Search

In this study, a multiparticulate matrix system was produced, containing two different active pharmaceutical ingredients (APIs): enalapril-maleate and hydrochlorothiazide. The critical control points of the process were investigated by means of factorial design. Beside the generally used microcrystalline cellulose, ethylcellulose was used as matrix former to achieve modified drug release ensured by diffusion. The matrix pellets were made by extrusion-spheronization using a twin-screw extruder. Some pellet properties (aspect ratio, 10% interval fraction, hardness, deformation process) were determined. The aim of our study was to investigate how the two different APIs with different solubility and particle size influence the process. The amount of the granulation liquid plays a key role in the pellet shaping. A higher liquid feed rate is preferred in the pelletization process.

The search for excipients to replace microcrystalline cellulose (MCC) in the production of pellets by extrusion-spheronization in cases of drug incompatibility or the lack of pellet matrix disintegration forms the basis of this study. A combination of к-carrageenan as a spheronization aid, chitosan as a diluent and Carbopol(®) 974P as a binder in the production of pellets containing no MCC has been investigated using acetaminophen as a model drug. Design of experiments allowed assessment of formulation and processing effects on pellet responses that included size, shape, fines, yield and friability. Statistical analysis revealed that the main factors and some of the two-factor interactions had a significant effect on pellet characteristics. Formulations containing high levels of к-carrageenan required more water to produce a wetted mass with good extrudability and extrudate capable of being spheronized. Although only a low level of Carbopol was used in the formulation, it imparted cohesiveness to the wetted mass as well as the extrudate. Furthermore, it was discovered that Carbopol could act as an extrusion aid, enabling the wetted mass to flow easily through the extruder screen holes without building up heat. Spherical and rugged pellets were produced that met the immediate release criterion.

The performance of the standardized extrusion-spheronization technique, operational conditions, formulation parameters and storage of the final product over the bioactivity of papain containing pellets has been evaluated to obtain an insight into the potential of the technique for the manufacture of solid protein formulations. The pellets produced were assayed in terms of biological activity - monitored at each operational stage using N-benzoyl-dl-arginine ρ-nitroanilide as a substrate, and according to the physical properties - evaluated by means of size distribution, apparent density and friability. The produced pellets presented adequate physical and mechanical properties. Monitoring biological activity at each production stage revealed that the most critical steps corresponded to drying and storage, with bioactivity decay ranging from 5 to 30% and 5 to 20% for each process. Dry mixing and extrusion did not hold any influence over papain activity, while wet massing decreased the bioactivity by approximately 0-5% and the spheronization 0-2%. The results varied as a function of the experimental conditions and formulation components. In conclusion, the extrusion--spheronization technique was suitable to produce solid multiparticulate dosage forms for papain, considering the possibility to originate pellets with relatively low bioactivity decay. However, weak points of the technique corresponded to the wet massing and drying stages as well as storage.

In this study, a new co-processed excipient composed of microcrystalline cellulose (MCC), sorbitol, chitosan and Eudragit® E, easily obtained by wet massing, to increase the dissolution rate of active ingredients of low water solubility from pellets prepared by extrusion-spheronization is evaluated. Indomethacin, nifedipine, furosemide, ibuprofen, prednisolone and hydrochlorothiazide are used as model drugs of different solubility. All pellet formulations evaluated showed adequate morphological, flow and mechanical properties. Pellets prepared with the co-processed excipient show a higher drug dissolution rate than those prepared with MCC and even higher than the pure drug powder. The fast drug dissolution and the complete disintegration (<3 min) of the pellets can be explained by the great porosity of the formulations, the high solubility of the sorbitol, the disintegrant capacity of the chitosan and the distribution of the Eudragit® E polymer particles in-between the other components of the co-processed mixture. In conclusion, this new co-processed excipient is very suitable to increase the dissolution rate of poorly soluble drugs from pellets prepared by extrusion-spheronization. Moreover, the drug release rate can be estimated from the Ln of the drug solubility in acidic medium.

