Tablets

Jean Baudrillard sees in today’s simulation the model ‘of a real but without origin or reality: a hyperreal’. With the hyperreal, the individual is unable to distinguish what is real and what is not. In this article, I argue how the pervasiveness of media, in the form of mobile phones, tablets with their applications and social networking sites, singularly or in unison create and sustain the existence of the hyperreal. They succeed at once through an imagined call for urgency and an implosion of meaning that cannot be contained. This type of media is a priori a form of simulation, and has not only erased the boundaries that exit between the real and the unreal but has also developed as a site accountable for continual deference of the being-in-theworld, forcing on the latter a perpetual existence in the hyperreal.

Simple and sensitive synchronous fluorimetric, and second derivative synchronous fluorometric methods were developed for the validated and simultaneous determination of sulpiride (SLP) and its alkaline degradation product (DSLP). The method is based on measuring the synchronous fluorescence of both the drug and its degradation product in borate buffer of pH 8 at of 45 nm. The peak amplitude ( 2 D) was measured at 295.5 and 342 nm for SLP and DSLP, respectively. The different experimental parameters affecting the synchronous fluorescence intensity of both compounds were studied and optimized. The fluorescence-concentration plots were rectilinear over the range of 0.05-1.0 and 2-10 g mL −1 for SLP and DSLP, respectively. The limits of detection (LOD) were 0.02 and 0.4 g mL −1 and quantification limits (LOQs) were 0.05 and 1.2 g mL −1 for SLP and DSLP, respectively. The proposed methods were successfully applied to commercial capsules and tablets. Statistical comparison of the results with those of the official method revealed good agreement and proved that there were no significant difference in the accuracy and precision between the two methods, respectively. The method was utilized to study the kinetics of the alkaline induced degradation of the drug. The application was further extended to include the in vivo and in vitro determination of sulpiride. The mean % recoveries (n = 3) were 100.22 ± 2.04 and 92.00 ± 3.00 for spiked and real human plasma, respectively.

The present study reports the optimization and validation of a dissolution test for selegiline•HCl tablets using a new high-performance liquid chromatographic (HPLC) method. Rapid separation of the analyte from sample matrix was achieved in less than 60 s using a Cromolith ® RP-18e monolithic column using UV detection at 220 nm. Thorough validation of the assay based on pre-defined criteria included linearity, LOD/LOQ, accuracy, precision, selectivity and ruggedness. The dissolution test was optimized in terms of dissolution medium, basket (type I)/paddle (type II) agitation and rotation speed. Its ruggedness was also validated. The presented analytical and dissolution procedures are currently being applied in the quality and stability control of Cosmopril ® tablets (5 mg/tablet selegiline•HCl, Cosmopharm Ltd., Korinthos, Greece).

In this note, a novel probe fitted to a texture analyzer was described. This probe has the ability to simultaneously measure, in real-time, dimensional changes in the swollen layer and the glassy core of hydrophilic matrices when exposed to aqueous dissolution media. The utility of this probe was demonstrated on directly compressed tablets containing polymer blends, a water soluble additive, and theophylline as a model drug. Both the erosion and swelling fronts were measured for the same tablet every hour for 12 h. The probe provided accurate thickness data of the swollen region and the glassy core, and was able to demonstrate the swelling and subsequent erosion of the tablet with time. With this method, it is possible to simultaneously measure the swelling rate of the rubbery region and the erosion rate of the glassy core without operator intervention, which provides many advantages over the conventional approaches frequently reported in the literature.

We developed and validated a new analytical method for the simultaneous quantification of artemether and lumefantrine in fixed-dose tablets and powders for reconstitution into pediatric suspensions (PSs). The method showed linearity (r 2 > 0.9947), precision (coefficient of variation < 2%), accuracy (deviation of mean from actual concentrations < 4%), and specificity (peak purities > 99%). The validated method was used to analyze 24 batches of fixed-dose tablets and PSs of artemether and lumefantrine. Of the samples, 23 were obtained using convenience sampling of commonly available brands within Accra in Ghana and one was obtained from Aarhus University Hospital. In all, 83.3% (confidence interval: 80-120%) passed for both artemether and lumefantrine contents, 16.7% failed by the U.S. Pharmacopoeia standards, 8.3% failed for one content, and 8.3% failed for both contents. All four products (16.7%) that failed were PSs, and two (8.3%) showed higher levels of artemether than prescribed (222% and 756%).

