HPLC quantification of the HIV‐1 protease inhibitor saquinavir in brain and testis of mice

Mudigonda, Koteshwara; Jukanti, Raju; Apte, S. S.; Ajjala, Devender Reddy; Shrivastava, Wishu; Kandikere, Vishwottam; Nirogi, Ramakrishna

doi:10.1002/bmc.631

Cited by 7 publications

(5 citation statements)

References 22 publications

(20 reference statements)

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“…The elution profile of radioactive saquinavir was compared with that of unlabeled saquinavir by UV absorption. The retention time of the tracer was 4.5 min consistent with previous methodology (Mudigonda et al. 2006).…”

Section: Methodssupporting

confidence: 82%

Nicotine and cotinine increases the brain penetration of saquinavir in rat

Manda

Mittapalli

Bohn

et al. 2010

Journal of Neurochemistry

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Endothelial tight junctions and efflux transporters of the bloodbrain barrier (BBB) significantly limit brain accumulation of many drugs, including protease inhibitors such as saquinavir. The cholinergic agonist nicotine is one of the most commonly used drugs in the world and the incidence is even higher in the human immune deficiency virus population ($70%). We examined the ability of nicotine and its primary metabolite cotinine to modify brain uptake of saquinavir in rats. Both nicotine and cotinine at pharmacological concentrations matching those in smokers, increased brain saquinavir uptake by two fold. Co-perfusion with nicotinic receptor antagonists and passive permeability markers showed that the effect was not caused by receptor activation or BBB permeability disruption. Transport inhibition studies demonstrated that brain saquinavir uptake is limited by multiple efflux transporters, Pglycoprotein (P-gp), breast cancer resistance protein and multidrug resistance-associated protein.In situ perfusion and in vitro experiments using a classical P-gp substrate rhodamine 123 linked the effect of nicotine to inhibition of BBB P-gp transport. The effect was confirmed in vivo in chronic 14 day nicotine administration animals. These data suggest nicotine increases antiretroviral drug exposure to brain and may represent a significant in vivo drug-drug interaction at the BBB. Although this may slightly benefit CNS antiretroviral efficacy, it may also expose the brain to potential serious neurotoxicity. Keywords: blood-brain barrier, breast cancer resistance protein, highly active antiretroviral therapy, nicotine, P-glycoprotein, protease inhibitors, saquinavir. 2010; Lindl et al. 2010). Although this neurological complication is more subtle than HIV encephalitis, it is an emerging problem (Lindl et al. 2010). Importantly, HIVpositive individuals who smoke progress to this HIVassociated neurological condition faster than those who do not smoke (Burns et al. 1996;Galai et al. 1997).Although there is a significant prevalence of smoking in the HIV-infected population ($70%), $three-to four fold higher than in the general population (Hershberger et al. 2004;Benard et al. 2007) there are no studies that have evaluated the brain distribution of protease inhibitors or other HAART therapeutics in the presence of chronic nicotine exposure. This is of importance given smoking and or nicotine has been shown to affect the peripheral pharmacokinetics of lopinavir and atazanavir (Higgins et al. 2007), the brain distribution of MPTP/MPP+ (Liou et al. 2007), methyllylcacotinine (Lockman et al. 2005b), and other more permeable markers presumably through increased cerebral blood flow (Chen et al. 1995). However, there are contrasting reports regarding the interactions of nicotine with P-gp and none with other BBB efflux transporters. For example, nicotine significantly reduces the efflux of the P-gp substrate vinblastine (Gaertner et al. 1998); yet in a membrane ATPase assay nicotine and cotinine had no apparent interaction (W...

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Section: Methodssupporting

confidence: 82%

Nicotine and cotinine increases the brain penetration of saquinavir in rat

Manda

Mittapalli

Bohn

et al. 2010

Journal of Neurochemistry

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“…A C18 column (Phenomenex, Torrance, CA), 5 µm, 250×4.6 mm i.d., was used for analysis with isocratic mode at a flow rate of 1.0 mL/min. Methods used to analyze EFV and SQV were based on those described previously for detecting SQV [30]. The mobile phase consisted of a mixture of 10 mM ammonium acetate buffer in HPLC grade water and acetonitrile at a 35∶65 ratio (v/v).…”

