scholarly journals Bio-Distribution and Pharmacokinetics of Topically Administered γ-Cyclodextrin Based Eye Drops in Rabbits

2021 ◽  
Vol 14 (5) ◽  
pp. 480
Author(s):  
Martin Kallab ◽  
Kornelia Schuetzenberger ◽  
Nikolaus Hommer ◽  
Bhavapriya Jasmin Schäfer ◽  
Doreen Schmidl ◽  
...  

The purpose of this study was to evaluate the ocular pharmacokinetics, bio-distribution and local tolerability of γ-cyclodextrin (γCD) based irbesartan 1.5% eye drops and candesartan 0.15% eye drops after single and multiple topical administration in rabbit eyes. In this randomized, controlled study, a total number of 59 New Zealand White albino rabbits were consecutively assigned to two study groups. Group 1 (n = 31) received irbesartan 1.5% and group 2 (n = 28) candesartan 0.15% eye drops. In both groups, single dose and multiple administration pharmacokinetic studies were performed. Rabbits were euthanized at five predefined time points after single-dose administration, whereas multiple-dose animals were dosed for 5 days twice-daily and then euthanized 1 h after the last dose administration. Drug concentration was measured by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the retinal tissue, vitreous humor, aqueous humor, corneal tissue and in venous blood samples. Pharmacokinetic parameters including maximal drug concentration (Cmax), time of maximal drug concentration (Tmax), half-life and AUC were calculated. To assess local tolerability, six additional rabbits received 1.5% irbesartan eye drops twice daily in one eye for 28 days. Tolerability was assessed using a modified Draize test and corneal sensibility by Cochet Bonnet esthesiometry. Both γCD based eye drops were rapidly absorbed and distributed in the anterior and posterior ocular tissues. Within 0.5 h after single administration, the Cmax of irbesartan and candesartan in retinal tissue was 251 ± 142 ng/g and 63 ± 39 ng/g, respectively. In the vitreous humor, a Cmax of 14 ± 16 ng/g for irbesartan was reached 0.5 h after instillation while Cmax was below 2 ng/g for candesartan. For multiple dosing, the observed Cmean in retinal tissue was 338 ± 124 ng/g for irbesartan and 36 ± 10 ng/g for candesartan, whereas mean vitreous humor concentrations were 13 ± 5 ng/g and <2 ng/g, respectively. The highest plasma concentrations of both irbesartan (Cmax 5.64 ± 4.08 ng/mL) and candesartan (Cmax 4.32 ± 1.04 ng/mL) were reached 0.5 h (Tmax) after single administration. Local tolerability was favorable with no remarkable differences between the treated and the control eyes. These results indicate that irbesartan and candesartan in γCD based nanoparticle eye drops can be delivered to the retinal tissue of the rabbit’s eye in pharmacologically relevant concentrations. Moreover, safety and tolerability profiles appear to be favorable in the rabbit animal model.

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Danielle Levin

We would like to present the first report of severe acute dystonic reaction after a single administration of metoclopramide during cesarean section under combined spinal-epidural anesthesia.  During elective cesarean section, a 30-year-old female vomited four times and was treated with 10mg intravenous metoclopramide and 8mg intravenous ondansetron.  Nausea subsided with the antiemetic treatment, but two minutes later, patient had rapid eye blinking, uncontrollable head movement, and became unresponsive.  Bolus of 50mg intravenous diphenhydramine resolved the acute dystonic symptoms within seconds.  Patient was again oriented times three, with no recollection of symptoms, and remained symptom free for the rest of admission. 


2020 ◽  
Vol 21 (1) ◽  
pp. 31-35
Author(s):  
Basma El-Desoky ◽  
Shaimaa El-Sayed ◽  
El-Said El-Said

Objective: Investigating the effect of green tea extract (GTE) on the testicular damage induced by cadmium chloride CdCl2 in male rats. Design: Randomized controlled study. Animals: 40 male Wistar rats. Procedures: Rats were randomly divided into four groups: A) control group (each rat daily received pellet diet); B) GTE group each rat daily received pellet diet as well as 3 ml of 1.5 % w/v GTE, C) CdCl2 group each rat was I/P injected a single dose of 1 mg/kg CdCl2, then daily received pellet diet, and D) CdCl2+GTE group each rat was I/P injected a single dose of 1 mg/kg CdCl2 then daily received pellet diet as well as 3 ml of 1.5 % w/v GTE. After 30 days, blood samples were collected for hormonal assays (testosterone, FSH, and LH). In addition, both testes were collected; one of them was used for quantification of 17-beta hydroxysteroid dehydrogenase III (17β-HSDIII) gene expression using a real-time PCR. The other testis was used for determination of catalase and reduced glutathione; GSH, Nitric oxide (NO) and malondialdehyde (MDA) levels. Results: CdCl2 decreased serum testosterone levels and its synthesis pathway (17β-HSDIII testicular gene expression). While antioxidants catalase and GSH were reduced, oxidants MDA were enriched in the testes of CdCl2-poisoned rats. This CdCl2-promoted testicular dysfunction was corrected via the administration of GTE to male rats. Conclusion and clinical relevance: GTE could be used as a remedy for protecting against CdCl2-induced testicular damage in male rats.


2021 ◽  
Vol 18 ◽  
Author(s):  
Francine Rubião ◽  
Alan Cezar Faria Araújo ◽  
João Bernardo Sancio ◽  
Bárbara Silva Nogueira ◽  
Juçara Ribeiro Franca ◽  
...  

