An innovative wax-based enteric coating for pharmaceutical and nutraceutical oral products

Design of Crystal Growth Dimensionality in Synthetic Wax: The Kinetics of Nonisothermal Crystallization Processes

The demand for the development of multifunctional materials in emerging technologies has stimulated intensive research on the control of crystallization processes in numerous scientific and engineering fields. In this article, we examine the kinetics of nonisothermal melt crystallization in synthetic wax using differential scanning calorimetry (DSC) supported by polarized optical microscopy (POM) to describe crystallization modes in a multicomponent molecular system. We detected the macroscopic growth of three crystal phases and the formation of two crystal phases as a transformation from a disordered crystal mesophase into an ordered crystal. To characterize individual crystal phase formation, we examine the activation energy evaluated by isoconversional analysis and utilize the Ozawa and Mo methods to determine the kinetic details of the crystal growth from the isotropic phase. Our investigation reveals the possibility of the design of crystal growth dimensionality as three-dimensional spherulitic-like, two-dimensional rodlike, and one-dimensional needle-shaped crystal forms of shorter n-alkanes by controlling the solidification pathway of long-chain n-alkanes and the interplay of the thermodynamic and kinetic mechanisms of crystallization.

Film Coatings Based on Aqueous Shellac Ammonium Salt "Swanlac® ASL 10" and Inulin for Colon Targeting

Over the past decades, increasing interests took place in the realm of drug delivery systems. Beyond treating intestinal diseases such as inflammatory bowel disease, colon targeting can provide possible applications for oral administration of proteins as well as vaccines due to the lower enzymatic activity in the distal part of GIT. To date, many strategies are employed to reach the colon. This article encompasses different biomaterials tested as film coatings and highlights appropriate formulations for colonic drug delivery. A comparison of different films was made to display the most interesting drug release profiles. These films contained ethylcellulose, as a thermoplastic polymer, blended with an aqueous shellac ammonium salt solution. Different blend ratios were selected as well for thin films as for coated mini-tablets, mainly varying as follows: (80:20); (75:25); (60:40). The impact of blend ratio and coating level was examined as well as the addition of natural polysaccharide "inulin" to target the colon. In vitro drug release was measured in 0.1 M HCl for 2 h followed by phosphate buffer saline pH 6.8 to simulate gastric and intestinal fluids, respectively. Coated mini-tablets were exposed to fresh fecal samples of humans in order to simulate roughly colonic content. Several formulations were able to fully protect theophylline as a model drug up to 8 h in the upper GIT, but allowing for prolonged release kinetics in the colon. These very interesting colonic release profiles were related to the amount of the natural polysaccharide added into the system.

A Novel Alginate Film Based on Nanocoating Approach for Enteric-Release Tablets

The objective of this study was to propose a new coating film for biodegradable polymers and environmentally friendly processing. Here, a novel implementation of solid lipid nanoparticles (SLN) into a biodegradable alginate (ALG) film composition created a new gastric-resistant film for an enteric-release tablet. Experiments were performed on a water-soluble substance (thiamine nitrate) to characterize the effects of SLN upon the addition of the ALG coating formulation. The coated tablets or cast films were characterized based on delayed-release properties, surface morphology, moisture resistance, and chemical interactions. The SLN-ALG film displayed gastric-resistant properties (< 10% drug substance dissolved at pH 1.2) and rapid disintegration in the intestinal medium (pH 6.8). Morphological analysis using a microscope and scanning electron microscope confirmed the uniformity and smoothness of the SLN-ALG film, which improved the mechanical properties of the film. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated that SLN contributed to the formation of the film, which maintained free carboxylic groups, making the SLN-ALG film a higher acid resistance, but soluble in pH 6.8 buffer. These promising results suggest a novel nanotechnology-based coating formulation for various enteric-release dosage forms. Because of their biodegradability, the proposed ingredients and processes are safe and environment-friendly.

Exploration of polymethacrylate and Hypromellose for the development of a non-sulfhydryl ACE inhibitor mucoadhesive system using Box-Behnken design: in-vitro and ex-vivo evaluation

PURPOSE

To counteract early morning pathology like hypertension a time-dependent release of the drug is required. This study is focused to formulate a pulsatile and mucoadhesive drug delivery system of an ACE inhibitor Perindopril Erbumine.

METHOD

Two matrix tablets were punched with Eudragit RSPO, Eudragit RLPO, and HPMC K15M using a 3-3-3 Box-Behnken Design of Response Surface Methodology. Based on the design-optimized formulation P1T3 and P2T8 were coated for a lag time with compression coating of HPMC K4M and a blend of 1:1 ratio of ethylcellulose and carbopol polymer and further encapsulated in a Eudracap™ capsule to provide gastric resistance.

RESULT

The in-vitro release data confirmed an initial pause phase of 4.5 h then release of the drug for 5.2 ± 0.3 h to cope with the early morning rush in blood pressure. After that, a gap of 6 h and then sustained release of the drug for 10.5 ± 0.5 h. From the ex-vivo study, mucoadhesive strength was obtained as 55.13 ± 0.03 gm and 56.39 ± 0.02 gm for P1T3 and P2T8 respectively. The lag time for coated tablet P1T3 came to 2.15 ± 0.15 h and for P2T8 11.9 ± 0.10 h proving the coating efficiency of polymers.

CONCLUSION

The current study strongly suggests that perindopril Erbumine in association with Eudragit and Hypromellose polymer can open a path for the time-regulated release of the drug for hypertension chronotherapy with less risk of dose dumping.

