Design, characterization and in vitro evaluation of HPMC K100 M CR loaded Fexofenadine HCl microspheres

Abstract

The aim of the current study was to formulate Fexofenadine hydrochloride loaded sustained release microspheres using HPMC K100 M CR, a release retardant hydrophilic polymer by solvent evaporation method. The effect of different drug loading on drug content, drug encapsulation efficiency and release of drug was monitored. The studies on in vitro release mechanism were performed using USP paddle method with 900 ml of phosphate buffer (pH 6.8) for 10 h at 100 rpm. The mechanism of the drug release was determined by fitting in vitro release data to various release kinetic models such as the zero order, first order, Higuchi, Hixson Crowell and Korsemeyer–Peppas model and finding R2 values for the release profile corresponding to each model. The results confirm that the release rate of the drug from the microspheres is highly affected by the drug to polymer ratio. The study finds that Higuchi release kinetics, Korsmeyer–Peppas release kinetics and Hixson–Crowell release kinetics were the major release mechanism. The release mechanism was found to be non-Fickian with increase of polymer content. Scanning electron microscopic technique was performed to obtain the morphological changes due to different drug loading. Differential scanning calorimetry and Fourier transform infra-red spectroscopy was performed to determine any interaction of drug with the polymer. A statistically significant variation in release rate was observed for variation in the amount of HPMC K100 M CR. In the present study, a series of sustained release formulations of Fexofenadine hydrochloride were developed with different drug loading so that these formulations could further be evaluated from the in vivo studies. The formulations were found to be stable and reproducible.

Optimized chronomodulated dual release bilayer tablets of fexofenadine and montelukast: quality by design, development, and in vitro evaluation

“…For immediate release fexofenadine HCl formulations, the value of the coefficient of correlation (r 2 ) for the best fit model and diffusion exponent (n) ranges from 0.8107 to 0.9864 and 0.334 to 0.390, respectively. Depending upon the value of the diffusion exponent (n), the Fickian diffusion mechanism is dominant among immediate release formulations (Table 4) [28].…”

“…As a result, a glassy matrix gradually transforms into a rubbery swollen gel. The higher concentrations of HPMC resulted in enhanced viscosity that retards the drug's diffusion coefficient [28]. The magnesium stearate is hydrophobic in nature and forms a film at the surface of API and excipients that causes the dissolution medium to stay on the surface, thus decreasing wettability of the formulation and thereby decreasing the dissolution rate [29] (Fig.…”

Effect of Rumex Acetosa Extract, a Herbal Drug, on the Absorption of Fexofenadine

“…To evaluate the possible physicochemical interactions between R. acetosa extract and fexofenadine, FT-IR spectra of extract, fexofenadine and mixture were measured and are shown in Figure 6 . The FT-IR spectrum of fexofenadine HCl showed the characteristic absorption bands at 3291.03 (OH stretching), 2936.14 (CH stretching), 2639.82 (OH of carboxylate), 1698.68 (CO stretching), 1448.00, 1403.11 (C=C stretching of aromatic ring), 1167.57 (CO stretching of tertiary alcohol) and 1067.94 (CO stretching of secondary alcohol) [ 38 , 39 ]. According to Figure 6 , the mixture of R. acetosa extract and fexofenadine HCl showed the same bands compared to the pure fexofenadine HCl.…”

An overview of microcapsule dosage form

“…Microencapsulation [2][3][4]11,16,18,20,[23][24][25][26][27] Already established and yet to be improved methods are as follows: 6. Microcapsule Characterization: 3,15,26 Microcapsule is a significant technology by which a feasible protein, active agent or antigen medium can be developed. The characterization parameters are:…”

“…6,13,14 Many more uses and applications can be explored for obtaining better convenience for patients. 3,15 Conventional oral drug administration does not usually provide rate-controlled release or target specificity. 16 In many cases, conventional drug delivery provides sharp increase in drug concentration often achieving toxic level and following a relatively short period at the therapeutic level of the drug concentration eventually drops off until re-administration.…”