Formulation Reference Guide
Technical specifications, mathematical equations, and standard operating procedures (SOP) used in our calculators.
Molarity & Percentage w/w Calculations
Molarity (M) defines the concentration of a solute in a solution as moles of solute per liter of solution (mol/L).
Weight-in-Weight (% w/w) represents the mass of a solute divided by the total mass of the formulation, multiplied by 100.
Dilution & Scaling (C₁V₁ = C₂V₂)
The dilution equation relates the concentration and volume of a stock solution to the desired final concentration and volume.
To prepare a dilution, calculate the required stock volume (V₁ = (C₂ × V₂) / C₁), transfer this volume to your container, and add diluent until the final volume (V₂) is reached.
Molecular Weight & Chemical Formulas
Molecular weight (MW) is calculated by summing the atomic weights of all constituent atoms in a chemical formula. Our system parses standard chemical symbols, nested parentheses, and hydrates.
The parser matches element symbols against standard IUPAC values (e.g., Ca = 40.078, O = 15.999, H = 1.008) and resolves stoichiometry dynamically.
HLB & Disintegration Kinetics
The Hydrophilic-Lipophilic Balance (HLB) is a measure of the degree to which a surfactant is hydrophilic or lipophilic. Ideal emulsions require balancing surfactant HLB with the required HLB (rHLB) of the oil phase.
Tablet formulation models evaluate disintegration times based on the ratio of superdisintegrants (e.g. Croscarmellose Sodium) and compression binder profiles.
Frequently Asked Questions
What is a stock solution in laboratory dilution?
A stock solution is a concentrated solution that will be diluted to a lower concentration for actual laboratory use. Using stock solutions saves prep time, reduces material waste, and improves accuracy for trace components.
How does a hydrate affect molecular weight calculations?
Hydrated compounds contain chemically bound water molecules within their crystalline structure (e.g., CuSO₄·5H₂O). When weighing the dry chemical, the weight of the water molecules must be included in the molecular weight calculation to ensure accurate molar dosing.
What is HLB in cosmetic formulations?
HLB stands for Hydrophilic-Lipophilic Balance. It is a value between 0 and 20 indicating the affinity of an emulsifier for water (hydrophilic) or oil (lipophilic). Emulsifiers with low HLB (3-6) produce water-in-oil (W/O) emulsions, while high HLB (8-16) produce oil-in-water (O/W) emulsions.