The brain is a delicate organ, and nature has very efficiently protected it. The brain is shielded against potentially toxic substances by the presence of two barrier systems: the blood brain barrier (BBB) and the blood cerebrospinal fluid barrier (BCSFB). Unfortunately, the same mechanisms that protect it against intrusive chemicals can also frustrate therapeutic interventions. Despite aggressive research, patients suffering from fatal and/or debilitating central nervous system (CNS) diseases, such as brain tumours, HIV encephalopathy, epilepsy, cerebrovascular diseases and neurodegenerative disorders, far outnumber those dying of all types of systemic cancers or heart diseases. The abysmally low number of potential therapeutics reaching commercial success is primarily due to the complexity of the CNS drug development. The clinical failure of many probable candidates is often, ascribable to poor delivery methods which do not pervade the unyielding BBB. It restricts the passive diffusion of many drugs into the brain and constitutes a significant obstacle in the pharmacological treatment of central nervous system (CNS) disorders. General methods that can enhance drug delivery to the brain are, therefore, of great pharmaceutical interest. Various strategies like non-invasive methods, including drug manipulation encompassing transformation into lipophilic analogues, prodrugs, chemical drug delivery, carrier-mediated drug delivery, receptor/vector mediated drug delivery and intranasal drug delivery, which exploits the olfactory and trigeminal neuronal pathways to deliver drugs to the brain, are widely used. On the other hand the invasive methods which primarily rely on disruption of the BBB integrity by osmotic or biochemical means, or direct intracranial drug delivery by intracerebroventricular, intracerebral or intrathecal administration after creating reversible openings in the head, are recognised. Extensive review pertaining specifically, to the patents relating to drug delivery across the CNS is currently available. However, many patents e.g. US63722506, US2002183683 etc., have been mentioned in a few articles. It is the objective of this article to expansively review drug delivery systems for CNS by discussing the recent patents available.

The aim of the present work was to investigate the efficacy of nanostructured lipid carriers (NLCs) to enhance the brain targeting of lamotrigine (LMT) following intranasal (IN) administration. Formulation was optimized using four-factor three levels Box- Behnken design to establish the functional relationships between variables on responses, that is, particle size, entrapment efficiency (EE) and percentage cumulative drug release of LMT-loaded NLCs. NLCs were evaluated for particle size, surface morphology, %EE and in vitro release and ex vivo permeation. The developed formulation was subjected to stability study, in vivo efficacy and scintigraphic study in Wistar rat model. The NLCs had a mean particle size of 151.6 ± 7.6 nm, polydispersity index of 0.249 ± 0.035, zeta potential of 11.75 ± 2.96 mV and EE of 96.64 ± 4.27%. The drug release from NLCs followed Fickian diffusion with a flux value of 11.73 μgcm(-2)h(-1). Sustained drug concentration was obtained in NLCs carrying LMT after IN administration after 24 h. γ scintigraphy studies further proved high accumulation of drug in brain. Hence we can conclude that IN administration of LMT NLCs in rats is able to maintain higher brain concentration of LMT compared to IN and oral drug solution.

Background: Neuronal hyperexcitability and excessive production of free radicals have been implicated in the pathogenesis of a considerable range of neurological disorders, including epilepsy. The high rate of oxidative metabolism, coupled with the low antioxidant defenses and the richness in polyunsaturated fatty acids, makes the brain highly vulnerable to free radical damage. The increased susceptibility of the brain to oxidative damage highlights the importance of understanding the role of oxidative stress in the pathophysiology of seizures. Objectives: The present review aims not only to address the link between mitochondrial dysfunction, oxidative stress and seizures, but also the modulation of the pro-oxidant/antioxidant balance following seizures and treatment with antioxidants and antiepileptic drugs. Methods: A literature review revealed that there are articles that address the role of oxidative stress and mitochondrial dysfunction in neurological disorders, including those involving different se...