Exploration of Parteck® SRP 80 and Hypromellose for Chronomodulated Release of LTD4 Receptor Antagonist and Statistical Optimization Using Central Composite Design

To manage early morning symptoms of nocturnal bronchial asthma, a chronotherapeutic drug delivery system (ChrDDS) of montelukast sodium was designed and developed utilizing non-saccharide, fully synthetic Parteck® SRP 80, and hydrophilic cellulose derivative hydroxypropyl methylcellulose (HPMC). Recurrent lag phase, each followed by the release of a fraction of the drug dose, can be achieved by formulating a "tablets in a capsule" system containing more than one compressed coated tablet encapsulated in an enteric-coated capsule. Lag time in this study was controlled by the compressed coating of HPMC K4M and a blend of ethyl cellulose and Carbopol polymer. Assembly of the system includes two compressed coated tablets encapsulated in a capsule which was further proceeded for enteric coating in a conventional, a novel wax-based, and a Eudracap™ enteric-coated capsule. The optimized formulation of directly compressed tablets of Parteck ® SRP 80 showed a hardness of 8.8 kg/cm² which is 1.25-fold higher than wet granulated tablets of HPMC. In vitro release data of matrix tablets of Parteck® SRP 80 demonstrated controlled release of drug for a duration of up to 10.8-11 h with changing ratio of polymer and filler. Eudracap™ capsule showed a minimum acid uptake value of 1.75%. The current approach can open a path for the time-regulated release of montelukast that may be beneficial for individuals with episodes of asthma attacks mostly in the early morning.

A Novel Multilayer Natural Coating for Fed-State Gastric Protection

Several nutraceutical products require gastric protection against the hostile environment in the stomach. Currently marketed synthetic and semi-synthetic coatings suffer from major shortcomings such as poor gastric protection, slow-release response to pH change, and the use of artificial ingredients. The challenge of coating natural products is further exacerbated by the relatively high gastric pH in the fed state. In this work, a novel natural enteric coating is presented as a breakthrough alternative to current solutions. Two coating systems were devised: (i) a triple-layer coating that comprises a wax layer embedded between two alginate-based coatings, and (ii) a double-layer coating, where an overcoat of organic acids (fumaric or citric acid) is applied to an alginate-based coating. The multi-layer architecture did not impact the pH-responsive nature of the coating even when more biologically relevant Krebs bicarbonate buffer of lower buffer capacity was used. Interestingly, the gastric protection barrier of organic acid-based coating remained resistant at elevated gastric pH 2, 3, or 4 for 2 h. This is the first report of using an alginate-based coating to provide gastric protection against fed-state stomach conditions (pH 2–4). Being biodegradable, naturally occurring, and with no limit on daily intake, the reported novel coating provides a superior platform to current coating solutions for pharmaceutical and nutraceutical products.

Going green: Development of a sustainable lipid-based enteric coating formulation for low-dose aspirin multiparticulate systems

There is a rising awareness of pharmaceutical industry of both patient-centric and sustainable product development. Manufacturing of multiparticulate systems (MPS) with functional coating via solvent-free hot melt coating (HMC) can fulfill both requirements. An innovative lipid-based formulation was developed with the composition of palmitic acid and Grindsted® citrem BC-FS (BC-FS) for enteric coating of acetylsalicylic acid (ASA). The ASA crystals were directly hot melt coated to produce user-friendly low-dose ASA MPS for thromboembolism prophylaxis. Prior to HMC, rational boundaries for the process temperature were defined based on the melting and crystallization behavior of coating blend. Stability of coating in terms of resistance to heat stress and solidstate stability were screened via Fourier-transform infrared spectroscopy and x-ray diffraction. Exposure of coating blend to 100 °C for two hours did not cause any chemical degradation. Crystal growth of palmitic acid and polymorphic transformation in BC-FS were observed after storage under accelerated conditions, however did not significantly affect the ASA release from coating. The developed formulation is a unique solvent-free, lipid-based enteric composition and paves the way for sustainable green pharmaceutical manufacturing.

Solvent-free temperature-facilitated direct extrusion 3D printing for pharmaceuticals

In an era moving towards digital health, 3D printing has successfully proven its applicability in providing personalised medicine through a technology-based approach. Among the different 3D printing techniques, direct extrusion 3D printing has been demonstrated as a promising approach for on demand manufacturing of solid dosage forms. However, it usually requires the use of elevated temperatures and/or the incorporation of an evaporable solvent (usually water). This can implicate the addition of a drying step, which may compromise the integrity of moisture- or temperature-sensitive drugs, and open the door for additional quality control challenges. Here, we demonstrate a new approach that simplifies direct extrusion 3D printing process with the elimination of the post-printing drying step, by merely adding a fatty glyceride, glyceryl monostearate (GMS), to a model drug (theophylline) and permeable water insoluble methacrylate polymers (Eudragit RL and RS). Indeed, rheological studies indicated that the addition of a combination of a plasticiser, (triethyl citrate), and GMS to theophylline: methacrylate polymer blends significantly reduced the extensional viscosity (to <2.5 kPa·Sec) at 90 °C. Interestingly, GMS demonstrated a dual temperature-dependant behaviour by acting both as a plasticiser and a lubricant at printing temperature (90-110 °C), while aiding solidification at room temperature. X-ray powder diffraction indicated incomplete miscibility of GMS within the polymeric matrix at room temperature with the presence of a subtle diffraction peak, at 2(Θ) = 20°. The 3D printed tablets showed acceptable compendial weight and content uniformity as well as sufficient mechanical resistance. In vitro theophylline release from 3D printed tablets was dependant on Eudragit RL:RS ratio. All in all, this work contributes to the efforts of developing a simplified, facile and low-cost 3D printing for small batch manufacturing of bespoke tablets that circumvents the use of high temperature and post-manufacturing drying step.