Dear Pharma Pals,

People not normally exposed to pharmaceutical manufacturing believe that injectables are sterile compounds that are extremely difficult to manufacture whereas tablets are a simple powder compressed until a tablet is formed. But the exact opposite is usually true: tablets are complex blends of powders blended to an exact potency and compressed into tablets at very high speeds, says Fred Rowley, an internationally recognized solid dosage expert and a pioneer in solid dosage training, in the exclusive in this issue on solid dosage manufacturing.

On a tablet press or encapsulator, good powder flow is everything! It is a basic yet paramount need. You cannot produce quality products or solve problems until you establish good powder flow. In tablet or capsule manufacturing, powders must flow like a liquid. Essentially the powder must take the form of a liquid and flow into the die unassisted, he says.

Flow issues resulting in both content uniformity and weight variation are very often operator and machine related problems. Tablet presses are the most complicated, simple machines to misunderstand. Constant refresher training is required to maintain the skills necessary to operate a tablet press at the highest level. Tablet press operators should periodically review their practices to avoid making mistakes.

Both science and skill have their place in successful tablet manufacturing, adds Fred Rowley. The science relies on the formula the R & D department develops while the skill is usually assumed to mean the adjustment of critical tablet press machine settings during tablet manufacturing. The science is present in the form of machine set point ranges stated on the approved batch record while the skill is the selection of the exact set points for this particular drug within the range.

“It is my experience that many formulas will compress well: If powder blends are stored correctly and compressed at the proper time, and if the tablet press is operated correctly,” Mr. Rowley gets to the point.

Harjit Singh Dhaul
Publisher & Editor