You have been appointed a member of a development team that has been given the task to reformulate the two products. The brief from marketing is simple. Solve the problems. The new products have to be stable over a wide temperature range $(040C)$ and offer the same or improved performance benefits than the existing products, without exceeding the current pricing structure.

The Problem

The brands in question are variants of the same formulation. The products are:

i$)\text{'}2$ in $1\text{'}$ conditioning shampoo

ii$)\text{'}3$ in $1\text{'}$ antidandruff shampoo containing zinc pyrithione

Both products have been found to separate on storage at $0C,$ ambient temperatures $(20-25C)$ and $40C.$ Phase separation has been observed to occur after two or three weeks at both low and elevated temperatures. The products have suffered from significant variations in the viscosity at these temperatures. In particular, the fall in the observed viscosity at $0C$ and $40C$ of both products compared to those measured at ambient temperatures is worrying. The variable rheology would lead to problems for the consumer when they try to dose the formulation from the bottle.

Additionally, there have been complaints regarding the poor foaming of the products and it often requires vigorous rubbing to generate the lather.

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The Formulations

$2$ in $1\text{'}$ Conditioning Shampoo

$\backslash$table$[[$Component$,$Solids $(\%),$W$/$W $(\%)],[$Ammonium lauryl sulphate $(25\%),12,48],[$Cocoamidopropyl betaine $(30\%),3,10],[$Coconut monoethanolamide $(100\%),2,2],[$Ammonium chloride $(100\%),2-3,2-3$