Oral delivery of indinavir using mPEG-PCL nanoparticles: preparation, optimization, cellular uptake, transport and pharmacokinetic evaluation.

Introduction: Indinavir (IDV) is a potent HIV protease inhibitor used in the treatment of human immunodeficiency virus (HIV). IDV is a weak base with limited aqueous solubility in its unprotonated form; therefore, solubility of IDV in the gastrointestinal tract fluids is the rate-limiting step of its absorption and onset of action. However, in many cases, drugs are not absorbed well in the gastrointestinal tract; polymer nanoparticles were recognized as an effective carrier system for drug encapsulation and are now studied as a vehicle for oral delivery of insoluble compounds. Preparation of methoxy poly (ethylene glycol)-poly (e-caprolactone) (mPEG-PCL) nanoparticles is among the strategies to overcome low bioavailability of drugs with poor aqueous solubility. Materials and method: The structure of the copolymers was characterized using 1H NMR, FTIR, DSC and GPC techniques. IDV loaded mPEG- PCL nanoparticles prepared by emulsification solvent evaporation method were optimized using D-optimal experimental design and were characterized by various techniques such as DLS, DSC, XRD, AFM and SEM. Using Caco-2 cells as a cellular model, we studied the cellular uptake and transport. Results: In vivo pharmacokinetic studies were performed in rats. The plasma AUC (0-t), t1/2 and Cmax of IDV-mPEG-PCL NPs were increased by 5.30, 5.57 and 1.37 fold compared to the IDV solution, respectively. Conclusion: The results of this study are promising for the use of biodegradable polymeric nanoparticles to improve oral drug delivery.

Neuropharmacokinetic evaluation of lactoferrin-treated indinavir-loaded nanoemulsions: remarkable brain delivery enhancement.

OBJECTIVE: Indinavir (IDV), an antiretroviral protease inhibitor used in treatment of HIV infection, has limited entry into brain due to efflux by the P-glycoprotein presented in blood-brain barrier. The aim of present study was to develop lactoferrin-treated nanoemulsion containing indinavir (Lf-IDV-NEs) for delivery to brain. METHODS: Indinavir-loaded nanoemulsions (IDV-NEs) were prepared by high-speed homogenization method, and then lactoferrin was coupled to IDV-NEs by water soluble EDC method. RESULTS: The hydrodynamic diameters, polydispersity index, and zeta potential of IDV-NEs were 112 ± 3.5 nm, 0.20 ± 0.02, and -33.2 ± 2.6 mV, respectively. From in vivo studies in animal model of rats, the AUC0-4 h of brain concentration-time profile of IDV-NEs and Lf-IDV-NEs were 1.6 and 4.1 times higher than free drug, respectively. The brain uptake clearance of IDV-NEs and Lf-IDV-NEs were, interestingly, 393- and 420-times higher than the free drug. CONCLUSIONS: It can be concluded that applying both lactoferrin-treated and non-treated nanoemulsions clearly leads to significant brain penetration enhancement of indinavir, an effect which is more pronounced in the case of Lf-IDV-NEs with the higher drug residence time in brain.

α7-Nicotinic acetylcholine receptor inhibition by indinavir: implications for cognitive dysfunction in treated HIV disease.

OBJECTIVE: The study set out to determine if the HIV protease inhibitor, indinavir, alters responsiveness of α7-nicotinic acetylcholine receptors to acetylcholine. DESIGN: Treatment with HAART has dramatically reduced development of HIV-associated dementia and more severe forms of cognitive impairment. However, many individuals continue to experience cognitive decline of uncertain cause. Previous studies have failed to demonstrate significant alterations of functional brain connectivity, structural brain changes, or changes in cerebral blood flow sufficient to explain cognitive decline in virally suppressed individuals. This suggests that the mechanisms underlying development and progression of cognitive problems likely occurs at a micro rather than macro level, such as disruptions in neurotransmitter system signaling. MATERIALS AND METHODS: Indinavir's effects on α7-nicotinic acetylcholine receptor activity was tested using a ScreenPatch IonWorks Barracuda-based assay in a mammalian cell model. RESULTS: At low concentrations (0.0003-10 µmol/l) indinavir acts as a positive allosteric modulator (EC50 = 0.021 µmol/l), whereas at concentrations greater than 10 µmol/l (30-100 µmol/l) indinavir acts as an inhibitor of the α7-nicotinic acetylcholine receptor. CONCLUSION: At concentrations greater than 10 µmol/l indinavir reduces synaptic transmission in the acetylcholine neurotransmitter system, which could possibly contribute to cognitive dysfunction. These results suggest that further experiments should be considered to assess whether patients might benefit from treatment with cholinesterase inhibitors that counteract the effects of indinavir.

