Solvent-Free Melting Techniques for the Preparation of Lipid-Based Solid Oral Formulations

Abstract

Lipid excipients are applied for numerous purposes such as taste masking, controlled release, improvement of swallowability and moisture protection. Several melting techniques have evolved in the last decades. Common examples are melt coating, melt granulation and melt extrusion. The required equipment ranges from ordinary glass beakers for lab scale up to large machines such as fluid bed coaters, spray dryers or extruders. This allows for upscaling to pilot or production scale. Solvent free melt processing provides a cost-effective, time-saving and eco-friendly method for the food and pharmaceutical industries. This review intends to give a critical overview of the published literature on experiences, formulations and challenges and to show possibilities for future developments in this promising field. Moreover, it should serve as a guide for selecting the best excipients and manufacturing techniques for the development of a product with specific properties using solvent free melt processing.

Optimization of carvedilol solid lipid nanoparticles: An approach to control the release and enhance the oral bioavailability on rabbits

“…When the percent of Gelucire increased the release percentage will increased which can be explained by the higher hydrophilic lipophilic balance of Gelucire 44/14 (HLB = 11), which make it a suitable water dispersible surfactant for lipid based formulation and lipid soluble drugs through the enhancement of the wettability and dissolution of the lipophilic drugs. And by increase its concentration in the formulation, the percentage of the drug released was increased [ 36 ]. In addition, the surface activity of Gelucire 44/14 reduces the interfacial tension between the SLNs and the dissolution medium and minimizes the aggregation of drug particles and boosts the dissolution rate of CVD [ 37 ].…”

Role of Lipid Blooming and Crystallite Size in the Performance of Highly Soluble Drug-Loaded Microcapsules

“…However, there are no works in pure melting techniques such as HMC because the crystallization of the thermodynamically stable β‐form is significantly slower than that of the α‐form. Therefore, difficulties that can compromise the process such as agglomeration in the hot‐melt coater or incomplete resolidification after spray chilling are expected . Here, we performed HMC of a highly soluble drug model (anhydrous citric acid) with tristearin: (1) at conventional temperatures below T m of α (microcapsules A) and (2) at temperatures above the melting point of the unstable α‐form (microcapsules B).…”

“…So far, microcapsules produced via melting techniques and using TAGs as coating material were prone to changes in the dissolution rate during storage, which has been associated with polymorphic transformation to more stable forms and fat blooming . Interestingly, the effect of this alteration on drug release described in the literature points toward two different directions.…”

Influence of Different Meltable Binders on the Solid-State Behaviour and Dissolution Profiles of Solid Lipid Extrudates Processed Via Continuous Hot Melt Granulation

“…9). For instance, the transformation from the thermodynamically instable and less dense α-form to the most stable and densely packed βform had resulted in the reduction of wettability [36][37][38]. This is the reason of usage of stable β form, in sustained release dosage forms.…”