Preparation and Evaluation of Naproxen Adsorbate as an Attempt to Improve Drug Dissolution Characteristics

Abstract

Naproxen is a nonsteroidal anti-inflammatory drug which shows variable absorption and bioavailability due to its poor solubility. In this study we aimed to improve the dissolution rate of the drug by solvent deposition onto certain adsorbents including porous silica, Avicel and Bentonite. Physical mixtures of naproxen with the investigated adsorbents were also prepared. The molecular behavior of naproxen in the investigated systems were studied using infrared absorption spectra, differential scanning calorimetry and X-ray diffraction analysis. The dissolution rate of the drug was also investigated. The obtained results indicated that naproxen was transformed to the amorphous state in case of mixtures loaded with porous silica. This transformation resulted in a significant enhancement of the dissolution rates of the drug. In addition, it was noticed that, the drug: adsorbents weight ratio of the prepared mixtures influenced the drug dissolution rate enhancement. Accordingly, it can be concluded that, by increasing the weight ratio of the used adsorbent in the mixture, the larger the enhancement in the dissolution rate of naproxen will be obtained.

The Effect of Betacyclodextrin on the Solubility and Dissolution of Spironolactone Using Physical Mixing and Co-Evaporation Methods

“…The percent released after one hour in case of Solubility µg/ml Solubility µg/ml SIF was 56.14,59.63,51.28,58.62,60.08,49.68 and 57.08 for plain drug, physical mixtures (1:1, 1:2 and 1:3) and co-evaporates (1:1, 1:2 and 1:3), respectively. The increased dissolution rate of spironolactone from physical mixtures may be due to the deaggregation of spironolactone clumps achieved by the carriers in the dissolution medium (Kadir et al, 2012, Ismail et al, 2004. The dissolution improvement of spironolactone from solid dispersion might be due to lowering of surface tension between drug and solvent as well as decreased crystallinity of the product (Kalaiselvan et al, 2006).…”

Utilization of Co-evaporation Technique for Enhancement the Solubility and Dissolution Rate of Etodolac

“…Regarding solid dispersion, there are several types of hydrophilic carriers that could be used in the preparation of solid dispersion systems such as polyethylene glycols (PEGs) [17], polyvinyl pyrollidones (PVPs) [18], cellulose derivatives [19], urea [20], sugars (lactose, mannitol and sorbitol) [21] and organic acids such as citric acid [22][23][24]. Alternatively, several insoluble inert carriershave been used for drugs deposition (surface adsorption), including disintegerants [25], microcrystalline cellulose (Avicel) [26], colloidal silicon dioxide (Aerosil 200) [27], porous calcium silicates (Florite R) [28], magnesium aluminum silicate (kaolin) [29] and colloidal hydrated aluminum silicate (Bentonite) [30]. Solid coevaporates of ETD with different excipients can be characterized by different physicochemical methods such as powder x-ray diffraction analysis (XRD), IR spectroscopy, ultraviolet spectrophotometry [15] and thermal analysis such as the differential scanning calorimetry (DSC), thermo mechanical analysis (TMA), hot stage microscopy (HSM) and thermogravimetry (TG).…”