Functionality comparison of 3 classes of superdisintegrants in promoting aspirin tablet disintegration and dissolution

Application of cocoa butter for formulation of fast melt tablets containing memantine hydrochloride

INTRODUCTION

Fast melt tablets (FMTs) provide a convenient dosage form that rapidly dissolves on the tongue without the need for water. Cocoa butter serves as a suitable matrix system for FMTs formulation, facilitating rapid disintegration at body temperature.

OBJECTIVES

This study aimed to formulate FMTs using cocoa butter as a base and investigate the effect of various disintegrants and superdisintegrants on their characteristics.

METHODS

Cocoa butter-based FMTs were prepared via the fusion molding technique. Different disintegrants and superdisintegrants were added at varying concentrations and subjected to characterization. The optimal formulation was selected and incorporated with 10 mg memantine hydrochloride.

RESULTS

The optimal FMT formulation consisted of 340 mg cocoa butter, 75 mg starch, and 75 mg crospovidone, exhibiting a hardness of 17.12 ± 0.31 N and a disintegration time of 32.67 ± 0.17 s. Furthermore, FMTs demonstrated a faster release profile compared to the commercially available product, Ebixa. SEM micrographs revealed homogenous blending of individual ingredients within the cocoa butter matrix and FT-IR analysis confirmed the chemical stability of memantine hydrochloride in the formulation. The dissolution profile of F17 suggested that the drug in FMTs released faster compared to Ebixia. Memantine hydrochloride achieved 98.07% of drug release in FMTs at 10 min. Moreover, the prepared FMTs exhibited stability for at least 6 months.

CONCLUSION

The successful development of cocoa butter-based FMTs containing memantine hydrochloride highlights the potential of cocoa butter as viable alternative matrix-forming material for FMTs production. This innovative formulation offers patients a convenient alternative for medication administration.

Tailoring of Rosuvastatin Calcium and Atenolol Bilayer Tablets for the Management of Hyperlipidemia Associated with Hypertension: A Preclinical Study

Hyperlipidemia is still the leading cause of heart disease in patients with hypertension. The purpose of this study is to make rosuvastatin calcium (ROS) and atenolol (AT) bilayer tablets to treat coexisting dyslipidemia and hypertension with a single product. ROS was chosen for the immediate-release layer of the constructed tablets, whereas AT was chosen for the sustained-release layer. The solid dispersion of ROS with sorbitol (1:3 w/w) was utilized in the immediate-release layer while hydroxypropyl methylcellulose (HPMC), ethylcellulose (EC), and sodium bicarbonate were incorporated into the floating sustained-release layer. The concentrations of HPMC and EC were optimized by employing 3² full factorial designs to sustain AT release. The bilayer tablets were prepared by the direct compression method. The immediate-release layer revealed that 92.34 ± 2.27% of ROS was released within 60 min at a pH of 1.2. The second sustained-release layer of the bilayer tablets exhibited delayed release of AT (96.65 ± 3.36% within 12 h) under the same conditions. The release of ROS and AT from the prepared tablets was found to obey the non-Fickian diffusion and mixed models (zero-order, Higuchi and Korsmeyer–Peppas), respectively. Preclinical studies using rabbit models investigated the impact of ROS/AT tablets on lipid profiles and blood pressure. A high-fat diet was used to induce obesity in rabbits. Bilayer ROS/AT tablets had a remarkable effect on decreasing the lipid profiles, slowing weight gain, and lowering blood pressure to normal levels when compared to the control group.

