Retinal Vein Occlusion
Glenn J. Jaffe, Paul Ashton, P. Andrew Pearson in Intraocular Drug Delivery, 2006
Triamcinolone acetonide is a corticosteroid that is commercially available and inexpensive. Intravitreal injection of triamcinolone acetonide is nontoxic in animal studies (17–19). McCuen et al. (17) injected1 mg of triamcinolone acetonide into the vitreous cavity of 21 rabbit eyes. Throughout the three-month course of follow-up ophthalmoscopy, intraocular pressure, electroretinography (scotopic and photopic responses), and light and electron microscopy all remained normal. Schindler et al. (18) studied the clearance of intravitreally injected triamcinolone acetonide (0.5 mg) in 30 rabbit eyes. In nonvitrectomized eyes, the average clearance rate was 41 days. In eyes having undergone vitrectomy or combination vitrectomy and lensectomy, the average clearance rate was 17 and 7 days, respectively (18). It was found that the ophthalmoscopic disappearance of injected triamcinolone acetonide correlated well with a spectrophotometric analysis for clearance of the drug. Scholes et al. (19) also studied the clearance of intravitreally injected triamcinolone acetonide (0.4 mg) in 24 rabbit eyes. Using high-performance liquid chromatography complete clearance of the drug was noted by 21 days. Nondetectable drug levels were present before ophthalmoscopic disappearance.
Regulatory Standards for Approval of Topical Dermatological Drug Products
Tapash K. Ghosh in Dermal Drug Delivery, 2020
The preliminary work conducted by Hollander in 1951 (Hollander et al. 1951) discovered that intra-articular steroids produced blanching (whitening) of the engorged synovial membrane in rheumatoid arthritis. It was postulated that vasoconstriction produced in normal skin may be an indicator of percutaneous absorption. From the 1950s to 1960s, research began in the area of topical therapy and skin blanching. It was in 1962 that McKenzie and Stoughton published an article on assaying the potency of steroids by using vasoconstriction as an index of percutaneous absorption (McKenzie and Stoughton 1962). Three corticosteroids – Dexamethasone alcohol, Triamcinolone Acetonide and Fluocinolone Acetonide – were studied. The different corticosteroids were applied to the forearm of healthy subjects under occlusion with a perforated guard of the application sites for 16 hours after which the intensity of the skin blanching response was measured by visual assessment.
Trachyonychia
Nilton Di Chiacchio, Antonella Tosti in Therapies for Nail Disorders, 2020
Nail unit steroid injections of triamcinolone acetonide have been described in a number of studies.30,31,33 Dosing schedule of triamcinolone varied between studies and included 2.5–10 mg/mL single injection,31 5 mg/mL monthly,30 and 10 mg/mL twice a week.33 In a study of 19 patients with trachyonychia who completed 6 months of treatment with monthly intralesional injections of 5 mg/mL (0.1–0.2 mL) of triamcinolone acetonide, 11 of the patients showed at least 75% improvement.30 Relapse occurred in about 62% of patients within 6 months, but relapse was also responsive to treatment. Side effects of treatment included pain (36%), proximal nail fold atrophy (24%), subungual hematoma (20%), and vasovagal syncope (4%).30 In a case report, a patient suffered mild atrophy and telangiectasias of the proximal nail fold as well as a subungual hematoma as side effects to nail unit steroid injections.33
Transdermal delivery via medical device technologies
Published in Expert Opinion on Drug Delivery, 2022
Shubhangi Shukla, Ryan H. Huston, Blake D. Cox, Abhay R. Satoskar, Roger J. Narayan
Researchers have chosen to avoid the water solubility issue by using other nontoxic organic solvents for their iontophoresis buffer mixture. One study dissolved triamcinolone acetonide in a solution of N-N,-dimethylacetamide (as the organic solvent) and water at a ratio of 7/3 v/v [129]. Triamcinolone acetonide is an uncharged drug that is used to inhibit collagen synthesis for keloid and hypertrophic scar treatment. This drug was typically administered via pressure jet injection; however, this approach caused discomfort to patients, necessitating the development of alternative delivery methods [129]. Rats that were treated with iontophoresis for 30 minutes were found to retain triamcinolone acetonide in their skin 24 hours after treatment, indicating the success of N-N,-dimethylacetamide as an alternative solvent for drugs that may not otherwise be suitable for delivery using iontophoresis [129].
Herpetic Anterior Uveitis in a Chinese Referral Center: Clinical Manifestations and Laboratory Test Results
Published in Ocular Immunology and Inflammation, 2020
Zhuyun Qian, Hua Fan, Yong Tao, Wensheng Li, Wei Gu
Additional differences in the clinical features between the HSV-AU group and the VZV-AU group included the age of the patients and the occurrence of scleritis and diffuse iris atrophy. The average age of the patients with HSV-AU was less than the average of the patients with VZV-AU. Van der Lelij et al. also found that HSV was more common in adults under the age of 50, while VZV predominantly affected adults older than. 6017 In our study, anterior scleritis was diagnosed in two eyes infected with VZV-AU. One eye presented with scleral staphyloma and underwent allo-sclera transplantation. Loureiro et al. proposed that VZV-associated scleritis triggered an immune response in addition to direct viral damage, which caused the development of scleritis even with antiviral therapy.18 In our cases, a high dose of sub-conjunctival triamcinolone acetonide (TA) (10 mg) was given to suppress the inflammation. We also found a significantly high rate of diffuse iris atrophy in eyes infected with VZV-AU. The large transillumination defect consisted of multifocal pigment epithelial atrophy, which is different from the diffuse iris atrophy caused by CMV or rubella virus (RV) infection. We speculated that this clinical feature was associated with higher viral load and more severe intraocular inflammation in VZV-AU.
Recent advances in slow and sustained drug release for retina drug delivery
Published in Expert Opinion on Drug Delivery, 2019
Suprachoroidal delivery has been described almost 50 years ago [47] but was disregarded until our group described in 2002 the suprachoroidal injection of a semi-solid poly(ortho)ester biodegradable material, that was showed to diffuse toward the posterior segment when injected at the pars plana [48]. More recently, the microneedle technology has been developed to inject in a controlled manner, drugs into the suprachoroidal space, in order to position the dug closer to the targeted tissues as compared to the periocular injections. Lower but more targeted doses of triamcinolone acetonide could lead to similar efficacy but reduced side-effects [49,50]. This technology is developed by Clearside for the treatment of diabetic macular edema, macular edema secondary to uveitis [51], or to vein occlusion [52]. It is important to consider the clearance mechanisms for each specific drug and each route of administration, as elimination of the drug through the anterior aqueous humor pathway, the retinal pathway, or through the retinal vessels, target to efflux proteins, degradation mechanisms, influence the effectiveness of drug delivery system [22,24]
Related Knowledge Centers
- Allergic Rhinitis
- Mouth Ulcer
- Organic Compound
- Corticosteroid
- Lesion
- Topical Medication
- Skin Condition
- Joint Injection
- Arthropathy
- Macular Edema