Section: Methodsmentioning

confidence: 99%

Drug Synergy of Tenofovir and Nanoparticle-Based Antiretrovirals for HIV Prophylaxis

et al. 2013

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BackgroundThe use of drug combinations has revolutionized the treatment of HIV but there is no equivalent combination product that exists for prevention, particularly for topical HIV prevention. Strategies to combine chemically incompatible agents may facilitate the discovery of unique drug-drug activities, particularly unexplored combination drug synergy. We fabricated two types of nanoparticles, each loaded with a single antiretroviral (ARV) that acts on a specific step of the viral replication cycle. Here we show unique combination drug activities mediated by our polymeric delivery systems when combined with free tenofovir (TFV).Methodology/Principal FindingsBiodegradable poly(lactide-co-glycolide) nanoparticles loaded with efavirenz (NP-EFV) or saquinavir (NP-SQV) were individually prepared by emulsion or nanoprecipitation techniques. Nanoparticles had reproducible size (d ∼200 nm) and zeta potential (-25 mV). The drug loading of the nanoparticles was approximately 7% (w/w). NP-EFV and NP-SQV were nontoxic to TZM-bl cells and ectocervical explants. Both NP-EFV and NP-SQV exhibited potent protection against HIV-1 BaL infection in vitro. The HIV inhibitory effect of nanoparticle formulated ARVs showed up to a 50-fold reduction in the 50% inhibitory concentration (IC50) compared to free drug. To quantify the activity arising from delivery of drug combinations, we calculated combination indices (CI) according to the median-effect principle. NP-EFV combined with free TFV demonstrated strong synergistic effects (CI50 = 0.07) at a 1∶50 ratio of IC50 values and additive effects (CI50 = 1.05) at a 1∶1 ratio of IC50 values. TFV combined with NP-SQV at a 1∶1 ratio of IC50 values also showed strong synergy (CI50 = 0.07).ConclusionsARVs with different physicochemical properties can be encapsulated individually into nanoparticles to potently inhibit HIV. Our findings demonstrate for the first time that combining TFV with either NP-EFV or NP-SQV results in pronounced combination drug effects, and emphasize the potential of nanoparticles for the realization of unique drug-drug activities.

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“…The organic layer (4 ml) was quantitatively transferred to a 6 ml glass tube and evaporated to dryness using an evaporator at 40 C under a stream of nitrogen. Then the dried extract was reconstituted in 100 ml of water-methanol (50:50, v/v; diluents) and a 20 ml aliquot was injected into chromatographic system (Mudigonda et al, 2006). The whole procedure was carried out at room temperature.…”

Section: Processing Of Samplesmentioning

confidence: 99%

Nanoemulsion-based intranasal drug delivery system of saquinavir mesylate for brain targeting

et al. 2013

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The central nervous system (CNS) is an immunological privileged sanctuary site-providing reservoir for HIV-1 virus. Current anti-HIV drugs, although effective in reducing plasma viral levels, cannot eradicate the virus completely from the body. The low permeability of anti-HIV drugs across the blood-brain barrier (BBB) leads to insufficient delivery. Therefore, developing a novel approaches enhancing the CNS delivery of anti-HIV drugs are required for the treatment of neuro-AIDS. The aim of this study was to develop intranasal nanoemulsion (NE) for enhanced bioavailability and CNS targeting of saquinavir mesylate (SQVM). SQVM is a protease inhibitor which is a poorly soluble drug widely used as antiretroviral drug, with oral bioavailability is about 4%. The spontaneous emulsification method was used to prepare drug-loaded o/w nanoemulsion, which was characterized by droplet size, zeta potential, pH, drug content. Moreover, ex-vivo permeation studies were performed using sheep nasal mucosa. The optimized NE showed a significant increase in drug permeation rate compared to the plain drug suspension (PDS). Cilia toxicity study on sheep nasal mucosa showed no significant adverse effect of SQVM-loaded NE. Results of in vivo biodistribution studies show higher drug concentration in brain after intranasal administration of NE than intravenous delivered PDS. The higher percentage of drug targeting efficiency (% DTE) and nose-to-brain drug direct transport percentage (% DTP) for optimized NE indicated effective CNS targeting of SQVM via intranasal route. Gamma scintigraphy imaging of the rat brain conclusively demonstrated transport of drug in the CNS at larger extent after intranasal administration as NE.

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HPLC quantification of the HIV‐1 protease inhibitor saquinavir in brain and testis of mice

Cited by 7 publications

References 22 publications

Nicotine and cotinine increases the brain penetration of saquinavir in rat

Nicotine and cotinine increases the brain penetration of saquinavir in rat

Drug Synergy of Tenofovir and Nanoparticle-Based Antiretrovirals for HIV Prophylaxis

Nanoemulsion-based intranasal drug delivery system of saquinavir mesylate for brain targeting

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