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  • 1
    Electronic Resource
    Electronic Resource
    Comparison of penetration-enhancing ability of laurocapram, N-methyl-2-pyrrolidone and dodecyl-L-pyroglutamate (1988)
    Springer
    Pharmacy world & science 10 (1988), S. 189-192 
    Details
    ISSN: 1573-739X
    Keywords: Absorption, transdermal ; Brilliant Blue ; Dodecyl-l-pyroglutamate ; Insulin ; Laurocapram ; N-Methyl-2-pyrrolidone ; Permeability, enhancement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The study reports on penetration enhancers used to improve drug absorption through the skin. All experiments were carried out in permeation cellsin vitro. Insulin (2.5 mg/ml) and Brilliant Blue (50.0 mg/ml) served as model drugs. They were formulated into a 40% solution of propylene glycol with increasing concentrations ofN-methyl-2-pyrrolidone (NMP) (0.0 to 20.0%), dodecylazacycloheptan-2-one (laurocapram) and a new compound dodecyl-l-pyroglutamate (DLP; 0.0 to 0.5%). The maximum amount of insulin permeated within 24 h was almost 200 μU/ml in the case of 0.1% laurocapram, while in the case of 0.1% DLP it was approximately half of that. The optimum concentration of NMP was 12.0%. Experiments performed with Brilliant Blue showed no significant difference among formulations containing either 6.0, 12.0 or 20.0% of NMP. When NMP was omitted, flux, permeability as well as the maximum concentration estimated after 26 h reached 50% of the values obtained with NMP. The lag time was twice as long in this case in comparison with the formulations containing NMP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01956869
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  • 2
    Electronic Resource
    Electronic Resource
    Rates of Systemic Degradation and Reticuloendothelial System Uptake of Calcein in the Dipalmitoylphosphatidylcholine Liposomes with Soybean-Derived Sterols in Mice (1995)
    Springer
    Pharmaceutical research 12 (1995), S. 49-52 
    Details
    ISSN: 1573-904X
    Keywords: dipalmitoylphosphatidylcholine (DPPC) liposomes ; soybean-derived sterols (SS) ; systemic degradation ; reticuloendothelial system (RES) uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The systemic degradation and the reticuloendothelial system (RES) uptake of calcein entrapped in dipalmitoylphosphatidylcholine (DPPC) liposomes with soybean-derived sterols (SS) were examined after intravenous administration to mice by measuring the free and liposomal calcein levels in the blood. The results indicate that the rates of systemic degradation and the RES uptake of liposomes decrease with the addition of SS in DPPC liposomes since the SS has the ability to stabilize the liposomes. The rate of uptake by RES is larger than the rate of systemic degradation. The rate of leakage of calcein from liposomes by incubation in plasma in vitro is almost the same as that of systemic degradation in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1016230518884
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  • 3
    Electronic Resource
    Electronic Resource
    Pharmacokinetic and Pharmacological Profiles of Free and Liposomal Recombinant Human Erythropoietin After Intravenous and Subcutaneous Administrations in Rats (1997)
    Springer
    Pharmaceutical research 14 (1997), S. 1621-1628 
    Details
    ISSN: 1573-904X
    Keywords: recombinant human erythropoietin ; liposome ; intravenous administration ; subcutaneous administration ; pharmacokinetics ; pharmacological effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. Recombinant human erythropoietin (Epo) is used frequently through intravenous (i.v.) and subcutaneous (s.c.) administration for the clinical treatment of the last stage of renal anemia. We encapsulated Epo in liposomes to develop an alternative administration route. The purpose of our study was to evaluate the pharmacokinetics and the pharmacological effects of liposomal Epo in comparison with the Epo after i.v. and s.c. administration to rats. Methods. Epo was encapsulated in liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and soybean-derived sterol mixture (SS) prepared by the reversed-phase evaporation vesicle method. After filtration through a 0.1 μm polycarbonate membrane, liposomes were gel filtered (Epo/liposomes). Results. Epo/liposomes showed higher pharmacological activity than Epo/liposomes before gel filtration after i.v. administration to rats. Non-encapsulated Epo lost its activity, whereas encapsulated Epo in liposomes retained it. The pharmacological effects of Epo/liposomes were greater than those of Epo after i.v. administration. Epo/liposomes afforded 3−9 times higher AUC, lower clearance and lower steady-state volume of distribution than Epo after both i.v. and s.c. administrations. Epo/liposomes had an improved pharmacokinetic profile compared with Epo. S.c. administration of Epo/liposomes at 7 h may penetrate primarily (40% of dose) through the blood as a liposome and partly (7% of dose) in lymph. Conclusions. Epo/liposomes may reduce the frequency of injections required for a certain reticulocyte effect in comparison to Epo. The lower clearance of Epo/liposomes may increase the plasma concentrations of Epo, which increases the efficacy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012142704924
