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PubMed2002

Determination of iodine values using 1,3-dibromo-5,5-dimethylhydantoin (DBH) without the employment of chlorinated hydrocarbons. Analytical methods of pharmacopoeias with DBH in respect to environmental and economical concern. Part 17.

Low and medium iodine values of fixed oils and fats can be determined in glacial acetic acid within reduced waiting times of only 5 min. Highly unsaturated compounds such as those of linseed oil, cod-liver oil, sunflower oil, soybean oil, wheat germ oil and the emulsifier sorbitan trioleate result too low values in comparison to PH. EUR. 2002 [2] and USP 2000 [3]. Cocoa butter with a low iodine number is insoluble in glacial acetic acid. The iodine values of nonionogenic emulsifiers such as ceteareth-30 (Macrogol cetostearyl ether PH. EUR. 2002), oleth-10 resp. 20 (Macrogol oleyl ether PH. EUR. 2002) and polysorbate-80 PH. EUR. 2002 are obtained in aqueous solutions. Oleth-2 (Macrogol oleyl ether PH. EUR. 2002), polyoxyl-40 castor oil (Macrolglycerol ricinoleate PH. EUR. 2002), polysorbate-60 PH. EUR. 2002 and sorbitan trioleate PH. EUR. 2002 need the addition of ethyl acetate. Fixed oils even with high iodine values can be determined in an o/w emulsion with a reaction time of 5 min in most cases, when nonionogenic emulsifiers such as ceteareth-30, polyoxyl-30 glycerol monolaurate or polyoxyl-60 hydrogenated castor oil (Macrolglycerol hydroxystearate PH. EUR. 2002) are used.

Acetates↗
PubMed1991

A comparative "in vitro" study of permeability with different synthetic and biological membranes.

Permeability coefficients of seven compounds belonging to a true homologous series (4-alkylanilines) through several different synthetic and biological membranes were assayed in a two-chamber diffusion cell. Permeability-lipophilicity relationships for the experimental data were established and compared in order to ascertain whether the behaviour of these membranes was similar to that of the human skin. In all cases, the best fit for the permeation-lipophilicity correlation was provided by the bilinear model. It was demonstrated that this type of correlation, when a dimethylpolysiloxane membrane is used, is due to the existence of a supplementary stagnant aqueous layer adjacent to the membrane in the receptor compartment. This is clear from the fact that when Polysorbate 80 is added to the receptor solution, the effect of this layer is abolished. In these conditions, hyperbolic equation gives, consequently, the best fit for penetration-lipophilicity correlation. On the basis of the data obtained with rat skin and Polysorbate 80 in the receptor solution, it can be concluded that for biological membranes the bilinear model obtained is due to their heterogeneous nature. The optimum lipophilicity value for penetration according to the bilinear model was not the same for all the membranes assayed. Human and rat skin were qualitatively similar in behaviour.

Amines↗
PubMed1985

Vasculopathic hepatotoxicity associated with E-Ferol syndrome in low-birth-weight infants.

A fatal syndrome characterized by progressive clinical deterioration with unexplained thrombocytopenia, renal dysfunction, cholestasis, and ascites developed in certain infants throughout the United States who had received E-Ferol, an intravenous vitamin E supplement. We reviewed the clinical course of all 36 infants from one (index) nursery who had received E-Ferol, which contains 25 units per milliliter of dl-alpha-tocopheryl acetate solubilized with 9% polysorbate 80 and 1% polysorbate 20. The syndrome was recognized in eight of the 36 infants; affected infants had a lower birth weight (less than 1,200 g) and had received a higher total dose of E-Ferol for longer periods than the unaffected cases. We reviewed autopsy-derived tissue from 20 infants (six from the index nursery and 14 from three other collaborating nurseries) who had received the intravenous vitamin E preparation in a reported dose of 25 to 137 units/kg/day for six to 45 days between October 1983 and March 1984. The hepatic histology in the affected cases indicated a progressive injury characterized initially by Kupffer cell exfoliation, central lobular accumulation of cellular debris, and centrally accentuated panlobular congestion. Prolonged exposure to E-Ferol was associated with progressive intralobular cholestasis, inflammation of hepatic venules, and extensive sinusoidal veno-occlusion by fibrosis. We propose that vasculocentric hepatotoxicity is the basis for the observed clinical syndrome that represents the cumulative effect of one or more of the constituents of E-Ferol.

