Displaying publications 101 - 120 of 240 in total

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  1. Fulltext Enhancing the Bioavailability of the Ellagitannin, Geraniin: Formulation, Characterization, and in vivo Evaluation
    Elendran S, Shiva Kumar V, Sundralingam U, Tow WK, Palanisamy UD
    Int J Pharm, 2024 Jul 20;660:124333.
    PMID: 38866080 DOI: 10.1016/j.ijpharm.2024.124333
    Geraniin (GE), an ellagitannin (ET) renowned for its promising health advantages, faces challenges in its practical applications due to its limited bioavailability. This innovative and novel formulation of GE and soy-phosphatidylcholine (GE-PL) complex has the potential to increase oral bioavailability, exhibiting high entrapment efficiency of 100.2 ± 0.8 %, and complexation efficiency of 94.6 ± 1.1 %. The small particle size (1.04 ± 0.11 μm), low polydispersity index (0.26 ± 0.02), and adequate zeta potential (-26.1 ± 0.12 mV), indicate its uniformity and stability. Moreover, the formulation also demonstrates improved lipophilicity, reduced aqueous and buffer solubilities, and better partition coefficient. It has been validated by various analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) studies. Oral bioavailability and pharmacokinetics of free GE and GE-PL complex investigated in rabbits demonstrated enhanced plasma concentration of ellagic acid (EA) compared to free GE. Significantly, GE, whether in its free form or as part of the GE-PL complex, was not found in the circulatory system. However, EA levels were observed at 0.5 h after administration, displaying two distinct peaks at 2 ± 0.03 h (T1max) and 24 ± 0.06 h (T2max). These peaks corresponded to peak plasma concentrations (C1max and C2max) of 588.82 ng/mL and 711.13 ng/mL respectively, signifying substantial 11-fold and 5-fold enhancements when compared to free GE. Additionally, it showed an increased area under the curve (AUC), the elimination half-life (t1/2, el) and the elimination rate constant (Kel). The formulation of the GE-PL complex prolonged the presence of EA in the bloodstream and improved its absorption, ultimately leading to a higher oral bioavailability. In summary, the study highlights the significance of the GE-PL complex in overcoming the bioavailability limitations of GE, paving the way for enhanced therapeutic outcomes and potential applications in drug delivery and healthcare.
    Matched MeSH terms: Biological Availability*
  2. Effect of permeation enhancers in the mucoadhesive buccal patches of salbutamol sulphate for unidirectional buccal drug delivery
    Prasanth VV, Puratchikody A, Mathew ST, Ashok KB
    Res Pharm Sci, 2014 Jul-Aug;9(4):259-68.
    PMID: 25657797
    The purpose of this work was to study the effect of various permeation enhancers on the permeation of salbutamol sulphate (SS) buccal patches through buccal mucosa in order to improve the bioavailability by avoiding the first pass metabolism in the liver and possibly in the gut wall and also achieve a better therapeutic effect. The influence of various permeation enhancers, such as dimethyl sulfoxide (DMSO), linoleic acid (LA), isopropyl myristate (IPM) and oleic acid (OA) on the buccal absorption of SS from buccal patches containing different polymeric combinations such as hydroxypropyl methyl cellulose (HPMC), carbopol, polyvinyl alcohol (PVA), polyvinyl pyrollidone (PVP), sodium carboxymethyl cellulose (NaCMC), acid and water soluble chitosan (CHAS and CHWS) and Eudragit-L100 (EU-L100) was investigated. OA was the most efficient permeation enhancer increasing the flux greater than 8-fold compared with patches without permeation enhancer in HPMC based buccal patches when PEG-400 was used as the plasticizer. LA also exhibited a better permeation enhancing effect of over 4-fold in PVA and HPMC based buccal patches. In PVA based patches, both OA and LA were almost equally effective in improving the SS permeation irrespective of the plasticizer used. DMSO was more effective as a permeation enhancer in HPMC based patches when PG was the plasticizer. IPM showed maximum permeation enhancement of greater than 2-fold when PG was the plasticizer in HPMC based buccal patches.
    Matched MeSH terms: Biological Availability
  3. Liposomes in topical ophthalmic drug delivery: an update
    Agarwal R, Iezhitsa I, Agarwal P, Abdul Nasir NA, Razali N, Alyautdin R, et al.
    Drug Deliv, 2016 May;23(4):1075-91.
