Evaluation of Uniform-Sized Microcapsules Using a Vibration-Nozzle Method

Effects of nano zinc oxide and nano chitosan on the taste masking paracetamol granules

OBJECTIVE

The purpose of this study is to investigate the taste masking of Paracetamol granules in the range of 250-850 µm, coated by two nanocomposites prepared from Eudragit® E100, nanozinc oxide, and nanochitosan, respectively, from 1 to 5% by the weight of the granules.

METHODS

In this study, Paracetamol granules were coated in several formulas with two different types of nanocomposites (polymeric and mineral) on two sizes of granules to reduce bitter taste and with the FBC method and pH-sensitive polymers (Eudragit® E100).

RESULTS

The effect of nanoparticles (Nano zinc oxide and Nanochitosan) on taste-masking Paracetamol was studied with dissolution-coated granules in vitro by simulating in the oral (pH 6.8) range. Based on the results of the studies, the rate of drug release was confirmed by the taste test, and the formulated granule with 5% nano-chitosan (F14) had the best bitter taste mask function of all samples. These results were also confirmed by scanning electron microscopy (SEM) analysis, which showed a smoother and more stable surface than the samples obtained from other formulations.

CONCLUSION

In the comparison of the release of two types of nanocomposites in the dissolution test, it was shown that the type B granules of Paracetamol's 5% nano-chitosan-coated granule (F14) were released 99% less than Paracetamol's 5% nano-ZnO-coated granule (F11). and Paracetamol's 1% nano-chitosan-coated granule (F12) was released 91% less than Paracetamol's 1% nano-ZnO-coated granule (F9). The results showed that nano-chitosan-coated granules have better coverage of bitter taste instead of nano-ZnO.

pH- and ion-sensitive polymers for drug delivery

INTRODUCTION

Drug delivery systems (DDSs) are important for effective, safe, and convenient administration of drugs. pH- and ion-responsive polymers have been widely employed in DDS for site-specific drug release due to their abilities to exploit specific pH- or ion-gradients in the human body.

AREAS COVERED

Having pH-sensitivity, cationic polymers can mask the taste of drugs and release drugs in the stomach by responding to gastric low pH. Anionic polymers responsive to intestinal high pH are used for preventing gastric degradation of drug, colon drug delivery and achieving high bioavailability of weak basic drugs. Tumor-targeted DDSs have been developed based on polymers with imidazole groups or poly(β-amino ester) responsive to tumoral low pH. Polymers with pH-sensitive chemical linkages, such as hydrazone, acetal, ortho ester and vinyl ester, pH-sensitive cell-penetrating peptides and cationic polymers undergoing pH-dependent protonation have been studied to utilize the pH gradient along the endocytic pathway for intracellular drug delivery. As ion-sensitive polymers, ion-exchange resins are frequently used for taste-masking, counterion-responsive drug release and sustained drug release. Polymers responding to ions in the saliva and gastrointestinal fluids are also used for controlled drug release in oral drug formulations.

EXPERT OPINION

Stimuli-responsive DDSs are important for achieving site-specific and controlled drug release; however, intraindividual, interindividual and intercellular variations of pH should be considered when designing DDSs or drug products. Combination of polymers and other components, and deeper understanding of human physiology are important for development of pH- and ion-sensitive polymeric DDS products for patients.

The evaluation of coated granules to mask the bitter taste of dihydroartemisinin

The purpose of this study was to mask the bitter taste imparted by dihydroartemisinin (DHA) by the use of different coating materials. Trial-1 and trial-2 were conducted to prepare the DHA granules. The granules produced from trial-1 were irregular in shape and smaller in size while the trial-2 granules were more regular and larger in size. The granules obtained from both trials were then coated with two different coating methods, namely A and B, depending upon coating material. The trial-2 granules showed better flow properties than trial-1 granules. In vitro dissolution studies in phosphate buffer at pH 6.8 revealed that granules of trial-2B released only 34% ± 3 DHA in two minutes compared with trial-1A (57% ± 2), trial-1B (48% ± 2) and trial-2A (53% ± 7). The pleasant taste perception (PTP) test also confirmed the taste masking efficacy of trial-2B (P < 0.05). Scanning electron microscopy (SEM) revealed the more regular and smooth surface of trial-2B granules. In addition, the differential thermal and thermogravimetric analysis (TG-DTA) confirmed no interaction between the materials and pure DHA. DHA has shown its characteristic peaks in the x-ray diffraction (XRD) patterns which were also prominent in all the granules. In conclusion, the granules obtained from trial-2B displayed considerable decrease in the bitter taste of DHA thereby fulfilling the purpose of this study.

Design and optimization of mefloquine hydrochloride microparticles for bitter taste masking

The objective of the present investigation was to reduce the bitterness with improved dissolution, in acidic medium (pH 1.2), of mefloquine hydrochloride (MFL). Microparticles were prepared by coacervation method using Eudragit E (EE) as polymer and sodium hydroxide as precipitant. A 3(2) full factorial design was used for optimization wherein the drug concentration (A) and polymer concentration (B) were selected as independent variables and the bitterness score, particle size and dissolution at various pH were selected as the dependent variables. The desirability function approach has been employed in order to find the best compromise between the different experimental responses. The model is further cross validated for bias. The optimized microparticles were characterized by FT-IR, DSC, XRPD and SEM. Bitterness score was evaluated by human gustatory sensation test. Multiple linear regression analysis revealed that the reduced bitterness of MFL can be obtained by controlling the dissolution of microparticles at pH 6.8 and increasing the EE concentration. The increase in polymer concentration leads to reduction in dissolution of microparticles at pH > 5 due to its insolubility. However the dissolution studies at pH 1.2 demonstrated enhanced dissolution of MFL from microparticles might be due to the high porosity of the microparticles, hydrophilic nature of the EE, and improved wettability, provided by the dissolved EE. The bitterness score of microparticles was decreased to zero compared to 3+ of pure ARM. In conclusion the bitterness of MFL was reduced with improved dissolution at acidic pH.