Autopsy↗
PubMed1985

Experimental infection of pregnant and lactating goats with Leptospira interrogans serovars hardjo and szwajizak.

Pathogenesis of 2 Leptospira serovars, hardjo and szwajizak, was studied in pregnant and lactating goats. Although clinical signs of leptospiral infection were minimal, cultural isolations were made from the mammary gland of 2 goats and the kidney of 1 goat inoculated with serovar hardjo (C846). The isolations were made only on solid bovine albumin polysorbate-80 medium supplemented either with rabbit serum or sodium pyruvate. Cultural isolations of serovar szwajizak were made from kidney, liver, brain, urine, and mammary gland samples of 1 goat and the liver and kidney samples of its kids. These isolations were made in only the solid bovine albumin polysorbate-80 medium which had been supplemented with normal goat serum.

Animals↗
PubMed1982

Liposomes in topical drug delivery.

The possible use of liposomes as topical drug delivery vehicles for both water- and lipid-soluble drugs has been investigated. Data for two characteristic drugs, penicillin G and indoxole, are presented. Liposome uptake by the cornea is greatest for positively charged liposomes, less for negatively charged liposomes, and least for neutral liposomes, suggesting that the initial interaction between the corneal surface and liposomes is electrostatic adsorption. Positively charged unilamellar liposomes enhanced transcorneal flux of penicillin G across isolated rabbit cornea more than fourfold. Liposomal entrapment of drug is prerequisite to enhanced transport; corneal penetration was not enhanced when liposomes that were preformed in the absence of drug were mixed with penicillin G immediately before application to the cornea. Although penicillin G is water-soluble, the findings indicate that it secondarily associates with liposome membranes, possibly by insertion of its hydrophobic end into the lipid bilayer. Indoxole, however, was incorporated directly into the membranes of pure phosphatidyl choline liposomes. Liposome-mediated drug flux efficiency after topical instillation in rats was significantly greater than that obtained with equivalent concentration of drug delivered in polysorbate 80. Ten times more drug in polysorbate 80 was required to equal liposome-mediated flux efficiency. The findings suggest that liposomes enhance corneal penetration of drug by adsorbing to the corneal surface, with direct transfer of drug from liposomal to epithelial cell membranes.

Administration, Topical↗
PubMed1982

Leptospiral vaccines in dogs: immunogenicity of whole cell and outer envelope vaccines prepared in protein-free medium.

The immunogenicity of leptospires cultivated in modified bovine albumin-polysorbate 80 medium and those cultivated in protein-free medium were quantitatively evaluated in the dog. Vaccine preparations, whole cell or outer envelope, prevented leptospiremia; however, kidney culture data revealed that 1 of 4 dogs vaccinated with 0.1 to 1 mg of whole cell prepared from leptospires cultivated in the modified bovine albumin-polysorbate 80 medium was positive for Leptospira, whereas dogs vaccinated with whole cells prepared in protein-free medium were not. Dogs vaccinated with greater than or equal to 0.5 mg of outer envelope were refractory to infection after challenge exposure.

Animals↗
PubMed1980

In vitro dissolution of different brands of griseofulvin tablets.

An in vitro dissolution rate test was developed for possible use in formulation design and control of griseofulvin tablets. Dissolution profiles of five brands of griseofulvin tablets were obtained using a two-phase system consisting essentially of a 11 three-necked round-bottom flask. Appropriate sink conditions in the aqueous phase were maintained by means of an upper organic phase composed of a mixture of equal parts of benzene and chlorobenzene. The dissolution media tested were 0.02% polysorbate 80 in water (pH = 6--7), sodium desoxycholate (10 mmol/1) in water (pH = 7.2) and 0.02% polysorbate 80 in HCl (0.1 mol/l, pH = 2). Interbrand differences in dissolution were better seen in neutral medium containing the non-ionic surfactant. Reduced deaggregation tendencies of griseofulvin in acid medium and unfavourable partitioning conditions in the presence of bile salt masked the differences in dissolution in the other two media. Dissolution profiles obtained under sink conditions could be characterized by rate constants.

Griseofulvin↗
PubMed1978

Bactericidal activity of 40 potential disinfectant inactivators.