    PMID: 25116511 DOI: 10.3109/10717544.2014.943336
    Topical route of administration is the most commonly used method for the treatment of ophthalmic diseases. However, presence of several layers of permeation barriers starting from the tear film till the inner layers of cornea make it difficult to achieve the therapeutic concentrations in the target tissue within the eye. In order to circumvent these barriers and to provide sustained and targeted drug delivery, tremendous advances have been made in developing efficient and safe drug delivery systems. Liposomes due to their unique structure prove to be extremely beneficial drug carriers as they can entrap both the hydrophilic and hydrophobic drugs. The conventional liposomes had several drawbacks particularly their tendency to aggregate, the instability and leakage of entrapped drug and susceptibility to phagocytosis. Due to this reason, for a long time, liposomes as drug delivery systems did not attract much attention of researchers and clinicians. However, over recent years development of new generation liposomes has opened up new approaches for targeted and sustained drug delivery using liposomes and has rejuvenated the interest of researchers in this field. In this review we present a summary of current literature to understand the anatomical and physiological limitation in achieving adequate ocular bioavailability of topically applied drugs and utility of liposomes in overcoming these limitations. The recent developments related to new generation liposomes are discussed.
    Matched MeSH terms: Biological Availability
  4. Fulltext Pharmacokinetics of Naja sumatrana (equatorial spitting cobra) venom and its major toxins in experimentally envenomed rabbits
    Yap MK, Tan NH, Sim SM, Fung SY, Tan CH
    PLoS Negl Trop Dis, 2014 Jun;8(6):e2890.
    PMID: 24901441 DOI: 10.1371/journal.pntd.0002890
    BACKGROUND: The optimization of snakebite management and the use of antivenom depend greatly on the knowledge of the venom's composition as well as its pharmacokinetics. To date, however, pharmacokinetic reports on cobra venoms and their toxins are still relatively limited. In the present study, we investigated the pharmacokinetics of Naja sumatrana (Equatorial spitting cobra) venom and its major toxins (phospholipase A2, neurotoxin and cardiotoxin), following intravenous and intramuscular administration into rabbits.

    PRINCIPAL FINDINGS: The serum antigen concentration-time profile of the N. sumatrana venom and its major toxins injected intravenously fitted a two-compartment model of pharmacokinetics. The systemic clearance (91.3 ml/h), terminal phase half-life (13.6 h) and systemic bioavailability (41.9%) of N. sumatrana venom injected intramuscularly were similar to those of N. sputatrix venom determined in an earlier study. The venom neurotoxin and cardiotoxin reached their peak concentrations within 30 min following intramuscular injection, relatively faster than the phospholipase A2 and whole venom (Tmax=2 h and 1 h, respectively). Rapid absorption of the neurotoxin and cardiotoxin from the injection site into systemic circulation indicates fast onsets of action of these principal toxins that are responsible for the early systemic manifestation of envenoming. The more prominent role of the neurotoxin in N. sumatrana systemic envenoming is further supported by its significantly higher intramuscular bioavailability (Fi.m.=81.5%) compared to that of the phospholipase A2 (Fi.m.=68.6%) or cardiotoxin (Fi.m.=45.6%). The incomplete absorption of the phospholipase A2 and cardiotoxin may infer the toxins' affinities for tissues at the injection site and their pathological roles in local tissue damages through synergistic interactions.

    CONCLUSION/SIGNIFICANCE: Our results suggest that the venom neurotoxin is absorbed very rapidly and has the highest bioavailability following intramuscular injection, supporting its role as the principal toxin in systemic envenoming.

    Matched MeSH terms: Biological Availability
  5. Fate and cometabolic degradation of benzo[a]pyrene by white-rot fungus Armillaria sp. F022
    Hadibarata T, Kristanti RA
    Bioresour Technol, 2012 Mar;107:314-8.