Gastrointestinal dissolution, supersaturation and precipitation of the weak base indinavir in healthy volunteers.

This study investigated the impact of relevant gastrointestinal conditions on the intraluminal dissolution, supersaturation and precipitation behavior of the weakly basic drug indinavir. The influence of (i) concomitant PPI intake and (ii) the nutritional state on the gastrointestinal behavior of indinavir was assessed in order to identify the underlying mechanisms responsible for previously reported interactions. Five healthy volunteers were recruited into a crossover study containing the following arms: fasted state, fed state and fasted state with concomitant proton pump inhibitor (PPI) use. In each condition, one Crixivan® capsule (400mg indinavir) was orally administered with 240mL of water. Gastric and duodenal fluids, aspirated as a function of time, were monitored for total and dissolved indinavir concentrations on a UPLC-MS/MS system. Indinavir's thermodynamic solubility was determined in individual aspirates to evaluate supersaturation. The bioaccessible fraction of indinavir in aspirated duodenal fluids was determined in an ex vivo permeation experiment through an artificial membrane. A nearly complete dissolution of indinavir in the fasted stomach was observed (90±3%). Regardless of dosing conditions, less indinavir was in solution in the duodenum compared to the stomach. Duodenal supersaturation was observed in all three testing conditions. The highest degrees of duodenal supersaturation (6.5±5.9) were observed in the fasted state. Concomitant PPI use resulted in an increased gastric pH and a smaller fraction of indinavir being dissolved (58±24%), eventually resulting in lower intestinal concentrations. In fed state conditions, drug release from the capsule was delayed and more gradually, although a similar fraction of the intragastric indinavir dissolved compared to the fasted state (83±12%). Indinavir was still present in the lumen of the duodenum three hours after oral administration, although it already reached 70% (on average) of the fasted state concentrations (expressed as AUC0-3h). Based on a 2-h permeation experiment, the bioaccessible fraction of indinavir was 2.6-fold lower in a fed state sample compared to a fasted state sample. Our data indicate that the reported reduction in indinavir's bioavailability after concomitant PPI administration is caused by an elevated gastric pH resulting in less indinavir in solution in the stomach and, subsequently, reduced duodenal concentrations. In fed state conditions, however, intestinal micellar entrapment of indinavir appeared to cause the reported reduced bioavailability, regardless of duodenal concentrations.

Novel protease inhibitor-loaded Nanoparticle-in-Microparticle Delivery System leads to a dramatic improvement of the oral pharmacokinetics in dogs.

With the advent of the Highly Active Antiretroviral Therapy, the morbidity and the mortality associated to HIV have been considerably reduced. However, 35-40 million people bear the infection worldwide. One of the main causes of therapeutic failure is the frequent administration of several antiretrovirals that results in low patient compliance and treatment cessation. In this work, we have developed an innovative Nanoparticle-in-Microparticle Delivery System (NiMDS) comprised of pure drug nanocrystals of the potent protease inhibitor indinavir free base (used as poorly water-soluble model protease inhibitor) produced by nanoprecipitation that were encapsulated within mucoadhesive polymeric microparticles. Pure drug nanoparticles and microparticles were thoroughly characterized by diverse complementary techniques. NiMDSs displayed an encapsulation efficiency of approximately 100% and a drug loading capacity of up to 43% w/w. In addition, mucoadhesiveness assays ex vivo conducted with bovine gut showed that film-coated microparticles were retained for more than 6 h. Finally, pharmacokinetics studies in mongrel dogs showed a dramatic 47- and 95-fold increase of the drug oral bioavailability and half-life, respectively, with respect to the free unprocessed drug. These results support the outstanding performance of this platform to reduce the dose and the frequency of administration of protease inhibitors, a crucial step to overcome the current patient-incompliant therapy.

Exploring food effects on indinavir absorption with human intestinal fluids in the mouse intestine.

