In the pharmaceutical world, dissolution is a profound test of quality control. It is defined as the amount of solid solute or drug that is placed in a solution per unit time under standardized conditions of temperature, solvent composition, and liquid or solid interface. In the dissolution test process, solubility is the most important parameter to consider in order to achieve the desired effect. It is challenging for most scientists to develop most drugs due to their low aqueous solubility.
A drug needs to be in a solution state to be absorbed at the absorption site. Therefore, scientists have devised different methods to increase the solubility of drugs, ranging from modifying drug particle size and crystal formation to using surfactants. The final pharmaceutical product is a solution comprised of purified water, cosolvents, surfactants, preservatives, sweeteners such as glucose and saccharin, viscosity modifiers, antioxidants, colorants, flavors, and buffers to regulate pH levels. Therefore, it is essential to ensure that you have the right equipment on hand.
The entire process requires a variety of apparatus to ensure a high quality product. The following is a summary list of apparatus used in dissolution testing according to United States Pharmacopeia guidelines:
a) Rotating Basket: It has a retention capacity of about 500 to 4000 ml. It has 50 to 200 rpm and is used in dissolving immediate-release, delayed-release, and delayed-release suppository chewable tablets, extended-release tablets, and floating dosage forms.
b) The Palette: It has a rotation speed of 25 to 50 rpm and a capacity of 500 to 4000 ml. It is used in dissolving immediate-release tablets, orally disintegrating tablets, chewable tablets, delayed- and extended-release tablets and capsules, and suspensions.
c) The Reciprocating Cylinder: It has a rotation speed of 6 to 35 rpm and a capacity of 250 ml. It is used for controlled release formulations, chewable tablets and beads.
d) The Flow Cell: It has a volume capacity of up to 3 liters per hour. It is used for drugs with low solubility APIs, for powders and granules, and also for microparticles and implants.
e) The Paddle over Disk: It has a rotation speed of 25 to 50 rpm. It has a volume capacity of 500 to 4000 ml and is used for transdermal patches, ointments, floats, and emulsions.
f) The Rotating Cylinder: It has a rotation speed of 25 to 50 rpm. It has a volume capacity of 500 to 4000 ml and is used for transdermal patches.
g) The Reciprocating Holder: It has a rotation speed of 30 rpm and its medium volume capacity is variable. It is used for controlled release formulations, for pH profiling and for small volumes.
Conclusion
The need for dissolution apparatus in the pharmaceutical business cannot be stressed enough. Oral ingestion of drugs is the most convenient means of drug administration due to its high compliance among users, its cost-effectiveness, and its flexibility in accommodating the desired dose. As a result, most drug manufacturing companies are more inclined to perform dissolution testing in the production of bioequivalent oral products.