Preparation and Evaluation of Ketoprofen Hot-Melt Extruded Enteric and Sustained-Release Tablets

Surfactant-Assisted Wet Granulation-Based Matrix Tablets without Exceptional Additives: Prolonging Systemic Exposure of Model BCS Class II Ketoprofen

The present study was aimed to ameliorate the issue of solubility and thereby, bioavailability of ketoprofen, a BCS Class II drug. The sustained release matrix tablets (MT) were prepared using surfactant-assisted wet granulation (SAWG) with 1-5% of different surfactants. The tablet characteristics were within the compendial limits. The selected sustained release-compliant matrix tablet formulation containing granules prepared using 3% Soluplus® (MT2) released the drug by swelling-erosion. In human volunteers, MT2 attained the maximum plasma concentration (Cmax) of 5.72µg /ml ± 0.30 h, time to Cmax (Tmax) of 5.56 ± 0.30 h and maintained the plasma concentration above its minimum effective concentration (MEC), 0.7 µg.ml-1 till 24h. A control formulation, prepared from granules without surfactant (MT16), promptly attained Cmax of 9.62 ± 0.76 µg/ml within 1h but rapidly declined to below MEC in 8h. Area under the curve from initial point to infinity (AUC0-∞) of MT2 (78.65 ± 7.64 µg.h.ml-1) was 2.29 folds higher than 34.39 ± 3.06 µg.h.ml-1 of MT16. With decreased Cmax, increased AUC0-∞, delayed Tmax and retained ketoprofen concentration above MEC for longer time, MT2 corresponded with the in-vitro sustained drug release characteristic. There is a likelihood of administration of once-a-day single dose of MT2 without plasma fluctuations, expected from two doses of MT16. SAWG helped developing a swellable-erodible sustained release matrix tablet formulation of ketoprofen with the desired biopharmaceutical and pharmacokinetics properties, merely by addition of Soluplus® in granules and without incorporation of any special ingredients or the major manipulation of the formulative ingredients in the formulation.

A novel drug delivery system -- Drug crystallization encapsulated liquid crystal emulsion

Liquid crystals (LCs) are widely used for drug delivery due to their controlled and sustained drug release properties. In this paper, drug crystallization encapsulated liquid crystal emulsion, a novel drug delivery system, was proposed. The lamellar liquid crystals formed by hydrogenated lecithin, which are similar to the skin stratum corneum lipid structure, are adopted as the drug carrier to encapsulate non-steroidal anti-inflammatory drugs (NSAIDs). As the model drug, ketoprofen exists in the hydrophobic core of emulsion as a drug crystal when squalane is used as the oil phase. The microstructure, sustained drug release behaviors, physicochemical property and biocompatibility of the system were examined by polarized light microscopy, rheological measurements, differential scanning calorimetry, X-ray diffraction, small-angle X-ray scattering, in vitro release study, and in vitro cellular cytotoxicity assay. The results have shown that the novel system lowers the drug crystal melting point and improves the thermal stability of liquid crystal structure. Besides, the excellent biocompatibility and sustained release property through the additional dissolution step of drug crystal show its application potentials in the topical cosmeceuticals. The results will also be helpful for in-depth understanding of the physical state of encapsulated drug in the liquid crystal carrier systems.

Continuous Manufacturing of Ketoprofen Delayed Release Pellets Using Melt Extrusion Technology: Application of QbD Design Space, Inline Near Infrared, and Inline Pellet Size Analysis

Delayed-release dosage forms are mainly manufactured as batch processes and include coated tablets, pellets, or particles with gastric resistant polymers. Authors propose a novel approach using the hot-melt extrusion technique to prepare delayed release dosage forms via a continuous manufacturing process, a new trend in the pharmaceutical industry. A full factorial design was employed to correlate input variables, including stearic acid (SA) content, drug content, and pellet size with drug release properties of the pellets. PLS fit method suitably elaborated the relationship between input and output variables with reasonably good fit and goodness of prediction. All three input factors influenced drug release in enzyme-free simulated gastric fluid (SGF) after 120 min; however, SA content did not significantly affect drug dissolution in the enzyme-free simulated intestinal fluid (SIF). An optimized formulation and design space were determined by overlaying multiple contours established from regression equations. The continuous manufacturing process was successfully monitored using inline near-infrared (NIR) and inline particle size analysis, with drug load and pellet size being well-controlled within the design space. The obtained pellets released less than 5% after 120 min in SGF and more than 85% and 95% after 30 min and 45 min, respectively, after switching to SIF.

An update on the contribution of hot-melt extrusion technology to novel drug delivery in the twenty-first century: part II

INTRODUCTION

Interest in hot-melt extrusion (HME) technology for novel applications is growing day by day, which is evident from several hundred publications within the last 5 years. HME is a cost-effective, solvent free, 'green' technology utilized for various formulations with low investment costs compared to conventional technologies. HME has also earned the attention of the pharmaceutical industry by the transformation of this technology for application in continuous manufacturing.

