| 1. |
|
|
| 2. |
- Bramer, Tobias, et al.
(författare)
-
Pharmaceutical applications for catanionic mixtures
- 2007
-
Ingår i: Journal of Pharmacy and Pharmacology (JPP). - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 59:10, s. 1319-1334
-
Forskningsöversikt (refereegranskat)abstract
- Mixtures of oppositely charged surfactants, so called catanionic mixtures, are a growing area of research. These mixtures have been shown to form several different types of surfactant aggregates, such as micelles of various forms and sizes, and lamellar structures, such as vesicles. In this review, a short introduction to the field of catanionic mixtures is presented and the pharmaceutical possibilities offered by such mixtures are reviewed. There are several interesting ideas on how to apply catanionic mixtures to improve the delivery of, for example, drug compounds and DNA, or for HIV treatment.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Fransén, Nelly, et al.
(författare)
-
Physicochemical interactions between drugs and superdisintegrants
- 2008
-
Ingår i: Journal of Pharmacy and Pharmacology (JPP). - 0022-3573 .- 2042-7158. ; 60:12, s. 1583-9
-
Tidskriftsartikel (refereegranskat)abstract
- We have evaluated the interactions between superdisintegrants and drugs with different physicochemical characteristics, which may affect the in-vivo absorption e.g. after mucosal administration. The binding of sodium salicylate, naproxen, methyl hydroxybenzoate (methylparaben), ethyl hydroxybenzoate (ethylparaben), propyl hydroxybenzoate (propylparaben), atenolol, alprenolol, diphenhydramine, verapamil, amitriptyline and cetylpyridinium chloride monohydrate (CPC) to different superdisintegrants (sodium starch glycolate (SSG), croscarmellose sodium (CCS) and crospovidone) and one unsubstituted comparator (starch) was studied spectrophotometrically. An indication of the in-vivo effect was obtained by measuring the interactions at physiological salt concentrations. SSG was investigated more thoroughly to obtain release profiles and correlation between binding and ionic strength. The results showed that the main interactions with the anionic hydrogels formed by SSG and CCS were caused by ion exchange, whereas the neutral crospovidone exhibited lipophilic interactions with the non-ionic substances. The effect of increased ionic strength was most pronounced at low salt concentrations and the ion exchange interactions were almost completely eradicated at physiological conditions. The release profile of diphenhydramine was significantly affected by the addition of salt. It was thus concluded that the choice of buffer was of great importance for in-vitro experiments with ionic drugs. At physiological salt concentrations the interactions did not appear to be strong enough to influence the in-vivo bioavailability of any of the drug molecules.
|
|
| 6. |
|
|
| 7. |
- Monhaphol, T., et al.
(författare)
-
2-Ethylhexyl-2,4,5-trimethoxycinnamate and di-(2-ethylhexyl)-2,4,5-trimethoxybenzalmalonate as novel UVA filters
- 2007
-
Ingår i: Journal of Pharmacy and Pharmacology. - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 59:2, s. 279-288
-
Tidskriftsartikel (refereegranskat)abstract
- A series of 2-ethylhexylmethoxy substituted cinnamates and benzalmalonates have been synthesized and characterized. 2-Ethyl hexyl-2,4,5-trimethoxycinnamate (EB) and di-(2-ethylhexyl)-2,4,5-trimethoxybenzalmalonate (138) show UVA absorption with high molar absorption coefficients (12000-14000 cm(-1) m(-1) at 350 nm). ES undergoes trans to cis photoisomerization under UVA exposure causing the decrease in UV absorption efficiency. E8 is more photostable than butyl methoxydibenzoyl methane (BMDBM). For example, 41.64 J cm(-2) UVA irradiation produces 20 +/- 2% and 25 +/- 2% loss in UV absorption for ES and BMDBM, respectively. Similar irradiation produces no change in the UV absorption of B8. Both the oily liquid E8 and the yellow solid B8 can be dissolved in various organic solvents, ranging from methanol to hexane, various silicone fluids and 2-ethylhexyl-4-trimethoxycinnamate (EHMC, a widely used UVB filter). A liquid broadband filter comprising B8 and EHMC shows excellent photostability in both UVB and UVA regions.
|
|
| 8. |
- Persson, Ingrid, 1951-, et al.