Characterization and taste-masking evaluation of acetaminophen granules: comparison between different preparation methods in a high-shear mixer

The aim of this study was to prepare and to investigate acetaminophen taste-masked granules obtained in a high-shear mixer using three different wet granulation methods (method A: water granulation, method B: granulation with a polyvinylpyrrolidone (PVP) binding solution and method C: steam granulation). The studied formulation was: acetaminophen 15%, alpha-lactose monohydrate 30%, cornstarch 45%, polyvinylpyrrolidone K30 5% and orange flavour 5% (w/w). In vitro dissolution studies, performed at pH 6.8, showed that steam granules enabled the lower dissolution rate in comparison to the water and binding solution granules; these results were then confirmed by their lower surface reactivity (D(R)) during the dissolution process. Moreover, the results of the gustatory sensation test performed by six volunteers confirmed the taste-masking effects of the granules, especially steam granules (P<0.001). Morphological, fractal and porosity analysis were then performed to explain the dissolution profiles and the results of the gustatory sensation test. Scanning electron microscopy (SEM) analysis revealed the smoother and the more regular surface of steam granules with respect to the samples obtained using methods A and B; these results were also confirmed by their lower fractal dimension (D(s)) and porosity values. Finally, differential scanning calorimetry (DSC) results showed a shift of the melting point of the drug, which was due to the simple mixing of the components and not to the granulation processes. In conclusion, the steam granulation technique resulted a suitable method to comply the purpose of this work, without modifying the availability of the drug.

Preparation, characterization and taste-masking properties of polyvinylacetal diethylaminoacetate microspheres containing trimebutine

The objectives of this study were to produce acid soluble, polyvinylacetal diethylaminoacetate (AEA) microspheres containing trimebutine (as maleate), using a water-in-oil-in-water (w/o/w) emulsion solvent evaporation method, to characterize their in-vitro release properties, and to evaluate the taste-masking potential of this formulation in human volunteers. The pH of the external aqueous phase was the critical factor in achieving a high loading efficiency for trimebutine in the microencapsulation process; nearly 90% (w/w) loading efficiency was obtained at above pH 10. Trimebutine was completely released from AEA microspheres within 10 min in a dissolution test at pH 1.2, simulating conditions in the stomach, whereas at pH 6.8, the pH in the mouth, only small quantities of trimebutine were released in the initial 1-2 min. The results of a gustatory sensation test in healthy volunteers confirmed the taste-masking effects of the AEA microspheres. Finally, an attempt was made to encapsulate the salts of other basic drugs (lidocaine, imipramine, desipramine, amitriptyline, promethazine and chlorpheniramine) into AEA microspheres using the w/o/w emulsion evaporation method. The loading efficiencies were ranked in almost inverse proportion with the solubility of the drugs in the external aqueous phase. This study demonstrated the possibility of masking the taste of salts of basic drugs by microencapsulation with AEA using a w/o/w emulsion solvent evaporation method.

Taste masking as a consequence of the organisation of powder mixes

Usually, chemical or technological operations are used to mask the taste of unpleasant-tasting drugs. To reduce the development cost of such drugs, we propose a new approach which does not require the modification of the existing formulation nor the use of additional costly technological operations. Different particle size fractions of two unpleasant-tasting drugs (niflumic acid and ibuprofen) were blended in binary mixes with different particle size fractions of two non-tasting excipients (ethyl cellulose and hydroxypropyl methylcellulose). By selecting the appropriate mixes of identical composition but different organisations, as predicted from surface energy data, it was possible to use the different organisations to modify the taste of the mixes for a panel of 10 healthy volunteers.

Clarithromycin pharmacokinetics after oral administration with or without fasting in crossbred beagles

Clarithromycin was administered to eight dogs intravenously and orally. A suspension or a tablet was given to animals both immediately after feeding and on an empty stomach. Neither the formulation nor the time of administration in relation to feeding significantly influenced the pharmacokinetic parameters. The lowest mean (+/-SD) maximum plasma concentration (Cmax) of 3.0 +/- 0.6 micrograms/ml, the lowest bioavailability (F) of approximately 69 per cent and the shortest time above the proposed breakpoint of susceptibility (L) of 2.9 +/- 1.3 hours were observed with the suspension after feeding. The highest Cmax of 3.6 +/- 0.8 micrograms/ml, the highest F of 83 per cent and the longest L of 4.5 +/- 2.0 hours were observed with the suspension in the fasted group. The mean time at which Cmax occurred (tmax) was between one and two hours after administration. In conclusion, clarithromycin is potentially suitable for therapeutic use in dogs, pending species-specific studies of safety and therapeutic efficacy.