Purpose: Salvianolic acid B micro-porous osmotic pump controlled release pellets (SalB-CRPs) with suitable in vitro release profiles and good in vitro and in vivo correlation (IVIVC) were developed., Method: Extrusion-spheronization was used to prepare the starter cores containing SalB/MCC/Kollidon®CL-SF/Flowlac®100 of 30:40:15:15 [w/w, The formulation composition of SalB immediate-release pellets (SalB-IRPs)] and complexed with lactose. The pellets were subsequently coated with Surelease aqueous dispersion to achieve controlled-release properties. Furthermore, a single-dose pharmacokinetics study was carried out in New Zealand White (NZW) rabbits., Results: In the starter cores, the lactose content was 25% based on the SalB-IRPs constituent. The optimal coating polymer ratio of Surelease aqueous dispersion and polyvinyl alcohol-polyethylene glycol (PVA-PEG) graft copolymer (EC/PVA-PEG) was found to be 70:30 (w/w, %) with a coating weight of 5%. The prepared SalB-CRPs had similar in vitro release under three different pH release mediums. A good IVIVC was characterized by a high coefficient of determination (r=0.9801). The in vivo study indicated that the maximum plasma concentration (Cmax) of SalB-CRPs was decreased, peak concentration time (Tmax) and mean residence time (MRT) were all prolonged, as that of SalB-IRPs. In addition, the area under concentration-time curve from 0 to 24 h (AUC0-24 h) and 0 to infinity (AUC0-∞) were significantly higher, compared with those of SalB-IRPs., Conclusion: Collectively, these results manifested that SalB-CRPs were likely to be a more suitable formulation in treating cardiovascular disease with improved in vivo retention, decreased plasma drug concentration fluctuation.

Background: Coating of pellets poses difficulties in the tableting process, which is attributed to the fact that ethylcellulose is a fragile polymer having low resistance to compression. This property of ethylcellulose is the reason why obtaining a slow release profile from tableted pellets comparable with that of uncompressed pellets is practically impossible when traditional tableting process is employed., Method: This work presents a newly developed method of hot tableting of pellets. The pellets used in the process were tramadol hydrochloride (TH) coated with an Aquacoat ECD aqueous dispersion. A physical property of PEG 3000 (one of the components of the tablet formulation) to liquidify at a given temperature was used in the process of hot tableting carried out at about 56 degrees C., Results: During the hot tableting, when a low compression force of about 1 kN was applied, semiliquid granules containing melted PEG 3000 combined with TH pellets. As the temperature decreases to room temperature, a tablet matrix of good physical parameters was created. In the proposed hot tableting method, granulates containing PEG 3000 provide the tableted pellets sufficient protection from being destroyed. An evidence of such protection is confirmed by the fact that the TH slow release profile from the tableted pellets is comparable to that of uncompressed pellets., Conclusion: The hot tableting method allows to obtain the tablets containing compressed pellets with a TH slow release profile comparable to that of uncompresed pellets.

A water-in-oil-in-oil double-emulsion solvent/evaporation method was used to prepare vincristine sulfate (VCR) loaded poly(lactide-co-glycolide) microspheres, and then VCR microspheres were mixed with collagen and (or) chitosan swelling solution and lyophilized to form polymeric films. The films were cross-linked by 0.3% glutaraldehyde (GA). Encapsulation efficiency and release kinetics of VCR microspheres were determined, as well as release kinetics and in vitro degradation of the film. The rate of VCR release from the film submerged in PBS (pH 6.8) and the content were measured by high-performance liquid chromatography (HPLC). The physichemical properties of the film, such as surface morphology, mechanical function, and differential scanning calorimetry, were also measured. VCR was released from the film in a prolonged period and the initial burst release of the film was less significant. In the degradation experiment, the film containing chitosan degraded more slowly than that without chitosan. The films comprising collagen and chitosan could achieve the release kinectics of a relatively constant release. It has a promising future.