Purpose To be fully exploitable in both formulation and manufacturing, a drug cocrystal needs to demonstrate simultaneous improvement of multiple key pharmaceutical properties over the pure drug crystal. The present work was aimed at investigating such feasibility with two model profen-nicotinamide cocrystals. Methods Phase pure 1:1 ibuprofen-nicotinamide and flurbiprofen-nicotinamide cocrystals were prepared from solutions through rapid solvent removal using rotary evaporation, and characterized by DSC, PXRD, FTIR, phase solubility measurements, equilibrium moisture sorption analysis, dissolution testing and tabletability analysis. Results Temperature-composition phase diagrams constructed from DSC data for each profen and nicotinamide crystal revealed the characteristic melting point of the 1:1 cocrystal as well as the eutectic temperatures and compositions. Both cocrystals exhibited higher intrinsic dissolution rates than the corresponding profens. The cocrystals also sorbed less moisture and displayed considerably better tabletability than the individual profens and nicotinamide. Conclusions Phase behaviors of 1:1 profen-nicotinamide cocrystal systems were delineated by constructing their temperature-composition phase diagrams. Cocrystallization with nicotinamide can simultaneously improve tableting behavior, hygroscopicity, and dissolution performance of ibuprofen and flurbiprofen. This could pave the way for further development of such cocrystal systems into consistent, stable, efficacious and readily manufacturable drug products.

Oral administration is the most convenient route for drug therapy. The knowledge of the gastrointestinal transit and specific site for drug delivery is a prerequisite for development of dosage forms. The aim of this work was to demonstrate that is possible to monitor the disintegration process of film-coated magnetic tablets by multi-sensor alternate current Biosusceptometry (ACB) in vivo and in vitro. This method is based on the recording of signals produced by the magnetic tablet using a seven sensors array and signal-processing techniques. The disintegration was confirmed by signals analysis in healthy human volunteers' measurements and in vitro experiments. Results showed that ACB is efficient to characterize the disintegration of dosage forms in the stomach, being a research tool for the development of new pharmaceutical dosage forms. q

During the last few years, counterfeiters have become increasingly sophisticated by falsifying drugs and making them look identical to genuine tablets. In this paper, Raman spectroscopy is proposed as a fast and reliable method for the detection of counterfeit Viagra ® tablets. This technique can easily differentiate genuine from counterfeit tablets without the need of sample preparation. In total 18 tablets were analysed which all contained the active ingredient sildenafil, but different excipients were used, as could be observed in the Raman spectra between 1150 and 700 cm -1 . So, the spectra could be divided into genuine or counterfeit. Additionally, principal component analysis (PCA), combined with hierarchical cluster analysis (HCA), was used to establish an automated approach for the discrimination of counterfeit from genuine Viagra ® tablets. Raman spectroscopy, combined with principal components analysis, could be used in the future by customs or in the field to identify counterfeit tablets on the spot without involvement of trained chemists.

A novel stability-indicating reverse phase high performance liquid chromatography method was developed and validated for the simultaneous determination of Celecoxib (CEL) and Diacerein (DIN) and its impurities in capsule dosage form. The method was developed using L1 column with gradient using the mobile phase consist of Solution A (pH = 2.3 buffer) and Solution B (methanol and acetonitrile; 50 : 50, v/v). The eluted compounds were monitored at 255 nm. CEL and DIN were subjected to oxidative, acid, base, hydrolytic, thermal and photolytic stress conditions. The developed method was validated as per International Conference on Harmonisation guidelines with respect to specificity, linearity, limit of detection, limit of quantitation, accuracy, precision and robustness. The limit of quantitation results were ranged from 0.07 to 0.09 µg/mL for CEL impurities and 0.052 to 0.065 µg/mL for DIN impurities. This method is suitable for the estimation of impurities and assay of CEL and DIN in ...

RESUMO Este artigo trata das possibilidades de personalização características das tecnologias digitais, que se estendem aos livros, cujo projeto gráfico pode, muitas vezes, ser alterado pelos usuários. As questões que encaminham o texto dizem respeito à relação dos leitores com os livros digitais, com ênfase no uso, das possibilidades de customização dos livros digitais. Para abordar o tema, partimos de uma revisão bibliográfica sobre o design editorial, após a qual apresentamos os resultados de uma pesquisa junto a leitores, realizada através de questionários online. O texto termina com uma reflexão sobre o papel do designer frente às possibilidades de customização do livro digital. Palavras-chave: &quot;design editorial&quot;, &quot;e-book&quot; e &quot;tablets&quot;. INTRODUÇÃO Ao longo dos séculos que compõem a história do livro, diversos padrões de composição legitimaram-se e passaram a ser considerados sinônimos de conforto e eficácia de leitura ao usuário-bem como da capacida...