Food can have a significant impact on the pharmacokinetics of orally administered drugs, as it may affect drug solubility as well as permeability. Since fed state conditions cannot easily be implemented in the presently available permeability tools, including the frequently used Caco-2 system, exploring food effects during drug development can be quite challenging. In this study, we investigated the effect of fasted and fed state conditions on the intestinal absorption of the HIV protease inhibitor indinavir using simulated and human intestinal fluids in the in situ intestinal perfusion technique in mice. Although the solubility of indinavir was 6-fold higher in fed state human intestinal fluids (FeHIF) as compared to fasted state HIF (FaHIF), the intestinal permeation of indinavir was 22-fold lower in FeHIF as compared to FaHIF. Dialysis experiments showed that only a small fraction of indinavir is accessible for absorption in FeHIF due to micellar entrapment, possibly explaining its low intestinal permeation. The presence of ritonavir, a known P-gp inhibitor, increased the intestinal permeation of indinavir by 2-fold in FaHIF, while there was no increase when using FeHIF. These data confirm that drug-food interactions form a complex interplay between solubility and permeability effects. The use of HIF in in situ intestinal perfusions holds great promise for biorelevant absorption evaluation as it allows to directly explore this complex solubility/permeability interplay on drug absorption.

The antiretroviral protease inhibitor ritonavir accelerates glutathione export from cultured primary astrocytes.

Antiretroviral protease inhibitors are a class of important drugs that are used for the treatment of human immunodeficiency virus infections. Among those compounds, ritonavir is applied frequently in combination with other antiretroviral protease inhibitors, as it has been reported to boost their therapeutic efficiency. To test whether ritonavir affects the viability and the glutathione (GSH) metabolism of brain cells, we have exposed primary astrocyte cultures to this protease inhibitor. Application of ritonavir in low micromolar concentrations did not compromise cell viability, but caused a time- and concentration-dependent loss of GSH from the cells which was accompanied by a matching increase in the extracellular GSH content. Half-maximal effects were observed for ritonavir in a concentration of 3 µM. The ritonavir-induced stimulated GSH export from astrocytes was completely prevented by MK571, an inhibitor of the multidrug resistance protein 1. In addition, continuous presence of ritonavir was essential to maintain the stimulated GSH export, since removal of ritonavir terminated the stimulated GSH export. Ritonavir was more potent to stimulate GSH export from astrocytes than the antiretroviral protease inhibitors indinavir and nelfinavir, but combinations of ritonavir with indinavir or nelfinavir did not further stimulate astrocytic GSH export compared to a treatment with ritonavir alone. The strong effects of ritonavir and other antiretroviral protease inhibitors on the GSH metabolism of astrocytes suggest that a chronic treatment of patients with such compounds may affect their brain GSH metabolism.

Reduced indinavir exposure during pregnancy.

AIM: To describe the pharmacokinetics and safety of indinavir boosted with ritonavir (IDV/r) during the second and third trimesters of pregnancy and in the post-partum period. METHODS: IMPAACT P1026s is an on-going, prospective, non-blinded study of antiretroviral pharmacokinetics (PK) in HIV-infected pregnant women with a Thai cohort receiving IDV/r 400/100 mg twice daily during pregnancy through to 6-12 weeks post-partum as part of clinical care. Steady-state PK profiles were performed during the second (optional) and third trimesters and at 6-12 weeks post-partum. PK targets were the estimated 10(th) percentile IDV AUC (12.9 µg ml(-1)h) in non-pregnant historical Thai adults and a trough concentration of 0.1 µg ml(-1), the suggested minimum target. RESULTS: Twenty-six pregnant women were enrolled; thirteen entered during the second trimester. Median (range) age was 29.8 (18.9-40.8) years and weight 60.5 (50.0-85.0) kg at the third trimester PK visit. The 90% confidence limits for the geometric mean ratio of the indinavir AUC(0,12 h) and Cmax during the second trimester and post-partum (ante : post ratios) were 0.58 (0.49, 0.68) and 0.73 (0.59, 0.91), respectively; third trimester/post-partum AUC(0,12 h) and Cmax ratios were 0.60 (0.53, 0.68) and 0.63 (0.55, 0.72), respectively. IDV/r was well tolerated and 21/26 women had a HIV-1 viral load < 40 copies ml(-1) at delivery. All 26 infants were confirmed HIV negative. CONCLUSION: Indinavir exposure during the second and third trimesters was significantly reduced compared with post-partum and ∼30% of women failed to achieve a target trough concentration. Increasing the dose of IDV/r during pregnancy to 600/100 mg twice daily may be preferable to ensure adequate drug concentrations.