Tablet formulation development focusing on the functional behaviour of water uptake and swelling

The functional behaviour of tablets is strongly influenced by their manufacturing process and the choice of excipients. Water uptake and swelling are prerequisites for tablet disintegration, dispersion and hence active pharmaceutical ingredient (API) dissolution. High proportions of polymeric excipients in tablets, which are typically used as API carriers in amorphous solid dispersions (ASDs), may be challenging due to the formation of a gelling polymer network (GPN). In this study, systematic investigations into the formulation development of tablets containing polymeric and other excipients are performed by water uptake and swelling analysis. The impact of tablet composition and porosity as well as pH of the test medium are investigated. The pH affects the analysis results for Eudragit L100-55 and Eudragit EPO. HPMC and Kollidon VA64 inhibit water uptake and swelling of tablets due to the formation of a GPN. High tablet porosity, coarse particle size of the polymer and the addition of fillers and disintegrants can reduce the negative impact of a GPN on tablet performance. The application of lubricants slows down the analysed processes. Water uptake and swelling data are fitted to an empirical model obtaining four characteristic parameters to facilitate the simple quantitative assessment of varying tablet formulations and structural properties.

Immediate-Release Formulations Produced via Twin-Screw Melt Granulation: Systematic Evaluation of the Addition of Disintegrants

The current study evaluated the effect of location and amount of various superdisintegrants on the properties of tablets made by twin-screw melt granulation (TSMG). Sodium-croscarmellose (CCS), crospovidone (CPV), and sodium starch glycolate (SSG) were used in various proportions intra- and extra-granular. Tabletability, compactibility, compressibility as well as friability, disintegration, and dissolution performance were assessed. The extra-granular addition resulted in the fasted disintegration and dissolution. CPV performed superior to CCS and SSG. Even if the solid fraction (SF) of the granules was lower for CPV, only a minor decrease in tabletability was observed, due to the high plastic deformation of the melt granules. The intra-granular addition of CPV resulted in a more prolonged dissolution profile, which could be correlated to a loss in porosity during tableting. The 100% intra-granular addition of the CPV resulted in a distinct decrease of the disintegration efficiency, whereas the performance of SSG was unaffected by the granulation process. CCS was not suitable to be used for the production of an immediate-release formulation, when added in total proportion into the granulation phase, but its efficiency was less impaired compared to CPV. Shortest disintegration (78 s) and dissolution (Q₈₀: 4.2 min) was achieved with CPV extra-granular. Using CPV and CCS intra-granular resulted in increased disintegration time and Q₈₀. However, at a higher level of appx. 500 s and appx. 15 min, only SSG showed a process and location independent disintegration and dissolution performance.

Investigation of Plantago ovata Husk as Pharmaceutical Excipient for Solid Dosage Form (Orodispersible Tablets)

The objective of the study was to investigate the suitability of the Plantago ovata (PO) husk as a pharmaceutical excipient. Various phytoconstituents of the husk were determined according to the standard test procedures. The Plantago ovata husk was evaluated for various pharmaceutical parameters related to flow, swelling index, and compressibility index. Orodispersible tablets (ODTs) were prepared, containing different concentrations (2.5, 3, 5, 7.5, 10, and 15% w/w) of the Plantago ovata husk. Before compression, all the formulations were evaluated for their flow. Compressed ODTs were evaluated for physical characteristics (physical appearance, weight and weight variation, thickness, and moisture content), mechanical strength (crushing strength, specific crushing strength, tensile strength, and friability), disintegration behavior (disintegration time and oral disintegration time), drug content, and in vitro drug release. Phytochemical evaluation of the Plantago ovata husk confirmed the presence of various phytoconstituents like alkaloids, tannins, glycosides, saponins, flavonoids, and phenols. SEM photograph of the Plantago ovata husk showed that it has a fibrous structure, with a porous and rough surface. The Plantago ovata husk had a high swelling index (380%) which decreased by pulverization (310%). Precompression evaluation of the powder blend for all the formulations of ODTs showed good flow properties, indicating that the Plantago ovata husk improved the rheological characteristics of the powder blend. Compressed ODTs had good mechanical strength, and their friability was within the official limits (<1%). Best disintegration was observed with formulation F-6 containing 10% w/w of the Plantago ovata husk. It is concluded that the Plantago ovata husk can be used as a disintegrant in the formulation of ODTs.