Forty commonly used inactivators, both simple substances and mixtures, were tested by a quantitative suspension test for the property of being non-toxic to the bacterial cell. Some inactivators proved to be too inhibitory, even for undamaged organisms, namely cysteine in concentrations of 1.0% and higher, 0.3% and 2.0% lecithin (both especially for P. aeruginosa), and the mixtures 0.3% lecithin/2.0% polysorbate 80/0.1% histidine/2.0% turkey-oil red (for St. aureus) and 0.3% lecithin/3.0% polysorbate 80/0.4% sodium laurylsulfate (for both test organisms).

Bacteriolysis↗
PubMed1995

Cutaneous mast cell degranulation in rats receiving injections of recombinant human interleukin-1 receptor antagonist (rhIL-1ra) and/or its vehicle: possible clinical implications.

Human recombinant interleukin-1 receptor antagonist (rhIL-1ra), a 17.2 kd protein is currently in clinical trials for the treatment of rheumatoid arthritis (RA). Skin reactions in some patients with RA prompted investigation of a possible pathogenesis involving nonimmunologically mediated mast cell degranulation. Rats injected intradermally with 20 microliters of rhIL-1ra (100 or 200 mg/ml) or the rhIL-1ra vehicle CSEP (10 mmol/L Na-citrate, 0.5 mmol/L ethylenediaminetetraacetic acid (EDTA), 0.1% polysorbate 80, 140 mmol/L NaCl, pH 6.5) had marked (15x or 10x, respectively) Evans blue dye permeability increases as compared with rats injected with phosphate-buffered saline solution (PBS) or bovine serum albumin (BSA). The permeability changes were reduced or eliminated by subcutaneous or local treatment with the antihistamine diphenhydramine. Histologic evaluation of skin sections from rats injected intradermally with CSEP or rhIL-1ra in CSEP revealed mast cell degranulation and edema, features not seen in sites injected with PBS or BSA in PBS. Components of the vehicle were investigated individually for their capacity to cause the reaction. Na-citrate (10 mmol/L) induced a greater increase in permeability than did EDTA (0.5 mmol/L) or polysorbate 80 (0.1%), and all produced reactions that were significantly greater than those occurring at PBS-injected sites. Evans blue dye permeability increases after subcutaneous injection of 1 ml of rhIL-1ra (100 mg/ml) in CSEP (with and without diphenhydramine) or rhIL-1ra in PBS were evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

A prospective comparison of abdominal hysterectomy using absorbable staples.

Forty-eight abdominal hysterectomies performed using Polysorb (United States Surgical Corporation) [corrected] absorbable staples were compared prospectively with 46 hysterectomies performed using a regular suture technique. The two groups were demographically similar and it was found that the time of operation (p = 0.001) and the amount of blood loss at operation was significantly reduced (p = 0.03). The incidence of granulations at the vaginal vault at six weeks was significantly reduced (p = 0.001) and return to activity (p = 0.02) and work (p = 0.01) were also significantly reduced for the patients who had a hysterectomy performed using Polysorb staples. There was no statistical difference in morbidity, complications, use of analgesics and period of hospitalization. The continued use of absorbable staples in abdominal hysterectomy is supported, related to the advantages that were statistically significant.

Adult↗
PubMed1993

[Fat-soluble vitamins: Intestinal absorption].

General principals of drug absorption and bioavailability after the oral administration are discussed in each process of drug release and dissolution from the preparation, such as gastric emptying time and flow of drug in intestinal track, transport through intestinal mucosal microvilli, and the first pass effect of drug elimination in the liver. Character of lipid soluble vitamins in these absorption processes are elucidated with the low solubility in water and solubilization in bile acids micelle. Our studies on dl-alpha-tocopherol solubilization into micelles of bile acids and a detergent and the rat intestinal absorption by perfusion of the micellar solutions are introduced. Faster absorption of the tocopherol solubilized in bile acid micelles, than polysorbate 80, was observed in spite of the less solubilizing abilities of bile acids. Relatively high dependency on volume flow through the intestinal wall was observed in the absorption rate of tocopherol. The dependency is larger in bile acid micelles having smaller size than polysorbate 80 having large size.

Animals↗
PubMed1977

Growth, virulence, and immunogenicity of Leptospira interrogans serotype szwajizak.