Effect of HIV protease inhibitors on New World Leishmania.

The incidence of HIV/Leishmania co-infection decreases after antiretroviral drug therapy; therefore, the in vitro and in vivo activity of three antiretroviral drugs against Leishmania (Viannia) braziliensis and L. (L.) amazonensis was evaluated. Different concentrations of indinavir (IDV), atazanavir (ATV), and ritonavir (RTV) were added to promastigote cultures, and the 50% inhibitory concentration (IC50) was determined. IDV and RTV were also evaluated against intracellular amastigotes, and the Infection Index determined. BALB/c mice, infected with L. (L.) amazonensis in the left footpad, were treated orally with IDV and RTV for 30 days, and monitored by measuring the footpad thickness and parasite load of regional lymph nodes and spleen. For promastigotes, IDV exhibited an IC50 value of 100 µM against L.(L.) amazonensis. The RTV IC50 for L. (L.) amazonensis and L. (V.) braziliensis were 40 and 2.3 µM, respectively, and the ATV IC50 for L. (V.) braziliensis was 266 µM. For intracellular amastigotes, IDV (25, 50, and 100 µM) significantly decreased the Infection Index of L. (L.) amazonensis (56.8%, 47.9%, and 65.0%) and L. (V.) braziliensis (37.8%, 48.7%, and 43.2%). RTV (12.5, 25, and 50 µM) decreased the infection index of L. (L.) amazonensis by 26.3%, 42.4%, and 44.0%, and that of L. (V.) braziliensis by 27.6%, 37.3%, and 39.2%. Antiretroviral-treated mice had a significant reduction in footpad thickness after the third week of IDV and after the fifth week of RTV treatment. However, there was no reduction in parasite load. These results suggest that IDV and RTV have anti-Leishmania activity, but only in higher concentrations.

Impact of short-term HAART initiated during the chronic stage or shortly post-exposure on SIV infection of male genital organs.

BACKGROUND: The male genital tract is suspected to constitute a viral sanctuary as persistent HIV shedding is found in the semen of a subset of HIV-infected men receiving effective antiretroviral therapy (HAART). The origin of this persistent shedding is currently unknown. Phylogenetic studies indicated that HIV in semen from untreated men arises from local sources and/or passive diffusion from the blood. We previously demonstrated in human and macaque low levels and localized infection of several semen-producing organs by HIV/SIV. Using a macaque model, this study investigates the impact of short term HAART (2-4 weeks) initiated either during the asymptomatic chronic stage or 4 h post-intravenous inoculation of SIVmac251 on the infection of male genital organs. METHODOLOGY/PRINCIPAL FINDINGS: Short term HAART during the chronic stage decreased blood viral load. No major impact of HAART was observed on SIV DNA levels in male genital organs using a sensitive nested PCR assay. Using in situ hybridization, SIV RNA+ cells were detected in all male genital tract organs from untreated and treated animals with undetectable blood viral load following HAART. Infected CD68+ myeloid cells and CD3+ T lymphocytes were detected pre- and post-HAART. In contrast, short term HAART initiated 4 h post-SIV exposure led to a drastic decrease of the male genital tissues infection, although it failed to prevent systemic infection. In both cases, HAART tended to decrease the number of CD3+ T cells in the male organs. CONCLUSIONS: Our results indicate that the established infection of male genital organs is not greatly impacted by short term HAART, whereas the same treatment during pre-acute phase of the infection efficiently impairs viral dissemination to the male genital tract. Further investigations are now needed to determine whether infection of male genital organs is responsible for long term persistent HIV shedding in semen despite HAART.

Impact of the herbal medicine Sophora flavescens on the oral pharmacokinetics of indinavir in rats: the involvement of CYP3A and P-glycoprotein.

