Želatinske nanočestice presvučene mananom za polaganu i ciljanu isporuku didanozina: In vitro i in vivo vrednovanje

Macrophages of the reticuloendothelial system and brain act as major reservoir for HIV because of their long term survival after HIV infection and ability to spread virus particles to bystander CD4 positive lymphocyte cells. The objective of the present study was to investigate mannan-coated nanoparticles for macrophage targeting of didanosine. Different didanosine loaded nanoparticles were prepared using the double desolvation technique and were characterized in vitro, ex-vivo and in vivo. Results of the ex-vivo cellular uptake study indicated 5-fold higher uptake of didanosine from the mannan-coated nanoparticles formulation (62.5 ± 5.4%) by the macrophages in comparison with didanosine solution in phosphate buffer saline (PBS, pH 7.4) (12.1 ± 2.3%). The better cellular uptake from the nanoparticles formulation was further confirmed by fluorescence microscopy using hydrophilic 6-carboxyfluorescein as a marker. Results of the quantitative biodistribution study showed 1.7, 12.6 and 12.4 times higher localization of didanosine in the spleen, lymph nodes and brain, respectively, after administration of mannan-coated nanoparticles compared to that after injection of didanosine solution in PBS (pH 7.4). Results of the present study showed that the mannan-coated nanoparticles targeted didanosine to the macrophage by mannosyl receptor mediated endocytosis.Makrofagi retikuloendotelnog sustava i mozak djeluju kao glavni rezervoari za HIV zbog njihovog dugoročnog preživljavanja nakon infekcije HIV-om i sposobnosti da usmjere virusne čestice u CD4 pozitivne limfocite. Cilj rada bio je ispitati nanočestice obložene mananom za ciljanu isporuku didanozina u makrofage. Koristeći metodu dvostruke desolvatacije pripravljene su različite nanočestice s didanozinom te su zatim karakterizirane in vitro, ex vivo i in vivo. Rezultati ex vivo ispitivanja ukazuju da je unos didanozina u makrofage 5 puta veći iz nanočestica obloženih mananom (62,5 ± 5,4%) u usporedbi s otopinom didanozina u fosfatnom puferu (PBS, pH 7,4) (12,1 ± 2,3%). Bolji celularni unos iz nanočestica potvrđen je fluorescentnom mikroskopijom koristeći hidrofilni 6-karboksifluorescein kao marker. Rezultati kvantitativne biodistribucije pokazuju da je lokalizacija didanozina u slezeni, limfnim čvorovima i mozgu 1,7, 12,6, odnosno 12,4 puta veća nakon primjene nanočestica obloženih mananom nego nakon primjene otopine didanozina u PBS-u (pH 7,4). Nanočestice s mananom usmjeravaju didanozin u makrofage procesom endocitoze u kojoj posreduju receptori za manozu

Research Journal of Pharmaceutical, Biological and Chemical Sciences Recent Advances in NDDS (Novel drug delivery systems) for delivery of Anti- HIV drugs

ABSTRACT Novel drug delivery systems present an opportunity for formulation scientists to overcome the many challenges associated with antiretroviral (ARV) drug therapy, thereby improving the management of patients with HIV/AIDS. Currently available Anti-HIV drugs can be classified into three categories: nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors. Most of these drugs bear some significant drawbacks such as relatively short half-life, low bioavailability, poor permeability and undesirable side effects. Efforts have been made to design drug delivery systems for antiHIV agents to: a) reduce the dosing frequency, b) increase the bioavailability and decrease the degradation/metabolism in the gastrointestinal tract, c) improve the CNS penetration and inhibit the CNS efflux, and d) deliver them to the target cells selectively with minimal side effects. This paper provides a comprehensive review of the various ARV delivery systems that have been developed for achieving sustained drug release kinetics, specifically targeting drugs to the macrophages, brain and gastric mucosa, and for addressing formulation difficulties such as poor solubility, stability and drug entrapment. Studies on the potential of systems for alternative routes of ARV drug administration, i.e, transdermal and buccal are also highlighted. The physico-chemical properties and the in vitro/in vivo performances of various systems such as sustained release tablets, ceramic implants, nanoparticles, nanocontainers, liposomes, emulsomes, aspasomes, microemulsions, nanopowders and Pheroid TM are summarised. Further studies that remain to be undertaken for formulation optimisation are also identified. This review highlights the significant potential that novel drug delivery systems have for the future effective treatment of HIV/AIDS patients on ARV drug therapy