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  • 4
    Electronic Resource
    Electronic Resource
    Developments in cyclodextrin applications in drug formulations (1987)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 5 (1987), S. 29-38 
    Details
    ISSN: 1573-1111
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract With regard to recent developments in cyclodextrin (CD) applications in drug formulations, here will be described on the basis mainly of (a) novel preparative methods of CD inclusion complexes, (b) effects of CDs on bioavailability and disposion of drugs and (c) absorption enhancement by CD derivatives in transdermal application. (a) When inclusion complex of cinnarizine (CN) with β-CD was prepared by a spray-drying method, it was very stable under heating and highly humid conditions. (b-1) CDs gave influence on hypnotic potency and disposition of barbiturates in intravenous and intraperitoneal administrations. (b-2) The bioavailability of CN on oral administration of the complex, which was comparable with that of CN alone, was enhanced by simultaneous administration of competing agents, such as DL-phenylalanine. (c) When tolnaftate (TOL), antifungal drug, was administered percutaneously in the form of the complex with dimethyl-β-CD and water-soluble β-CD polymer, it was absorbed in the skin, and the concentration was kept high compared with the case of TOL alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00656398
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  • 5
    Electronic Resource
    Electronic Resource
    The inclusion complex of piromidic acid with dimethyl-β-cyclodextrin in aqueous solution and in the solid state (1987)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 5 (1987), S. 407-413 
    Details
    ISSN: 1573-1111
    Keywords: Piromidic acid/DM-β-CD inclusion complex ; phase-solubility ; DSC ; 1H-NMR ; dissolution profile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Inclusion complex formation of piromidic acid (PA) with dimethyl-β-cyclodextrin (DM-β-CD) in aqueous solution and in the solid state was confirmed by the solubility method, differential scanning calorimetry (DSC) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The apparent stability constant,K c , of the complex was estimated to be 244 M−1. The stoichiometry of the complex was given as the ratio 1:2 of PA to DM-β-CD. The dissolution rate of the PA/DM-β-CD complex was much greater than that of intact PA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00664095
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesis of degradable terpolymers responding to external stimuli such as pH, ionic strength and temperature (1992)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 193 (1992), S. 715-722 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Degradable copolymers which respond to external stimuli such as pH, ionic strength, and temperature were successfully prepared by direct polycondensation of L-lactic acid (LA), D,L-mandelic acid (MA), and 3-(p-hydroxyphenyl)propionic acid (HPPA) without the use of a catalyst at 200°C by bubbling nitrogen through the solution. The molecular weights of the copolymers obtained were relatively low because of the low polymerizability of MA and HPPA, e. g., number-average molecular weight M̄n ≦ 2100 and weight-average molecular weight M̄w ≦ 4100. Poly{(L-lactic acid)-co-(D,L-mandelic acid)-co-[3-(p-hydroxyphenyl)propionic acid]} (poly(LA/MA/HPPA)) with a composition of the monomeric units (in mol-%) LA:MA:HPPA = 80:10:10 showed rapid degradation after a lag time of 5 h within 48 h from the start of the test, in M/15 phosphate buffer solution (pH 7,2) at 37°C. With increasing pH and temperature, the rate of degradation was markedly accelerated.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1992.021930317
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  • 7
    Electronic Resource
    Electronic Resource
