Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1573-904X
    Keywords: lovastatin ; simvastatin ; sustained-release dosage forms ; 3-hydroxy-3-methylglutaryl–coenzyme A (HMG-CoA) reductase inhibitors ; dog ; humans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Seven sustained/controlled-release dosage forms were designed for gastrointestinal delivery of lovastatin or simvastatin, two potent HMG-CoA reductase inhibitors for the treatment of hypercholesterolemia. The in vivo performance of these formulations was evaluated in dogs and healthy volunteers in terms of the cholesterol lowering efficacy and/or systemic concentrations of HMG-CoA reductase inhibitors. Results from the present and previous studies suggest that, through the controlled release of HMG-CoA reductase inhibitors, sustained lower plasma concentrations of HMG-CoA reductase inhibitors may result in an equal or better therapeutic efficacy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-904X
    Keywords: absorption enhancer ; colon ; enteric-coated tablet ; dog ; rabbit ; stomach ; small intestine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The performance of tablets containing the absorption enhancer palmitoylcarnitine chloride (PCC) and the antibiotic cefoxitin (CEF) was determined by direct placement of tablets in the rat stomach, small intestine, and colon. While the bioavailability (F) of tablets containing 12 mg CEF without PCC ranged from 0.6 to 3.9%, the addition of 24 mg PCC resulted in an enhanced CEF bioavailability in the rat colon (mean ± SD: F = 57 ± 19%) and rat jejunum (F = 71 ± 16%) but not in the rat stomach. Following oral administration to dogs, tablets of 200 mg CEF without or with 600 mg PCC resulted in the same low bioavailabilities (7.0 ± 10.3 and 7.0 ± 3.6%, respectively). However, when these tablets were enteric coated, PCC improved CEF bioavailability from 2.44 ± 1.84 to 29.0 ± 13.4%. Therefore, the use of enteric-coated direct compressed tablets containing PCC and direct compression excipients improved the peroral bioavailability of a poorly absorbed compound.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Pharmaceutical research 10 (1993), S. 924-926 
    ISSN: 1573-904X
    Keywords: nasal absorption ; nasal drug delivery ; bisphosphonate ; rat ; dog ; alendronate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-904X
    Keywords: rabbit ; rat ; lesion ; creatine kinase ; extended release formulations ; sesame oil ; danofloxacin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. The goal of this study was to find a resource sparing alternative to the rabbit lesion model (RbLV) for assessing injection site toleration in extended release (ER) intramuscular (IM) formulation screening. Methods. ER formulations (danofloxacin oily and aqueous suspensions) were evaluated in RbLV, rat and rabbit plasma creatine phospho-kinase (CK), and rat foot edema (RFE) models as described in the companion article. Results. None of the short term models could consistently predict acute and chronic effects of the. For example, RFE predicted little muscle damage from aqueous vehicle (0.03 ± 0.03 g) and 60 mg/ml (0.08 ± 0.03 g) formulation; while RbLVdays l–3 was marked and greater (p 〈 0.05) for 60 mg/ml (6.0 ± 3.1) than vehicle (2.2 ± 2.9) formulations. Furthermore, RbLVdays l–3 for vehicle (6.5 ± 7.5) and 60 mg/ml (4.9 ± 4.6) danofloxacin oily formulations were worse (p 〈 0.05) than oil alone (1.4 ± 2.2); an observation not predicted by CK models, since they apparently reflected only the acute muscle damage of formulation components immediately available to surrounding tissue at the time of injection. Conclusions. The CK models may be useful to screen those ER formulations with unacceptable acute damage due to immediately available components. However, to evaluate potential delayed effects from ER formulations, the long-term model RbLV was still recommended.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-904X
    Keywords: L6 cell monolayer ; intramuscular formulations ; creatine kinase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1573-904X
    Keywords: rabbit ; rat ; lesion ; creatine kinase ; saline ; digoxin ; azithromycin ; danofloxacin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. The current animal model generally accepted by the pharmaceutical industry and the FDA for assessment of muscle damage following intramuscular injection (IM) is the rabbit lesion volume model (RbLV). However, this model is resource intensive. The goal of this study was to find a resource sparing alternative to the rabbit lesion model for assessing injection site toleration in IM formulation screening. Methods. Short term animal model alternatives to RbLV for evaluating IM formulations were examined. In addition to RbLV, myeloperoxidase (MPO), p-nitrophenyl N-acetyl-β-glucosaminide (NAβG) and/or plasma creatine phosphokinase (CK) activities were determined in rabbits (Rb) and rats (Rt) after injection of formulations (digoxin, azithromycin and danofloxacin). The edema from these formulations 24 hr after subcutaneous injection into the rat footpad (RFE) was also determined. Results. MPO and NAβG were not considered very useful as biochemical predictors of muscle damage for these formulations. Histology generally correlated with RbLV values. Compared to saline, RbLV was marked for all formulations within 1–3 days of injection. After day 3, lesions quickly resolved, and no significant differences were found. For these formulations, all CK animal models and RFE were generally predictive of RbLV. A formulation with RtCK 〉 1000 U/L or RbCK 〉 3000 U/L, was predicted to be poorly, tolerated. Conclusions. Due to ease, number of animals, time and intrinsic mechanism, we concluded that for most formulations, 2 and 4 hr RtCK data alone should be reasonably predictive of muscle damage.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-904X
