摘要:

SummaryNowadays, cosmetic as well as pharmaceutical forms must undergo many controls, i.e. in‐process controls on the finished product and stability testing. The authors suggest using first derivative spectroscopy for active ingredients assay presenting an ultra‐violet absorption. It offers the advantage of a direct assay through simple dilution and without active ingredient extraction.Tests were made on classic mixtures of the sunscreens benzimidazol and cinnamate derivative (pair 1), and a mixture of two benzophenones (pair 2). The studied forms were solutions in propylene glycol and commercialized W/O and O/W creams.After analytical method validation for each sunscreen by precision, reproducibility and repeatability studies, the percentages of error of the various assays have been reported in various preparations (solutions or creams).A comparative study between HPLC assay (traditionally used) and the proposed method was carried out. The results show that a highly significant linear correlation exists between the two methods for the four sunscreens (R>0.992). The speed and simplicity of the first derivative spectrometric method should find applications in routine control or in development of cosmetic or pharmaceutical preparati

ISSN:0142-5463    

DOI:10.1111/j.1467-2494.1994.tb00087.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SynopsisThe kinetics of decomposition of the sodium salt of dehydroacetic acid (DHA.Na) in presence of formaldehyde and formaldehyde donors was investigated. The possibility of preparing systems capable of providing the cosmetic preparation with increasing amounts of DHA.Na corresponding to portions interacted with formaldehyde was explored. Data relevant to matrices prepared from ethylcellulose and polyethylene by casting and moulding process, respectively, are reported and discussed. Experimental data demonstrate the possibility of preparing polymeric systems able to control in terms of rate and duration the relase of DHA.Na, according to time and concentration needs of a typical cosmetic formulation.

ISSN:0142-5463    

DOI:10.1111/j.1467-2494.1994.tb00088.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryMeasurements were carried out on 19 commercial cosmetic samples. Initially, their anti‐infrared properties were quantified,in vivo, on healthy volunteers, by measuring variations in the Colorimetric Erythema Index ΔCEI, before and after application of a normalized quantity of product. Subsequently, the physico‐chemical response of the product was testedin vitroby measuring the infrared reflection coefficient ΔIR at 800 nm.The correlation established between these two parameters enables products to be ranked in three categories. A good correlation was demonstrated between reflective power (ΔIR) and anti‐erythemic properties (—ΔCEI) of the products in the first two groups.A qualitative examination of the diffraction of X‐rays confirms the presence of titanium dioxide, TiO2rutile, in most products with high IR protection properties whereas TiO2anatase was detected in a sample with no IR reflecti

ISSN:0142-5463    

DOI:10.1111/j.1467-2494.1994.tb00089.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SynopsisFrequently, the incoporation of the polar phase, as a second step in the formulation of a cosmetic, is considered as a simple dilution process. This work shows the influence of the polar phase on the final formulation, according to its constitution as well as the method of incorporation. Modelling the system through a regular tetrahedron suggests alternative ways to the usual method of incorporation (direct titration with a polar phase with a given composition), based on selective incorporation of the polar ingredients (double titration procedures). Depending on the constitution of the polar phase, it is possible to obtain different kinds of formulations (gel, liquids, …), and, depending on the different possibilities of incorporation of the polar ingredients, identical compositions can be formulated in terms of percentage of their components, but showing different rheological characteristics, allowing an adaptation to the required specific needs of formulatio

ISSN:0142-5463    

DOI:10.1111/j.1467-2494.1994.tb00090.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0142-5463    

DOI:10.1111/j.1467-2494.1994.tb00091.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY