Colloid & Surface Phenomena Loition Jason Ashbery Jonathan Danner Haohao Huang Leigh Vorreuter

I. Product Design Considerations Customer Needs Heals dry skin Prevents dry skin Non-greasy Fast absorbing Non-irritating Non-scented or Scented Contains sun screen Prevent further aging of the skin Long lasting

Product Design Considerations Different Types of Lotion For Dry Skin For Extra Dry Skin For Sensative Skin Manufacturers Bath & Body Works Suave Keri Bristol Meyer Squibb Clairol

Product Design Considerations Product Specifications Shelf life Duration Consistency Viscous properties Fragrance Color Absorption Delivery systems of alpha hydroxide, sunscreen, moisturizing agents

II.Components and Composition

III. Colloids and Surface Interactions Functions of colloids in Moisturizing Lotion Diluent Humectant Smoothing aid Emollient Surfactant

Liquid/ Liquid Emulsion An emulsion is formed when a mixture of two immiscible liquids are separated by a surfactant molecule. Oil-in-Water (O/W) Water-in-Oil (W/O)

O/W and W/O Emulsion

Phase Inversion of Emulsion Inversion from W/O to O/W Variables which lead to phase inversion Temperature – Ethoxylate emulsifiers Surfactant composition – Hydrophilic emulsifier concentration Water concentration – Andrew Jergens Co.

Effect of Amphiphiles on Delivery to the Skin Cationic Surfactants Effect of Temperature and Salt on micelle stability Effect of Temperature on delivery Pemulen® Polymeric emulsifiers Triggered release mechanism upon contact with electrical charge of skin

Traditional Surfactant Emulsion

Pemulen ® Polymeric Emulsifiers

IV. Product Attributes Shelf Life –Emulsion stability is what determines the product’s shelf like –If the emulsion becomes unstable the lotion will separate –Adjusting the hyrophilic and lipophile balance of the emulsifier achieves the emulsions stability –The emulsions are thermodynamically unstable due to its positive interfacial energy –When the emulsion tries to reach it thermodynamic equilibrium it causes the emulsion to break up back to its component phase

Product Attributes Shelf Life –The delay of the component break up can be accomplished by adding specific mixed emulsions compiled of non-ionic and ionic surfactants and combined with fatty amphiphiles Examples can be found in Table 3 –Previously blended emulsifying wax into the the formulation can also help prevent the decay of the emulsions Examples can be found in Table 4

Product Attributes

Shelf Life –The gel network theory of emulsion stability is why both emulsifiers and mixed wax help the shelf life period –The emulsifiers stabilize the oil droplets by the formation of an interfacial film

Product Attributes Consistency –It is related to swelling properties and concentration of the α-crystalline gel phase –When the α-crystalline form is in presence of very small quantities of ionic surfactants and a fatty aclohol and is dispersed in water the amount of swelling increases –This leads to the swelling of the α-crystalline gel phase –The water is in between the bilayers of the gel phase and when it swells the volume ratio of dispersed phase to the free continuous phase water increases

Product Attributes Evaporation and Absorption –When lotion is rubbed into the skin water evaporates and the oil droplets coalesce Coalescence occurs when the interfacial energy between substrates and adatoms is small –The clusters can detach themselves from any given location on the surface and diffuse as entities over the surface –The clusters behave more like liquid than solid crystallites

Product Attributes Evaporation and Absorption –After the application of the lotion the composition changes as the water and other other volatiles solvents evaporate –A film stays on the skin as a protector and the nutrients are absorbed –Absorption capacity increases with decreasing viscosity

Product Attributes Viscosity –Emulsion size and concentration determines the viscous properties –At the same shear stress and droplet concentrations the viscosity of concentrated emulsions containing smaller droplets was significantly greater –This suggests that electrostatic repulsion plays an important role in determining the rheology of concentrated emulsions

Product Attributes Viscosity –The droplets become closely packed causing the emulsions to be come rigid at lower concentrations for smaller droplets because of their effective volume fraction is greater –This explains why low emulsifier concentrations are good for structured lotions –Lotions are not suppose to be very thick and viscous

Product Attributes Fragrance –Fragrances are applied by collodial systems like emulsions –The lipid part of the stratum corneum is organized in lamellar structures –The lamellar liquid crystals in lotions contain the fragrance molecules –The similarity of the configuration of the crystals in lotion compared to the stratum corneum is why it easy for the fragrance to be absorbed into the skin –The location of the interlayer spacings and the geometrical characteristics play a big role on where the location of the fragrance is

Product Attributes Improvements made to the skin –Liposomes have positive effects on the appearance of the skin –Improve cutaneous hydration, skin structure, depths of wrinkles –Liposomes are spherical vesicles that have an aqueous cavity at their center –They are used to carry water-soluble molecules and hydrophobic molecules –Liposomes have been evaluated as delivery systems for drugs, vitamins and cosmetic materials

Product Attributes Delivery Systems –Particulate systems are very small particles that range from micrometers to millimeter –These particles deliver essential active ingredients such as amino acids, plant extracts, minerals, vitamins, antioxidants, and UV protectants –They also prolong the time during which the ingredient remains on the skin

V. HAOHAO

VI. Manufacturing Process The objective is to disperse one liquid within another in an extremely fine form to make certain that separation due to settling either does not occur or takes place very slowly. Does not normally involve any extraction or chemical reaction.

A Few Parameters that may influence liquid-liquid emulsion formation Shear rate Sufficient stabilizers need to be present to maintain the smallest droplet size produced for long periods of time. Blend time and standard deviation of circulation time. These along with many other parameters make it difficult to specify a mixing process based on desired droplet size. Most predictions are based on existing data.

Pilot Scale Manufacturing Process (US Patent# 6,017,548)

Federal Rules and Regulations CGMP’s – Primary objective is to ensure that manufacturers provide consumers with safe and effective products. Parts 210 and 211 apply to manufacturing of drugs and finished pharmaceuticals. Part 210 contains a basic overview and some definitions that are used in Part 211.

Part 211 Gives a description of responsibilities of the quality control unit. States that proper training procedures must be in place. Buildings and Facility requirements Cleaning requirements- Rooms and Equipment Proper labeling and storage of materials Batch Records

Marketing Considerations Packaging aesthetics Fragrance Color of Lotion Shelf Location