Regulations, Guidelines and Clinical Trials, Advantages and Disadvantages of Pharmaceutical Emulsions, Problems Encountered During Trituration and Possible Solutions, Mechanisms Involved in the Mixing of Pharmaceutical Powders, Mixing of Pharmaceutical Powders in Small-Scale Operations, Intramuscular Route of Drug Administration: Advantages and Disadvantages, List of Pharmaceutical Companies in Denmark, Physical Stability Issues Frequently Encountered In Suspensions, 6 Striking Things Every Cancer Patient Had In Common, How to Reconstitute Oral Suspensions [Step-by-Step Guide], Preformulation Studies: Bulk Characterization, National Agency for Food & Drugs Admin & Control, Journal of Pharmaceutical Development and Industrial Pharmacy, Changing punch design to reduce curvature on upper and lower faces and. Coating Deterioration Kenneth B. Tator, KTA-Tator, Inc. PAINTS AND COATINGS of all types are widely used to provide color and pleasing aes-thetics, and to prevent deterioration of the underlying substrate when exposed to various environments. In some cases, several defects may occur simultaneously and hinder the determination of the causes and redemption works. Film coating is also applicable to mask taste and improve patient compliance. Once this has been achieved, further improvement can be achieved by adjusting coating process conditions (from the thermodynamic standpoint to balance spray rates and drying rates) to ensure that most droplets arrive at the tablet surface in a suitably solvated state to facilitate droplet spreading. Recovery of film-coated tablets thus typically involves milling of the tablets to produce “granules” that can be introduced (at a predetermined level) into other batches of compression mix (of the same product). Notify me of follow-up comments by email. 2-22. Your email address will not be published. For example, fi­lm coatings based on poly (vinyl) alcohol as well as delayed-release coating based on acrylic polymers are well known for their increased tackiness behaviours. However, the addition of alcohol, the use of spray nozzles capable of finer atomization, optimizing the mixing process either by setting mixer height correctly, choosing mixer blade of correct size (about 30% of tank diameter), choosing optimal mixer speed and incorporation powder into water as fast as possible to avoid excessive viscosity build-up before all powder has been wetted out have been found to be effective. optimizing blending process (prior to tabletting) to minimize the chance of producing agglomerates. Use mild drying conditions. J.A. Tablet-to-tablet colour variability corresponds to inter-tablet variation of coating. Dark Field focuses on industries and applications where high value products must be produced at high speed against rigorous quality standards and prevent plastics defects. Tablets momentarily stick together, often just after they pass through the spray zone, and then break apart leaving defects in the surface of the... Read More. Tablet scuffi­ng involves the generation of grey-to-black marks on the surface of white (or lightly coloured/ pastel) film-coated tablets. Course Outline . Optimizing spray gun setup so that there is no mis-spraying, that all spray guns are spraying at the same rate, and that each is providing the same area of coverage over the tablet bed surface. Similarly, when ingredients that become liquid and bleed through the coating do so as a result of high processing temperatures, an increase in spray rate and/or reduction in processing temperature can be helpful. While visually similar to logo bridging, infilling of logos typically occur during the … It’s also a common area for defects. Alternatively, if discolouration occurs on storage, use of a moisture barrier coating can also be effective. It is a coating defect where the film becomes detached from the substrate forming a blister. Contaminants can include water-soluble salts, dust from abrasive blasting of the substrate surface, as well as environmental dirt and dust that was not properly cleaned off the surface. Although a number of factors may be involved here, the most prominent one is the impact of coating process conditions on tablet core behaviour, rather than the impact of the applied coating itself (through chemical interaction with an ingredient in the core). Toward a greater understanding of the scuffi­ng defect observed on Fi­lm-coated tablets. Ensuring that the coating process is optimized with respect to, Spray rate (increased spray rate provides protection for tablets), Pan loading (underloaded pans potentially create more attritional problems, especially because tablets can strike the exposed edges of baffles), Pan speed, which can be reduced to minimize mechanical stress. Tablet Coating With Its Defects - Free download as Powerpoint Presentation (.ppt / .pptx), PDF File (.pdf), Text File (.txt) or view presentation slides online. Using high solids film-coatings systems (such as Aquarius Preferred HSP) that facilitates the use of lower processing temperatures, Adjusting core formulation to improve dissolution behaviour and offset sensitivity to processing conditions. In the case in which foamy material tends to build up within the logo, it is interesting to note that the addition of conventional antifoam agents does not decrease the incidence of this defect. All Rights Reserved . Usually, however, a portion of the coating will remain in the compression mix. Interference is simply the addition of the fields of the various waves involved. Keywords: substrate; centrifugal force; spin coating; thin film; photolithography; acceleration 1. However, potential discolouration issues are more effectively dealt with during product development, especially when past experience suggests that this kind of problem is likely to occur in the current product being developed. Conventional solvent-based film coating involves deposition of a thin polymer film on the surface of the tablet core, typically using a spray method. While ensuring that the surfaces of the coating equipment are perfectly clean, an approach that can be augmented by pan passivation is a relatively simple approach that can help reduce scuffing problems, a more proactive formulation approach can provide a long-term solution. Causes and Remedies of Blistering: Causes: Remedies: 1. In addition to unsuitable punch design, core surface erosion can be facilitated by over-wetting (which causes the tablet surface to soften and hence become less resistant to attritional effects), presence of centrally placed logo, insufficient film strength (to provide resistance to edge damage) and too high pan speed. The general buildup of prematurely dried material can be corrected by optimizing the atomization process to give a more uniform distribution of droplet sizes. Advanced Defect Detection Film Inspection, Dynamic Evaluation, System Testing & Development. Rosoff and Sheen have commented on this phenomenon, linking it to polymorphism that exists with different forms of titanium dioxide. Common Defects A paint defect is in many cases due to a number of causes. The spraying air pressure affected the film-core interface and the occurrence of coating defects. in film coating is the consistency of tablet hardness. We also offer practical tips and outline the considerations that are needed to ensure high coating uniformity when working with slot-die coating. Once the foam/material has accumulated to a level approaching the outer contour of the tablet surface, normal attrition can occur, allowing the structure to be covered with a continuous film. Coating Failures and Defects Coatings are a complex combination of raw materials that must be mixed, applied to a prepared substrate, and dried and cured correctly to perform to their maximum capability. Increasing the number of spray guns to expand the spray zone and give better surface coverage. Pigmented, fully-formulated film coating systems, containing either hypromellose (HPMC) or polyvinyl alcohol (PVA) as the base polymers, were used in the study. Causes: Cratering can occur in certain instances where there is insufficient drying time to seal the film or a high volume of coating solution is applied. 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