    PMID: 22209445 DOI: 10.1016/j.biortech.2011.12.046
    Armillaria sp. F022, a white-rot fungus isolated from a tropical rain forest in Samarinda, Indonesia, was used to biodegrade benzo[a]pyrene (BaP). Transformation of BaP, a 5-ring polycyclic aromatic hydrocarbon (PAH), by Armillaria sp. F022, which uses BaP as a source of carbon and energy, was investigated. However, biodegradation of BaP has been limited because of its bioavailability and toxicity. Five cosubstrates were selected as cometabolic carbon and energy sources. The results showed that Armillaria sp. F022 used BaP with and without cosubstrates. A 2.5-fold increase in degradation efficiency was achieved after addition of glucose. Meanwhile, the use of glucose as a cosubstrate could significantly stimulate laccase production compared with other cosubstrates and not using any cosubstrate. The metabolic pathway was elucidated by identifying metabolites, conducting biotransformation studies, and monitoring enzyme activities in cell-free extracts. The degradation mechanism was determined through the identification of several metabolites: benzo[a]pyrene-1,6-quinone, 1-hydroxy-2-benzoic acid, and benzoic acid.
    Matched MeSH terms: Biological Availability
  6. Physico-chemical effects of the major quassinoids in a standardized Eurycoma longifolia extract (Fr 2) on the bioavailability and pharmacokinetic properties, and their implications for oral antimalarial activity
    Low BS, Teh CH, Yuen KH, Chan KL
    Nat Prod Commun, 2011 Mar;6(3):337-41.
    PMID: 21485270
    A simple validated LC-UV method for the phytochemical analysis of four bioactive quassinoids, 13alpha(21)-epoxyeurycomanone (EP), eurycomanone (EN), 13alpha,21-dihydroeurycomanone (ED) and eurycomanol (EL) in rat plasma following oral (200 mg/kg) and intravenous administration (10 mg/kg) of a standardized extract Fr 2 of Eurycoma longifolia Jack was developed for pharmacokinetic and bioavailability studies. The extract Fr 2 contained 4.0%, 18.5%, 0.7% and 9.5% of EP, EN, ED and EL, respectively. Following intravenous administration, EP displayed a relatively longer biological half-life (t1/2 = 0.75 +/- 0.25 h) due primarily to its lower elimination rate constant (k(e)) of 0.84 +/- 0.26 h(-1)) when compared with the t1/2 of 0.35 +/- 0.04 h and k(e) of 2.14 +/- 0.27 h(-1), respectively of EN. Following oral administration, EP showed a higher C(max) of 1.61 +/- 0.41 microg/mL over that of EN (C(max) = 0.53 +/- 0.10 microg/mL). The absolute bioavailability of EP was 9.5-fold higher than that of EN, not because of chemical degradation since both quassinoids were stable at the simulated gastric pH of 1. Instead, the higher log K(ow) value of EP (-0.43) contributed to greater membrane permeability over that of EN (log K(ow) = -1.46) at pH 1. In contrast, EL, being in higher concentration in the extract than EP, was not detected in the plasma after oral administration because of substantial degradation by the gastric juices after 2 h. Similarly, ED, being unstable at the acidic pH and together with its low concentration in Fr 2, was not detectable in the rat plasma. In conclusion, upon oral administration of the bioactive standardized extract Fr 2, EP and EN may be the only quassinoids contributing to the overall antimalarial activity; this is worthy of further investigation.
    Matched MeSH terms: Biological Availability
  7. Apparent bioavailability of isoflavones in urinary excretions of postmenopausal Malay women consuming tempeh compared with milk
    Haron H, Ismail A, Shahar S, Azlan A, Peng LS
    Int J Food Sci Nutr, 2011 Sep;62(6):642-50.
    PMID: 21574819 DOI: 10.3109/09637486.2011.570742
    Quantitation of isoflavones in humans is important to establish the benefits of these compounds to the populations. Urinary isoflavones are frequently used as a biomarker of isoflavone bioavailability from food or supplement since urine contains 100-fold higher concentrations of isoflavones. The objective of the present study was to determine and compare the urinary excretions of daidzein (DA), genistein (GE) and equol (EQ) in postmenopausal Malay women following the consumption of tempeh and milk in a calcium absorption study and to test the hypothesis that the excretion of isoflavones following consumption of tempeh maybe higher compared with milk. The amounts of DA (47.06 ± 4.18 μmol/h), GE (33.27 ± 3.71 μmol/h) and EQ (24.35 ± 4.34 μmol/h) excreted in urine following tempeh consumption were significantly higher (P < 0.05) compared with those in milk (3.51 ± 0.62 μmol/h DA, 2.79 ± 0.35 μmol/h GE and 0 μmol/h EQ). Almost all studied postmenopausal Malay women were able to excrete EQ following consumption of 240 g tempeh but only one subject can be classified as an equol producer. We concluded that most postmenopausal Malay women excreted DA, GE and EQ in their urine following tempeh consumption and the amount of the excreted isoflavones were higher compared with those in milk. However, further studies are needed to determine whether longer periods of time are required to capture EQ producers.