Background: The most common treatment for primary open-angle glaucoma (POAG) is the daily use of eye drops. Sustained-release drug delivery systems have been developed to improve patient adherence by achieving prolonged therapeutic drug concentrations in ocular target tissues while limiting systemic exposure. The purpose of this study is to compare the efficacy and safety of bimatoprost inserts with bimatoprost eye drops in patients with POAG and ocular hypertension (OH). Methods: We include OH and POAG patients aged between 40 and 75 years-old. Both OH and POAG patients had intraocular pressure (IOP) greater than 21 and ≤30 mmHg at 9:00 am without glaucoma medication and normal biomicroscopy. Five normal patients with IOP≤14 mmHg constitute the control group. A chitosan-based insert of bimatoprost was placed at the upper conjunctival fornix of the right eye. In the left eye, patients used one drop of LumiganTM daily at 10:00 pm. For statistical analysis, we used a two-way analysis of variance (ANOVA), Student t-test, and paired t-test. Results: Sixteen POAG and 13 OH patients with a mean age of 61 years were assessed. In both eyes, IOP reduction was similar during three weeks of follow-up (19.5±2.2 mmHg and 16.9±3.1 mmHg), insert, and eye drop, respectively; P=0.165). The percentage of IOP reduction in the third week was 30% for insert and 35% for eye drops (P=0.165). No intolerance or discomfort with the insert was reported. Among the research participants, 58% preferred the use of the insert while 25% preferred eye drops, and 17% reported no preference. Conclusions: Bimatoprost-loaded inserts showed similar efficacy to daily bimatoprost eye drops during three weeks of follow up, without major side effects. This might suggest a possible change in the daily therapeutic regimen for the treatment of POAG and OH.


2021 ◽  
Vol 10 (10) ◽  
pp. 2198
Author(s):  
Rosario Musumeci ◽  
Pasquale Troiano ◽  
Marianna Martinelli ◽  
Matteo Piovella ◽  
Claudio Carbonara ◽  
...  

A multicenter, nonrandomized, prospective, controlled study was conducted to evaluate, as perioperative prophylactic treatment, the anti-infective effectiveness of 0.66% povidone-iodine eye drops (IODIM®) against the bacterial flora of the conjunctival surface of patients who undergo cataract surgery. Eye drops containing 0.66% povidone-iodine were applied to the eye undergoing cataract surgery; the untreated contralateral eye was used as control. One hundred and twenty patients set to receive unilateral cataract surgery were enrolled in 5 Italian Ophthalmology Centers and pretreated for three days with 0.66% povidone-iodine eye drops. The contralateral eye, used as control, was left untreated. Conjunctival swabs of both eyes were collected at the baseline visit and after three days of treatment, just before the cataract surgery. A qualitative and quantitative microbiological analysis of bacterial presence was evaluated by means of bacterial culture, followed by identification. Methicillin resistance determination was also performed on staphylococci isolates. Bacterial load before and after treatment of the eye candidate for cataract surgery was evaluated and compared to the untreated eye. A reduction or no regrowth on the culture media of the bacterial load was observed in 100% of the study subjects. A great heterogenicity of bacterial species was found. The 0.66% povidone-iodine eye drops, used for three days prior to cataract surgery, were effective in reducing the conjunctival bacterial load. The 0.66% povidone-iodine eye drops (IODIM®) might represent a valid perioperative prophylactic antiseptic adjuvant treatment to protect the ocular surface from microbial contamination in preparation of the surgical procedure.


2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Qiao Wang ◽  
Wenjin Liu ◽  
Junjun Wang ◽  
Hong Liu ◽  
Yong Chen

Abstract In this study, daidzein long-circulating liposomes (DLCL) were prepared using the ultrasonication and lipid film-hydration method. The optimized preparation conditions by the orthogonal design was as follows: 55 to 40 for the molar ratio of soybean phosphatidylcholine (SPC) to cholesterol, 1 to 10 for the mass ratio of daidzein to total lipid (SPC and cholesterol) (w:w), the indicated concentration of 5% DSPE-mPEG2000 (w:w), 50 °C for the hydration temperature, and 24 min for the ultrasonic time. Under these conditions, the encapsulation efficiency and drug loading of DLCL were 85.3 ± 3.6% and 8.2 ± 1.4%, respectively. The complete release times of DLCL in the medium of pH 1.2 and pH 6.9 increased by four- and twofold of that of free drugs, respectively. After rats were orally administered, a single dose of daidzein (30 mg/kg) and DLCL (containing equal dose of daidzein), respectively, and the MRT0−t (mean residence time, which is the time required for the elimination of 63.2% of drug in the body), t1/2 (the elimination half-life, which is the time required to halve the plasma drug concentration of the terminal phase), and AUC0−t (the area under the plasma drug concentration-time curve, which represents the total absorption after a single dose and reflects the drug absorption degree) of daidzein in DLCL group, increased by 1.6-, 1.8- and 2.5-fold as compared with those in the free group daidzein. Our results indicated that DLCL could not only reduce the first-pass effect of daidzein to promote its oral absorption, but also prolong its mean resident time to achieve the slow-release effect.


2010 ◽  
Vol 49 (20) ◽  
pp. 2211-2218 ◽  
Author(s):  
Kunihiro Ichinose ◽  
Tomoki Origuchi ◽  
Shin-ya Kawashiri ◽  
Naoki Iwamoto ◽  
Keita Fujikawa ◽  
...  

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