Techceuticals

After making a good tablet, you must often coat it. The coating can have several functions. It can strengthen the tablet, control its release, improve its taste, color it, make it easier to handle and package, and protect it from moisture. This article reviews the basics of tablet coating and describes common tablet coating defects. There are many ways to coat tablets. Sugar coating was one of the earliest methods, and the process is still widely used in the confectionery industry. Wurster coating is another means. It employs a cylindrical chamber in which tablets are suspended by air and a coating solution is introduced into the air stream. Fluid-bed coating is a similar process. Dry coating is the technique of making a tablet within a tablet. But the principle means of applying a coating to pharmaceutical and nutraceutical tablets is called film coating, and it is the focus of this article. Coating Solutions Film coatings are a mixture of solids and liquids. For many years, th...

Tablet specifications are tight, and the list of possible defects is long: Variable weight, sticking, picking, black spots, streaks, capping, lamination, variable hardness, among others. This article focuses on variations in tablet weight and tablet hardness. It pinpoints the possible causes of these defects and offers advice on preventing and fixing the source of the problems. It also discusses the problems of formulations with too many fines. Every product behaves differently on a tablet press, even if it’s the same product run on a different day. The variation often stems from changes in the properties of the raw materials — active ingredients and excipients — from batch to batch. Naturally, the goal is to minimize these changes. Tablet press operators, however, don’t have any control over formulation and granulation. They have to work with what they’re given, and their employers expect them to make good tablets day in, day out. Tablet Weight: Sources of Variation Product var...

Sticking occurs when granules attach themselves to the faces of tablet press punches. Picking is a more specific term that describes product sticking only within the letters, logos, or designs on the punch faces. This article explains the causes of sticking and picking and describes the steps you can take to resolve both problems. When a product begins sticking to the punch face, the blame game starts. Unchecked, the finger-pointing can zoom around to encompass every person with a hand in the tablet-making process. No one wants to bear the responsibility for the problem. From your colleagues in R&D you hear, “It didn’t stick to the punches in our single-station lab press. Check with the tablet press operators. They’re not running the tablet press correctly.” When you check with the tablet press operators, they say it’s a granulation problem. “If the product had been granulated correctly we wouldn’t have sticking problems.” The people in quality assurance point out that the pro...

Basic Technologies for Tablet Making This article presents the basic technologies for preparing powders for tablet making. Granulation is the process of collecting particles together by creating bonds between them. Bonds are formed by compression or by using a binding agent. If one were to make tablets from granulated sugar versus powdered sugar, for example, powdered sugar would be difficult to compress into a tablet and granulated sugar would be easy to compress. Powdered sugar’s small particles have poor flow and compression characteristics. These small particles would have to be compressed very slowly for a long period of time to make a worthwhile tablet. Unless the powdered sugar is granulated, it could not efficiently be made into a tablet that has good tablet characteristics such as uniform content or consistent hardness. The granulation process combines one or more powders and forms a granule that will allow the tableting process to be predictable and will produce quality ta...

A tablet press is one of the most complex machines used in the manufacturing environment. Clearly defining the basic principles in tablet press operation is essential to having a successful run. Learning key factors can help to avoid the many obstacles that can interrupt a successful run. Worldwide, more than 18 different companies make tablet presses. All tablet presses operate in the same basic way with only a few exceptions. This fact allowed the industry to define and create a standard for tablet press machines and tablet press tooling, which was published in the Tablet Specification Manual (TSM) by the American Pharmaceutical Association. The TSM can be acquired through any tooling or tablet press supplier. This article discusses how tablet press performance can be optimized by clearly distinguishing between granulation and machine issues; focusing on the importance of flow, compression, and ejection; and performing the necessary maintenance and quality control checks. Tablet...