    Matched MeSH terms: Biological Availability
  8. Correcting endogenous concentrations of testosterone influences bioequivalence and shows the superiority of TDS(R)-testosterone versus Androgel(R)
    Chik Z, Johnston A, Tucker AT, Kirby K, Alam CA
    Int J Clin Pharmacol Ther, 2009 Apr;47(4):262-8.
    PMID: 19356392
    Circulating concentrations of endogenous compounds such as testosterone, complicate the analysis of pharmacokinetic parameters when these compounds are administered exogenously. This study examines the influence of three correction methods of accounting for endogenous concentrations on the determination of bioequivalence between two testosterone formulations.
    Matched MeSH terms: Biological Availability
  9. Comparative bioavailability study of two salbutamol tablets in healthy adult volunteers
    Chik Z, Basu RC, Pendek R, Lee TC, Mohamed Z
    Int J Clin Pharmacol Ther, 2009 Jun;47(6):413-8.
    PMID: 19473604
    This study was carried out to compare the rate and extent of absorption of a generic salbutamol in oral dosage form (Brethmol, 4 mg) with the proprietary equivalent product (Ventolin, 4 mg), in healthy adult subjects, under fasting conditions. The study was a single dose, randomized, two way crossover study with a four-week washout period. It involved 22 healthy volunteers who received a single dose (4 mg) of the test and the reference products after an overnight fast of at least 10 hours. Blood samples were collected at pre-dose and a serial of 14 samples were collected from each of the subject from 1 h until 48 h post-dose. Plasma concentrations of salbutamol were analyzed using GCMS method. The mean AUC(0-yen) values were 91.26 and 96.45 h.ng/ml for reference and test product, respectively. The mean C(max) values were 12.26 and 12.38 ng/ml and the mean t(max) values were 2.80 and 2.33 hours for reference and test product, respectively. Analysis of variance showed that the 90% confidence intervals on the relative difference of the ratio for the AUC(0-yen) and the C(max) for the test and reference products were contained within the bioequivalence limit (80 - 125%) (C(max): 89.8 - 110.5% and AUC(0-yen): 91.6 - 121.5%). There was no statistically significant difference for the t(max) between the test and reference formulations (p = 0.30). The test formulation was found to be bioequivalent to the reference formulation with regard to AUC(0-yen) and C(max). There was no statistically significant difference in Brethmol and Ventolin t(max). In conclusion, Brethmol and Ventolin are bioequivalent in healthy subjects.
    Matched MeSH terms: Biological Availability
  10. Crystalline style and tissue redistribution in Perna viridis as indicators of Cu and Pb bioavailabilities and contamination in coastal waters
    Yap CK, Ismail A, Cheng WH, Tan SG
    Ecotoxicol Environ Saf, 2006 Mar;63(3):413-23.
    PMID: 16406592
    The concentrations of Cu, Pb, and Zn in the crystalline style (CS) and in the remaining soft tissues (ST) of the green-lipped mussel Perna viridis from 10 geographical sites along the coastal waters off peninsular Malaysia were determined. The CS, compared with the remaining ST, accumulated higher levels of Cu in both contaminated and uncontaminated samples, indicating that the style has a higher affinity for the essential Cu to bind with metallothioneins. The similar pattern of Cu accumulation in the different ST of mussels collected from clean and Cu-contaminated sites indicated that the detoxification capacity of the metallothioneins had not been overloaded. For Pb, higher levels of the metal in the CS than in the remaining ST were found only in mussels collected from a contaminated site at Kg. Pasir Puteh. This indicated a tissue redistribution of Pb due to its binding to metallothioneins for Pb detoxification and the potential of the CS as an indicator organ of Pb bioavailability and contamination. For Zn, the above two phenomena were not found since no obvious patterns were observed (lower levels of Zn in the CS than in the remaining ST) in contaminated and uncontaminated samples due to the mechanism of partial regulation. Generally, all the different STs studied (foot, mantle, gonad, CS, gill, muscle, and byssus) are good biomonitoring tissues for Cu and Pb bioavailabilities and contamination. Among these organs, the CS was found to be the best organ for biomonitoring Cu. The present data also suggest the use of the tissue redistribution of Pb in P. viridis as an indicator of Pb bioavailability and contamination in coastal waters.
