Fast-dissolving tablets of glyburide based on ternary solid dispersions with PEG 6000 and surfactants

Prediction of enhanced drug solubility related to clathrate compositions and operating conditions: Machine learning study

Although complexation technique has been documented as a promising strategy to enhance the dissolution rate and bioavailability of water-insoluble drugs, prediction of the enhanced drug solubility related to clathrate compositions and operating conditions is still a challenge. Herein, clathrate compositions (drug content (DC), drug molecular weight (M) and molar ratio (Ratio)), operating conditions (drug concentration (C), pH, pressure (P), temperature (T) and dissolution time (t)) under the different excipients (PEG, PVP, HPMC and cyclodextrin) as main solubilizers of the clathrates condition as input parameters were used to predict two indexes (drug dissolved percentage and dissolution efficiency) simultaneously through machine learning methodfor the first time. The results show that PVP as the main solubilizer of clathrates had higher prediction accuracy to the drug dissolved percentage, and HPMC as the main solubilizer of clathrates had higher prediction accuracy to the drug dissolution efficiency. In addition, the influence of various factors and interactions on the target variables were analyzed. This study affords achievable hints to the quantitative prediction of the drug solubility affected by various compositions and different operating conditions.

Microchannel-embedded implantable device with fibrosis suppression for prolonged controlled drug delivery

For the prolonged, controlled delivery of systemic drugs, we propose an implantable drug-delivery chip (DDC) embedded with pairs of a microchannel and drug-reservoir serving as a drug diffusion barrier and depot, respectively. We pursued a DDC for dual drugs: a main-purpose drug, diclofenac (DF), for systemic exposure, and an antifibrotic drug, tranilast (TR), for local delivery. Thus, the problematic fibrotic tissue formation around the implanted device could be diminished, thereby less hindrance in systemic exposure of DF released from the DDC. First, we separately prepared DDCs for DF or TR delivery, and sought to find a proper microchannel length for a rapid onset and sustained pattern of drug release, as well as the required drug dose. Then, two distinct DDCs for DF and TR delivery, respectively, were assembled to produce a Dual_DDC for the concurrent delivery of DF and TR. When the Dual_DDC was implanted in living rats, the DF concentration in blood plasma did not drop significantly in the later periods after implantation relative to that in the early periods before fibrotic tissue formation. When the Dual_DDC was implanted without TR, there was a significant decrease in the blood plasma DF concentration as the time elapsed after implantation. Biopsied tissues around the Dual_DDC exhibited a significant decrease in the fibrotic capsule thickness and collagen density relative to the Dual_DDC without TR, owing to the effect of the local, sustained release of the TR.

Physical Characterization and In Vitro Evaluation of Dissolution Rate from Cefpodoxime Proxetil Loaded Self Solidifying Solid SNEDDS

BACKGROUND

Cefpodoxime Proxetil (CPD) is a broad-spectrum cephalosporin indicated in respiratory and urinary tract infections. CPD is a BCS class IV drug with pH-dependent solubility and has poor bioavailability. This study investigated the challenges of developing ternary components based on solid SNEDDS of CPD for in vitro dissolution rate enhancement and self-solidifying behaviour.

METHODS

Tween 80, Transcutol and PEG6000 were employed as surfactants, solvents and solidifiers for a base of ternary components to develop self-solidifying solid SNEDDS, respectively. Ternary phase diagrams were used to characterize solidifying behaviour of ternary components in different proportions. S-SNEDDS formulations were drawn on the solidification areas available in the phase diagram and characterized for IR, XRD, DSC and in vitro drug release in various pH media.

RESULTS

Ternary components for the preparation of self-solidifying solid SNEDDS were selected based on drug solubility. FTIR and DSC characterization studies ruled out any drug interaction between CPD and components chosen to prepare S-SNEDDS. CPD was transformed from a crystalline into an amorphous state in ternary dispersions as revealed from XRD data. Optimized formulation (S-S 1) demonstrated more than 95% of drug release irrespective of the pH environments of the medium. Calculation of dissolution efficiency and similarity factors indicate that S SNEDDS resulted in a higher drug dissolution rate over binary dispersion (p<0.01). The stability studies showed that the S SNEDDS were stable in performances and CPD assay.

CONCLUSION

The present investigation provides an alternative approach for enhancing the CPD dissolution rate using self-solidifying solid SNEDDS exhibited solidification behaviour at ambient temperature conditions and drug loading, which could be exploited over conventional dosage form.

