Surfactants and pharmaceuticals

The use of surfactants in the manufacture of ointments, emulsions and suspensions has been known already in the time when chemistry was in the period of alchemy . By now, the common term external preparations is in use in pharmacy, and the choice of surfactants is focussed on the stabilisation of dispersed systems (foams, emulsions, suspensions). 

The role of dynamic surface tension is studied in the paper by Fainerman et al [117] using a number of biological objects as an example (blood, urine, amniotic fluids etc.), and the possibility is shown of using this test for primary diagnostics of a number of diseases. However, it is not the task of this chapter to discuss this phenomenon in detail here. 

It is emphasized in [119] that the surfactant administration is day-to-day practice in the cure of babies with inborn respiratory distress syndromes and, as a rule, is accompanied by an improvement of the lung function. For adults, this effect is manifested weaker. The role of surfactant antifoams for pharmaceuticals is shown in [120, 121]. A complex of an antifoam (e.g. Span 65 0.025% and cetyl alcohol 0.05%) with alpha-protease contributes to protein diffusion to the lung tissue and enhances the pharmaceutical effect. 

New surfactants produced both by biosynthesis [4] and by synthesis are now being tested along with conventional synthetic surfactants. In this respect, cationics on the basis of arginine, which show a high inhibiting power to staphylococci, streptococci and other bacteria, are of special interest as bactericidal compositions [127]. 

The use of pharmaceuticals in form of emulsions is of special interest. Thus, for example, o/w emulsions stabilised by surfactants, such as mono- and diglycerides, are successfully used as pseuo-doxime-proxetil protection from intestinal lumen hydrolysis through oral administration [128]. Multiple w/o/w emulsions stabilised by Tween 20/Span 20 or Tween 80/Span 80 mixtures contributed to a prolonged retention of cytarabine in one of the phases, and its gradual release ensured a prolonged action of the drug [129]. 

---

Butylene oxide may be hydrolyzed to butylene glycol, which is used to make plasticizers. 1,2-Butylene oxide is a stabilizer for chlorinated solvents and also an intermediate in organic synthesis such as in surfactants and pharmaceuticals. 

GuSulf may serve for the prepn of the free base by treating with Ba hydroxide in w, or with NaOH or NaNH2 in liq ammonia. It has been used as a fireproofing agent, as an intermediate in the prepn of surfactants and pharmaceuticals and for prepn of resins... 

Schulz, R., Titration of Surfactants and Pharmaceuticals (in German), Verlag fUr Chemische Industrie, Augsburg, 1996. 

Applications. These materials are stiU in developmental infancy. Current production is limited to one commercial process in Europe and a demonstration-scale process in North America. The lignins produced in these processes have potential appHcation in wood adhesives, as flame retardants (qv), as slow-release agents for agricultural and pharmaceutical products, as surfactants (qv), as antioxidants (qv), as asphalt extenders, and as a raw material source for lignin-derived chemicals. 

The production of alkylphenols exceeds 450,000 t/yr on a worldwide basis. Alkylphenols of greatest commercial importance have alkyl groups ranging in size from one to twelve carbons. The direct use of alkylphenols is limited to a few minor appUcations such as epoxy-curing catalysts and biocides. The vast majority of alkylphenols are used to synthesize derivatives which have appUcations ranging from surfactants to pharmaceuticals. The four principal markets are nonionic surfactants, phenoUc resins, polymer additives, and agrochemicals. 

Miscellaneous Derivatives. Fimehc acid is used as an intermediate in some pharmaceuticals and in aroma chemicals ethylene brassylate is a synthetic musk (114). Salts of the diacids have shown utUity as surfactants and as corrosion inhibitors. The alkaline, ammonium, or organoamine salts of glutaric acid (115) or C-5—C-16 diacids (116) are useflil as noncorrosive components for antifreeze formulations, as are methylene azelaic acid and its alkah metal salt (117). Salts derived from C-21 diacids are used primarily as surfactants and find apphcation in detergents, fabric softeners, metal working fluids, and lubricants (118). The salts of the unsaturated C-20 diacid also exhibit anticorrosion properties, and the sodium salts of the branched C-20 diacids have the abUity to complex heavy metals from dilute aqueous solutions (88). 

DOSS, because of its use in foods and pharmaceuticals, was the target of numerous studies concerning toxicity, bioaccumulation, and reproduction as well as gastroenterological issues, so it can be concluded that DOSS is one of the best examined surfactants in the sulfosuccinates. 

Some phosphorus-containing surfactants have bacteriostatic properties. In combination with their physiological acceptance they are used in cosmetics and pharmaceuticals. In mutanase oral anticarie compositions the combination of alkyl phosphates and nonionic surfactants stabilizes mutanase. A dentifrice useful for prevention of dental caries contains 0.5% sodium lauryl phosphate and 1.5% polyoxyethylene (20) sorbitan monooleate [222]. 

Organophosphate flame retardants and plasticisers Perfluorinated compounds Pharmaceuticals and personal care products Polar pesticides and their degradation/transformation products Surfactants and their metabolites... 

Normal-phase chromatography is still widely used for the determination of nonpolar additives in a variety of commercial products and pharmaceutical formulations, e.g. the separation of nonpolar components in the nonionic surfactant Triton X-100. Most of the NPLC analyses of polymer additives have been performed in isocratic mode [576]. However, isocratic HPLC methods are incapable of separating a substantial number of industrially used additives [605,608,612-616], Normal-phase chromatography of Irgafos 168, Irganox 1010/1076/3114 was shown [240]. NPLC-UV has been used for quantitative analysis of additives in PP/(Irganox 1010/1076, Irgafos 168) after Soxhlet extraction (88%... 