Sophora flavescens is a Chinese medicinal herb used for the treatment of gastrointestinal hemorrhage, skin diseases, pyretic stranguria and viral hepatitis. In this study the herb-drug interactions between S. flavescens and indinavir, a protease inhibitor for HIV treatment, were evaluated in rats. Concomitant oral administration of Sophora extract (0.158 g/kg or 0.63 g/kg, p.o.) and indinavir (40 mg/kg, p.o.) in rats twice a day for 7 days resulted in a dose-dependent decrease of plasma indinavir concentrations, with 55%-83% decrease in AUC(0-∞) and 38%-78% reduction in C(max). The CL (Clearance)/F (fraction of dose available in the systemic circulation) increased up to 7.4-fold in Sophora-treated rats. Oxymatrine treatment (45 mg/kg, p.o.) also decreased indinavir concentrations, while the ethyl acetate fraction of Sophora extract had no effect. Urinary indinavir (24-h) was reduced, while the fraction of indinavir in faeces was increased after Sophora treatment. Compared to the controls, multiple dosing of Sophora extract elevated both mRNA and protein levels of P-gp in the small intestine and liver. In addition, Sophora treatment increased intestinal and hepatic mRNA expression of CYP3A1, but had less effect on CYP3A2 expression. Although protein levels of CYP3A1 and CYP3A2 were not altered by Sophora treatment, hepatic CYP3A activity increased in the Sophora-treated rats. All available data demonstrated that Sophora flavescens reduced plasma indinavir concentration after multiple concomitant doses, possibly through hepatic CYP3A activity and induction of intestinal and hepatic P-gp. The animal study would be useful for predicting potential interactions between natural products and oral pharmaceutics and understanding the mechanisms prior to human studies. Results in the current study suggest that patients using indinavir might be cautioned in the use of S. flavescens extract or Sophora-derived products.

Pharmacokinetics and 48 week efficacy of adjusted dose indinavir/ritonavir in rifampicin-treated HIV/tuberculosis-coinfected patients: a pilot study.

HIV/tuberculosis (HIV/TB)-coinfected patients intolerant/resistant to nonnucleoside reverse transcriptase inhibitors (NNRTIs) have limited treatment options. We evaluated the pharmacokinetics (PK)/safety/efficacy of an adjusted dose of indinavir/ritonavir (IDV/r) 600/100 mg plus two NRTIs in HIV/TB-coinfected Thais receiving rifampicin-based anti-TB treatment. This was a prospective, open-label study. Eighteen Thai, HIV/TB-coinfected patients between 18 and 60 years were recruited. IDV/r 600 mg/100 mg plus lamivudine and stavudine were administered every 12 h (bid). When rifampicin was stopped, IDV/r was reduced to 400/100 mg BID. Clinical outcomes, adverse events, and concomitant drugs were intensively collected. Intensive 12-h PK was performed after 2 weeks of IDV/r while on rifampicin. Samples were collected: predosing and 1, 2, 3, 4, 6, 8, 10, and 12 h after drug intake. The median body weight was 55 kg. The median CD4 was 26 cells/µl. The median HIV RNA was 5.05 log(10) copies/ml. Then 15/18 underwent intensive PK at week 2. The median time between initiating rifampicin and IDV/r was 4.5 months. The median duration of rifampicin during study (rifampicin/IDV/r together) was 15.6 weeks. All received a total of 9 months of antituberculous drugs. The geometric means (GM) of indinavir AUC(0-12) and C(12) were 8.11 mg*h/liter and 0.03 mg/liter, respectively. After stopping rifampicin and reducing IDV/r to 400/100 bid, the GM indinavir C(12) increased to 0.68 mg/liter (p=0.004). In all, 8/18 (44%) had asymptomatic ALT elevation and 2/18 (11%) had symptomatic hepatotoxicity requiring IDV/r discontinuation. All 13 patients who remained on IDV/r treatment had HIV RNA <50 copies/ml at 48 weeks. Concomitant use of rifampicin and IDV/r resulted in subtherapeutic indinavir concentrations. Although 44% of them developed asymptomatic Grade 3/4 transaminitis, the rate of study drug discontinuation due to hepatotoxicity was low. Despite good virological outcome in our cohort, prolonged exposure to subtherapeutic indinavir concentrations may lead to treatment failure.

Lack of a pharmacokinetic drug-drug interaction with venlafaxine extended-release/indinavir and desvenlafaxine extended-release/indinavir.

