<p>A Comprehensive Review on Pharmaceutical Film Coating: Past, Present, and Future</p>

Abstract

Pharmaceutical film coating is considered a key part in the production of solid pharmaceutical dosage forms since it gives superior organoleptic properties products. In addition, it can improve the physical and chemical stability of dosage forms, and modify the release characteristics of the drug. Several troubleshooting problems such as twinning mottling, chipping, etc., may arise during or after or even during the shelf life of the film coated dosage forms. These troubleshooting problems may be due to tablet core faults, coating formulation faults and/or coating process faults. These problems must be overcome to avoid unnecessary product problems. Film coating as well as other parts of the pharmaceutical technology is subjecting to continuous innovation. The innovation may be at different levels including pharmaceutical excipients, processes, software, guidelines and equipment. In fact, of particular note is the growing interest in process analytical technology, quality by design, continuous coating processing and the inclusion of new ready for use coating formulations. In this review, we tried to explore and discuss the status of pharmaceutical film coating, the challenges that face this manufacturing process and the latest technological advances in this important manufacturing process.

Aqueous Film Coating the Current Trend

“…In FC a thin layer/coat of a FFP is deposited surrounding the substrate, by spraying the same in the form of coating compositions, in liquid state, through one or more spray guns onto a small portion of rotating or fluidised bed of the substrates using panning equipment that is ether conventional or sophisticated one, to accomplish efficient drying, automation of higher degree, and reducing coating time [11][12][13] . Said composition of coating is either a solution or a suspension in a suitable liquid medium (a solvent either AS or VOSs), accordingly the FC process can be classed into two broader categories as follows [7][8][9][10][11][12] :…”

“…[8][9][10] Furthermore in today's competitive environment of business any costcutting will improve market viability of any product thus its success [9][10][11] . Existing stringent regulatory control along with concern regarding the increasing cost of VOSs, and market viability of any product thus its success [10][11][12]58 ; therefore as alternative to counterfeit these adverse situation requirement is reverting back to aqua as medium/solvent for coating of substrate 58,59 .…”

“…To reduce processing time and overcoming requirement for skilled-operator, as in SC, developing is FC 10,11 . Here coating of substrate is achieved by spraying solution of FFP in AS or VOS [11][12][13] . Furthermore the FC can improve stability by protecting substrate from humidity, temperature, and light; improve aesthetic property by masking obnoxious taste or odour, improving the appearance, facilitating swallowing; provide tablet identity; and modify or control release of the active [12][13][14] .…”

“…Here coating of substrate is achieved by spraying solution of FFP in AS or VOS [11][12][13] . Furthermore the FC can improve stability by protecting substrate from humidity, temperature, and light; improve aesthetic property by masking obnoxious taste or odour, improving the appearance, facilitating swallowing; provide tablet identity; and modify or control release of the active [12][13][14] . The FC find applications for achieving release profile of the drug(s) that is either modified or conventional; accordingly the FC is either modified release FCs or conventional FCs [6][7][8] .…”

3D-printed construct from hybrid suspension as spatially and temporally controlled protein delivery system

“…Meanwhile, polyacrylate colloidal particles have extensively applied in pharmaceutical controlled release formulations during the past years. 12–17 The mechanism for the controlled release relies on the formation of diffusion retardant membrane or matrix from aqueous colloid such that the drug will be released from a reservoir. However, protein agents present a challenge for polyacrylate based controlled release system as proteins were considered too large to slowly release from the non-erodible hydrophobic polymers by Fickan diffusion mechanism.…”