    Synthesis and in vitro degradations of low-molecular-weight copolyesters composed of L-lactic acid and aromatic hydroxy acids (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 2077-2082 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: L-lactic acid (LA) was copolycondensed with various aromatic hydroxy acids such as p-hydroxybenzoic acid (HBA), p-hydroxyphenylacetic acid (HPAA), and p-3-(hydroxyphenyl)propionic acid (HPPA) in the absence of catalysts, in order to investigate the copolymerizability and in vitro degradation. The results of 1H NMR spectroscopy and gel permeation chromatography (GPC) showed that the reaction proceeds quantitatively, but the molecular weight of the copolyesters is relatively low. The in vitro degradation pattern of copoly(LA/HPPA) was changed into an S-type from a parabolic-type with increasing HPPA content in the copolyester, in contrast to only parabolic-type for both copoly(LA/HBA) and copoly(LA/HPAA).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021910910
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  • 8
    Electronic Resource
    Electronic Resource
    Effect of phosphoric acid on the polycondensation of ε-caprolactone with δ-valerolactone and biodegradation of their copolyesters (1991)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 192 (1991), S. 1067-1072 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Copolycondensation of ε-caprolactone (CL) and δ-valerolactone (VL) was performed in the presence and absence of phosphoric acid, in order to clarify the competition between the ring-opening reaction of lactones and the polycondensation of linear compounds produced by this reaction. The gel permeation chromatography data showed that the monomer peaks remained in the system even after 7 h from start of the reaction when polymerized in the absence of phosphoric acid and, on the contrary, in the presence of phosphoric acid the peaks disappear perfectly within 1 h. The weight-average molecular weights (M̄w) of poly(CL-co-VL), obtained by copolycondensation with and without phosphoric acid at 200°C for 1 h, were approximately 540 and 8900, suggesting that phosphoric acid markedly accelerates not only the rate of ring-opening but also the rate of copolycondensation. On the other hand, the biodegradation of the copolyesters obtained is characterized by the action of a lipase-type enzyme, showing a typical parabolic-type degradation pattern.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1991.021920505
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  • 9
    Electronic Resource
    Electronic Resource
    Artificial Neural Network as a Novel Method to Optimize Pharmaceutical Formulations (1999)
    Springer
    Pharmaceutical research 16 (1999), S. 1-6 
    Details
    ISSN: 1573-904X
    Keywords: artificial neural networks ; response surface method ; multi-objective optimization ; polynomial equation ; pharmaceutical formulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract One of the difficulties in the quantitative approach to designing pharmaceutical formulations is the difficulty in understanding the relationship between causal factors and individual pharmaceutical responses. Another difficulty is desirable formulation for one property is not always desirable for the other characteristics. This is called a multi-objective simultaneous optimization problem. A response surface method (RSM) has proven to be a useful approach for selecting pharmaceutical formulations. However, prediction of pharmaceutical responses based on the second-order polynomial equation commonly used in RSM, is often limited to low levels, resulting in poor estimations of optimal formulations. The aim of this review is to describe the basic concept of the multi-objective simultaneous optimization technique in which an artificial neural network (ANN) is incorporated. ANNs are being increasingly used in pharmaceutical research to predict the non-linear relationship between causal factors and response variables. The usefulness and reliability of this ANN approach is demonstrated by the optimization for ketoprofen hydrogel ointment as a typical numerical example, in comparison with the results obtained with a classical RSM approach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011986823850
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  • 10
    Electronic Resource
    Electronic Resource
    Isolation, purification, and characterization of cyclomaltodecaose (ε-CD) (1996)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 25 (1996), S. 17-20 
    Details
    ISSN: 1573-1111
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract ɛ-Cyclodextrin (ɛ-CD) is a cyclic oligosaccharide, composed of ten α-1,4-linked D-glucoses reported by Frenchet al. in 19651), but has not been studied because of the difficulty in the preparation and purification of large-ring CDs composed of more than nine α-1,4-linked D-glucose units. This report describes the purification and characterization of ɛ-CD. Furthermore, the crystal and molecular structure of ɛ-CD hydrate ɛ-CD 19H2O) was elucidated by X-ray analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01041527
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