The formation and physical stability of two-phase solid dispersion systems of indomethacin in supercooled molten mixtures with different matrix formers

Preparation and characterisation of kaempferol composite carrier solid dispersion: evaluation of its application in preventing soybean oil spoilage

Kaempferol (KPF) can be used as a natural antioxidant and food additive in food processing. However, the poor solubility of KPF limited its bioavailability and application. In order to improve the solubility of KPF, kaempferol composite carrier solid dispersion (KPF-CC-SD) was prepared and the process was optimised. When the ratio of KPF: CA (citric acid): Soluplus reached 1:4:6, the dissolution rate was the highest, and the sample was stable over 12 weeks. The characterisation results indicated that KPF-CC-SD exists in an amorphous form. Peroxidation value and acid value of soybean oil showed that the preservation effect of KPF-CC-SD was better than that of KPF, and the inhibition effect of KPF-CC-SD on acid value was better than that of butylated hydroxytoluene. In conclusion, KPF-CC-SD can change the solubility, crystal form and spatial stability of KPF through the carrier, which has a great application prospect in the field of food preservation.

Sugars and Polyols of Natural Origin as Carriers for Solubility and Dissolution Enhancement

Crystalline carriers such as dextrose, sucrose, galactose, mannitol, sorbitol, and isomalt have been reported to increase the solubility, and dissolution rates of poorly soluble drugs when employed as carriers in solid dispersions (SDs). However, synthetic polymers dominate the preparation of drugs: excipient SDs have been created in recent years, but these polymer-based SDs exhibit the major drawback of recrystallisation upon storage. Also, the use of high-molecular-weight polymers with increased chain lengths brings forth problems such as increased viscosity and unnecessary bulkiness in the resulting dosage form. An ideal SD carrier should be hydrophilic, non-hygroscopic, have high hydrogen-bonding propensity, have a high glass transition temperature (Tg), and be safe to use. This review discusses sugars and polyols as suitable carriers for SDs, as they possess several ideal characteristics. Recently, the use of low-molecular-weight excipients has gained much interest in developing SDs. However, there are limited options available for safe, low molecular excipients, which opens the door again for sugars and polyols. The major points of this review focus on the successes and failures of employing sugars and polyols in the preparation of SDs in the past, recent advances, and potential future applications for the solubility enhancement of poorly water-soluble drugs.

In vitro profiling of fenofibrate solid dispersion mediated tablet formulation to treat high blood cholesterol

OBJECTIVE

Fenofibrate (FNF), an anti-hyperlipidemic agent, suffers from poor water solubility (0.000707mg/ml) and belongs to class II drug as per BCS, shows a slow dissolution rate. The current investigation aimed to fabricate a fast-dissolving tablet of FNF (not available in the commercial market) using solid dispersion technique employing Vitamin E-D-α-Tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) as molecular biomaterial to enhance dissolution rate and reduce the time required to reach the systemic circulation.

MATERIALS AND METHODS

Firstly, carrier material was selected based on the release study via preparing solid dispersion using the melting method, and prepared solid dispersion was characterized. Secondly, fast-dissolving tablets from solid dispersion were fabricated using the direct compression tool and characterized for X-ray diffraction (XRD) pattern, friability, hardness, content uniformity, weight variation and in vitro disintegration test.

RESULTS

The X-ray diffraction study confirmed the successful formation of solid dispersion using vitamin E TPGS by analyzing the change in physical state. The fabricated solid dispersion exhibited higher drug content than a physical mixture of FNF. An excipient interference study was also performed in methanol and 0.75% w/v sodium lauryl sulphate. It revealed no significant alterations in the absorption peak of FNF as analyzed using UV spectroscopy at 287nm. In addition, water absorption ratio phase solubility and wetting time were also assessed. In -vitro release of FNF from developed tablets was found significantly higher (93.23%±3.11; p<0.001) as compared to prepared compressed tablet of pure FNF (12.21±2.34%). The dissolution rate was also determined, and data were then kept to various kinetic models such as zero-order chemical kinetic, first-order chemical kinetic, Hixon-Crowell and Higuchi chemical kinetic.

CONCLUSION

A complete and sequential in vitro and physicochemical characterization of developed formulation was carried out to set-up improved and effective treatment for high blood cholesterol.

