scholarly journals In Situ Gelling Ophthalmic Drug Delivery System for the Optimization of Diagnostic and Preoperative Mydriasis: In Vitro Drug Release, Cytotoxicity and Mydriasis Pharmacodynamics

Pharmaceutics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 360
Author(s):  
Pierre-Louis Destruel ◽  
Ni Zeng ◽  
Françoise Brignole-Baudouin ◽  
Sophie Douat ◽  
Johanne Seguin ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Delivery System ◽  
Delivery Systems ◽  
Eye Drops ◽  
Active Ingredients ◽  
In Vitro Drug Release ◽  
In Situ Gelling

Mydriasis is required prior to many eye examinations and ophthalmic surgeries. Nowadays, phenylephrine hydrochloride (PHE) and tropicamide (TPC) are extensively used to induce mydriasis. Several pharmaceutic dosage forms of these two active ingredients have been described. However, no optimal therapeutic strategy has reached the market. The present work focuses on the formulation and evaluation of a mucoadhesive ion-activated in situ gelling delivery system based on gellan gum and hydroxyethylcellulose (HEC) for the delivery of phenylephrine and tropicamide. First, in vitro drug release was studied to assess appropriate sustained drug delivery on the ocular surface region. Drug release mechanisms were explored and explained using mathematical modeling. Then, in situ gelling delivery systems were visualized using scanning electron microscopy illustrating the drug release phenomena involved. Afterward, cytotoxicity of the developed formulations was studied and compared with those of commercially available eye drops. Human epithelial corneal cells were used. Finally, mydriasis intensity and kinetic was investigated in vivo. Mydriasis pharmacodynamics was studied by non-invasive optical imaging on vigilant rabbits, allowing eye blinking and nasolacrimal drainage to occur physiologically. In situ gelling delivery systems mydriasis profiles exhibited a significant increase of intensity and duration compared with those of conventional eye drops. Efficient mydriasis was achieved following the administration of a single drop of in situ gel reducing the required amount of administered active ingredients by four- to eight-fold compared with classic eye drop regimen.

scholarly journals A hydrogel based quasi-stationary test system for in vitro dexamethasone release studies for middle ear drug delivery systems

2021 ◽  
Vol 7 (2) ◽  
pp. 692-695
Author(s):  
Thomas Eickner ◽  
Michael Teske ◽  
Natalia Rekowska ◽  
Volkmar Senz ◽  
Klaus-Peter Schmitz ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery System ◽  
Delivery System ◽  
Drug Concentration ◽  
Drug Delivery Systems ◽  
Test System ◽  
Delivery Systems ◽  
In Vitro Drug Release

Abstract For the investigation of in vitro drug release, methods have been used in which samples of drug delivery systems are immersed in release medium. The medium is used to measure drug concentration via chromatography or photometry. These systems are suitable to investigate the drug release of different systems or to simulate tissue environments. When considering predominantly humid regions, e.g. for drug release into the cochlea through the round window membrane by a drug delivery system placed at that membrane, reproducible in vitro determination of drug release becomes particularly challenging. In this study the development of a system is reported that allows the investigation of the in vitro drug release simulating such conditions. The presented test system consists of an alginate hydrogel in glass vials simulating the biological membrane, which separates the drug delivery system from the medium filled compartment. Saline is used as release medium and injected under the hydrogel. The samples are placed on top of the hydrogel, which slightly contacts the medium surface. The drug concentration in the release medium was determined by HPLC measurements. This system allows for testing the release of dexamethasone without the samples being completely surrounded by medium. The hydrogel mediates the diffusion of the drug by ensuring the contact with the medium. Release was monitored for more than 23 days. The presented concept was successfully designed and manufactured. The system is inexpensive and can be duplicated easily. In this study, it was used to monitor the drug release of dexamethasone from PEGDA700 derived polymer. One challenge that remains to be considered is the low mechanical stability of the hydrogel, which results in a need for repeated manufacturing during the handling of the system.

Sustained ophthalmic delivery of pH triggered Cromolyn sodium in situ gel

2021 ◽  
pp. 6211-6215
Author(s):  
S. Subramanian ◽  
B. Prasanth
Keyword(s):  
Drug Release ◽  
Cromolyn Sodium ◽  
Fickian Diffusion ◽  
Molar Ratio ◽  
Eye Drops ◽  
In Vitro Drug Release ◽  
In Situ Gel ◽  
In Situ Gelling

The research study intends to formulate pH triggered in situ gel of Cromolyn sodium composed of Polyacrylic acid (carbopol 934) polymer in combination with Hydroxypropyl Methylcellulose (HPMC K4M) polymer at 1:1, 1.5:1, 2:1 molar ratio by utilizing pH trigger method. Formulations were evaluated for pH, viscosity, gelling capacity, drug content and in vitro drug release. Results of Carbopol 934 and HPMC K4M based in situ gelling systems at 1:1, 1.5:1, 2:1 shown that the formulations were fluid state at room temperature in a formulated pH (pH 4.5) and went through fast progress into the viscous gel phase at the pH of the tear fluid 7.4. The viscosity of formulated pH triggered in situ gel at 2:1 molar ratio shown excellent result compares to 1:1, 1.5:1 molar ratio. The in vitro drug release of the developed in situ gelling formulations at 1:1, 1.5:1, 2:1 molar ratios increases the contact time and showed a non – fickian diffusion type of release behavior with 94.45%, 83.26%, 70.48% respectively over 8 hours periods compared with that of marketed formulation that shows 99.4% over 4 hours. Thus, the developed system at 2:1 molar ratio acts as a viable alternative to conventional eye drops and also prevent the rapid drainage.

