Effect of concentration and degree of saturation of topical fluocinonide formulations on in vitro membrane transport and in vivo availability on human skin
- Schwarb, Fabian P, Imanidis, Georgios, Smith, Eric W, Haigh, John M, Surber, Christian
- Authors: Schwarb, Fabian P , Imanidis, Georgios , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1999
- Language: English
- Type: text , Article
- Identifier: vital:6425 , http://hdl.handle.net/10962/d1006560
- Description: Purpose. The thermodynamic acitvity of drugs in topical vehicles is considered to significantly influence topical delivery. In vitro diffusion across a synthetic membrane was shown to be correlated to the degree of saturation of the drug in the applied vehicle and therefore offers a potential for increased topical drug delivery. Fluocinonide a topical corticosteroid, was chosen as a model compound to investigate in vitro and in vivo availability from formulations with different degrees of saturation. Methods. Sub-, as well as, supersaturated drug solutions were prepared using PVP as an antinucleant agent. In vitro membrane diffusion experiments across silicone membrane and in vivo pharmacodynamic activity assessments, using the human skin blanching assay, were carried out. Results. Over the concentration range studied, the in vitro membrane transport of fluocinonide was proportional to the degree of saturation of the respective formulations. The in vivo pharmacodynamic response in the human skin blanching assay was related to the concentration of the drug in the vehicle irrespective of the degree of saturation. Conclusions. From the membrane permeation experiment it can be concluded, that the drug flux might be increased supra-proportionally with increasing donor concentration, drug (super-)saturation (proportional), beyond what would be anticipated based on ideal donor concentration and partition coefficient considerations only. These findings could not be confirmed in the in vivo investigation, probably due to additional vehicle effects (e.g., enhancement, irritation, drug binding) which have to be expected and could have altered the integrity of the stratum corneum and therewith topical bioavailability of the drug.
- Full Text: false
- Date Issued: 1999
- Authors: Schwarb, Fabian P , Imanidis, Georgios , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1999
- Language: English
- Type: text , Article
- Identifier: vital:6425 , http://hdl.handle.net/10962/d1006560
- Description: Purpose. The thermodynamic acitvity of drugs in topical vehicles is considered to significantly influence topical delivery. In vitro diffusion across a synthetic membrane was shown to be correlated to the degree of saturation of the drug in the applied vehicle and therefore offers a potential for increased topical drug delivery. Fluocinonide a topical corticosteroid, was chosen as a model compound to investigate in vitro and in vivo availability from formulations with different degrees of saturation. Methods. Sub-, as well as, supersaturated drug solutions were prepared using PVP as an antinucleant agent. In vitro membrane diffusion experiments across silicone membrane and in vivo pharmacodynamic activity assessments, using the human skin blanching assay, were carried out. Results. Over the concentration range studied, the in vitro membrane transport of fluocinonide was proportional to the degree of saturation of the respective formulations. The in vivo pharmacodynamic response in the human skin blanching assay was related to the concentration of the drug in the vehicle irrespective of the degree of saturation. Conclusions. From the membrane permeation experiment it can be concluded, that the drug flux might be increased supra-proportionally with increasing donor concentration, drug (super-)saturation (proportional), beyond what would be anticipated based on ideal donor concentration and partition coefficient considerations only. These findings could not be confirmed in the in vivo investigation, probably due to additional vehicle effects (e.g., enhancement, irritation, drug binding) which have to be expected and could have altered the integrity of the stratum corneum and therewith topical bioavailability of the drug.
- Full Text: false
- Date Issued: 1999
The release of betamethasone 17-valerate from extemporaneous dilutions of a proprietary topical cream
- Magnus, Ashley D, Haigh, John M, Kanfer, Isadore
- Authors: Magnus, Ashley D , Haigh, John M , Kanfer, Isadore
- Date: 1981
- Language: English
- Type: Article
- Identifier: vital:6397 , http://hdl.handle.net/10962/d1006322
- Description: Six different vehicles for topical use were used to prepare 50% dilutions of Betnovate@ (betamethasone 17-valerate, 0.1 %) cream. Blanching assessment was undertaken immediately after preparing the various dilutions and at 1 and 3 months thereafter. Few statistically significant differences were noted between any of the preparations tested indicating that the rate of release of betamethasone 17-valerate is relatively unaffected by dilution. All preparations were assayed by a stability indicating high pressure liquid chromatographic technique for corticosteroid content. A diminution in the content of betamethasone 17-valerate in the E45 dilution was found 14 months after preparation. All other formulations tested were found to comply with label claim specifications.
- Full Text:
- Date Issued: 1981
- Authors: Magnus, Ashley D , Haigh, John M , Kanfer, Isadore
- Date: 1981
- Language: English
- Type: Article
- Identifier: vital:6397 , http://hdl.handle.net/10962/d1006322
- Description: Six different vehicles for topical use were used to prepare 50% dilutions of Betnovate@ (betamethasone 17-valerate, 0.1 %) cream. Blanching assessment was undertaken immediately after preparing the various dilutions and at 1 and 3 months thereafter. Few statistically significant differences were noted between any of the preparations tested indicating that the rate of release of betamethasone 17-valerate is relatively unaffected by dilution. All preparations were assayed by a stability indicating high pressure liquid chromatographic technique for corticosteroid content. A diminution in the content of betamethasone 17-valerate in the E45 dilution was found 14 months after preparation. All other formulations tested were found to comply with label claim specifications.
