Enhancement of the dissolution profile of the diuretic hydrochlorothiazide by elaboration of microspheres

Abstract

Hydrochlorothiazide (HCTZ), which was developed and introduced in the late 1950s, is still one of the most frequently employed drugs in antihypertensive treatments. Its poor aqueous solubility is one of the reasons for its limited bioavailability after oral administration. The present paper provides details of the preparation of HCTZ-loaded microspheres by the solvent evaporation technique. A total of seven formulations were prepared using ethyl cellulose, poly(?-caprolactone) (PCL), ?-cyclodextrin (?-CD) and synthesized poly-(methyl methacrylate) (PMMA) of different molecular weights in different drug-to-carrier ratios in order to investigate their effect on the encapsulation efficiency and drug release kinetics. The prepared formulations were characterized by Fourier transform-infrared (FTIR) spectroscopy, powder X-ray diffractometry, differential scanning calorimetry, yield, drug loading, optical microscopy, surface morphology by scanning electron microscopy (SEM), and in vitro release studies in simulated gastrointestinal tract fluid. The loading efficiency was found in the range from 18?0.34 to 39?0.95 %. The microspheres were spherical, and the mean Sauter diameter (d32) of the obtained microparticles ranged from 26?0.16 to 107?0.58 ?m. The presence of the drug and polymer carriers in the microparticles was confirmed by FTIR spectroscopy and XRD analysis. In vitro dissolution studies showed that the release rate was largely affected by the characteristics of the microparticles, namely the particle size and the nature of the matrix. The release data are best fitted to the Higuchi model with high correlation coefficients (r?).

Crystal products of lamotrigine-citric acid for improvement of in vitro drug release in simulated gastric fluid

“…The release profile of the drug from different crystal products was estimated in a USP XXIII dissolution testing apparatus (Dissolution tester (USP) TDT06L, Electrolab) using rotating paddle method. 10,18 For the experiment, a weighed amount of powder sample of LT (100 mg) and selected crystal products (100 mg equivalent LT) were placed in a dissolution vessel rotated at 50 rpm at 37±0.5 °C. Simulated gastric fluid (900 ml of 0.1 M HCl at pH 1.2) was taken as the release medium.…”

Improved dissolution of ibuprofen after crystallization from polymeric solution: Correlation with crystal parameter

“…However, being a class II type drug (under Biopharmaceutical Classification System), the main problem associated with the oral administration is its extremely low solubility in aqueous media. 7,8 Thus, its dissolution rate is the major limiting step for the successful absorption of the drug to achieve desired onset of action. Several advanced formulation techniques have been reported over the past years to improve the solubility and bioavailability of IBU.…”

Effect of Polymers nature and Stirring Speeds on Physicochemical Properties and the Controlled Release of Allopurinol-loaded Microspheres

“…In addition, several carrier systems have recently been used to produce fast-release solid formulations. Cellulose derivatives such as ethylcellulose (EC) [11][12][13][14][15][16][17][18] and hydroxypropylmethylcellulose HPMC [12,15,19,20] with non-toxic and non-irritating properties, as well as hydrophilic properties, were selected for the development of controlled-release technology in the formulation of pharmaceutical products.…”

“…Therefore, the biocompatibilities of different biodegradable polymers such as poly (ε-caprolactone) PCL [18,21,22,23] as candidate materials for different biomedical applications have been extensively investigated. Then, due to their broad spectrum of physical properties and hydrolytic degradation profiles, they have become attractive candidates for human use as surgical sutures, implantable devices, and drug delivery systems by the United States Food and Drug Administration (FDA) [24][25][26].…”

“…Our research group recently reported on the production of HCTZ loaded microspheres using various matrices such as ethylcellulose, poly (ε-caprolactone), β-cyclodextrin and poly (methyl methacrylate) (PMMA), synthesized in different fractions to investigate their effects on encapsulation efficiency and drug release kinetics [18]. Continuing our efforts to discover new drug formulations that gradually release the active ingredient to remedy the deficiencies of conventional dosage forms and, in particular, to avoid the need for repeated administrations [18], we present Allopurinol encapsulation using various matrices with different compositions such as EC, HPMC, β-CD and PCL, so the solvent evaporation method is used for the sustained release of this active ingredient. The study also aimed to characterize the Allop interaction with these carriers in the solid-state using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) to check the dissolution behavior of microparticles.…”