Leptospira interrogans serotype szwajizak was characterized by (1) its growth in polysorbate 80-bovine albumin medium, (2) its virulence and course of infection in laboratory animals, and (3) its immunogenicity. Growth of this organism was continuous and vigorous at 29 C and 37 C in liquid medium for 10 serial subcultures. Some specific lots of agar were superior to other agars if tested for the ability to support the growth of small inoculums. Individual colonies resulted from growth of small inoculums on solid polysorbate medium. Virulence of the organisms did not appear to be altered by 10 serial subcultures in liquid medium incubated at 29 C. The estimated median lethal dose of szwajizak for hamsters by the intraperitoneal route was 2 cells. Virulence, infectivity, and pathogenicity of szwajizak were shown in the hamster and the guinea pig. Protection results indicate the heat-inactivated szwajizak bacterin was a substantially better immunizing agent than the chemically inactivated bacterin. Serotype hardjo bacterins provided hamsters some protection against death if challenge exposed with szwajizak, but afforded no protection against infection.

Animals↗
PubMed1998

The formulation of recombinant factor IX: stability, robustness, and convenience.

A lyophilized recombinant factor IX (rFIX) formulation has been developed that is stable and contains no preservatives. No blood or plasma products are used in the production or formulation of rFIX. The formulation contains 10 mmol/L histidine, 0.26 mol/L glycine, 1% sucrose, and 0.005% polysorbate-80 (pH 6.8). Polysorbate-80 acts as a protectant for the protein from freezing-induced damage (eg, aggregation). Sucrose provides protection to the protein in the freeze-dried state. Glycine provides for a high-quality cake morphology. Histidine provides optimal buffering stability at the desired pH and minimizes aggregate formation upon storage in the lyophilized state. This optimized combination of excipients provides a high degree of long-term stability, as demonstrated by a variety of analytical methods, including clotting assays, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing (IEF), size-exclusion chromatography (SEC), peptide mapping, oligosaccharide fingerprinting, and reverse-phase high-performance liquid chromatography (HPLC). The rFIX product is easy to reconstitute and demonstrates excellent stability in solution after reconstitution.

Chemistry, Pharmaceutical↗
PubMed1998

Taxoids in combination with anthracyclines and other agents: pharmacokinetic considerations.

The combination in clinical trials of taxoids with doxorubicin has focused attention on possible drug interactions. One specific finding requiring explanation is the relative lack of cardiotoxicity of the docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France)/doxorubicin combination compared with that of the paclitaxel/doxorubicin combination. Data in mice demonstrate that epirubicin concentrations in cardiac tissue 24 hours after treatment are approximately doubled by the coadministration of paclitaxel. This effect appears to be less marked with docetaxel administered in its normal polysorbate vehicle or when the drug is given in Cremophor EL (Sigma, St Louis, MO). Both Cremophor EL or polysorbate appear to cause an increase in epirubicin tissue levels, although the levels were less than those seen with paclitaxel. Pharmacokinetic data from women being treated with combination therapy for advanced breast cancer demonstrate that the administration of docetaxel following doxorubicin does not alter doxorubicin's area under the plasma concentration-time, curve, maximum plasma concentration, or time until maximum plasma concentration is reached. However, the area under the curve of docetaxel is significantly increased by the prior administration of doxorubicin. These findings may explain both the low cardiotoxicity and the high clinical efficacy of the docetaxel/doxorubicin combination. Phase I clinical trials of combinations in which docetaxel was used together with vinorelbine, ifosfamide, or 5-fluorouracil have shown no evidence of relevant pharmacokinetic interactions.

Animals↗
PubMed1997

Intestinal absorption kinetics of amiodarone in rat small intestine.

Amiodarone is a widely used antiarrhythmic agent with highly variable therapeutic effects. These seem to be related, at least in part, to the pharmacokinetics of the drug and particularly to some features of its gastrointestinal absorption process. The drug exhibits physico-chemical properties highly suitable for diffusion across lipophilic absorbing membranes, but its low aqueous solubility can act as the rate limiting step for absorption, making the process erratic and variable. In order to gain an insight into the intestinal absorption mechanism of the drug and detect possible non-linearities, a series of experiments using a classical rat gut in situ preparation were carried out with three amiodarone hydrochloride solutions (10, 75, and 200 micrograms mL-1). A synthetic non-ionic surfactant, polysorbate 80, at supramicellar concentration (2 mM) was used as the drug solubilizer. Amiodarone was assayed in biological samples by HPLC using a rapid, sensitive technique that was validated. The amiodarone first-order absorption rate constants obtained in these conditions were similar. No significant differences between ka values were found. Amiodarone absorption was clearly identified as a passive diffusion process.