Vacuum Compression Molding as a Screening Tool to Investigate Carrier Suitability for Hot-Melt Extrusion Formulations

Hot-melt extrusion (HME) is the most preferred and effective method for manufacturing amorphous solid dispersions at production scale, but it consumes large amounts of samples when used for formulation development. Herein, we show a novel approach to screen the polymers by overcoming the disadvantage of conventional HME screening by using a minimum quantity of active pharmaceutical ingredient (API). Vacuum Compression Molding (VCM) is a fusion-based method to form solid specimens starting from powders. This study aimed to investigate the processability of VCM for the creation of amorphous formulations and to compare its results with HME-processed formulations. Mixtures of indomethacin (IND) with drug carriers (Parteck^® MXP, Soluplus^®, Kollidon^® VA 64, Eudragit^® EPO) were processed using VCM and extrusion technology. Thermal characterization was performed using differential scanning calorimetry, and the solid-state was analyzed via X-ray powder diffraction. Dissolution studies in the simulated gastric fluid were performed to evaluate the drug release. Both technologies showed similar results proving the effectiveness of VCM as a screening tool for HME-based formulations.

Hypromellose acetate succinate based amorphous solid dispersions via hot melt extrusion: Effect of drug physicochemical properties

In this study, the impact of drug and hydroxypropyl methylcellulose acetate succinate (HPMCAS) grades physicochemical properties on extrusion process, dissolution and stability of the hot melt extruded amorphous solid dispersions (ASDs) of nifedipine and efavirenz was investigated. Incorporation of drugs affected the extrusion temperature required for solid dispersion preparation. Differential scanning calorimetry and powder X-ray diffraction studies confirmed the amorphous conversion of the drugs in the prepared formulations. The amorphous nature of ASDs was unchanged after 3 months of stability testing at 40 °C and 75% relative humidity. The dissolution efficiency of the ASDs was dependent on the log P of the drug. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and dose of the drug. The dissolution efficiency and dissolution rate of the ASDs were dependent on the log P of the drug and solubility and hydrophilicity of the polymer grade respectively. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and the dissolution dose of the drug.

Development and Characterisation of Modified Release Hard Gelatin Capsules, Based on In Situ Lipid Matrix Formation

A new technology was developed to form extended release hard gelatin capsules, based on the lipid matrix formation of Gelucire 50/13 and cetostearyl alcohol. Matrices were formed in situ by filling pulverised lipids, ethylcellulose and active ingredients such as diclofenac sodium, acetaminophen and metronidazol into capsules and heating at 63°C for 11 min. Effects of heating were investigated also on the brittleness of capsule shells. Inhibition of the evaporation of water reduced capsule damage. Dissolution tests and texture analysis were performed to discover the release and mechanical profiles of the matrices. Tests were repeated after 1 month storage and results were compared. Gelucire 50/13 alone prolonged drug release but cetostearyl alcohol slowed drug liberation even further. Drug release from all compositions was found to follow first-order kinetic. Significant softening of the matrices was detected during storage in composition containing only Gelucire 50/13, ethylcellulose and diclofenac sodium. Thermal analysis and IR tests were also performed to discover physicochemical interactions between active pharmaceutical ingredients and excipients. Thermal analysis confirmed a notable interaction between diclofenac sodium and Gelucire 50/13 which could be the cause of the observed softening. In conclusion, modified release hard gelatin capsules were developed by a simple and fast monolithic lipid matrix formation method.

Lacidipine Amorphous Solid Dispersion Based on Hot Melt Extrusion: Good Miscibility, Enhanced Dissolution, and Favorable Stability

The present study aimed to increase the in vitro dissolution rate of lacidipine, a poorly water-soluble drug, by formulating amorphous solid dispersions (ASDs) using hot-melt extrusion (HME). Differential scanning calorimetry, powder X-ray diffraction, polarized light microscopy, and Fourier transform infrared were used to characterize the optimal formulations and evaluate the physical stability for the stress test. Film-casting method and hot-stage microscopy were applied to study the miscibility of lacidipine and the drug carriers. In vitro dissolution tests were conducted as the final evaluation index. The optimal formulations were successfully obtained with Soluplus and PVP VA64 at a drug/carrier ratio of 1:10 (w/w), Fourier transform infrared studies revealed the hydrogen bonding between drug and polymers, and in vitro dissolution rates of the optimal formulations were extremely enhanced compared to bulk lacidipine and physical mixtures, similar with that of the commercial tablet. The ASD formulated with Soluplus showed better physical stability than that with PVP VA64. A strong hydrogen bonding and good drug-polymer miscibility were essential to hinder the recrystallization of lacidipine ASDs. In conclusion, the lacidipine ASD formulated with Soluplus showed a significant increase in in vitro dissolution rate and favorable physical stability in the stress test.