Lakhasly

??Miyamoto et al.57 studied the effects of surfactants and bile salts on the gastrointestinal absorption of antibiotics using an in situ rat-gut perfusion technique.Some surfactants increase the rate of intestinal absorption, whereas others decrease it. Some of these effects may result from alteration of the membrane by the surfactant.in the effective concentration] Quaternary ammonium compounds are examples of surface-active agents that in them-se ies posses antibacterial activity." This may depend in par tant. The agents are adsorbed on the cell surface and suppos ody bring about destruction by increasing the permeabili or "eakiness" of the lipid cell memorase Death then occus irough a loss of essential mambrant the el. Boin to the negative and gram-postite rigs rems are suspink.?A surfactant may affect the activity of a drug or may itself exert drug action As an example of the first case, the penetration of hexylresorcinol into the pinworm ?Ascaris, ?is increased by the presence of a low concentration of sur-factant.to the action of the cation quaive any compound, nand anionic agents attack grin quaterine organisms more

?than gram-negative bacteria.

‏ addition to the use of surfactants as emulsifying agents, detergents, wetting agents, and solubilizing agents, they find application as antibacterial and other protective agents and as aids to the absorption of drugs in the body.
‏A surfactant may affect the activity of a drug or may itself exert drug action As an example of the first case, the penetration of hexylresorcinol into the pinworm
‏Ascaris,
‏is increased by the presence of a low concentration of sur-factant. This potentiation of activity is due to a reduction in interfacial tension between the liquid phase and the cell wall of the organism As a result, the adsorption and spreading of hexylresorcinol over the surface of the organism is facilitated When the concentration of surface-active agent present exceeds that required to form micelles, however, the rate of penetration of the anthelmintic decreases nearly to zero, This is because the drug is now partitioned between in micelles and the aqueous phase, resulting in a reduction. in the effective concentration] Quaternary ammonium compounds are examples of surface-active agents that in them-se ies posses antibacterial activity." This may depend in par tant. The agents are adsorbed on the cell surface and suppos ody bring about destruction by increasing the permeabili or "eakiness" of the lipid cell memorase Death then occus irough a loss of essential mambrant the el. Boin to the negative and gram-postite rigs rems are suspink. to the action of the cation quaive any compound, nand anionic agents attack grin quaterine organisms more

‏than gram-negative bacteria. Nonionic surfactants are least effective as antibacterial agents. In fact, they often aid rather than inhibit the growth of bacteria, presumably by providing long-chain fatty acids in a form that is easily metabolized by the organism.
‏Miyamoto et al.57 studied the effects of surfactants and bile salts on the gastrointestinal absorption of antibiotics using an in situ rat-gut perfusion technique. Polyoxyethyl-ene lauryl ether reduced the absorption of propicillin in the stomach and increased it in the small intestine. Some surfactants increase the rate of intestinal absorption, whereas others decrease it. Some of these effects may result from alteration of the membrane by the surfactant. The effects of surfactants on the solubility of drugs and their bioab-sortion have been reviewed by Mulley and Gibaldi and Feldman."