(författare)
-
Tea flavanols inhibit angiotensin-converting enzyme activity and increase nitric oxide production in human endothelial cells
- 2006
-
Ingår i: Journal of Pharmacy and Pharmacology (JPP). - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 58:8, s. 1139-1144
-
Tidskriftsartikel (refereegranskat)abstract
- A diversity of pharmacological effects on the cardiovascular system have been reported for Camellia sinensis: antioxidative, antiproliferative and anti-angiogenic activity, and nitric oxide synthase activation. The purpose of this study was to investigate if the connection between tea and angiotensin-converting enzyme (ACE) and nitric oxide (NO) might be an explanation of the pharmacological effects of tea on the cardiovascular system. Cultured endothelial cells from human umbilical veins (HUVEC) were incubated with extracts of Japanese Sencha (green tea), Indian Assam Broken Orange Pekoe (black tea) and Rooibos tea, respectively. The main flavanols and purine alkaloids in green and black tea were examined for their effects on ACE and NO. After incubation with green tea, black tea and Rooibos tea for 10 min, a significant and dose-dependent inhibition of ACE activity in HUVEC was seen with the green tea and the black tea. No significant effect on ACE was seen with the Rooibos tea. After 10-min incubation with (-)-epicatechin, (-)- epigallocatechin, (-)-epicatechingallate and (-)-epigallocatechingallate, a dose-dependent inhibition of ACE activity in HUVEC was seen for all four tea catechins. After 24-h incubation, a significantly increased dose-dependent effect on NO production in HUVEC was seen for the green tea, the black tea and the Rooibos tea. After 24-h incubation with (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechingallate and (-)-epigallocatechingallate, a dose-dependent increased NO production in HUVEC was seen. In conclusion, tea extracts from C. sinensis may have the potential to prevent and protect against cardiovascular disease. © 2006 The Authors.
|
|
| 9. |
- Wan, J, et al.
(författare)
-
Chlorzoxazone metabolism is increased in fasted Sprague-Dawley rats
- 2006
-
Ingår i: The Journal of pharmacy and pharmacology. - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 58:1, s. 51-61
-
Tidskriftsartikel (refereegranskat)abstract
- Earlier data showed that men fasted for 38 h had a reduced rate of chlorzoxazone metabolism, suggesting a decreased level of cytochrome P450 2E1 (CYP2E1). In contrast, the level of CYP2E1 in fasted rats had been shown to be elevated. In this study, we have investigated whether chlorzoxazone metabolism in fasted rats was changed by determining the pharmacokinetics of chlorzoxazone and its metabolite, 6-hydroxychlorzoxazone (6-OHCZ), as a CYP2E1 probe, and by measuring liver CYP2E1 using immunoblot techniques. Chlorzoxazone was administered by gavage (50 mg kg−1) or intravenously (25 mg kg−1) to control (nine for oral and three for intravenous) and 24 h-fasted (nine for oral and four for intravenous) male Sprague-Dawley rats. Following sampling of blood through a jugular vein cannula, chlorzoxazone and 6-OHCZ plasma concentrations were measured by HPLC with UV detection. Pharmacokinetic parameters for chlorzoxazone and 6-OHCZ in each treatment group were determined by model fitting and non-compartmental analysis. In parallel with the increased liver CYP2E1 level, the elimination of chlorzoxazone and 6-OHCZ was significantly increased in fasted rats in the oral and the intravenous study. A multiple analysis of variance covariance analysis and a multiple regression analysis revealed a significant correlation between 1/t½ and CYP2E1 level and aniline hydroxylase activity. However, the correlation between 1/t½ and pentoxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase and erythromycin N-demethylase was not significant. Therefore the contribution of other P450s to chlorzoxazone metabolism seemed to be minor in the concentration range that we tested. In conclusion, fasting rats for 24 h caused a measurable induction of CYP2E1, which produced a significant increase in the rate of chlorzoxazone metabolism and elimination.
|
|
| 10. |
- Fahlman, Andreas, et al.
(författare)
-
Metabolic costs of foraging and the management of O2 and CO2 stores in Steller sea lions
- 2008
-
Ingår i: The Journal of Experimental Biology. - Cambridge : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 211, s. 3573-3580
-
Tidskriftsartikel (refereegranskat)abstract
- The metabolic costs of foraging and the management of O2 and CO2 stores during breath-hold diving was investigated in three female Steller sea lions (Eumetopias jubatus) trained to dive between 10 and 50 m (N=1142 dives). Each trial consisted of two to eight dives separated by surface intervals that were determined by the sea lion (spontaneous trials) or by the researcher (conditioned trials). During conditioned trials, surface intervals were long enough for O2 to return to pre-dive levels between each dive. The metabolic cost of each dive event (dive+surface interval; DMR) was measured using flow-through respirometry. The respiratory exchange ratio (O2/CO2) was significantly lower during spontaneous trials compared with conditioned trials. DMR was significantly higher during spontaneous trials and decreased exponentially with dive duration. A similar decrease in DMR was not as evident during conditioned trials. DMR could not be accurately estimated from the surface interval (SI) following individual dives that had short SIs (<50 s), but could be estimated on a dive by dive basis for longer SIs (>50 s). DMR decreased by 15%, but did not differ significantly from surface metabolic rates (MRS) when dive duration increased from 1 to 7 min. Overall, these data suggest that DMR is almost the same as MRS, and that Steller sea lions incur an O2 debt during spontaneous diving that is not repaid until the end of the dive bout. This has important consequences in differentiating between the actual and `apparent' metabolic rate during diving, and may explain some of the differences in metabolic rates reported in pinniped species.
|
|