PURPOSE: To assess the effects of venlafaxine extended-release (XR) capsules and desvenlafaxine extended-release (XR) tablets upon indinavir pharmacokinetic properties when co-administrated to healthy volunteers. METHODS: This was an open-label, two-period, fixed-dose study conducted at the clinical research unit located on a university campus. Twenty-four healthy volunteers enrolled in the study (mean age 28.3 ± 8.0 years). Each subject received a single dose of indinavir 800 mg on day 1. Subsequently, subjects were then randomly assigned to either the venlafaxine XR group (N = 12) or the desvenlafaxine XR group (N = 12). Starting on day 2, venlafaxine XR was dosed at 37.5 mg/day for 4 days and increased to 75 mg/day for 6 days. Desvenlafaxine XR was dosed at 50 mg/day for 10 days. On day 12, indivanvir 800 mg was co-administered to both the venlafaxine XR and the desvenlafaxine XR groups. The pharmacokinetics of indinavir were determined both before and at the end of antidepressant dosing. Plasma indinavir, venlafaxine, and desvenlafaxine concentrations were assayed by high-performance liquid chromatography with ultra-violet (UV) detection. Indinavir pharmacokinetic parameters were calculated by noncompartmental analysis using validated computer software. RESULTS: Venlafaxine XR and desvenlafaxine XR did not produce any significant changes in indinavir disposition. Both antidepressants were well tolerated by the subjects with only minor adverse side effects. CONCLUSIONS: No pharmacokinetic drug-drug interaction was demonstrated between venlafaxine XR and indinavir or between desvenlafaxine XR and indinvair. The lack of interaction could be due to the venlafaxine and desvenlafaxine extended-release formulation.

Ten-year diabetes incidence in 1046 HIV-infected patients started on a combination antiretroviral treatment.

OBJECTIVE: To evaluate the incidence and determinants of diabetes in a cohort of HIV-infected adults initiated with combination antiretroviral treatment (cART) in 1997-1999 and followed up to 2009. DESIGN: Prospective study of 1046 patients at 47 French clinical sites. METHODS: Potential determinants of diabetes occurrence, defined by confirmed increased glycemia and/or initiation of antidiabetic treatment, were assessed by a proportional hazards model, including time-updated metabolic parameters and ART exposure. RESULTS: Among the cohort, representing 7846 person-years of follow-up (PYFU), 54% received indinavir, 75% stavudine and 52% didanosine. Overall, 111 patients developed diabetes, with an incidence of 14.1/1000 PYFU (14.6 in men, 12.6 in women). Incidence peaked in 1999-2000 (23.2/1000 PYFU) and decreased thereafter. The incidence of diabetes was associated [adjusted hazard ratio (aHR), all P<0.02] with older age (hazard ratio = 2.13 when 40-49 years, hazard ratio = 3.63 when ≥50 years), overweight (hazard ratio = 1.91 for a BMI 25-29 kg/m(2), hazard ratio = 2.85 >30 kg/m(2)), waist-to-hip ratio (hazard ratio = 3.87 for ≥0.97 male/0.92 female), time-updated lipoatrophy (hazard ratio = 2.14) and short-term exposure to indinavir (0-1 year: hazard ratio = 2.53), stavudine (0-1 year: hazard ratio = 2.56, 1-2 years: hazard ratio = 2.65) or didanosine (2-3 years: hazard ratio = 3.16). Occurrence of diabetes was not associated with HIV-related markers, hepatitis C, hypertension or family history of diabetes. Insulin resistance was predictive for incident diabetes. CONCLUSIONS: In this nationwide cohort, followed for 10 years after cART initiation, diabetes incidence peaked in 1990-2000, was markedly higher than that reported for European uninfected or other HIV-infected populations (4-6/1000 PYFU) and linked with age and adiposity. Adiposity and glycemic markers should be monitored in aging HIV-infected patients.

Chronic use of indinavir in albino rat pregnancy (Rattus norvegicus albinus, Rodentia, Mammalia): biological assay.