AREAS COVERED

Part II of the review focuses on various novel opportunities or innovations of HME such as multiple component systems (co-crystals, co-amorphous systems and salts), twin-screw granulation, semi-solids, co-extrusion, abuse deterrent formulations, solid self-emulsifying drug delivery systems, chronotherapeutic drug delivery systems, and miscellaneous applications.

EXPERT OPINION

HME is being investigated as an alternative technology for preparation of multicomponent systems such as co-crystals and co-amorphous techniques. Twin-screw granulation has gained increased interest in preparation of granules via twin-screw melt granulation or twin-screw dry granulation. This novel application of the HME process provides a promising alternate approach in the formulation of granules and solid dosage forms. However, this technology may need to be further investigated for scalability aspects of these novel applications for industrial production.

Chronotherapeutic Drug Delivery of Ketoprofen and Ibuprofen for Improved Treatment of Early Morning Stiffness in Arthritis Using Hot-Melt Extrusion Technology

This work developed a chronotherapeutic drug delivery system (CTDDS) utilizing a potential continuous hot-melt extrusion (HME) technique. Ketoprofen (KTP) and ibuprofen (IBU) were used as two separate model drugs. Eudragit S100 (ES100) was the matrix-forming agent, and ethyl cellulose (EC) (2.5 and 5%) was the release-retarding agent. A 16-mm extruder was used to develop the CTDDS to pilot scale. The obtained extrudate strands were transparent, indicating that the drugs were homogeneously dispersed in the matrix in an amorphous form, confirmed by both differential scanning calorimetry and powder X-ray diffraction. The strands were pelletized into 1, 2, and 3 mm size pellets. A 100% drug release from 1, 2, and 3 mm pellets with 2.5% EC was observed at 12, 14, and 16 h, whereas the drug release was sustained for 14, 16, and 22 h from 5% EC pellets, respectively, for KTP. The release characteristics of IBU were similar to those of KTP with modest variations in release at lag time. The in vitro drug release study conducted in three-stage dissolution media showed a desired lag time of 6 h. The percent drug release from 1, 2, and 3 mm pellets with 40% drug load showed < 20% release from all formulations at 6 h. The amount of ethyl cellulose and pellet size significantly affected drug release. Formulations of both KTP and IBU were stable for 4 months at accelerated stability conditions of 40°C/75% RH. In summary, HME is a novel technique for developing CTDDS.

Mechanical properties and drug release of venlafaxine HCl solid mini matrices prepared by hot-melt extrusion and hot or ambient compression

Objective/significance: To elucidate the role of plasticizers in different mini matrices and correlate mechanical properties with drug release.

METHODS

Cylindrical pellets were prepared by hot-melt extrusion (HME) and mini tablets by hot (HC) and ambient compression (AC). Venlafaxine HCl was the model drug, Eudragit^® RSPO the matrix former and citric acid or Lutrol^® F127 the plasticizers. The matrices were characterized for morphology, crystallinity, and mechanical properties. The influence of plasticizer's type and content on the extrusion pressure (P_e) during HME and ejection during tableting was examined and the mechanical properties were correlated with drug release parameters.

RESULTS

Resistance to extrusion and tablet ejection force were reduced by Lutrol^® F127 which also produced softer and weaker pellets with faster release, but harder and stronger HC tablets with slower release. HME pellets showed greater tensile strength (T) and 100 times slower release than tablets. P_e correlated with T and resistance to deformation of the corresponding pellets (r² = 0.963 and 0.945). For both HME and HC matrices the decrease of drug release with T followed a single straight line (r² = 0.990) and for HME the diffusion coefficient (D_e) and retreat rate constant (k_b) decreased linearly with T (r² = 0.934 and 0.972).

CONCLUSIONS

Lutrol^® F127 and citric acid are efficient plasticizers and Lutrol^® F127 is a thermal binder/lubricant in HC compression. The different bonding mechanisms of the matrices were reflected in the mechanical strength and drug release. Relationships established between T and drug release parameters for HME and HC matrices may be useful during formulation work.

A time-adjustable pulsatile release system for ketoprofen: In vitro and in vivo investigation in a pharmacokinetic study and an IVIVC evaluation

A time-adjustable pulsatile release system (TAPS) containing ketoprofen (KF) as an active pharmaceutical agent was developed having been designed for bedtime dosing and releasing drug in the early morning to control the symptoms of rheumatoid arthritis (RA). The formulation involved a tablet core (KF) and a control-release layer, and the coating membrane was composed of EC and Eudragit L100. A single-factor study, a central composite design and a response surface method were selected to optimize the formula and the optimum prescription was as follows: tablet core (KF 50mg, MCC 70mg, lactose 40mg, L-HPC 38mg), and film (EC 7.8g, Eudragit L100 4.2g, PEG 6000 1.8g in 95% alcohol each 200ml). The in vivo release behavior of the tablets was evaluated in Beagle dogs after a parallel oral administration of KF TAPS tablets and commercial KF capsules, when it was found that the KF TAPS tablets released the drug after a lag-time of 3.458h and the T_max was 5.833h. The relative bioavailability was 85.01%, and the two formulations were bioequivalent in terms of C_max and AUC_0-t and the in vitro- in vivo correlations indicated that test formulation had a good in vivo-in vitro correlation (r=0.9703). These results show that the novel drug delivery system (TAPS) has the potential to be used as a KF preparation with chronophamacokinetics characteristics.

