Optimization of fast dissolving etoricoxib tablets prepared by sublimation technique

A Critical Review on Analytical Methods for Recently Approved FDC Drugs: Pregabalin and Etoricoxib

Fixed-dose combinations (FDCs) refer to products containing two or more active ingredients combined in a single dosage form. The FDCs are justified because of several advantages. These are a) potentiating therapeutic efficacy, b) reducing the incidences of adverse drug effects, c) having pharmacokinetic advantages, d) reducing pills burden, e) reducing the dose of individual drugs and f) decreasing the drug resistance development. A recently approved FDC of Pregabalin IP (75 mg) and Etoricoxib (60 mg) recommended to control neuropathic chronic back pain. Analytical methods are available for individual quantitation of pregabalin (PGB) and etoricoxib (ETC), but an effective and reliable analytical method has not been reported for their combination. Thus, the objective of this literature survey was to gather information on various analytical instrumental methods used so far for the individual quantitation of PGB and ETC in various matrices. Such data would be useful to the scientific community to develop a novel analytical method for the analysis of recently approved FDC of PGB and ETC. Various scientific databases were explored to meet the objectives, and the information is synchronized. The reported methods are high-performance liquid chromatography (48% & 53%), hyphenated techniques (54% & 21%), spectroscopy (50% & 34%), and high-performance thin-layer chromatography, or thin-layer chromatography (6% & 13%) for pregabalin and etoricoxib, respectively. All these methods were specific and selective for the analysis of individual drugs.

Formulation and Characterization of Solid Dispersions of Etoricoxib Using Natural Polymers

Objectives

The main objective of the present investigation to develop and evaluate solid dispersions of BCS Class II drugs etoricoxib employing various natural polymers, compatible with conventional manufacturing method to enhance solubility of poorly soluble drugs.

Materials and Methods

In this study, etoricoxib solid dispersion were prepared using xanthan gum, gaur gum and acacia and their combinations by solvent evaporation method. Solid dispersions and pure etoricoxib in the form of powder were characterized in comparison with pure drug and corresponding physical mixtures in the same ratios by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), powder X-ray diffractogram, and in vitro drug release.

Results

Solid dispersion (ET11) prepared with 1: 2: 2: 2 drug carrier ratios were showed highest solubility in different solvents. Hence the solid dispersion (ET11) of 1: 2: 2: 2 ratios were selected for characterization. The DSC study indicated that the crystalline nature of etoricoxib was reduced to amorphous. The diffraction pattern of the solid dispersions in each figure indicates that diffraction peaks at 2ɵ values has less intensity than that of pure drugs. This indicated that the crystalline nature of drug sample was converted to amorphous with ET11. Scanning electron microscope photographs of solid dispersion seem to be more porous in nature. From the in vitro drug release profile, it can be seen that formulation ETM11 shows higher dissolution rate i.e. 98.2±1.3% compared with other formulations. It is predicted that, increasing concentration of carrier, increases the drug dissolution rate.

Conclusion

This study has shown that the solid dispersion of etoricoxib using natural carrier can be promising formulation for solubility and dissolution enhancement. Natural polymers used have shown promising results in the modification of drug release from the formulations.

Formulation and evaluation of mouth disintegrating tablets of atenolol and atorvastatin

In this study, mouth-disintegrating tablets of atenolol and atorvastatin combination were formulated using superdisintegrants to impart fast disintegration. Fifteen formulations were prepared based on different concentrations of two superdisintegrants, croscarmellose sodium and Kyron-T₁₃₄. Three different techniques such as direct compression, effervescent and sublimation were used to study the effect of manufacturing processes, nature and concentration of superdisintegrants on various features of these tablets. Five formulations were made using each method. Precompression studies like bulk density, tapped density, angle of repose, Carr's compressibility index, Hausner's ratio and compatibility studies such as Fourier transform infrared spectroscopy and differential scanning calorimetry were performed. Various features such as hardness, thickness, diameter, weight variation, friability, disintegration time, dissolution studies, wetting time, wetting volume, water absorption ratio, modified disintegration, uniformity of contents and stability were evaluated. Finally results were statistically analyzed by the application of one way ANOVA test. Formulation F₁₃ containing Kyron-T₁₃₄ (6%) and croscarmellose sodium (2%) was found to be the best among all fifteen formulations prepared in all aspects evaluated. Sublimation method is found to be the best among three methods of preparation used.

Solubility Enhancement of Etoricoxib by Cosolvency Approach

The purpose of the present study was to examine and compare the cosolvency using three different cosolvents, namely PEG 400, PG, and glycerin on the aqueous solubility enhancement of a poorly aqueous soluble drug, etoricoxib, since solubilization of nonpolar drugs constitutes one of the important tasks in the formulation design of liquid dosage forms. The aqueous solubility of etoricoxib was  mg/mL, which was significantly improved by the addition of PEG 400, PG, and glycerin as cosolvents. It was scrutinized that the less-polar solvents were found to increase the aqueous solubility by greater extent, thus accentuating hydrophobic interaction mechanism. Among various solvent-cosolvent blends investigated, water-PEG 400 showed highest solubilization potential. Thus, the study generated an important array of data to compare the effect of these cosolvents on the aqueous solubility of etoricoxib.