Ibuprofen is widely used as a prescription and non-prescription medicine. The aim of study is to prepare Ibuprofen tablets (200mg) using direct compression technique which is now days considered a cost effective and simple method of manufacturing. It is considered as an appropriate method for hygroscopic and thermolabile substances. In order to obtain the best, optimized product, nine different formulations were developed. Diluent (X1), disintegrant (X2) and lubricant (X3) were taken as independent variables. Weight variation (Y1), thickness (Y2), length and width (Y3), hardness (Y4), friability (Y5), disintegration (Y6), dissolution (Y7) and pharmaceutical assay (Y8) were studied as response variables. The results of all nine formulations were found within the acceptable limits conforming to those given in official compendia. However, F-6 was selected as an optimized product on the basis of high dissolution (99.05%) and Assay (100.04%). The variation of weight among the tablets of F-6 was least which showed best ratio of excipients in the formulation. Optimization has proven as an effective tool in product development. This is because no clear relationship exists between the variables.

The two-part article aimed to investigate poloxamer 407-based microspheres as a novel platform for enhancing and controlling the delivery of atenolol across the oromucosal tissue. In the Part I of the work, atenolol-loaded poloxamers 407 microparticles were prepared by the solvent free spray congealing technology. This approach was feasible upon the high viscosity of the systems allowing for high loaded (20% w/w) non-aggregated microspheres. Several formulations were studied and the results demonstrated that the drug release patterns, solubility data, mucoadhesion to buccal tissue and gelling properties in saliva could be modified by adding different amount of an amphiphilic polymer-lipid excipient (Gelucire(®) 50/13) to poloxamer 407. Particularly, microspheres based only on poloxamer 407 exhibited very high solubility, mucoadhesive strength and gelling behaviour. To assess their potential as matrix for buccal application, the gelling property and the drug release from tablets obta...

Sensitive and selective stability-indicating assay methods (SIAMs) are suggested for the determination of cilostazol (CIL) in the presence of its acid, alkaline and oxidative degradation products. Developing SIAMs is necessary to carry out any stability study. Stress testing of CIL was performed according to the International Conference on Harmonization (ICH) guidelines in order to validate the stability-indicating power of the analytical procedures. Stress testing showed that CIL underwent acid, alkaline and oxidative degradation; on the other hand, it showed stability towards photo-and thermal degradation. Two chromatographic SIAMs were developed, namely HPLC and HPTLC methods. The concentration range and the mean percentage recovery were 1.0-31.0 g/ml and 99.96 ± 0.46 and 0.6-14.0 g/spot and 99.88 ± 1.10 for HPLC and HPTLC methods, respectively. In addition, derivative spectrophotometric methods were developed in order to determine CIL in the presence of its acid degradation product; these were performed by using the third derivative spectra ( 3 D) and the first derivative of the ratio spectra ( 1 DD) methods. The linearity range and the mean percentage recovery were 2.0-34.0 g/ml and 100.27 ± 1.20 for the ( 3 D) method, while they were 2.0-30.0 g/ml and 99.94 ± 1.18 for the ( 1 DD) method. Also, two chemometric-assisted spectrophotometric methods, based on using partial least squares (PLS) and concentration residual augmented classical least squares method (CRACLS), for the determination of CIL were developed. Both methods were applied on zero order spectra of the mixtures of CIL and its acid degradation product, the mean percentage recovery was 100.03 ± 1.09 and 99.91 ± 1.27 for PLS and CRACLS, respectively. All methods were validated according to the International Conference on Harmonization (ICH) guidelines and applied on bulk powder and pharmaceutical formulations.

Forensic analysis of pharmaceutical preparations requires a comparative analysis with a standard of the suspected drug in order to identify the active ingredient. Purchasing analytical standards can be expensive or unattainable from the drug manufacturers. Direct Analysis in Real Time (DART ) is a novel, ambient ionization technique, typically coupled with a JEOL AccuTOF  (accurate mass) mass spectrometer. While a fast and easy technique to perform, a drawback of using DART  is the lack of component separation of mixtures prior to ionization. Various in-house pharmaceutical preparations were purified using thin-layer chromatography (TLC) and mass spectra were subsequently obtained using the AccuTOF -DART  technique. Utilizing TLC prior to sample introduction provides a simple, low-cost solution to acquiring mass spectra of the purified preparation. Each spectrum was compared against an in-house molecular formula list to confirm the accurate mass elemental compositions. Spectra of purified ingredients of known pharmaceuticals were added to an in-house library for use as comparators for casework samples. Resolving isomers from one another can be accomplished using collision-induced dissociation after ionization. Challenges arose when the pharmaceutical preparation required an optimized TLC solvent to achieve proper separation and purity of the standard. Purified spectra were obtained for 91 preparations and included in an in-house drug standard library. Primary standards would only need to be purchased when pharmaceutical preparations not previously encountered are submitted for comparative analysis. TLC prior to DART  analysis demonstrates a time efficient and cost saving technique for the forensic drug analysis community.