Applications SFE-SFC solves problems in such diverse areas as polymers/monomers, oils/lubricants, foods, pharmaceuticals, natural products, specialty chemicals, coatings, surfactants and others. Off-line SFE-SFC survives alongside on-line determinations of additives, because of the need for representative sample sizes. Off-line SFE-SFC was used for extraction of AOs from PP [102]. In cases where the analyst wishes to perform further analysis on the extracted species, it is useful to be able to isolate the extract from the solvent. The ability to remove the solvent easily is particularly important when SFE is coupled on-line to chromatographic techniques, but is equally important for trace analysis when it is useful to concentrate... 

Surfactants are useful in formulating a wide variety of disperse systems. They are required not only during manufacture but also for maintaining an acceptable physical stability of these thermodynamically unstable systems. Besides the stabilizing efficiency, the criteria influencing the selection of surfactants for pharmaceutical or cosmetic products include safety, odor, color, and purity. 

OI Corrigan, AM Healy. Surfactants in pharmaceutical products and systems. In J Swarbrick, JC Boy-lan, eds. Encyclopedia of Pharmaceutical Technology, Vol. 14. New York Marcel Dekker, 1996, pp 295-331. 

Some of the reports are as follows. Mizukoshi et al. [31] reported ultrasound assisted reduction processes of Pt(IV) ions in the presence of anionic, cationic and non-ionic surfactant. They found that radicals formed from the reaction of the surfactants with primary radicals sonolysis of water and direct thermal decomposition of surfactants during collapsing of cavities contribute to reduction of metal ions. Fujimoto et al. [32] reported metal and alloy nanoparticles of Au, Pd and ft, and Mn02 prepared by reduction method in presence of surfactant and sonication environment. They found that surfactant shows stabilization of metal particles and has impact on narrow particle size distribution during sonication process. Abbas et al. [33] carried out the effects of different operational parameters in sodium chloride sonocrystallisation, namely temperature, ultrasonic power and concentration sodium. They found that the sonocrystallization is effective method for preparation of small NaCl crystals for pharmaceutical aerosol preparation. The crystal growth then occurs in supersaturated solution. Mersmann et al. (2001) [21] and Guo et al. [34] reported that the relative supersaturation in reactive crystallization is decisive for the crystal size and depends on the following factors. 

Large amounts of water and oil can be admixed in microemulsions which find wide application in household and pharmaceutical products and have potential for enhanced oil recovery (Mackay, 1981 Bellocq et al., 1984). Microemulsions have been reported to form in the absence of surfactant over a very limited range of concentration, but there is a question as to the nature of these dispersions (Barden and Holt, 1979). 

Speciality chemicals adhesives, solvents, surfactants (e.g., in personal care products and soaps detergents), specialized organics and pharmaceutical and healthcare products (e.g., vitamins). 

CE has been applied extensively for the separation of chiral compounds in chemical and pharmaceutical analysis.First chiral separations were reported by Gozel et al. who separated the enantiomers of some dansylated amino acids by using diastereomeric complex formation with Cu " -aspartame. Later, Tran et al. demonstrated that such a separation was also possible by derivatization of amino acids with L-Marfey s reagent. Nishi et al. were able to separate some chiral pharmaceutical compounds by using bile salts as chiral selectors and as micellar surfactants. However, it was not until Fanali first showed the utilization of cyclodextrins as chiral selectors that a boom in the number of applications was noted. Cyclodextrins are added to the buffer electrolyte and a chiral recognition may... 

Structure-activity relationships are generally applied in the pharmaceutical sciences to drug molecules. The value of any structure-activity correlation is determined by the precision of the biological data. So it is with studies of the interaction of nonionic surfactants and biomembranes. Analysis of results is complicated by the difficulty in obtaining data in which one can discern small differences in the activity of closely related compounds, due to i) biological variability in tissues and animals, ii) potential differential metabolism of the surfactants in a homologous series (2), iii) kinetic and dynamic factors such as different rates of absorption of members of the surfactant homologous series (2) and iv) the typically biphasic concentration dependency of nonionic surfactant action (3 ). 

Toothpaste, toiletries, and cosmetics make up the largest sorbitol use (35%). Others uses include confections and food (30%), ascorbic acid (15%), industrial surfactants (10%), and pharmaceuticals (7%). 

Del Estal J.L., A.I. Alvarez, C. Villaverde, and J.G. Prieto (1993). Comparative effects of anionic, natural bile acid surfactants and mixed micelles on the intestinal absorption of the anthelmintic albendazole. International Journal of Pharmaceutics 91 105-109. 

Owing to its chemically highly aggressive nature, fluorine is difficult and hazardous to handle and it can be manufactured only via the electrolytic oxidation of fluoride. Fluorine gas has been produced commercially since 1946 and has found applications in many areas of fluorine chemistry (polymers, surfactants, lubricants, thermally stable liquids, blood replacement and pharmaceuticals, propellants, etc.). Inorganic fluorides such as Sp6 and UFe [21] have technical applications. Fluorous solvent systems [22] provide novel reaction environments fundamentally different from both aqueous and hydrocarbon media [23] and fluorine has been employed as a marker or spin label [24]. 

---