    Matched MeSH terms: Biological Availability
  11. Fulltext Comparative bioavailability study of a generic sustained release diclofenac sodium tablet
    Magosso E, Yuen KH, Choy WP, Ling SSN, Ng BH, Ur-Rahman N, et al.
    Med J Malaysia, 2004 Aug;59(3):352-6.
    PMID: 15727381
    The bioavailability of a generic diclofenac sodium sustained release tablet preparation (Zolterol, SR) was compared with the innovator product, Voltaren, SR. Twelve healthy adult male volunteers participated in the study, which was conducted according to a randomized, two-way crossover design with a wash out period of one week. The bioavailability of diclofenac was compared using the parameters area under the plasma concentration-time curve (AUC(0-infinity)), peak plasma concentration (Cmax) and time to reach peak plasma concentration (Tmax). No statistically significant difference was observed for both logarithmically transformed AUC(0-infinity), Cmax values and Tmax value of the two preparations.
    Matched MeSH terms: Biological Availability
  12. Iron-Binding Capacity of Defatted Rice Bran Hydrolysate and Bioavailability of Iron in Caco-2 Cells
    Foong LC, Imam MU, Ismail M
    J Agric Food Chem, 2015 Oct 21;63(41):9029-36.
    PMID: 26435326 DOI: 10.1021/acs.jafc.5b03420
    The present study was aimed at utilizing defatted rice bran (DRB) protein as an iron-binding peptide to enhance iron uptake in humans. DRB samples were treated with Alcalase and Flavourzyme, and the total extractable peptides were determined. Furthermore, the iron-binding capacities of the DRB protein hydrolysates were determined, whereas iron bioavailability studies were conducted using an in vitro digestion and absorption model (Caco-2 cells). The results showed that the DRB protein hydrolysates produced by combined Alcalase and Flavourzyme hydrolysis had the best iron-binding capacity (83%) after 90 min of hydrolysis. The optimal hydrolysis time to produce the best iron-uptake in Caco-2 cells was found to be 180 min. The results suggested that DRB protein hydrolysates have potent iron-binding capacities and may enhance the bioavailability of iron, hence their suitability for use as iron-fortified supplements.
    Matched MeSH terms: Biological Availability
  13. Polycyclic Aromatic Hydrocarbons (PAHs) and their Bioaccessibility in Meat: a Tool for Assessing Human Cancer Risk
    Hamidi EN, Hajeb P, Selamat J, Abdull Razis AF
    Asian Pac J Cancer Prev, 2016;17(1):15-23.
    PMID: 26838201
    Polycyclic aromatic hydrocarbons (PAHs) are primarily formed as a result of thermal treatment of food, especially barbecuing or grilling. Contamination by PAHs is due to generation by direct pyrolysis of food nutrients and deposition from smoke produced through incomplete combustion of thermal agents. PAHs are ubiquitous compounds, well-known to be carcinogenic, which can reach the food in different ways. As an important human exposure pathway of contaminants, dietary intake of PAHs is of increasing concern for assessing cancer risk in the human body. In addition, the risks associated with consumption of barbecued meat may increase if consumers use cooking practices that enhance the concentrations of contaminants and their bioaccessibility. Since total PAHs always overestimate the actual amount that is available for absorption by the body, bioaccessibility of PAHs is to be preferred. Bioaccessibility of PAHs in food is the fraction of PAHs mobilized from food matrices during gastrointestinal digestion. An in vitro human digestion model was chosen for assessing the bioaccessibility of PAHs in food as it offers a simple, rapid, low cost alternative to human and animal studies; providing insights which may not be achievable in in vivo studies. Thus, this review aimed not only to provide an overview of general aspects of PAHs such as the formation, carcinogenicity, sources, occurrence, and factors affecting PAH concentrations, but also to enhance understanding of bioaccessibility assessment using an in vitro digestion model.
    Matched MeSH terms: Biological Availability
  14. Endothelium dependent hyperpolarization-type relaxation compensates for attenuated nitric oxide-mediated responses in subcutaneous arteries of diabetic patients
    Mokhtar SS, Vanhoutte PM, Leung SW, Yusof MI, Wan Sulaiman WA, Mat Saad AZ, et al.
    Nitric Oxide, 2016 Feb 29;53:35-44.
    PMID: 26768833 DOI: 10.1016/j.niox.2015.12.007
    Diabetes impairs endothelium-dependent relaxations. The present study evaluated the contribution of different endothelium-dependent relaxing mechanisms to the regulation of vascular tone in subcutaneous blood vessels of humans with Type 2 diabetes mellitus. Subcutaneous arteries were isolated from tissues of healthy controls and diabetics. Vascular function was determined using wire myography. Expressions of proteins were measured by Western blotting and immunostaining. Endothelium-dependent relaxations to acetylcholine were impaired in arteries from diabetics compared to controls (P = 0.009). Acetylcholine-induced nitric oxide (NO)-mediated relaxations [in the presence of an inhibitor of cyclooxygenases (COX; indomethacin) and small and intermediate conductance calcium-activated potassium channel blockers (UCL1684 and TRAM 34, respectively)] were attenuated in arteries from diabetics compared to controls (P 
    Matched MeSH terms: Biological Availability
  15. Production, Characterization and Evaluation of Kaempferol Nanosuspension for Improving Oral Bioavailability
    Qian YS, Ramamurthy S, Candasamy M, Shadab M, Kumar RH, Meka VS
    Curr Pharm Biotechnol, 2016;17(6):549-55.
    PMID: 26813303
    CONTEXT: Kaempferol has a large particle size and poor water solubility, leading to poor oral bioavailability. The present work aimed to develop a kaempferol nanosuspension (KNS) to improve pharmacokinetics and absolute bioavailability.

    METHODS: A nanosuspension was prepared using high pressure homogenization (HPH) techniques. The physico-chemical properties of the kaempferol nanosuspension (KNS) were characterized using photon correlation spectroscopy (PCS), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and x-ray diffractometry (XRD). A reversephase high performance liquid chromatography (RP-HPLC) method for the analysis of the drug in rat plasma was developed and validated as per ICH guidelines. In vivo pharmacokinetic parameters of oral pure kaempferol solution, oral kaempferol nanosuspension and intravenous pure kaempferol were assessed in rats.

    RESULTS AND DISCUSSION: The kaempferol nanosuspension had a greatly reduced particle size (426.3 ± 5.8 nm), compared to that of pure kaempferol (1737 ± 129 nm). The nanosuspension was stable under refrigerated conditions. No changes in physico-chemical characteristics were observed. In comparison to pure kaempferol, kaempferol nanosuspension exhibited a significantly (P<0.05) increased in Cmax and AUC(0-∞) following oral administration and a significant improvement in absolute bioavailability (38.17%) compared with 13.03% for pure kaempferol.

    CONCLUSION: These results demonstrate enhanced oral bioavailability of kaempferol when formulated as a nanosuspension.

    Matched MeSH terms: Biological Availability
  16. In Situ Gelling Ophthalmic Drug Delivery System: An Overview and Its Applications
    Sheshala R, Kok YY, Ng JM, Thakur RR, Dua K
    Recent Pat Drug Deliv Formul, 2015;9(3):237-48.
    PMID: 26205681
    Ophthalmic drug delivery system is very interesting and challenging due to the normal physiologically factor of eyes which reduces the bioavailability of ocular products. The development of new ophthalmic dosage forms for existing drugs to improve efficacy and bioavailability, patient compliance and convenience has become one of the main trend in the pharmaceuticals industry. The present review encompasses various conventional and novel ocular drug delivery systems, methods of preparation, characterization and recent research in this area. Furthermore, the information on various commercially available in situ gel preparations and the existing patents of in situ drug delivery systems i.e. in situ gel formation of pectin, in situ gel for therapeutic use, medical uses of in situ formed gels and in situ gelling systems as sustained delivery for front of eye are also covered in this review.
    Matched MeSH terms: Biological Availability
  17. Anti-cancerous efficacy and pharmacokinetics of 6-mercaptopurine loaded chitosan nanoparticles
    Kumar GP, Sanganal JS, Phani AR, Manohara C, Tripathi SM, Raghavendra HL, et al.
    Pharmacol Res, 2015 Oct;100:47-57.
