Solubility Chart of Hydroxypropyl Methylcellulose (HPMC)
Hydroxypropyl methylcellulose (HPMC) is a widely used cellulose ether known for its excellent solubility and thickening properties. To effectively use HPMC in various applications, understanding its solubility characteristics in different solvents is crucial. This article provides a simple, easy-to-understand breakdown of HPMC's solubility in various solvents, accompanied by a clear solubility chart for quick reference.
What is HPMC?
Hydroxypropyl methylcellulose (HPMC) is a cellulose-based polymer used in pharmaceuticals, construction, and food. Its solubility depends on temperature, solvent type, and chemical modification.
HPMC Solubility Chart
Below is a simplified and clear solubility chart detailing how well HPMC dissolves in different solvents:
| Solvent | Solubility | Notes |
| Cold Water | Partially soluble | Forms gel; fully dissolves when heated |
| Hot Water | Fully soluble | Clear solution above 60°C |
| Ethanol | Insoluble | Requires water mixture (e.g., 70% ethanol) |
| Isopropanol | Insoluble | Used as co-solvent with water |
| Acetone | Insoluble | Not recommended |
| Chloroform | Insoluble | Rarely used with HPMC |
Detailed Solubility Breakdown
1. Cold Water
HPMC swells in cold water, forming a gel. Heating to 60–90°C dissolves it completely. Ideal for adhesives and coatings.
2. Organic Solvents (Ethanol, Methanol, etc.)
HPMC doesn’t dissolve in pure ethanol/isopropanol. Mix with 20–30% water for solubility. Methanol shows partial solubility but is toxic.
3. Industrial Applications
Pharma: Binder in tablets (water solubility).
Construction: Water retention in cement (cold water gel).
4.Ethanol, Methanol, and Isopropanol (Alcohols)
HPMC is practically insoluble in ethanol, methanol, and isopropanol. Using pure alcohol as a solvent will result in cloudy suspensions or precipitation rather than clear solutions. Alcohol can only be used in small amounts mixed with water to adjust certain properties.
Factors Affecting HPMC Solubility
1.Temperature: Heat improves water solubility.
2.Substitution Type: Methyl vs. hydroxypropyl ratios matter.
3.Concentration: Higher HPMC = slower dissolution.