The objective of the current study was to develop and validate a simple, precise and accurate isocratic stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay method for the determination of spironolactone and furosemide in solid pharmaceutical dosage forms. Isocratic RP-HPLC separation was achieved on an SGE 150 × 4.6 mm SS Wakosil II 5C8RS 5-μm column using a mobile phase of acetonitrile-ammonium acetate buffer (50:50, v/v) at a flow rate of 1.0 mL/min. The detection was carried out at 254 nm using a photodiode array detector. The drug was subject to oxidation, hydrolysis, photolysis and heat to apply stress conditions. The method was validated for specificity, linearity, precision, accuracy, robustness and solution stability. The method was found to be linear in the drug concentration range of 40-160 µg/mL with correlation coefficients of 0.9977 and 0.9953 for spironolactone and furosemide, respectively. The precision (relative standard deviation; RSD) among a six-sample preparation was 0.87% and 1.1% for spironolactone and furosemide, respectively. Repeatability and intermediate precision (RSD) among a six-sample preparation were 0.46% and 0.20% for spironolactone and furosemide, respectively. The accuracy (recovery) was between 98.05 and 100.17% and 99.07 and 100.58% for spironolactone and furosemide, respectively. Degradation products produced as a result of stress studies did not interfere with the detection of spironolactone and furosemide; therefore, the assay can be considered to be stability-indicating.

The in vitro dissolution of albendazole from three different commercially available products (200 mg tablets) was studied using U.S. Pharmacopeia (USP) Apparatus 2 and USP Apparatus 4 in order to compare the release performance of the drug in two essentially different dissolution systems. For both cases, 0.1 N HCl was used as dissolution medium. Only the reference product and one of the generic products studied met the 80% USP 24 specification for albendazole dissolved at 30 min, using USP Apparatus 2. Although the reference product reached 80% of albendazole dissolved at 30 min when Apparatus 4 was used, the generic products' dissolution performance was markedly reduced in this system. Though dissolution rate was slower using Apparatus 4, the total quantity of albendazole dissolved from the reference product, represented by area under the dissolution profile, was practically the same regardless of the system used. Dissolution kinetics of albendazole was adequately described by Weibull's function for all the products. The dissolution time (t d ) derived from data fitting to this function showed significant differences among the products studied. Data analysis based on analysis of variance (ANOVA) showed nonequivalence among the dissolution profiles of generic products compared with the reference product either with the dissolution vessel system or the flow-through cell, as well as nonequivalence among the dissolution profiles using both apparatuses with the same product. Though differences in the dissolution profiles for generic products against the reference product in both systems were found, USP Apparatus 4 showed higher discriminative capacity in differentiating the release characteristics of the products tested.

Objective: Domperidone is a synthetic benzimidazole compound that acts as a dopamine D 2 receptor antagonist. The main aim of this study was to optimize and evaluate the floating tablets of domperidone that prolongs the gastric residence time using Hibiscus rosa-sinensis mucilage. Methods: The directly compressible floating tablets of domperidone were formulated using varying amount of hydroxypropyl methylcellulose K100 M, carbopol 934P and H. rosa-sinensis mucilage. The effervescent components sodium bicarbonate is used for the generation of CO 2 gas. The prepared tablets were evaluated for physicochemical parameters and found to be within range, viz., hardness, swelling index, floating capacity, thickness, and weight variation. Further, tablets were evaluated for in vitro release characteristics. The concentration of H. rosa-sinensis mucilage with a gas-generating agent was optimized to get the sustained release of domperidone. Result: The % cumulative drug release of all formulation from F1 to F6 was within the range of 81.37% to 98.62% for 18 hrs. The release kinetics of all the dosage forms was calculated using zero order, first order, Higuchi, and Korsmeyer-Peppas. It concludes that the release followed zero order release, whereas the correlation coefficient (r 2 value) was higher for zero order release. The release mechanism follows Higuchi model, Korsmeyer-Peppas model, and non-Fickian diffusion. Conclusion: As a result of this study, it may be concluded that the floating tablets using H. rosa-sinensis mucilage in optimized concentrations can be used to increase the gastric retention time of the dissolution fluid in the stomach to deliver the drug in a sustained manner. Furthermore, from 1 month stability data shows no significant change compared to initial result.