A review of emerging technologies enabling improved solid oral dosage form manufacturing and processing

Tablets are the most widely utilized solid oral dosage forms because of the advantages of self-administration, stability, ease of handling, transportation, and good patient compliance. Over time, extensive advances have been made in tableting technology. This review aims to provide an insight about the advances in tablet excipients, manufacturing, analytical techniques and deployment of Quality by Design (QbD). Various excipients offering novel functionalities such as solubility enhancement, super-disintegration, taste masking and drug release modifications have been developed. Furthermore, co-processed multifunctional ready-to-use excipients, particularly for tablet dosage forms, have benefitted manufacturing with shorter processing times. Advances in granulation methods, including moist, thermal adhesion, steam, melt, freeze, foam, reverse wet and pneumatic dry granulation, have been proposed to improve product and process performance. Furthermore, methods for particle engineering including hot melt extrusion, extrusion-spheronization, injection molding, spray drying / congealing, co-precipitation and nanotechnology-based approaches have been employed to produce robust tablet formulations. A wide range of tableting technologies including rapidly disintegrating, matrix, tablet-in-tablet, tablet-in-capsule, multilayer tablets and multiparticulate systems have been developed to achieve customized formulation performance. In addition to conventional invasive characterization methods, novel techniques based on laser, tomography, fluorescence, spectroscopy and acoustic approaches have been developed to assess the physical-mechanical attributes of tablet formulations in a non- or minimally invasive manner. Conventional UV-Visible spectroscopy method has been improved (e.g. fiber-optic probes and UV imaging-based approaches) to efficiently record the dissolution profile of tablet formulations. Numerous modifications in tableting presses have also been made to aid machine product changeover, cleaning, and enhance efficiency and productivity. Various process analytical technologies have been employed to track the formulation properties and critical process parameters. These advances will contribute to a strategy for robust tablet dosage forms with excellent performance attributes.

Fast-Dissolving Solid Dispersions for the Controlled Release of Poorly Watersoluble Drugs

Solid dispersions offer many advantages for oral drug delivery of poorly water-soluble drugs over other systems, including an increase in drug solubility and drug dissolution. An improvement in drug absorption and the higher bioavailability of active pharmaceutical ingredients in the gastrointestinal tract have been reported in various studies. In certain circumstances, a rapid pharmacological effect is required for patients. Fastdissolving solid dispersions provide an ideal formulation in such cases. This report will provide an overview of current studies on fast-dissolving solid dispersions, including not only solid dispersion powders with fast dissolution rates but also specific dose form for the controlled release of poorly water-soluble drugs. Specifically, the applications of fast-dissolving solid dispersions will be described in every specific case. Moreover, pharmaceutical approaches and the utilization of polymers will be summarized. The classification and analysis of fastdissolving solid dispersions could provide insight into strategies and potential applications in future drug delivery developments.

Development and Characterization of Liquisolid Tablets Based on Mesoporous Clays or Silicas for Improving Glyburide Dissolution

The aim of this work was to evaluate the effectiveness of mesoporous clays or silicas to develop fast-dissolving glyburide tablets based on a liquisolid approach. Selected clay (Neusilin^®US2) and silica (Aeroperl^®300) allowed preparation of innovative drug liquisolid systems containing dimethylacetamide or 2-pyrrolidone as drug solvents, without using coating materials which are necessary in conventional systems. The obtained liquisolid powders were characterized for solid-state properties, flowability, compressibility, morphology, granulometry, and then used for directly compressed tablet preparation. The developed liquisolid tablets provided a marked drug dissolution increase, reaching 98% dissolved drug after 60 min, compared to 40% and 50% obtained from a reference tablet containing the plain drug, and a commercial tablet. The improved glyburide dissolution was attributed to its increased wetting properties and surface area, due to its amorphization/solubilization within the liquisolid matrix, as confirmed by DSC and PXRD studies. Mesoporous clay and silica, owing to their excellent adsorbent, flow, and compressibility properties, avoided use of coating materials and considerably improved liquid-loading capacity, reducing the carrier amount necessary to obtain freely flowing powders. Neusilin^®US2 showed a superior performance than Aeroperl^®300 in terms of the tablet’s technological properties. Finally, simplicity and cost-effectiveness of the proposed approach make it particularly advantageous for industrial scale-up.