Synthesis and Evaluation of Thiol-Conjugated Poloxamer and Its Pharmaceutical Applications

The current study was designed to convert the poloxamer (PLX) into thiolated poloxamer (TPLX), followed by its physicochemical, biocompatibilities studies, and applications as a pharmaceutical excipient in the development of tacrolimus (TCM)-containing compressed tablets. Thiolation was accomplished by using thiourea as a thiol donor and hydrochloric acid (HCl) as a catalyst in the reaction. Both PLX and TPLX were evaluated for surface morphology based on SEM, the crystalline or amorphous nature of the particles, thiol contents, micromeritics, FTIR, and biocompatibility studies in albino rats. Furthermore, the polymers were used in the development of compressed tablets. Later, they were also characterized for thickness, diameter, hardness, weight variation, swelling index, disintegration time, mucoadhesion, and in vitro drug release. The outcomes of the study showed that the thiolation process was accomplished successfully, which was confirmed by FTIR, where a characteristic peak was noticed at 2695.9968 cm-1 in the FTIR scan of TPLX. Furthermore, the considerable concentration of the thiol constituents (20.625 µg/g of the polymer), which was present on the polymeric backbone, also strengthened the claim of successful thiolation. A mucoadhesion test illustrated the comparatively better mucoadhesion strength of TPLX compared to PLX. The in vitro drug release study exhibited that the TPLX-based formulation showed a more rapid (p < 0.05) release of the drug in 1 h compared to the PLX-based formulation. The in vivo toxicity studies confirmed that both PLX and TPLX were safe when they were administered to the albino rats. Conclusively, the thiolation of PLX made not only the polymer more mucoadhesive but also capable of improving the dissolution profile of TCM.

Effect of excipients on oral absorption process according to the different gastrointestinal segments

INTRODUCTION

Excipients are necessary to develop oral dosage forms of any Active Pharmaceutical Ingredient (API). Traditionally, excipients have been considered inactive and inert substances, but, over the years, numerous studies have contradicted this belief. This review focuses on the effect of excipients on the physiological variables affecting oral absorption along the different segments of the gastrointestinal tract. The effect of excipients on the segmental absorption variables are illustrated with examples to help understand the complexity of predicting their in vivo effects.

AREAS COVERED

The effects of excipients on disintegration, solubility and dissolution, transit time, and absorption are analyzed in the context of the different gastrointestinal segments and the physiological factors affecting release and membrane permeation. The experimental techniques used to study excipient effects and their human predictive ability are reviewed.

EXPERT OPINION

The observed effects of excipient in oral absorption process have been characterized in the past, mainly in vitro (i.e. in dissolution studies, in vitro cell culture methods or in situ animal studies). Unfortunately, a clear link with their effects in vivo, i.e. their impact on Cmax or AUC, which need a mechanistic approach is still missing. The information compiled in this review leads to the conclusion that the effect of excipients in API oral absorption and bioavailability is undeniable and shows the need of implementing standardized and reproducible preclinical tools coupled with mechanistic and predictive physiological-based models to improve the current empirical retrospective approach.

In-Depth Study into Polymeric Materials in Low-Density Gastroretentive Formulations

The extensive use of oral dosage forms for the treatment of diseases may be linked to deficient pharmacokinetic properties. In some cases the drug is barely soluble; in others, the rapid transit of the formulation through the gastrointestinal tract (GIT) makes it difficult to achieve therapeutic levels in the organism; moreover, some drugs must act locally due to a gastric pathology, but the time they remain in the stomach is short. The use of formulations capable of improving all these parameters, as well as increasing the resident time in the stomach, has been the target of numerous research works, with low-density systems being the most promising and widely explored, however, there is further scope to improve these systems. There are a vast variety of polymeric materials used in low-density gastroretentive systems and a number of methods to improve the bioavailability of the drugs. This works aims to expedite the development of breakthrough approaches by providing an in-depth understanding of the polymeric materials currently used, both natural and synthetic, their properties, advantages, and drawbacks.