This investigation evaluated some new (Preflo) and existing commercially available (Starch 1500, Star Tab) modified starches as direct compression excipients. Preflo corn starches (CH-10, CH-20, CH-30) and Preflo potato starches (P-250, PI-10, PJ-20) were evaluated and compared with respect to their pharmaceutical properties such as particle size, density, flowability, friability, and compression properties. Preflo starches showed a high bulk density and good flowability. Preflo corn starches and Star Tab formed harder tablets than Preflo potato starches and Starch 1500. Data from the Athy-Heckel plots indicated that the Preflo starches are soft materials and, unlike Starch 1500, undergo plastic deformation. Tablets containing acetaminophen were also compressed with the starches and disintegration and dissolution studies were conducted. Starch 1500 tablets disintegrated in 3.5 min, whereas none of the Preflo starch tablets disintegrated in 30 min. While complete acetaminophen releas...

A sensitive and simple spectrophotometric method has been proposed for the determination of D-Penicillamine (PA) in pharmaceutical formulations. The proposed method is based on the reaction between the PA and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-CL) at alkaline medium (pH 10.5) to form deep brown-purple adduct, exhibiting maximum absorption (λ max) at 468nm. Under optimized reaction condition, the method was linear in the concentration range 1-15µg mL-1. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.11µg mL-1 , 0.38µg mL-1 , respectively. The method was applied successfully to the determination of PA in pharmaceutical dosage form. A proposal of the reaction pathway has been postulated. The results were in a good agreement with those obtained with the official USP method. The method is useful for routine analysis of PA in quality control laboratories.

The aim of the present research work was to systemically device a model of factors that would yield an optimized sustained release dosage form of an anti-hypertensive agent, losartan potassium, using response surface methodology by employing a 3-factor, 3-level Box-Behnken statistical design. Independent variables studied were the amount of the release retardant polymers -HPMC K15M (X 1 ), HPMC K100M (X 2 ) and sodium carboxymethyl cellulose (X 3 ). The dependent variables were the burst release in 15 min (Y 1 ), cumulative percentage release of drug after 60 min (Y 2 ) and hardness (Y 3 ) of the tablets with constraints on the Y 2 = 31-35%. Statistical validity of the polynomials was established. In vitro release and swelling studies were carried out for the optimized formulation and the data were fitted to kinetic equations. The polynomial mathematical relationship obtained Y 2 ¼ 32:91 À 2:30X 1 À 5:69X 2 À 0:97X 3 À 0:41X 1 X 2 þ 0:21X 1 X 3 À 0:92X 2 1 À 1:89X 2 2 ðr 2 ¼ 0:9944Þ explained the main and quadratic effects, and the interactions of factors influencing the drug release from matrix tablets. The adjusted (0.9842) and predicted values (0.9893) of r 2 for Y 2 were in close agreement. Validation of the optimization study indicated high degree of prognostic ability of response surface methodology. Tablets showed an initial burst release preceding a more gradual sustained release phase following a non-fickian diffusion process. The Box-Behnken experimental design facilitated the formulation and optimization of sustained release hydrophilic matrix systems of losartan potassium.

A sensitive method for the determination of the bismuth concentration in human serum is described. Analyses were carried out by inductively coupled plasma-mass spectromctry (ICP-MS), after a simple dilution of the samples with nitric acid. The detection limit of the applied method is O&o7 &I whereas relaitive standard deviations varied from 57 to 13,6% Determination of reference values in human serum of healthy adults gave a range from <0.007 to I (19 persons), Bismuth concentrations in serum were also measu and after the intake of therapeutic doses of colloidal bismuth subcitrate (CBS). About I S-2 h afux the intake of one tablet of CBS, the bismuth concentration in serum was found to have increased 5bi483 times (two apparentiy healthy volunteers and six hos;jitalized patients), showing that the serum bismuth concentrations can increase by several or&~ of magnitude during the intake of CBS. During the intake of four tablets of CBS per day by two apparently healthy volunteers, bismuth concentrations in serum after an overnight fast were I'ound to be, respectively, 5.56 and 8.1 &l on day 15 and 4.28 and 13,6 &I on day 29. After stopping the therapy, the concentration of bismuth in serum slowly returned towards normal over a period of months. Ke)v WON&: Bismuth; Human strum; Colloidal bismuth subcitrate; Inductively coupled plasma-mass spectrometry (ICP-MS) l Corresponding author. 0009-898U93/$06.00 0 1993 Elsevier Science Publishers B.V. All rights reserved. SSDf 0009-898 I (93)05601 -A