Insight into the Dissolution Molecular Mechanism of Ternary Solid Dispersions by Combined Experiments and Molecular Simulations

With the increase concern of solubilization for insoluble drug, ternary solid dispersion (SD) formulations developed more rapidly than binary systems. However, rational formulation design of ternary systems and their dissolution molecular mechanism were still under development. Current research aimed to develop the effective ternary formulations and investigate their molecular mechanism by integrated experimental and modeling techniques. Glipizide (GLI) was selected as the model drug and PEG was used as the solubilizing polymer, while surfactants (e.g., SDS or Tween80) were the third components. SD samples were prepared at different weight ratio by melting method. In the dissolution tests, the solubilization effect of ternary system with very small amount of surfactant (drug/PEG/surfactant 1/1/0.02) was similar with that of binary systems with high polymer ratios (drug/PEG 1/3 and 1/9). The molecular structure of ternary systems was characterized by differential scanning calorimetry (DSC), infrared absorption spectroscopy (IR), X-ray diffraction (XRD), and scanning electron microscope (SEM). Moreover, molecular dynamic (MD) simulations mimicked the preparation process of SDs, and molecular motion in solvent revealed the dissolution mechanism of SD. As the Gordon-Taylor equation described, the experimental and calculated values of Tg were compared for ternary and binary systems, which confirmed good miscibility of GLI with other components. In summary, ternary SD systems could significantly decrease the usage of polymers than binary system. Molecular mechanism of dissolution for both binary and ternary solid dispersions was revealed by combined experiments and molecular modeling techniques. Our research provides a novel pathway for the further research of ternary solid dispersion formulations.

Characterization and evaluation of different mesoporous silica kinds as carriers for the development of effective oral dosage forms of glibenclamide

This work evaluated the suitability of various mesoporous silicas as carriers for developing an oral formulation endowed with improved dissolution properties of glibenclamide, hypoglycemic agent poorly water-soluble. The different silicas were examined for solid-state, morphology, and technological and physical-chemical properties (granulometry, specific surface area, wettability, water content, water activity, apparent density, flowability, compactability). A pairwise comparison allowed a ranking, by importance order, of the parameters examined and, for each parameter, a score was assigned to each silica type. Data statistical treatment (JMP software) indicated Neusilin®US2 and Syloid®XDP3150 as the best materials. Different loading methods were tested: physical mixing; addition of drug dissolved in a volatile solvent, subsequently evaporated; addition of drug dissolved in a solvent. Methods involving drug dissolution enabled drug amorphization and intimate dispersion within the silica porous structure. Dissolution tests indicated Syloid®XDP3150 as the most effective silica in enhancing drug dissolution properties, providing a release rate clearly faster than from commercial tablets. Drug amorphization, improved wettability, increased surface area of the drug, finely dispersed into the highly porous silica, were the main factors responsible for this finding. Moreover, the obtained results suggested that drug dissolution rate can be properly tuned, based on the suited choice of the silica type.

Preparation and evaluation of solid dispersions of a new antitumor compound based on early-stage preparation discovery concept

Ensuring sufficient drug solubility is a crucial problem in pharmaceutical-related research. For water-insoluble drugs, various formulation approaches are employed to enhance the solubility and bioavailability of lead compounds. The goal of this study was to enhance the dissolution and absorption of a new antitumor lead compound, T-OA. Early-stage preparation discovery concept was employed in this study. Based on this concept, a solid dispersion system was chosen as the method of improving drug solubility and bioavailability. Solid dispersions of T-OA in polyvinylpyrrolidone (PVP) K30 were prepared by the solvent evaporation method. Dissolution testing determined that the ideal drug-to-PVP ratio was 1:5. X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry were employed to confirm the formation of solid dispersions. Scanning electron microscopy demonstrated that T-OA was converted into an amorphous form. Both in vitro dissolution testing and the in vivo studies demonstrated that the solubility and bioavailability of T-OA were significantly improved when formulated in a solid dispersion with PVP. The dissolution rate of the T-OA/PVP solid dispersion was greatly enhanced relative to the pure drug, and the relative bioavailability of T-OA solid dispersions was found to be 392.0%, which is 4-fold higher than the pure drug.

Highly efficient miniaturized coprecipitation screening (MiCoS) for amorphous solid dispersion formulation development

Microprecipitated bulk powder (MBP) is a novel solid dispersion technology to manufacture amorphous formulations of poorly soluble compounds that cannot be processed by spray drying or melt extrusion. An efficient high-throughput screening method has been developed to aid the selection of polymer type, drug loading and antisolvent to solvent ratio for MBP formulation development. With a 96-well platform, the miniaturized coprecipitation screening (MiCoS) includes mixing of drug and polymer in dimethylacetamide, controlled precipitation to generate MBP, filtration/washing, drying and high throughput characterization. The integrated MiCoS approach has been demonstrated with a model compound, glybenclamide. Based on the solid state stability and kinetic solubility of the MBP, hydroxypropylmethylcellulose acetate succinate polymer with 40% or lower drug loading, and antisolvent (0.01 N HCl) to solvent (dimethylacetamide) ratio of 5:1 or higher were selected to make glybenclamide MBP. MiCoS can be applied to both early and late stage formulation processing. In early stage research programs, the system can be used to enable efficacy, pharmacokinetics or mini-toxicology studies for poorly water soluble molecules using minimal amount of drug substance (2-10mg). In late stage development programs, MiCoS can be used to optimize MBP formulation by expanding the experimental design space to include additional formulation variants.

