![bcs class 1 drugs more profitable bcs class 1 drugs more profitable](https://d3i71xaburhd42.cloudfront.net/2543a42fe35e1cfd2b7c0c663f53f49df800d44e/4-TableI-1.png)
![bcs class 1 drugs more profitable bcs class 1 drugs more profitable](https://www.dovepress.com/cr_data/article_fulltext/s68000/68909/img/DDDT-68909-F04.jpg)
Specifically, Gelucires ® with high HLB (44/14, 58/18, 50/13 and the most recently marketed 48/16) are composed of PEG-esters of long chain fatty acids, a small glyceride fraction and, sometimes, free PEG. Starting from the early 1990s, these materials have been used as bases for modified-release dosage forms, as the wide range of hydrophobicities available allowed to obtain multiple drug-release rates, depending on the type of Gelucire ® chosen. In general, Gelucires ® are a family of semi-solid or waxy excipients with an amphiphilic nature, characterized by two numbers, the first one referring to the melting point and the second one referring to the Hydrophilic Lipophilic Balance (HLB) value. Alternatively to PEG, a class of hydrophilic surface-active PEG derivatives called Gelucires ® has been proposed as a carrier for the production of semicrystalline solid dispersions. Multiple aspects about drug-PEG dispersions, including their microstructure, crystallinity, interactions, stability, and dissolution performances have been described. The majority of studies on semicrystalline dispersions employed PEG as a carrier.
![bcs class 1 drugs more profitable bcs class 1 drugs more profitable](https://www.mdpi.com/pharmaceutics/pharmaceutics-11-00567/article_deploy/html/images/pharmaceutics-11-00567-g001.png)
These systems have attracted extensive attention due to their complexity in terms of physical state, as both the carrier and the API can undergo crystalline phase modifications during production of the solid dispersion and/or during storage on one hand, the hydrophilic carrier can accelerate, slow down, or have no effect on the crystallization of the drug on the other hand, the drug can affect the crystallization of the carrier. In pharmaceutical semicrystalline SD, the hydrophilic carrier contains both crystalline and amorphous domains and the API can be amorphous, crystalline, or partially crystalline. SD can be prepared using amorphous carriers (e.g., polyvinylpyrrolidone (PVP)), crystalline carriers (e.g., sugars), or semicrystalline carriers (e.g., polyethylene glycol (PEG)). Solid dispersion (SD) of active pharmaceutical ingredients (APIs) in hydrophilic carriers is a well-established strategy to increase the solubility and/or the dissolution rate of poorly water-soluble compounds. Among the tested APIs, TBM-Gelucire dispersions showed the highest enhancement in drug dissolution as a result of the reduced drug crystallinity. The in vitro tests suggested that the drug solubility was mainly influenced by carrier composition, while the drug dissolution behavior was affected by the API solid state in the MPs after the spray congealing process. The solid-state characterization showed that the properties of the incorporated drug had a profound influence on the structure of the obtained solid dispersion: CBZ recrystallized in a different polymorphic form, TBM crystallinity was significantly reduced as a result of specific interactions with the carrier, while smaller crystals were observed in case of CIN. The obtained MPs were investigated in terms of morphology, particles size, drug content, solid state properties, drug-carrier interactions, solubility, and dissolution performances. In this study, solid dispersions based on hydrophilic Gelucires ® (Gelucire ® 50/13 and Gelucire ® 48/16 in different ratio) of three BCS class II model compounds (carbamazepine, CBZ, tolbutamide, TBM, and cinnarizine, CIN) having different physicochemical properties (logP, pKa, Tm) were produced by spray congealing process. Delivery of poorly water soluble active pharmaceutical ingredients (APIs) by semi-crystalline solid dispersions prepared by spray congealing in form of microparticles (MPs) is an emerging method to increase their oral bioavailability.