    PMID: 26232590 DOI: 10.1016/j.phrs.2015.07.025
    6-Mercaptopurine is a cytotoxic and immunosuppressant drug. The use of this drug is limited due to its poor bioavailability and short plasma half-life. In order to nullify these drawbacks, 6-mercaptopurine-chitosan nanoparticles (6-MP-CNPs) were prepared and evaluated to study the influence of preparation conditions on the physicochemical properties by using DLS, SEM, XRD and FTIR. The in vitro drug release profile at pH 4.8 and 7.4 revealed sustained release patterns for a period of 2 days. The nanoformulations showed enhanced in vitro anti-cancer activities (MTT assay, apoptosis assay, cell cycle arrest and ROS indices) on HT-1080 and MCF-7 cells. In vivo pharmacokinetics profiles of 6-MP-CNPs showed improved bioavailability. Thus, the results of the present study revealed that, the prepared 6-MP-CNPs have a significant role in increasing anti-cancer efficacy, bioavailability and in vivo pharmacokinetics profiles.
    Matched MeSH terms: Biological Availability
  18. Fulltext Solubility enhancement studies on lurasidone hydrochloride using mixed hydrotropy
    Madan JR, Pawar KT, Dua K
    Int J Pharm Investig, 2015 Apr-Jun;5(2):114-20.
    PMID: 25838997 DOI: 10.4103/2230-973X.153390
    Low aqueous solubility is a major problem faced during formulation development of new drug molecules. Lurasidone HCl (LRD) is an antipsychotic agent specially used in the treatments of schizophrenia and is a good example of the problems associated with low aqueous solubility. Lurasidone is practically insoluble in water, has poor bioavailability and slow onset of action and therefore cannot be given in emergency clinical situations like schizophrenia. Hence, purpose of this research was to provide a fast dissolving oral dosage form of Lurasidone. This dosage form can provide quick onset of action by using the concept of mixed hydrotropy. Initially, solubility of LRD was determined individually in nicotinamide, sodium citrate, urea and sodium benzoate at concentration of 10, 20, 30 and 40% w/v solutions using purified water as a solvent. Highest solubility was obtained in 40% sodium benzoate solution. In order to decrease the individual hydrotrope concentration mixed hydrotropic agents were used. Highest solubility was obtained in 15:20:5 ratio of Nicotinamide + sodium benzoate + sodium citrate. This optimized combination was utilized in the preparation of solid dispersions by using distilled water as a solvent. Solid dispersions were evaluated for X-ray diffraction, differential scanning calorimetry and Fourier-transform infrared to show no drug-hydrotropes interaction has occurred. This solid dispersion was compressed to form fast dissolving tablets. Dissolution studies of prepared tablets were done using USP Type II apparatus. The batch L3 tablets show 88% cumulative drug release within 14 min and in vitro dispersion time was 32 min. It was concluded that the concept of mixed hydrotropic solid dispersion is novel, safe and cost-effective technique for enhancing the bioavailability of poorly water-soluble drugs. The miraculous enhancement in solubility and bioavailability of Lurasidone is clear indication of the potential of mixed hydrotropy to be used in future for other poorly water-soluble drugs in which low bioavailability is a major concern.
    Matched MeSH terms: Biological Availability
  19. Effects of high temperature melting on fractionation of heavy metals in sewage sludge
    Idris A, Saed K
    J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002;37(6):1123-31.
    PMID: 12090284
    Sewage sludge from aerobic treatment plant was found to contain high amounts of heavy metals. Research was carried out to investigate the speciation and leaching behavior of heavy metals when using high temperature melting technology for treatment. This was achieved by conducting a sequential chemical extraction procedure and EP-TOX leaching test. The thermal treatment led to increased shift of metals from organic fraction to residual fraction, indicating that the thermal treatment caused metals in sewage sludge to become stable. Furthermore, results from leaching test revealed that metals were not leached from the final product after thermal treatment and this was verified using US EPA standard limits. Results from this study indicated that melting technology could convert the sludge to product that can be either reused or landfilled without an adverse environmental impact.
    Matched MeSH terms: Biological Availability
  20. Bioequivalence of a generic metformin tablet preparation
    Yuen KH, Wong JW, Billa N, Julianto T, Toh WT
    Int J Clin Pharmacol Ther, 1999 Jul;37(7):319-22.
    PMID: 10442505
    The bioavailability of a generic preparation of metformin (Diabetmin from Hovid Sdn Bhd) was evaluated in comparison with a proprietary product (Glucophage from Lipha Pharma Ltd., UK).
    Matched MeSH terms: Biological Availability
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