Fast disintegrating tablets: Opportunity in drug delivery system

Fast disintegrating tablets (FDTs) have received ever-increasing demand during the last decade, and the field has become a rapidly growing area in the pharmaceutical industry. Oral drug delivery remains the preferred route for administration of various drugs. Recent developments in the technology have prompted scientists to develop FDTs with improved patient compliance and convenience. Upon introduction into the mouth, these tablets dissolve or disintegrate in the mouth in the absence of additional water for easy administration of active pharmaceutical ingredients. The popularity and usefulness of the formulation resulted in development of several FDT technologies. FDTs are solid unit dosage forms, which disintegrate or dissolve rapidly in the mouth without chewing and water. FDTs or orally disintegrating tablets provide an advantage particularly for pediatric and geriatric populations who have difficulty in swallowing conventional tablets and capsules. This review describes various formulations and technologies developed to achieve fast dissolution/dispersion of tablets in the oral cavity. In particular, this review describes in detail FDT technologies based on lyophilization, molding, sublimation, and compaction, as well as approaches to enhancing the FDT properties, such as spray drying and use of disintegrants. In addition, taste-masking technologies, experimental measurements of disintegration times, and dissolution are also discussed.

Solid dispersion of prednisolone: solid state characterization and improvement of dissolution profile

BACKGROUND

Dissolution testing is an important test for judging the effectiveness of a pharmaceutical dosage form. Many drugs create adverse effect because of insufficient solubility at the physiological pH. This study is aimed to improve the dissolution properties of prednisolone (PRD) that falls under the category of class II biopharmaceutics system.

METHODS

In this study, preparation of solid dispersions with various water-soluble carriers was studied to improve the dissolution of PRD. To obtain the optimized formulation, solid dispersions were prepared employing different methods using different carriers with various drug:carrier ratios. Their dissolution behaviors were also compared. Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction, and thermal analysis were studied to characterize the prepared solid dispersion.

RESULTS

PRD formed stable complexes with carriers as indicated by the stability constants (K(a)) of 9.5-597.2 M(-1). The results indicated that in vitro dissolution rate of PRD was remarkably improved in the solid dispersion of the drug compared with physical mixture and drug alone. This can be attributed to improved wettability, dispersibility, decrease in crystallinity, and increase in amorphous fraction of the drug. The results obtained from Fourier transform infrared spectroscopy and powder X-ray diffraction showed good evidence of drug-carrier interaction while using carriers such as hydroxypropyl-β-cyclodextrin (HP-βCD) and polyethylene glycol (PEG). Crystallinity of the drug was reduced in the solid dispersions prepared with hydroxypropyl-β-cyclodextrin, polyvinylpyrrolidone-co-vinyl acetate 64, and PEG as revealed from the differential scanning calorimetry thermograms.

CONCLUSION

The results suggested that the solid dispersion with selected excipients is a powerful tool to accelerate the dissolution of poorly water-soluble drugs.

Preparation and in vitro evaluation of solid dispersions of total flavones of Hippophae rhamnoides L

The purpose of this study was to enhance the dissolution of total flavones of Hippophae rhamnoides L. (TFH) by solid dispersions consisting of the drug and a polymeric carrier, poloxamer 188 (PXM). The solvent evaporation method was used to prepare solid dispersions. A 3(2) full-factorial design approach was used for optimization wherein the amount of solvent (X(1)) and the drug-to-polymer ratio (X(2)) were selected as independent variables and the percentage of TFH dissolved in 10 min (Q(10)) was selected as the dependent variable. Multiple linear regression analysis revealed that a suitable level of (1) and X(2) was required for obtaining higher dissolution of TFH from PXM solid dispersions. Solid dispersions were characterized by differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and dissolution tests. Characterization studies revealed that solid dispersion of TFH-PXM showed enhancement of TFH dissolution due to the conversion of TFH into a less crystalline and/or amorphous form. In conclusion, dissolution enhancement of TFH was obtained by preparing its solid dispersions in PXM using solvent method.