Manufacturing of Pharmaceuticals of Semi-solid Dosage Forms


Semi-solid drugs form a large portion of the existing medicines produced by various pharmaceutical firms today. They include everything from ointments to toothpaste, and need specialized methods for their manufacturing process to be successful. Several qualities can be attributed to semi-solid drug forms today. They should be smooth to the touch, minimize dehydration, and be cosmetically elegant. Many of them are required to have a pleasant scent, as well. Producing low-quality semi-solid drugs that don’t meet the above criteria can even affect the patient’s health.Here is a basic overview of the factors that are involved in the manufacturing of Semi-solid dosage forms:

Particle Distribution

Homogeneity is the first physical property that needs to be present in the drugs. Being homogeneous ensures that the distribution of various medicinal drugs in the liquid base has been uniform. The proportional distribution must be consistent in the medicine irrespective of whether it is in a 1000-gallon tank or a small 1-ounce tube. The particle distribution can be ensured by using a machine with a powerful mixing mechanism that prepares the oil and water bases systematically. The ointment also needs to be spreadable enough to ensure the patient can apply it without any constraints. This requires the mixture to be in just the right proportion. Lumps should also be avoided during manufacturing for desirable results.


Grittiness is an undesirable characteristic in semi-solid forms. This means that the medicine would be sand-like to the touch and is usually caused by an imbalance in the particle size and shape. Semi-solid dosage forms that are gritty can cause skin irritation and create other problems for the patient. Using a process to break down large solid particles before mixing can minimize this effect in the final ointment. However, this can sometimes cause the ointment to start bleeding, requiring fixing by adding a more potent binding agent to the mixture.


The location of the manufacturing plant can also affect the final quality of the product. Most semi-solid products that are manufactured in temperate climates would require cooling to keep them consistent. Without proper treatment for the oil and water bases prior to manufacturing, they can end up coagulating and ruining the ointment. The humidity in the air and atmospheric pressure also impact production just as much and should be considered. Most gel-based ointments need to be manufactured in temperatures close to 4 degrees Celsius, while cream-based ones can stand temperatures of up to 70 degrees. This makes the location quite an essential factor in the manufacturing process of ointments.
When you look at the above factors, it is easy to see the impact that little details can have on the final product. While most of these aren’t in our control, it’s possible to overcome most other factors with quality manufacturing equipment.