Melt-Extruded Eudragit® FS-Based Granules for Colonic Drug Delivery

The purpose of this study is to characterize the properties of Eudragit® FS-based granules prepared using melt extrusion process for colonic drug delivery. 5-Aminosalicylic acid (5-ASA), theophylline, and diclofenac sodium were used as the model compounds. Drug and polymer blends were melt-extruded into thin rods using a single screw extruder. Drugs were found to be dispersed as crystalline particles in the granules. A hammer mill was used to reduce the extrudate into 16-40 mesh granules, which were mixed with lactose and filled into hard gelatin capsules. Three-stage dissolution testing performed using USP paddle method was used to simulate drug release in gastrointestinal tract. In this study, melt extrusion has been demonstrated to be a suitable process to prepare granules for colonic delivery of 5-amino salicylic acid. At 30% drug loading, less than 25% 5-ASA was released from melt-extruded granules of 20-30 mesh in the first two stages (0.1 N hydrochloric acid solution and phosphate buffer pH 6.8) of the dissolution testing. All 5-ASA was released within 4 h when dissolution medium was switched to phosphate buffer pH 7.4. Drug loading, granule size, and microenvironment pH induced by the solubilized drug were identified as the key factors controlling drug release. Granules prepared with melt extrusion demonstrated lower porosity, smaller pore size, and higher physical strength than those prepared with conventional compression process. Eudragit® FS was found to be stable even when processed at 200°C.

pH-independent immediate release polymethacrylate formulations--an observational study

Using Eudragit® E PO (EudrE) as a polymethacrylate carrier, the aim of the study was to develop a pH-independent dosage form containing ibuprofen (IBP) as an active compound via chemical modification of the polymer (i.e. quaternization of amine function) or via the addition of dicarboxylic acids (succinic, glutaric and adipic acid) to create a pH micro-environment during dissolution. Biconvex tablets (diameter: 10 mm; height: 5 mm) were produced via hot melt extrusion and injection molding. In vitro dissolution experiments revealed that a minimum of 25% of quaternization was sufficient to partially (up to pH 5) eliminate the pH-dependent effect of the EudrE/IBP formulation. The addition of dicarboxylic acids did not alter IBP release in a pH 1 and 3 medium as the dimethyl amino groups of EudrE are already fully protonated, while in a pH 5 solvent IBP release was significantly improved (cf. from 0% to 92% release after 1 h dissolution experiments upon the addition of 20 wt.% succinic acid). Hence, both approaches resulted in a pH-independent (up to pH 5) immediate release formulation. However, the presence of a positively charged polymer induced stability issues (recrystallization of API) and the formulations containing dicarboxylic acids were classified as mechanically unstable. Hence, further research is needed to obtain a pH-independent immediate release formulation while using EudrE as a polmethacrylate carrier.

Encapsulation of ketoprofen and ketoprofen lysinate by prilling for controlled drug release

In this paper, ketoprofen and ketoprofen lysinate were used as model drugs in order to investigate release profiles of poorly soluble and very soluble drug from sodium alginate beads manufactured by prilling. The effect of polymer concentration, viscosity, and drug/polymer ratio on bead micromeritics and drug release rate was studied. Ketoprofen and ketoprofen lysinate loaded alginate beads were obtained in a very narrow dimensional range when the Cross model was used to set prilling operative conditions. Size distribution of alginate beads in the hydrated state was strongly dependent on viscosity of drug/polymer solutions and frequency of the vibration. The release kinetics of the drugs showed that drug release rate was related with alginate concentration and solubility of the drug. Alginate solutions with concentration higher than 0.50% (w/w) were suitable to prepare ketoprofen gastro-resistant formulation, while for ketoprofen lysinate alginate, concentration should be increased to 1.50% (w/w) in order to retain the drug in gastric environment. Differential scanning calorimetry thermograms and Fourier transform infrared analyses of drug-loaded alginate beads indicated complex chemical interactions between carboxyl groups of the drug and polymer matrix in drug-loaded beads that contribute to the differences in release profile between ketoprofen and ketoprofen lysinate. Total release of the drugs in intestinal medium was dependent on the solubility of the drug and was achieved between 4 and 6 h.

Applications of hot-melt extrusion for drug delivery

In today's pharmaceutical arena, it is estimated that more than 40% of new chemical entities produced during drug discovery efforts exhibit poor solubility characteristics. However, over the last decade hot-melt extrusion (HME) has emerged as a powerful processing technology for drug delivery and has opened the door to a host of molecules previously considered unviable as drugs. HME is considered to be an efficient technique in developing solid molecular dispersions and has been demonstrated to provide sustained, modified and targeted drug delivery resulting in improved bioavailability. This article reviews the range of HME applications for pharmaceutical dosage forms, such as tablets, capsules, films and implants for drug delivery through oral, transdermal, transmucosal, transungual, as well as other routes of administration. Interest in HME as a pharmaceutical process continues to grow and the potential of automation and reduction of capital investment and labor costs have made this technique worthy of consideration as a drug delivery solution.