    Keywords: acylcarnitines ; cefoxitin ; lucifer yellow ; rat colon ; tissue permability ; transepithelia electrical resistance (TEER) ; Sweetana–Grass diffusion cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A simple modification of the commercially available Sweetana–Grass (S-G) side-by-side diffusion cells, allowing the simultaneous measurement of tissue permeability and transepithelial electrical resistance (TEER), has been described and validated for rat excised, muscle-free intestinal tissue. The TEER-lowering effects of a series of acylcarnitines were shown to be correlated with previously reported in vitro (i.e., membrane perturbation) and in vivo (i.e., absorption enhancement) activity. The TEER-lowering effect of palmitoyl carnitine chloride (PCC) was also shown to be reversible. The effects of PCC on TEER and the permeability of poorly absorbed compounds (cefoxitin and lucifer yellow) were simultaneously determined. Compared to controls (mannitol-treated), PCC immediately produced a rapid drop in colon TEER. By 5 min post-PCC addition, colon TEER was 50% of control; by 10 min post-PCC addition, colon TEER was 17% of control. After a lag of about 5–10 min post-PCC addition, the cefoxitin or lucifer yellow permeability coefficient increased more than 20-fold. The modified S-G cells provide a simple and reproducible method whereby flux and TEER can be simultaneously determined, providing a valuable link between the effect of absorption enhancers on TEER measurements and the increased permeability of poorly absorbed compounds.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-904X
    Keywords: diltiazem ; controlled release ; deconvolution ; dog ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The in vivo performance of two extended-release (ER) osmotic formulations of diltiazem were evaluated in the beagle dog. Both ER formulations had similar bioavailabilities (F) as the diltiazem solution. Although F was somewhat variable following ER administration, this variability may be related to the drug entity since intra- and interanimal variability of orally administered diltiazem solutions was substantial. Deconvolution of the ER plasma diltiazem data with absorption data from the orally administered diltiazem solutions provided an estimate of the in vivo drug release from the ER formulations. The two ER formulations, designed with different in vitro release profiles, reflected these differences in vivo, with nearly identical respective in vivo and in vitro release profiles.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-904X
    Keywords: acylcarnitines ; fluorescence polarization ; 1,6-diphenyl-l,3,5-hexatriene (DPH) ; rat intestine ; brush border membranes ; absorption enhancers ; membrane lipid order
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Acylcarnitines with chain lengths of 2 to 18 carbon atoms were tested for their effects on rat intestinal brush border membrane order (S) by fluorescence polarization of 1,6-diphenyl-l ,3,5-hexatriene (DPH). These results were compared to the previously reported effectiveness of the acylcarnitines as absorption enhancers of the poorly absorbed antibiotic cefoxitin. Acylcarnitines with fatty acids less than 12 carbon units in length were ineffective in increasing drug absorption and perturbing brush border membrane order. Long-chain acylcarnitines (12–18 carbons) significantly increased the bioavailability of cefoxitin and decreased the lipid order of brush border membranes. The results suggest that, in order to promote drug absorption, the acylcarnitines must surpass a critical chain length (10 carbon units) to partition effectively into the membrane and, in addition, must perturb the lipid order beyond a threshold value (15–20%). Membrane perturbing capacity may serve as an indicator of the absorption enhancing potential of other aliphatic-type compounds.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-904X
    Keywords: osmotic pump ; microporous coat ; solubility modulation ; diltiazem hydrochloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A generalized method was investigated for conversion of controlled-porosity osmotic pump release profiles from first-order to zero-order kinetics using diltiazem · HC1 as a model drug. Diltiazem · HC1 has an aqueous solubility 〉590 mg/ml (37°C) and was released from controlled-porosity osmotic pump devices with first-order kinetics. This high solubility was markedly reduced (155 mg/ ml; 37°C) in the presence of NaCl (1 M). Based on theory for osmotically actuated drug release, this reduced solubility would be expected to result in a zero-order release profile of 〉80% of an initial diltiazem · HC1 load. Devices were prepared with cores that contained diltiazem · HC1 and sufficient NaCl granules coated with a microporous cellulose acetate butyrate 381-20 film to maintain a 1 M NaCl concentration within the drug compartment over a 16-hr period. This resulted in release of ∼75% of the initial diltiazem HC1 load with zero-order kinetics over a 14- to 16-hr period. The in vivo performance of these devices in beagle dogs was analyzed. The in vivo percentage diltiazem absorbed profiles were superimposable with the in vitro release profile. These results suggest that diltiazem release and absorption from the solubility modulated osmotic pump occur throughout the GI tract in a fashion predictable from in vitro dissolution data.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...