- Full Text:
- Date Issued: 1981
The simultaneous determination of trimethoprim, sulphamethoxazole and N4-acetylsulphamethoxazole in biological fluids by high pressure liquid chromatography
- Gochin, Rosa, Kanfer, Isadore, Haigh, John M
- Authors: Gochin, Rosa , Kanfer, Isadore , Haigh, John M
- Date: 1981
- Language: English
- Type: text , Article
- Identifier: vital:6364 , http://hdl.handle.net/10962/d1006064
- Description: The simultaneous determination of trimethoprim, sulphamethoxazole and N4-acetylsulphamethoxazole in serum and urine by high-performance liquid chromatography using sulphafurazole as internal standard is described. The separation was achieved on a reversed-phase column employing acetic acid-methanol as the mobile phase with spectrophotometric detection at 230 nm. Precise simultaneous quantitative analysis of the relative components has been achieved at levels of 0.1 μg/ml for both sulphamethoxazole and its N4-acetyl metabolite using 1 ml of serum or urine.
- Full Text:
- Date Issued: 1981
- Authors: Gochin, Rosa , Kanfer, Isadore , Haigh, John M
- Date: 1981
- Language: English
- Type: text , Article
- Identifier: vital:6364 , http://hdl.handle.net/10962/d1006064
- Description: The simultaneous determination of trimethoprim, sulphamethoxazole and N4-acetylsulphamethoxazole in serum and urine by high-performance liquid chromatography using sulphafurazole as internal standard is described. The separation was achieved on a reversed-phase column employing acetic acid-methanol as the mobile phase with spectrophotometric detection at 230 nm. Precise simultaneous quantitative analysis of the relative components has been achieved at levels of 0.1 μg/ml for both sulphamethoxazole and its N4-acetyl metabolite using 1 ml of serum or urine.
- Full Text:
- Date Issued: 1981
Assessment of some variables affecting the blanching activity of betamethasone 17-valerate cream
- Magnus, Ashley D, Haigh, John M, Kanfer, Isadore
- Authors: Magnus, Ashley D , Haigh, John M , Kanfer, Isadore
- Date: 1980
- Language: English
- Type: text , Article
- Identifier: vital:6396 , http://hdl.handle.net/10962/d1006320
- Description: The effect of concentration and occlusion time on the ability of Betnovate ® cream (betamethasone 17-valerate 0.1%) to produce skin blanching was assessed. Generally, increased concentration or occlusion time produce and increase in the degree of blanching observed, however, a plateau stage is eventually reached where no further increase of blanching occurs.
- Full Text:
- Date Issued: 1980
- Authors: Magnus, Ashley D , Haigh, John M , Kanfer, Isadore
- Date: 1980
- Language: English
- Type: text , Article
- Identifier: vital:6396 , http://hdl.handle.net/10962/d1006320
- Description: The effect of concentration and occlusion time on the ability of Betnovate ® cream (betamethasone 17-valerate 0.1%) to produce skin blanching was assessed. Generally, increased concentration or occlusion time produce and increase in the degree of blanching observed, however, a plateau stage is eventually reached where no further increase of blanching occurs.
- Full Text:
- Date Issued: 1980
Comparative blanching activities of proprietary diflucortolone valerate topical preparations
- Coleman, Gerald L, Kanfer, Isadore, Haigh, John M
- Authors: Coleman, Gerald L , Kanfer, Isadore , Haigh, John M
- Date: 1978
- Language: English
- Type: Article
- Identifier: vital:6350 , http://hdl.handle.net/10962/d1006032
- Description: The blanching activities and hence bioavailabilities of the cream, ointment and fatty ointment preparations of Nerisone and Temetex (diflucortolone valerate 0.1%) were evaluated using an occluded and unoccluded blanching assay. These products were compared to Synalar ointment and cream (fluocinolone acetonide 0.025%), established topical corticosteroid preparations. Statistical analysis showed no significant differences between similar formulations of diflucortolone valerate. Significant differences were noted between diflucortolone valerate and fluocinolone acetonide preparations.
- Full Text:
- Date Issued: 1978
- Authors: Coleman, Gerald L , Kanfer, Isadore , Haigh, John M
- Date: 1978
- Language: English
- Type: Article
- Identifier: vital:6350 , http://hdl.handle.net/10962/d1006032
- Description: The blanching activities and hence bioavailabilities of the cream, ointment and fatty ointment preparations of Nerisone and Temetex (diflucortolone valerate 0.1%) were evaluated using an occluded and unoccluded blanching assay. These products were compared to Synalar ointment and cream (fluocinolone acetonide 0.025%), established topical corticosteroid preparations. Statistical analysis showed no significant differences between similar formulations of diflucortolone valerate. Significant differences were noted between diflucortolone valerate and fluocinolone acetonide preparations.
- Full Text:
- Date Issued: 1978
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