drug delivery systems. Ocular drugs delivered via eye drops have a low residence time in the eye resulting in as low as 5% bioavailability of the therapeutic agent. This study investigates the effect of varying concentrations of the photoinitiator diphenyl (2,4,6-trimethylbenzoyl)-phosphine oxide (TPO) on the physicochemical properties of hydrogel soft contact lenses for ophthalmic drug delivery purposes. Contact lens samples were synthesised via photopolymerisation with a range of initiator concentration. Gel fraction and swelling results indicated that increasing the photoinitiator concentration increased the efficiency of the gel network and reduced the water content of contact lens samples. Fourier transform infra-red spectroscopy (FTIR) analysis was employed to confirm polymerisation of the lenses and also indicated the presence of residual photoinitiator in lenses with higher TPO concentrations.


Biomaterials ◽  
2009 ◽  
Vol 30 (7) ◽  
pp. 1348-1355 ◽  
Author(s):  
Jose-Fernando Rosa dos Santos ◽  
Carmen Alvarez-Lorenzo ◽  
Maite Silva ◽  
Luis Balsa ◽  
Jose Couceiro ◽  
...  

2020 ◽  
Vol 9 (4) ◽  
pp. 59-64
Author(s):  
D. K. Naplekov ◽  
E. T. Zhilyakova ◽  
A. Yu. Malyutina ◽  
A. V. Bondarev ◽  
N. B. Demina ◽  
...  

Introduction. This article provides a tentative justification of use of soft contact lenses as a carrier of ophthalmological solutions to eye tissues.Aim. The aim of the research is to develop the composition of the ophthalmic transport system for the treatment of glaucoma. Also, the proposed manufacturing algorithms were proposed for drug loading ophthalmological solutions.Materials and methods. Preparation of sodium hyaluronate solution was carried out based on the methodology described in EP 7.0 [01/2011:1472] (Sodium hyaluronate).Results and discussion. The conducted investigation with the purpose to justify a concentration of sodium hyaluronate helped to determine its concentration that gives the viscosity level as close to the upper limit stated in Russian Pharmacopoeia as possible. Buffer solution was chosen with criteria to use as less components in ophthalmological solution as possible. Also, it was found out that the more components are added to the viscous solution, the more viscosity level is decreased. Thus, initial viscosity of solution containing sodium hyaluronate was 149.59 mm2/s, and after addition of active pharmaceutical substance it dropped down to 88.49 mm2/s and 81.36 mm2/s for model solution number 1 and 2, respectively. After addition of citric acid and disodium hydrophosphate, the viscosity of model solution was found to be 78.11 mm2/s and 75.28 mm2/s for model solution number 1 and 2, respectively.Conclusion. As a result of the studies, two alternative model compositions of an ophthalmic solution for the saturation of soft contact lenses for the treatment of glaucoma were proposed. The choice of active pharmaceutical substances, and excipients has been justified. Technological procedure of preparation of model solution was described and explained, where the most attention was paid on dissolving of sodium hyaluronate in purified water.


2020 ◽  
Vol 115 ◽  
pp. 60-74
Author(s):  
Xin Fan ◽  
Cesar Torres-Luna ◽  
Marjan Azadi ◽  
Roman Domszy ◽  
Naiping Hu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document