Differences in the dynamics of powder densification between eccentric and rotary machine were pointed out by compressing at different compression pressures microcrystalline cellulose, lactose monohydrate and dicalcium phosphate dihydrate and recovering the corresponding stress/strain data in both machines equipped to monitor punches displacement and compression forces. Heckel plots were then obtained from these stress/strain data.

In a previous study aimed to compare the bioavailability of two levothyroxine tablets, we found a good relation between their pharmacokinetics parameters and dissolution profiles, employing the USP dissolution conditions in use at that time (24th edition). Despite the formulations were considered bioequivalent, the test product presented values of AUC and concentrations at steady-state significantly lower (about 10%) than the reference ones. The purpose of the present study was to evaluate if the actual pharmacopeial conditions (with alterations introduced in the first supplement of USP 24) would also allow a good correlation between bioavailability and dissolution data. The partial AUCs were correlated with cumulative levothyroxine amount dissolved at three different times, for each dissolution condition. Employing the old method, test tablets had a slower dissolution rate than the reference ones, resulting in a quite good multiple level C in vitro/in vivo (IVIV) correlation. On the other hand, the very fast dissolution profiles obtained in the actual condition lead to a worse IVIV correlation. Present work indicates that the mild conditions proposed in the older US Pharmacopeia were better than the actual in order to discriminate dissolution profiles of levothyroxine tablets which present subtle, but significant, differences in their pattern of absorption.

The objective of the present study was to develop once-daily sustained-release matrix tablets of nicorandil, a novel potassium channel opener used in cardiovascular diseases. The tablets were prepared by the wet granulation method. Ethanolic solutions of ethylcellulose (EC), Eudragit RL-100, Eudragit RS-100, and polyvinylpyrrolidone were used as granulating agents along with hydrophilic matrix materials like hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose, and sodium alginate. The granules were evaluated for angle of repose, bulk density, compressibility index, total porosity, and drug content. The tablets were subjected to thickness, diameter, weight variation test, drug content, hardness, friability, and in vitro release studies. The granules showed satisfactory flow properties, compressibility, and drug content. All the tablet formulations showed acceptable pharmacotechnical properties and complied with in-house specifications for tested parameters. According to the theoretical release profile calculation, a oncedaily sustained-release formulation should release 5.92 mg of nicorandil in 1 hour, like conventional tablets, and 3.21 mg per hour up to 24 hours. The results of dissolution studies indicated that formulation F-I (drug-to-HPMC, 1:4; ethanol as granulating agent) could extend the drug release up to 24 hours. In the further formulation development process, FIX (drug-to-HPMC, 1:4; EC 4% wt/vol as granulating agent), the most successful formulation of the study, exhibited satisfactory drug release in the initial hours, and the total release pattern was very close to the theoretical release profile. All the formulations (except FIX) exhibited diffusion-dominated drug release. The mechanism of drug release from FIX was diffusion coupled with erosion.

Background Ponesimod is a potent selective sphingosine-1-phosphate receptor 1 (S1P 1 ) modulator, which leads to a reduction in circulating lymphocytes, reflecting their sequestration within lymphoid organs. Modulation of the S1P 1 receptor has been previously described to be an effective treatment of autoimmune diseases (e.g., multiple sclerosis).

Micellar high-performance liquid chromatography (HPLC) and firstderivative ultraviolet spectrophotometry were used to simultaneously determine fluconazole (FLZ) and tinidazole (TNZ) in combined pharmaceutical dosage forms. The derivative procedure is based on the linear relationship between the drug concentration and the first derivative amplitudes at 220 and 288 nm for FLZ and TNZ, respectively. The calibration graphs were linear in the range of 1.5 -9.0 mg/mL for FLZ and 10.0-60.0 mg/mL for TNZ. Furthermore, an HPLC procedure with ultraviolet detection at 210 nm was developed. For the HPLC procedure, good chromatographic separation was achieved using an ODS C18 column (250 3 4.6 mm i.d.). The mobile phase containing 0.15M sodium dodecyl sulphate, 0.3% triethylamine and 12% n-propanol in 0.02M orthophosphoric acid at pH 5.5 was pumped at a flow rate of 1 mL/min. Indapamide was used as an internal standard. The method showed good linearity over the concentration ranges of 1.5 -30.0 and 10.0-200.0 mg/mL, with limits of detection of 0.36 and 2.70 mg/mL and limits of quantification of 1.1 and 8.2 mg/mL for FLZ and TNZ, respectively. The suggested methods were successfully applied for the simultaneous analysis of the drugs in their laboratory prepared mixture, co-formulated tablet and single dosage forms. Moreover the second method was also extended to the determination of the drugs in biological fluids.

