Introduction
Liquid has a specific surface tension when it is at a particular temperature. When inorganic salts or sugars are added to water, the surface tension of the water somewhat rises, falls little when low-grade fatty alcohols or fatty acids are added to the water, but dramatically drops when soap is put to the water. A surfactant is often a substance that, when added to a liquid in small amounts, causes the surface tension to drop quickly.
The solubilizing effect of surfactants is mainly based on the fact that surfactants have the basic property of forming micelles. When the concentration of surfactant in solution reaches the critical micelle concentration, it has solubilizing effect. Nonpolar drug that is partially encapsulated by the aggregation of lipophilic groups of the micelles, solubilizing sites in the inner core of the micelles, medium-polar drugs, partly in the hydrocarbon nucleus, partly in the lattice layer, polar or water-soluble drugs, adsorbed on the surface of the hydrophilic group of the micelles.
Subtypes of Surfactants
Anionic Surfactants
Anionic surfactants possess a negatively charged head group and are commonly used as solubilizers in pharmaceutical formulations. They can enhance solubility by forming micelles or emulsions that stabilize hydrophobic drugs. Examples of anionic surfactant excipients include sodium lauryl sulfate (SLS) and dioctyl sodium sulfosuccinate (DOSS).
Cationic Surfactants
Cationic surfactants have a positively charged head group, making them useful for formulating medicines that require interactions with negatively charged surfaces. They can enhance drug solubility and permeability. Cetyltrimethyl ammonium bromide (CTAB) and benzalkonium chloride are common cationic surfactants used in pharmaceutical applications.
Nonionic Surfactants
Nonionic surfactants have no charged head group, but they possess both hydrophobic and hydrophilic regions. These excipients enhance solubility by reducing the surface tension between immiscible substances. Polysorbates (e.g., Polysorbate 80) and Tweens (e.g., Tween 80) are examples of nonionic surfactant excipients frequently employed in pharmaceutical formulations.
Examples of Surfactants
Sodium Lauryl Sulfate (SLS)
SLS is a widely used anionic surfactant excipient in oral and topical pharmaceutical preparations. It enhances drug solubility, promotes wetting and dispersibility, and aids in emulsification and foaming. SLS is commonly utilized in oral solutions, topical creams, and ophthalmic formulations.
Polysorbate 80
Polysorbate 80, a nonionic surfactant, is a well-known excipient in the pharmaceutical industry. It is commonly used as a solubilizer, emulsifier, and stabilizer in various parenteral formulations, such as intravenous solutions, protein formulations, and vaccines. Polysorbate 80 enhances drug solubility and aids in the dispersion of poorly soluble compounds.
Cetyltrimethyl Ammonium Bromide (CTAB)
CTAB is a cationic surfactant excipient utilized in different pharmaceutical formulations, including nasal sprays, inhalers, and peptide delivery systems. It can improve drug absorption, solubility, and mucoadhesion, making it an essential component in drug delivery systems.
Conclusion
Surfactants are essential components in drug formulation and development. They aid in the dispersal of hydrophobic drug substances, improve drug absorption, and facilitate controlled release and targeted delivery. These excipients enable the formulation of various dosage forms, including tablets, capsules, creams, and injections. Partnering with Protheragen-ING, a reputable supplier, ensures the availability of high-quality excipients and supports the development of stable and efficacious pharmaceutical products. If you have any excipient requirements, please contact us by phone or email, and we will respond within 2-4 working days.