Development of sildenafil-loaded orally disintegrating tablet with new lactate salt

To develop a sildenafil lactate-loaded orally disintegrating tablet with a faster drug effect onset and immediate action of erection, the orally disintegrating tablets were prepared with various amounts of menthol and colloidal silica using the direct compression technique followed by vacuum drying. Their tablet properties such as friability, hardness, wetting time and disintegration time were investigated. The oral bioavailability of sildenafil in the orally disintegrating tablet was then compared with the sildenafil citrate-loaded commercial tablet (Viagra(®)) in rabbits. Sildenafil lactate was a new salt form with more improved solubility and alleviated bitterness compared with commercial salt, sildenafil citrate. As the amount of menthol in the orally disintegrating tablet increased, the friability increased and hardness decreased, resulting in a shorter wetting time and disintegration time. Colloidal silica did the opposite. The sildenafil lactate-loaded orally disintegrating tablet prepared with 45 mg/tab of menthol and 1.5 mg/tab of colloidal silica gave a hardness of 3-4 KP, friability less than 0.5% and disintegration time less than 30 s, suggesting that it was a practical and commercial product with good tablet property and excellent efficacy. Furthermore, it gave higher AUC and C(max), and shorter T(max) values than did the commercial tablet, indicating that it improved the oral bioavailability of sildenafil in rabbits compared with the commercial tablet. Thus, the sildenafil lactate-loaded orally disintegrating tablet might induce a fast onset of action and immediate erection compared with the sildenafil citrate-loaded commercial tablet.

Solubility and dissolution enhancement of etoricoxib by solid dispersion technique using sugar carriers

The aim of the present study was to improve solubility and dissolution of the poorly aqueous soluble drug, etoricoxib by solvent evaporation technique using various sugar carriers, such as lactose, sucrose, and mannitol. Etoricoxib solid dispersions and their respective physical mixtures using lactose, sucrose, and mannitol were prepared in different ratios by solvent evaporation technique. The percent yield, drug content, saturation solubility, and in vitro dissolution of etoricoxib solid dispersions and physical mixtures were analyzed. Etoricoxib solid dispersions were characterized by FTIR spectroscopy, XRD, and DSC analysis. The FTIR spectroscopic analysis revealed the possibility of intermolecular hydrogen bonding in various solid dispersions. The XRD and DSC studies indicated the transformation of crystalline etoricoxib (in pure drug) to amorphous etoricoxib (in solid dispersions) by the solid dispersion technology. Both the aqueous solubility and dissolution of etoricoxib were observed in all etoricoxib solid dispersions as compared with pure etoricoxib and their physical mixtures. The in vitro dissolution studies exhibited improved dissolution in case of solid dispersion using lactose than the solid dispersions using both sucrose and mannitol. The in vitro dissolution of etoricoxib from these solid dispersions followed Hixson-Crowell model.

The technologies used for developing orally disintegrating tablets: a review

Orally disintegrating tablets (ODTs), also known as fast melts, quick melts, fast disintegrating and orodispersible systems, have the unique property of disintegrating in the mouth in seconds without chewing and the need of water and are thus assumed to improve patient compliance. Conventional methods like direct compression, wet granulation, moulding, spray-drying, freeze-drying and sublimation were used to prepare ODTs. New advanced technologies like Orasolv®, Durasolv®, Wowtab®, Flashtab®, Zydis®, Flashdose®, Oraquick®, Lyoc®, Advatab®, Frosta®, Quick-Disc® and Nanomelt® have been introduced by some pharmaceutical companies for the production of ODTs. The main objective of this review is to give a comprehensive insight into conventional and recent technologies used for the preparation of ODTs.

A pilot human pharmacokinetic study and influence of formulation factors on orodispersible tablet incorporating meloxicam solid dispersion using factorial design

Meloxicam (MLX) suffers from poor aqueous solubility leading to slow absorption following oral administration; hence, immediate release MLX tablet is unsuitable in the treatment of acute pain. This study aims to overcome such a drawback by increasing MLX solubility and dissolution using PEG solid dispersion (SD), then, to investigate the feasibility of incorporating the SD into orodispersible tablets (ODTs). A 2(3) full factorial design was employed to investigate the influence of three formulation variables on MLX ODTs. The selected factors: camphor (X(1)) as pore-forming material, and croscarmellose sodium (X(2)) as superdisintegrant, showed significant positive influence, while PEG content (X(3)) was proved to negatively affect both disintegration and wetting times. In addition, isomalt increased disintegration and wetting times when compared to mannitol as diluents. The pharmacokinetic assessment of the optimum ODT formulation in healthy human subjects proved that the faster MLX dissolution by using PEG solid dispersion at pH 6.8 resulted in more rapid absorption of MLX. The rate of absorption of MLX from ODT was significantly faster (p = 0.030) with a significantly higher peak plasma concentration (P = 0.037) when compared to the marketed immediate release MLX tablet with a mean oral disintegration time of 17 ± 3 s.