In Vitro and In Vivo Drug Release from a Novel In Situ Forming Drug Delivery System

2007 ◽  
Vol 25 (6) ◽  
pp. 1347-1354 ◽  
Author(s):  
Heiko Kranz ◽  
Erol Yilmaz ◽  
Gayle A. Brazeau ◽  
Roland Bodmeier
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery System ◽  
Delivery System ◽  
In Situ Forming

scholarly journals Formulation and characterization of a novel pH-triggered in-situ gelling ocular system containing Gatifloxacin

1970 ◽  
Vol 1 (3) ◽  
pp. 43-49 ◽  
Author(s):  
Jovita Kanoujia ◽  
Kanchan Sonker ◽  
Manisha Pandey ◽  
Koshy M Kymonil ◽  
Shubhini A Saraf
Keyword(s):  
Drug Release ◽  
Research Work ◽  
Gelling Agent ◽  
In Vitro Drug Release ◽  
Drug Content ◽  
Carbopol 940 ◽  
In Situ Gelling ◽  
Gel Transition

The present research work deals with the formulation and evaluation of in-situ gelling system based on sol-to-gel transition for ophthalmic delivery of an antibacterial agent gatifloxacin, to overcome the problems of poor bioavailability and therapeutic response exhibited by conventional formulations based a sol-to-gel transition in the cul-de-sac upon instillation. Carbopol 940 was used as the gelling agent in combination with HPMC and HPMC K15M which acted as a viscosity enhancing agent. The prepared formulations were evaluated for pH, clarity, drug content, gelling capacity, bioadhesive strength and in-vitro drug release. In-vitro drug release data of optimized formulation (F12) was treated according to Zero, First, Korsmeyer Peppas and Higuchi kinetics to access the mechanism of drug release. The clarity, pH, viscosity and drug content of the developed formulations were found in range 6.0-6.8, 10-570cps, 82-98% respectively. The gel provided sustained drug release over an 8 hour period. The developed formulation can be used as an in-situ gelling vehicle to enhance ocular bioavailability and the reduction in the frequency of instillation thereby resulting in better patient compliance. Key Words: In-situ gelation; Gatifloxacin; Carbopol 940; HPMC K15M. DOI: http://dx.doi.org/10.3329/icpj.v1i3.9661 International Current Pharmaceutical Journal 2012, 1(3): 43-49

Fabrication and Characterization of Ocular Phase Transition Systems for Blepharitis: A Novel Approach

2020 ◽  
Vol 10 (1) ◽  
pp. 24-37
Author(s):  
Deepali Verma ◽  
Shreya Kaul ◽  
Neha Jain ◽  
Upendra Nagaich
Keyword(s):  
Drug Release ◽  
Ex Vivo ◽  
Eye Drops ◽  
Stability Studies ◽  
In Vitro Drug Release ◽  
In Situ Gel ◽  
Drug Content ◽  
Erythromycin Estolate

Introduction: In the present research, erythromycin estolate loaded in-situ gel was formulated and evaluated for blepharitis in order to improve its therapeutic efficacy, precorneal residence time of the system and to enhance the ocular bioavailability. Material and Methods: The developed formulation was characterized by several parameters viz. FTIR, clarity, pH, gelation temperature, rheological studies, drug content, in vitro drug release studies, transcorneal permeation studies, bioadhesion studies, isotonicity and stability studies. Results: The optimized formulation exhibited non-fickian release diffusion with a sustained release of drug 82.76 ± 0.94% up to 8h and drug content 93.64%. Isotonicity revealed that the formulation was isotonic in nature and there was no shrinkage and busting of cells. Bioadhesion study was performed to check the adherence of the prepared in situ gel to the corneal surface for 4h. Ex vivo transcorneal permeation was observed to be significantly higher when compared with market eye drops. Histopathological studies were conducted to confirm the presence of normal ocular surface tissues by maintaining their morphological structures without causing damage to the tissues. The formulation was nonirritant as confirmed by the HET-CAM test. Stability studies and accelerated stability studies were conducted for 13 weeks and 26 weeks respectively and formulations were analyzed for the visual appearance, pH, viscosity, gelling capacity, drug content and in vitro drug release and results showed no change in the formulations. Conclusion: The formulation was therapeutically efficacious, sterile, stable and provided controlled release over a period of time. The developed system could be a viable alternative to conventional eye drops for treatment of various ocular diseases.

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