The influence of ethanol on superdisintegrants and on tablets disintegration

Disintegration of immediate release tablets originates from the volume expansion of disintegrants within the formulation. Here, we study the impact of ethanol on the disintegrant expansion and on tablets disintegration. The three most commonly used superdisintegrants, namely sodium starch glycolate (SSG), crospovidone (PVPP) and croscarmellose sodium (CCS) were investigated alone and incorporated in dicalcium phosphate and in drug-containing tablets. High (i.e. 40%), but not moderate (i.e. 10%), aqueous ethanol concentrations reduce the size expansion of the three disintegrants compared to water. This "ethanol effect" is the greatest for SSG, followed by CCS and then PVPP. Moreover, the presence of ethanol in the media can significantly influence the disintegration time of drug-containing tablets via affecting both the disintegrant action itself and the drug solubility. For example, the disintegration time of theophylline tablets containing SSG is 8.1-fold greater in 40% aqueous ethanol compared to water. Overall, this study brought to light the existence of a potentially significant interference of alcohol with the disintegration phenomenon, suggesting that the concomitant administration of tablets and intake of alcoholic beverages may affect, in some cases, tablets disintegration. More studies are now needed to verify the importance of the "ethanol effect" on disintegration of commercial dosage forms. Our findings also suggest that PVPP is the disintegrant that is the least affected by alcohol.

The Impact of Amorphisation and Spheronization Techniques on the Improved in Vitro & in Vivo Performance of Glimepiride Tablets

Purpose: Triple solid dispersion adsorbates (TSDads) and spherical agglomerates (SA) present new techniques that extensively enhance dissolution of poorly soluble drugs. The aim of the present study is to hasten the onset of hypoglycemic effect of glimepiride through enhancing its rate of release from tablet formulation prepared from either technique.

Methods: Drug release from TSDads or SA tablets with different added excipients was explored. Scanning electron microscopy (SEM) and effect of compression on dissolution were illustrated. Pharmacodynamic evaluation was performed on optimized tablets.

Results: TSDads & SA tablets with Cross Povidone showed least disintegration times of 1.48 and 0.5 min. respectively. Kinetics of drug release recorded least half-lives (54.13 and 59.83min for both techniques respectively). Cross section in tablets displayed an organized interconnected matrix under SEM, accounting for the rapid access of dissolution media to the tablet core. Components of tablets filled into capsules showed a similar release profile to that of tablets after compression as indicated by similarity factor. The onset time of maximum reduction in blood glucose in male albino rabbits was hastened to 2h instead of 3h for commercial tablets.

Conclusion: After optimization of tablet excipients that interacted differently with respect to their effect on drug release, we could conclude that both amorphisation and spheronization were equally successful in promoting in vitro dissolution enhancement as well as providing a more rapid onset time for drug action in vivo.

Torsemide Fast Dissolving Tablets: Development, Optimization Using Box-Bhenken Design and Response Surface Methodology, In Vitro Characterization, and Pharmacokinetic Assessment

The present study planed to develop new fast dissolving tablets (FDTs) of torsemide. Solid dispersions (SDs) of torsemide and sorbitol (3:1) or polyvinylpyrrolidone (PVP) k25 were prepared. The prepared SDs were evaluated for in-vitro dissolution. Fourier transform infrared spectroscopy and differential scanning calorimetry for SDs revealed no drug/excipient interactions and transformation of torsemide to the amorphous form. Torsemide/sorbitol SD was selected for formulation of torsemide FDTs by direct compression method. Box-Bhenken factorial design was employed to design 15 formulations using croscarmellose sodium and crospovidone at different concentrations. The response surface methodology was used to analyze the effect of changing these concentrations (independent variables) on disintegration time (Y₁), percentage friability (Y₂), and amount torsemide released at 10 min. The physical mixtures of torsemide and the used excipients were evaluated for angle of repose, Hausner's ratio, and Carr's index. The prepared FDTs tablets were evaluated for wetting and disintegration time, weight variation, drug content, percentage friability, thickness, hardness, and in vitro release. Based on the in-vitro results and factorial design characterization, F10 and F7 were selected for bioavailability studies following administration to Albino New Zealand rabbits. They showed significantly higher C _max and (AUC_0-12) and shorter T _max than those obtained after administration of the corresponding ordinary commercial Torseretic ® tablets. Stability study was conducted for F10 that showed good stability upon storage at 30°C/75% RH and 40°C/75% RH for 3 months.