Antioxidant phytoconstituents from Onosma bracteata Wall. (Boraginaceae) ameliorate the CCl4 induced hepatic damage: in vivo study in male wistar rats

Onosma bracteata Wall. (Boraginaceae) is a highly valuable medicinal herb that is used for the treatment of fever, bronchitis, asthma, rheumatism, stomach irritation, and other inflammatory disorders. The present study aims to explore the hepatoprotective potential of ethanolic extract (Obeth) from O. bracteata aerial parts against carbon tetrachloride (CCl4) which causes hepatic damage in the male Wistar rats. Obeth showed effective radical quenching activity with an EC50 of 115.14 and 199.33 µg/mL in superoxide radical scavenging and lipid peroxidation analyses respectively along with plasmid DNA protective potential in plasmid nicking assay. The Obeth modulated mutagenicity of 2 Aminofluorine (2AF) in the pre-incubation mode of investigation (EC50 10.48 µg/0.1 mL/plate) in TA100 strain of Salmonella typhimurium. In in vivo studies, pretreatment of Obeth (50, 100, and 200 mg/kg) had the potential to normalize the biochemical markers aggravated by CCl4 (1mL/kg b.wt.) including liver antioxidative enzymes. Histopathological analysis also revealed the restoration of CCl4-induced liver histopathological alterations. Immunohistochemical studies showed that the treatment of Obeth downregulated the expression levels of p53 and cyclin D in hepatocytes. and downregulation in the Western blotting analysis revealed the downregulation of p-NF-kB, COX-2, and p53. HPLC data analysis showed the supremacy of major compounds namely, catechin, kaempferol, epicatechin, and Onosmin A in Obeth. The present investigation establishes the hepatoprotective and chemopreventive potential of O. bracteata against CCl4-induced hepatotoxicity via antioxidant defense system and modulation of the expression of proteins associated with the process of carcinogenesis in hepatic cells

Development and characterization of gastroretentive sustained-release formulation by combination of swelling and mucoadhesive approach: a mechanistic study

BACKGROUND: Acyclovir has pharmacokinetic limitations, including poor oral bioavailability of 15%–30%, high variability, and short elimination half-life of 2.3 hours. These limitations necessitate frequent administration of acyclovir, up to five times daily, leading to poor patient compliance, which in turn leads to a reduction in therapeutic efficacy and development of resistance. METHODS: A gastroretentive sustained-release (GR) formulation of acyclovir, based on a combination of swelling and mucoadhesive mechanisms, has been developed. Composition has been optimized after evaluation of different polymers, carbomer, polyethylene oxide, and sodium alginate alone and/or in combination. GR formulations were characterized for in-process quality-control tests, drug release and release rate kinetics, similarity factor analysis, swelling index, and matrix erosion. RESULTS: A formulation containing a combination of carbomer and polyethylene oxide had the highest similarity of drug release compared with a target drug-release profile obtained by pharmacokinetic simulations. The measurement of mucoadhesive strength, carried out with a texture analyzer, showed that the mucoadhesive strength of the GR formulation was significantly higher than that of the immediate-release (IR) tablet. The optimized GR formulation was found to be retained in the upper part of the gastrointestinal tract for 480 minutes; the IR tablet was retained for only 90 minutes as measured using a gastrointestinal retention study in albino rabbits. The GR formulation was also found to maintain more sustained plasma concentrations than the IR tablet. Mean residence time of the GR formulation was 7 hours versus 3.3 hours for the IR formulation. The relative bioavailability of the GR formulation was 261% of the IR formulation. CONCLUSION: The GR formulation of acyclovir, based on swelling and mucoadhesive mechanisms, has prolonged retention in the upper gastrointestinal tract, sustained in vitro drug release, prolonged in vivo absorption, and better bioavailability than the IR formulation. Such a formulation would improve patient compliance and increase the efficacy of therapy