Evaluation of natural and pregelatinized forms of three tropical starches as excipients in tramadol tablet formulation

Characterization of Channeling Effects Applied to Extended-Release Matrix Tablets Containing Pirfenidone

Pirfenidone (PRF) is an anti-fibrotic agent that has been approved by the Food and Drug Administration (FDA) for the treatment of mild to moderate idiopathic pulmonary fibrosis. However, the current oral administration dosing regimen of PRF is complex and requires high doses. Patients are instructed to take PRF three times daily, with each dose consisting of up to three capsules or tablets (600 mg/d or 1.8 g/d of PRF) taken with food. To improve the dosing regimen, efforts are being made to develop an extended-release tablet with a zero-order release pattern. In this study, two types of extended-release matrix tablets were compared: non-channeled extended-release matrix tablets (NChMT) and channeled extended-release matrix tablets (ChMT). In vitro release tests, swelling and erosion index, rheology studies, and X-ray microcomputed tomography (XRCT), were conducted. The results indicated that ChMT maintained a zero-order release pattern with a constant release rate, while NChMT exhibited a decreased release rate in the latter half of the dissolution. ChMT exhibited accelerated swelling and erosion compared to other formulations, and this was made possible by the presence of channels within the tablet. These channels allowed for thorough wetting and swelling throughout the entire depth of the tablet. The formation of channels was confirmed through XRCT images. In conclusion, the presence of channels in ChMT tablets increased the rate of swelling and erosion, resulting in a zero-order release pattern. This development offers the potential to improve the dosage of PRF and reduce its associated side effects.

Role of Surfactant Micellization for Enhanced Dissolution of Poorly Water-Soluble Cilostazol Using Poloxamer 407-Based Solid Dispersion via the Anti-Solvent Method

This study aimed to investigate the role of micellization of sodium lauryl sulfate (SLS) in poloxamer 407 (POX)-based solid dispersions (POX-based SDs) using the anti-solvent method in enhancing the dissolution rate of practically water-insoluble cilostazol (CLT). Herein, SLS was incorporated into CLT-loaded SDs, at a weight ratio of 50:50:10 of CLT, POX, and SLS by three different methods: anti-solvent, fusion (60 °C), and solvent (ethanol) evaporation. The SDs containing micellar SLS in the anti-solvent method were superior in the transformation of the crystalline form of the drug into a partial amorphous state. It was notable that there was an existence of a hydrophobic interaction between the surfactant and the hydrophobic regions of polymer chain via non-covalent bonding and the adsorption of micellar SLS to the POX-based SDs matrix. Moreover, SLS micellization via the anti-solvent method was effectively interleaved in SDs and adhered by the dissolved CLT, which precluded drug particles from aggregation and recrystallization, resulting in improved SD wettability (lower contact angle) and reduced particle size and dissolution rate. In contrast, SDs without micellar SLS prepared by the solvent method exerted drug recrystallization and an increase of particle size, resulting in decreased dissolution. Incorporation of surfactant below or above critical micellar concentration (CMC) in SDs using the anti-solvent method should be considered in advance. Dissolution results showed that the pre-added incorporation of micellar SLS into POX-based SDs using the anti-solvent method could provide a way of a solubilization mechanism to enhance the dissolution rate of poorly water-soluble drugs.

Preparation and characterization of metformin hydrochloride controlled-release tablet using fatty acid coated granules

Metformin hydrochloride (MFM) is often used as a controlled-release (CR) tablet to reduce dosing frequency. However, the MFM CR tablet contains significant amounts of excipients and the tablet size is also large. Dosing convenience and patient compliance can be increased by reducing the size of the CR tablets. The aim of this study was to prepare and evaluate the MFM controlled-release tablet (MFM-CRT) using two types of release modulators, inner and outer. The MFM-CRT was prepared by coating the MFM granules using a binder solution containing aluminum stearate (ALS) as the inner release-modulator, and polyethylene oxide (PEO) as the outer release-modulator. The dispersion stability of the binder solution was optimized by the dispersion analyzer. The MFM-CRT was evaluated for dissolution rate and tablet volume. Additionally, dissolution behavior and dissolution kinetics of the MFM-CRT were analyzed using micro-computed tomography (micro-CT). Although the optimal MFM-CRT showed no difference in the release rate as compared to the commercially available product of Glucophage^® XR 500 mg (f₂ value: 72), the length of the long axis was reduced by 6 mm and the weight was reduced by about 27%. We expect patient compliance to improve because of effective sustained release and volume reduction of MFM-CRT.