Disintegration performance was measured by analysing both water ingress and tablet swelling of pure microcrystalline cellulose (MCC) and in mixture with croscarmellose sodium using terahertz pulsed imaging (TPI). Tablets made from pure MCC with porosities of 10% and 15% showed similar swelling and transport kinetics: within the first 15 s, tablets had swollen by up to 33% of their original thickness and water had fully penetrated the tablet following Darcy flow kinetics. In contrast, MCC tablets with a porosity of 5% exhibited much slower transport kinetics, with swelling to only 17% of their original thickness and full water penetration reached after 100 s, dominated by case II transport kinetics. The effect of adding superdisintegrant to the formulation and varying the temperature of the dissolution medium between 20°C and 37°C on the swelling and transport process was quantified. We have demonstrated that TPI can be used to non-invasively analyse the complex disintegration kineti...

A sensitive method for the determination of berberine, a plant alkaloid, was developed by capillary electrophoresis coupled with laser induced fluorescence detection. With the addition of (2-hydroxypropyl)-␤-cyclodextrin (2-HP-␤-CD) to the separation electrolyte, the low fluorescence signal intensity of berberine in aqueous medium was enhanced considerably by 162 fold. The optimal background electrolyte was selected as 20 mM acetic acid, 35 mM 2-HP-␤-CD, and 20% methanol at pH 5. The limit of detection of the method for berberine was 15.7 ng/mL. The intra and interday repeatabilities of corrected peak areas as RDSs were 1.83% and 3.75%, respectively. The developed method was successfully applied for the determination of berberine contents in Chinese medicinal plants and herbal supplemental tablets.

It has been observed previously that xanthan gum (XG) and hydroxypropylmethyl cellulose (HPMC) show different drug release behavior. In order to clarify these findings, the rheological properties of both polymers have been determined by oscillatory as well as by steady shear measurements. Aqueous solutions of 4 and 7% (w/w) polymer have been used to simulate the outer surface of a hydrated tablet. The dynamic moduli, i.e., storage modulus (G′) and loss modulus (G″) of the two polymers have been determined in pure water and USP phosphate buffer pH 7.4 at different dilutions. In this concentration range XG solution exhibits “gel-like” behavior, while HPMC behaves as a typical polymer solution. These findings are quite consistent with the reported higher ability of XG matrices to retard drug release than HPMC matrices for controlled-release formulation. The effects of differences in drug solubility and acidity, as well as the addition of lactose, and of the ionic strength of the medium on the rheological properties of XG and HPMC solutions have been studied in detail. Among these parameters, only the salt concentration exerts an enhancing effect on both moduli of XG, while no detectable influence on HPMC solution could be observed.

Xanthan is a well-known biopolymer. It is an anionic polysaccharide, whose primary structure depends on the bacterial strain and fermentation conditions. Xanthan was extensively studied in combination with galactomannans, and over 90 patents cover the technology of this preparation. Our aim was to investigate the relation between the physical properties of a xanthan matrix in the absence or presence of calcium ions and its influence on the release of pentoxifylline. The release of pentoxifylline from xanthan tablets in purified water was shown to be very slow and governed by the process of polymer relaxation. The presence of calcium ions significantly increased the drug release, changing the release mechanism into a more diffusion controlled one. Xanthan matrices showed substantially faster and more extensive swelling in water than in the presence of Ca 2+ ions. Surprisingly, negative correlation between drug release and degree of swelling was obtained for xanthan: the higher the swelling, the slower the drug release. Higher ionic strength led to lower erosion of xanthan tablets, and the gel layers formed were more rigid and of firmer texture, as shown by rheological experiments and textural profiling. The results indicate that the presence of Ca 2+ ions in the solution or in matrices does not cause crosslinking of xanthan polymers, but causes charge screening of ionized groups on the trisaccharide side chains of xanthan, leading to lower inter-molecular repulsion and changing water arrangement. The understanding of the parameters influencing drug release leads to the conclusion that xanthan is suitable for controlled release formulations, especially with the incorporation of certain small counterions.