AIM: Assess possible adverse effects of the chronic use of indinavir during pregnancy in a rat model. METHODS: 40 pregnant EOM-1 albino rats were randomly allocated into four groups of 10 animals each: a control (Ctr) group (without any handling) and three experimental groups (Exp 1, Exp 2 e Exp 3) which received indinavir 9, 27 e 81 mg/kg, respectively). Rats were treated by gavage once daily. The treatment period extended from day 0 until the 20th day of pregnancy. Body weights were recorded on days 0, 7, 14 and 20. At term, the rats were sacrificed, and the implantation sites, number of live and dead fetuses and placentas, resorptions, fetal and placental weights were recorded. The fetuses were evaluated for external abnormalities under a stereomicroscope. RESULTS: Weight gain during pregnancy did not differ significantly between the groups. Average weight gains between the 7th and 20th day were 7.95-42.70 g; 7.22-45.27 g; 7.12-46.26 g and 8.05-42.29 g in groups Ctr, Exp 1, Exp 2 and Exp 3, respectively. All other parameters assessed did not differ significantly between groups. CONCLUSIONS: Chronic use of various dosages of indinavir during pregnancy was not associated significant adverse outcomes.

Development of indinavir submicron lipid emulsions loaded with lipoamino acids-in vivo pharmacokinetics and brain-specific delivery.

The aim of our present work was to develop indinavir O/W submicron lipid emulsions (SLEs) loaded with lipoamino acids for specific delivery to brain. Tetradecyl aspartic acid (A) and decyl glutamic acid (G) loaded stable SLEs of indinavir having a mean size range of 210-220 nm and average zeta potential of -23.54±1.2 mV were developed using homogenization and ultrasonication. The cumulative % drug release from different SLEs varied in between 26% and 85%. The formulations, SLE, SLE-A3, and SLE-G3 were stable to the centrifugal stress, dilution stress, and storage at RT. The total drug content and entrapment efficiency were determined by HPLC method. During pharmacokinetic studies in male Wistar rats there was no significant difference in the serum levels of indinavir for SLE, SLE-A3 and SLE-G3 formulations at all time points. In tissue distribution studies, the therapeutic availability (TA) of indinavir in brain and kidneys for SLE-A3 were 4.27- and 2.66-fold whereas for SLE-G3 were 2.94 and 2.12 times, respectively, higher than that of indinavir solution. But when compared with that of SLE, in brain tissue the levels of indinavir from SLE-G3 and SLE-A3 varied in between 2.5- and 3.38-fold. While in case of the kidney, it was between 1.23- and 1.54-fold only. However, the TA is not significantly different in tissues like the heart, liver, and spleen. Thus, brain-specific delivery of indinavir was improved by including tetradecyl aspartic acid and decyl glutamic acid in submicron lipid emulsions.

Brain specific delivery of pegylated indinavir submicron lipid emulsions.

The aim of this study was to develop stable parenteral pegylated indinavir submicron lipid emulsions (SLEs) for improving brain specific delivery. The O/W SLEs were prepared by homogenization and ultra sonication process. The sizes of oil globules varied from 241.5 to 296.4nm and zeta potential from -26.6 to -42.4mV. During in vitro drug release studies the cumulative amount of drug released within 12h from SLE-5, DSP2-3 and DPP5-3 was 71.8±0.76, 66.09±1.45 and 68.33±1.29, respectively. The total drug content and entrapment efficiencies were determined. The optimized formulations were stable for the effect of centrifugal stress, thermal stress, dilution stress and storage. In vivo pharmacokinetic and tissue distribution studies were performed in Swiss albino mice, the therapeutic availability (TA) of DSP2-3 was 3.59 times and 2.36 times in comparison to drug solution and SLE-5 respectively, where as DPP5-3 showed TA 2.8 and 1.84 times the drug solution and SLE-5, respectively. The brain to serum ratio of indinavir from DSP2-3 and DPP5-3 varied between 0.4 and 0.7 at all time points indicated the preferential accumulation of drug in brain. In conclusion, pegylated SLEs improved brain specific delivery of indinavir and will be useful in treating chronic HIV infection.

Comparative manufacture and cell-based delivery of antiretroviral nanoformulations.

Nanoformulations of crystalline indinavir, ritonavir, atazanavir, and efavirenz were manufactured by wet milling, homogenization or sonication with a variety of excipients. The chemical, biological, immune, virological, and toxicological properties of these formulations were compared using an established monocyte-derived macrophage scoring indicator system. Measurements of drug uptake, retention, release, and antiretroviral activity demonstrated differences amongst preparation methods. Interestingly, for drug cell targeting and antiretroviral responses the most significant difference among the particles was the drug itself. We posit that the choice of drug and formulation composition may ultimately affect clinical utility.