ROHIT SINGH BISHT 20SCSE1180036

Topical drug administration for back of the eye delivery is extremely challenging due to the presence of protection mechanisms and physiological barriers. Self-assembled polymeric nanomicelles have emerged as promising vehicles for drug delivery. Apart from serving as an inert nanocarrier for therapeutic agents, polymeric nanomicelles are known to bypass mononuclear phagocytic system (MPS) and efflux transporters thereby improving drug bioavailability. In this investigation, a highly efficacious biotinylated lipid prodrug of cyclic cidofovir (B-C12-cCDF) was formulated within polymeric nanomicelles as a carrier for targeted retinal delivery. Polymeric nanomicelles were prepared from polyoxyethylene hydrogenated castor oil 40 (HCO-40) and octoxynol 40 (OC-40). In vitro release studies revealed that B-C12-cCDF-loaded nanomicelles released B-C12-cCDF at a faster rate in stimulated tear fluid (STF) in comparison to PBST. MTT and LDH assays demonstrated negligible cytotoxicity of B-C12-c...

This study aimed to develop and evaluate an ex vivo eye model for intravitreal drug sampling and tissue distribution of connexin43 mimetic peptide (Cx43MP) following intravitreal injection using the microdialysis technique and LC-MS/MS. An LC-MS/MS method was developed, validated, and applied for quantification of Cx43MP in ocular tissues. Microdialysis probes were calibrated for in vitro recovery studies. Bovine eyes were fixed in a customized eye holder and after intravitreal injection of Cx43MP, microdialysis probes were implanted in the vitreous body. Vitreous samples were collected at particular time intervals over 24 h. Moreover, 24 and 48 h after intravitreal injection ocular tissues were collected, processed, and analyzed for Cx43MP concentrations using LC-MS/MS. The LC-MS/MS method showed good linearity (r (2) = 0.9991). The mean percent recovery for lower (LQC), medium (MQC), and higher quality control (HQC) (0.244, 3.906, and 125 μg/mL) was found to be 83.83, 84.92, and 9...

Frequent intravitreal injections are currently the preferred treatment method for diseases affecting the posterior segment of the eye. However, these repeated injections have been associated with pain, risk of infection, hemorrhages, retinal detachment and high treatment costs. To overcome these limitations, light-responsive in situ forming injectable implants (ISFIs) may emerge as novel systems providing site-specific controlled drug delivery to the retinal tissues with great accuracy, safety, minimal invasiveness and high cost efficiency. Area covered: Complex ocular barriers, routes for drug delivery, types of injectable implants, ocular application of light and benefits of light-responsive systems are discussed with regards to challenges and strategies employed for effective drug delivery to the posterior segment of the eye. In particular, we have highlighted photoresponsive moieties, photopolymerization mechanisms and different development strategies with their limitations as well as recent advancements in the field. Expert opinion: Biodegradable light-responsive ISFIs are promising drug delivery systems that have shown a high degree of biocompatibility with sustained drug release in a number of applications. However, their use in intravitreal drug delivery is still in the very early stages. Issues related to the biocompatibility of the photoinitiator and the elimination of photo-degraded by-products from the ocular tissues need careful consideration, not only from a chemistry standpoint, but also from a biological perspective to improve the suitability of these systems for clinical applications.

Parkinson's disease is a neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra pars compacta along with decreased striatal dopamine levels, and consequent extra pyramidal motor dysfunctions occur. It has been reported that Ceftriaxone, a β-lactam antibiotic recently had shown to have neuroprotective effects in various neurodegenerative disorder. Therefore the present study was designed to investigate the effects of Ceftriaxone (CFX) in a MPTP model of Parkinson in rats. MPTP was administered intranigrally for the induction of PD in Male Wistar rats. Ceftriaxone (100 and 200mg/kg) and Ropinirole (1.5 and 3mg/kg) were given intraperitonially, after induction of Parkinson's disease for 14 days. Different behavioral performance was carried on 1st, 14th, 21st, 28th consecutive days and biochemical parameters were estimated on 28th day. Central administration of MPTP showed significant impairment of motor behavior and marked increase of oxidative damage and neuro-inflammmation in rats. However, post treatment with Ceftriaxone (100 and 200mg/kg) significantly improved the motor deficits and attenuated the oxidative damage indicating decreased rise of LPO and nitrite concentration and restored the decreased activities of endogenous antioxidant enzyme (Glutathione, Catalase, SOD). In addition Ceftriaxone also attenuates the pro-inflammatory cytokines like TNF-α and IL-β in striatum region of MPTP induced PD in rats. Ropinirole (1.5mg/kg) pretreatment with sub-effective dose of a Ceftriaxone (100mg/kg) had significantly enhanced the protective effect of Ceftriaxone as compare to its effect with per se group. These results suggested that Ceftriaxone exhibit Neuroprotective effect by mediating brain antioxidant defense mechanism and by up regulating of dopaminergic pathway and down regulation of glutamatergic pathway.

Tardive dyskinesia is a serious motor disorder of the orofacial region, resulting from chronic neuroleptic treatment of schizophrenia. Candesartan (AT1 antagonist) and lisinopril (ACE inhibitor) has been reported to possess antioxidant and neuroprotective effects. The present study is designed to investigate the effect of candesartan and lisinopril on haloperidol-induced orofacial dyskinesia and oxidative damage in rats. Tardive dyskinesia was induced by administering haloperidol (1 mg/kg i.p.) and concomitantly treated with candesartan (3 and 5 mg/kg p.o.) and lisinopril (10 and 15 mg/kg p.o.) for 3 weeks in male Wistar rats. Various behavioral parameters were assessed on days 0, 7, 14 and 21 and biochemical parameters were estimated at day 22. Chronic administration of haloperidol significantly increased stereotypic behaviors in rats, which were significantly improved by administration of candesartan and lisinopril. Chronic administration of haloperidol significantly increased oxidative stress and neuro-inflammation in the striatum region of the rat's brain. Co-administration of candesartan and lisinopril significantly attenuated the oxidative damage and neuro-inflammation in the haloperidol-treated rat. The present study supports the therapeutic use of candesartan and lisinopril in the treatment of typical antipsychotic-induced orofacial dyskinesia and possible antioxidant and neuro-inflammatory mechanisms.