Tablets zijn nadrukkelijk aanwezig in onze maatschappij. Dit stelt ook het onderwijs voor nieuwe uitdagingen. Steeds meer scholen gaan ermee werken, maar wat zegt wetenschappelijk onderzoek eigenlijk over de randvoorwaarden voor een succesvolle integratie?

There have been few studies conducted to determine the efficiency of ascorbic acid absorption in humans. Differences in the extent of its absorption among individuals may contribute to the outcome of clinical trials. Ascorbic acid absorption in four subjects was investigated from several oral dosage forms containing 1 g of the vitamin (solution, tablet, chewable tablet, and timed-release capsule). Approximately 85% of an intravenous dose was recovered in the urine as ascorbic acid and its major metabolites. In contrast, only -30% of the dose was recovered from the solution and tablet forms. A considerably smaller fraction of the dose (-14%) was recovered from the timed-release capsule. There was considerable intersubject variation in ascorbic acid absorption and there appeared to be good and poor absorbers of the vitamin. Consideration should be given to the influence of the extent of ascorbic acid absorption on the results of clinical trials.

About 4 per cent of schoolchildren suffer from migraine. In some cases the attacks can be frequent and severe. Often symptomatic and prophylactic treatments are either ineffective or cause pronounced side effects. Therc have been reports on studies in which a prophylactic effect on migraine by propranolol has been noted. This beta-receptor blocking agent has been tested in a double-blind single crossover study in 32 children aged 7-16 with migraine. Propranolol had an excellent prophylactic effect on migraine attacks. Since propranolol does not cause serious sidc effects provided certain patients are excluded, it seems justifiable to recommend this preparation where prophylactic therapy is indicated in cases of severe and frequent migraine.

The objective of the present study was to develop a once-daily sustained-release (SR) matrix tablet of famotidine. Nine different formulations (F1–F9) were prepared by direct compression method using Avicel PH101 as filler/binder in the range of 41–27% in F1–F3, 18–22% in F4–F7, and 16–18% in F8–F9 and hydroxypropyl methylcellulose (4,000 cps) as hydrophilic matrix was used in F1–F3 from 19% to 30%, around 40% in F4–F7, and 42–45% in F8–F9. Talc and Aerosil were added in the ratio of 0.7–1.2%. The tablets were subjected to various physical parameters including weight variation test, hardness, thickness, diameter, friability, and in vitro release studies. Assay was also performed according to the USP 30 NF 25 procedure. The results of the physical parameters and assay were found to be within the acceptable range. In vitro dissolution results indicated that formulation F4–F7, having around 40% of rate control polymer, produced a SR pattern throughout 24 h. F1–F3 showed drug release at a faster rate, while F8–F9 released much slower, i.e., r 2 = 0.984) and F6 in Korsmeyer and Higuchi (r 2 = 0.992 and 0.988). The parameter n indicated anomalous diffusion, while β in Weibull showed a parabolic curve with higher initial slope. The f 2 similarity test was performed taking F4 as a reference formulation. Only the F5–F7 formulations were similar to the reference formulation F4. The mean dissolution time was around 10 h for the successful formulation.

The aim of the study was to evaluate the suitability of alginates for Soft Tableting. For this purpose the compaction properties of alginates, varying in molecular weight, guluronic acid/mannuronic acid ratio and salt, were investigated and compared to MCC. Based on the mechanical properties, the suitability of the tested excipients for Soft Tableting was predicted. In order to test the prediction the tested materials were used to tablet enteric coated pellets, which served as a pressure sensitive material. The tableting behaviour was analysed by the 3-D modeling technique. The tablet properties were analysed by determining the elastic recovery and the compactibility. Alginates in general deformed elastically. The compression behaviour depended on the chemical composition of the alginates with sodium alginates being more elastic than potassium alginates. Tablets containing alginates with low guluronic acid content exhibited higher elasticity than tablets with alginates having a low mannuronic acid content. The plasticity of potassium alginates was higher than for sodium alginates. However, the plasticity of all tested alginates was lower than the plasticity of MCC. The compactibility of the tested alginates was sufficient. The proposed prediction, which states that tableting excipients with higher elasticity are more suitable for tableting sensitive materials than plastic excipients, was valid for the tested materials. The elastic alginates inflicted less damage on the pellets than the plastic MCC. Thus, all alginates were more appropriate for tableting pressure sensitive materials than MCC.