Administration, Oral↗
PubMed2003

Effects of annealing lyophilized and spray-lyophilized formulations of recombinant human interferon-gamma.

The purpose of this study was to examine the effects of adsorption of recombinant human interferon-gamma (rhIFN-gamma) on ice surfaces and subsequent drying during processing by spray-lyophilization and lyophilization. Ice/liquid interfacial areas were manipulated by the freezing method as well as by the addition of an annealing step during lyophilization; that is, rhIFN-gamma adsorption was modified by the addition of nonionic surfactants. rhIFN-gamma was lyophilized or spray-lyophilized at a concentration of 1 mg/mL in 5% sucrose, 5% hydroxyethyl starch (HES) +/- 0.03% polysorbate 20 in 140 mM KCl, and 10 mM potassium phosphate, pH 7.5. After the samples were frozen, half were annealed on the lyophilizer shelf. Recovery of soluble protein was measured at intermediate points during processing. On drying, the secondary structure of rhIFN-gamma was determined by second-derivative infrared (IR) spectroscopy, specific surface areas (SSAs) were measured, scanning electron micrographs (SEM) were taken, and dissolution times were recorded. Adsorption of rhIFN-gamma to ice/liquid interfaces alone was not responsible for aggregation. Rather, drying was necessary to cause aggregation in lyophilized sucrose formulations. Addition of an annealing step to the lyophilization cycle resulted in more native-like secondary protein structure in the dried solid, eliminated cracking of the dried cakes, and suppressed both the formation of air/liquid interfaces and rhIFN-gamma aggregation on reconstitution.

Adsorption↗
PubMed2003

Solubilization of flurbiprofen in pH-surfactant solutions.

Based on an investigation on furbiprofen solubilization in polysorbate 80 solutions at different pH, this study proposed an equilibrium-based model to characterize the drug-surfactant interactions in pH controlled system. The model reflected both interactions and interdependence among all drug-containing species: unionized drug in water D(u), ionized drug in water D(i), unionized drug in micelles D(u)M, and ionized drug in micelles D(i)M. The micelles were defined and quantitated as the micellized surfactants, so both D(u)M and D(i)M were also seen as unionized and ionized drug associated with micellized surfactants. This mathematical treatment enables the modeling of the drug solubilization in pH-surfactant solutions without making unsound approximations. Using a separate set of solubility data at a different pH, a comparison was conducted between experimental data and the solubility estimated by this model, and by the partition model proposed by Rippie et al. It was found that both models yielded reasonably good estimation compared with experimental data. It was also found that the solubility data estimated by the proposed model were more reliable especially when the surfactant concentration was high in the system. This suggests that the consideration of interrelations and interdependence of all drug species in pH-surfactant solutions by this model is justified and appropriate.

Chemistry, Pharmaceutical↗
PubMed2006

Permeability assessment of poorly water-soluble compounds under solubilizing conditions: the reciprocal permeability approach.

The objective of this study was to develop a general method to assess the intestinal permeability of poorly water-soluble drugs where low-aqueous drug solubility requires conduct of experiments under solubilizing experimental conditions. The permeability (Papp) of diazepam (DIA) was assessed across excised rat jejunum in the absence (Pappcontrol) and presence (Pappuncorr) of polysorbate-80 (PS-80). The micellar association constant (Ka) of DIA, estimated via equilibrium solubility studies, was used to correct Pappuncorr data and obtain an estimate of the true permeability coefficient (Pappcorr). An alternate approach was also developed (the reciprocal permeability approach) to allow direct estimation of Pappcorr without the need for independent estimation of Ka. The approach was further examined experimentally using a range of model drugs. DIA Pappcorr values obtained using the Ka from equilibrium solubility studies deviated from Papp(control) values, especially at PS-80 concentrations above 0.1% w/v. In contrast, data obtained using the reciprocal permeability method were consistent with Pappcontrol across the PS-80 concentration range. Similar trends were observed with propranolol (PRO), antipyrine (ANT), naproxen (NAP), and cinnarizine (CIN). The reciprocal permeability approach therefore provides a simple and accurate method by which the permeability of poorly water-soluble compounds may be estimated under solubilizing conditions.

Animals↗