Current Status of Supersaturable Self-Emulsifying Drug Delivery Systems

Self-emulsifying drug delivery systems (SEDDSs) are a vital strategy to enhance the bioavailability (BA) of formulations of poorly water-soluble compounds. However, these formulations have certain limitations, including in vivo drug precipitation, poor in vitro in vivo correlation due to a lack of predictive in vitro tests, issues in handling of liquid formulation, and physico-chemical instability of drug and/or vehicle components. To overcome these limitations, which restrict the potential usage of such systems, the supersaturable SEDDSs (su-SEDDSs) have gained attention based on the fact that the inclusion of precipitation inhibitors (PIs) within SEDDSs helps maintain drug supersaturation after dispersion and digestion in the gastrointestinal tract. This improves the BA of drugs and reduces the variability of exposure. In addition, the formulation of solid su-SEDDSs has helped to overcome disadvantages of liquid or capsule dosage form. This review article discusses, in detail, the current status of su-SEDDSs that overcome the limitations of conventional SEDDSs. It discusses the definition and range of su-SEDDSs, the principle mechanisms underlying precipitation inhibition and enhanced in vivo absorption, drug application cases, biorelevance in vitro digestion models, and the development of liquid su-SEDDSs to solid dosage forms. This review also describes the effects of various physiological factors and the potential interactions between PIs and lipid, lipase or lipid digested products on the in vivo performance of su-SEDDSs. In particular, several considerations relating to the properties of PIs are discussed from various perspectives.

Facile fabrication of hyaluronated starch nanogels for efficient docetaxel delivery

In this study, we designed and synthesized polysaccharidic nanogels comprising starch cross-linked with hyaluronic acid. These hyaluronated starch nanogels were prepared by cross-linking primary hydroxyl groups in polysaccharides (starch and hyaluronic acid) and epoxide groups in 1,4-butanediol diglycidyl ether (used as a cross-linking agent). The nanogels take advantage of hyaluronic acid as a specific ligand for CD44 receptors overexpressed on tumors and the hyaluronic acid/starch core as a compartment for the encapsulation of docetaxel (as model antitumor drug). Here, hyaluronic acid can be enzymatically degraded by tumor cell–specific enzyme (e.g. hyaluronidase-1), which could significantly accelerate docetaxel release from the nanogels. Our experimental results demonstrate that the nanogels promote the release of docetaxel content in the presence of hyaluronidase-1 enzyme. As a result, the nanogels selectively inhibited MCF-7 (with CD44 receptor and hyaluronidase-1 enzyme) tumor cell growth in vitro, suggesting their therapeutic potential for efficient tumor ablation.

Characterization and evaluation of the performance of different calcium and magnesium salts as excipients for direct compression

The performance of a series of inorganic salts as direct compression excipients was systematically evaluated. The physical-chemical and technological properties of the different salts were investigated in terms of crystalline/amorphous state, morphology, granulometry, apparent/tapped density, specific surface area, flowability, compressibility, dilution and distribution coefficients. To achieve a comprehensive evaluation of the performance of the different salts, the data obtained by the various analyses were normalized, giving a score to each excipient for each evaluated property/parameter. Statistical elaboration (JMP software) of the full dataset provided a final ranking of the powders based on their effectiveness as direct compression excipients. The salt emerged as the best was used to prepare direct-compression tablets, using cefixime as model drug, by modifying the composition of marketed tablets. A significant improvement of the mechanical properties of the new tablets was observed, compared to the marketed ones, with a crushing strength increase of over 30%, without variations of the drug dissolution profile. Even though the resulted ranking cannot have an absolute value, being the behavior of the different excipients susceptible to the kind of drug and other formulation excipients, the proposed approach can provide a useful model for a systematic evaluation and comparison of potentially similar excipients.

Multivariate Statistical Optimization of Tablet Formulations Incorporating High Doses of a Dry Herbal Extract

The development of oral tablet formulation for herbal medicines has been restricted by large drug loadings and the poor physicochemical and mechanical properties of dry herbal extracts (DHEs). Herein, statistical experimental designs were applied to herbal tablet formulation development and optimization using Wuzi Yanzong dry extract (WYE). The tablet disintegration time and hardness were identified as the critical quality attributes (CQAs) of the product. The tablet formulation was designed to achieve a high drug loading (50% or higher of WYE), shorter tablet disintegration time (less than 30 minutes), and suitable hardness (6.0 to 7.5 kp). A D-optimal mixture design was used to evaluate the effects of excipients on CQAs to minimize the risk compression failure and improve the tabletability in formulations containing WYE at 50% and 65% by weight. A partial least squares model was used to elucidate the multivariate relationships between a large number of formulation variables and product CQAs, and determine the maximum possible WYE loading. From overlaid plots of the effects of formulation variables on CQAs, it was found that a maximum WYE loading of 67% in tablet formulation satisfied the acceptance criteria of CQAs. In conclusion, this study shows that multivariate statistical tools are useful for developing tablet formulations containing high doses of herbal extracts and establishing control strategies that ensure product quality.