A Review of Disintegration Mechanisms and Measurement Techniques

Pharmaceutical solid dosage forms (tablets or capsules) are the predominant form to administer active pharmaceutical ingredients (APIs) to the patient. Tablets are typically powder compacts consisting of several different excipients in addition to the API. Excipients are added to a formulation in order to achieve the desired fill weight of a dosage form, to improve the processability or to affect the drug release behaviour in the body. These complex porous systems undergo different mechanisms when they come in contact with physiological fluids. The performance of a drug is primarily influenced by the disintegration and dissolution behaviour of the powder compact. The disintegration process is specifically critical for immediate-release dosage forms. Its mechanisms and the factors impacting disintegration are discussed and methods used to study the disintegration in-situ are presented. This review further summarises mathematical models used to simulate disintegration phenomena and to predict drug release kinetics.

Development and optimization of a meloxicam/β-cyclodextrin complex for orally disintegrating tablet using statistical analysis

The purpose of this research was to develop an inclusion complex of meloxicam (MEL)/β-cyclodextrin (β-CD) incorporated into an orally disintegrating tablet (ODT), using statistical analysis to optimize the ODT formulation based on a quality by design (QbD) approach. MEL/β-CD complexation was performed by kneading, co-precipitation and spray drying methods under different molar ratios. Fourier transform infrared spectroscopy, X-ray diffraction and thermal analysis were utilized to evaluate the complexes. A central composite design (α = 2) was applied to optimize and assess the influence of Primojel, Primellose and crushing strength (CS) as independent variables on tablet friability, disintegration behavior, wicking properties and drug release. The spray drying method induced formation of an amorphous complex and enhanced solubility and drug release of MEL. Furthermore, a QbD-based statistical analysis was successfully utilized to optimize the ODT formulation. Primojel, Primellose and CS showed unique main effects and interactions at different levels. CS was the dominant factor, affecting friability, disintegration behavior and drug release, while wicking properties were affected by Primojel and its interaction with Primellose. Therefore, according to the overlay plot, CS was dominant factor in determining the optimum region based on a QbD approach.

Improvement of Meloxicam Solubility Using a β-Cyclodextrin Complex Prepared via the Kneading Method and Incorporated into an Orally Disintegrating Tablet

Purpose: The aim of this research was to formulate and develop an orally disintegrating tablet (ODT) that incorporated a MEL/β-CD complex, using a quality by design (QbD) approach to enhance solubility and drug release. Methods: Multiple regression linear analysis was conducted to develop the kneading process and ODT formulation. Mixing time and amount of solvent were used as independent variables in kneading process optimisation, while the superdisintegrants were used to obtain the desired formulation. Fourier transform infrared spectroscopy and differential scanning calorimetry were performed for complex characterization. Results: MEL/β-CD complexation was successful in enhancing MEL solubility. The results suggest that increasing the amount of solvent and mixing time enhances drug loading and drug release. However, increased solvent amounts present the problem of removing the solvent. Primojel and Polyplasdone had a significant effect on the water wicking and tablet disintegration process (p<0.05), although Polyplasdone negatively affected tablet hardness. Both an optimized KN process and ODT formulation were obtained using a QbD approach. Conclusion: Incorporation of the MEL/β-CD complex during ODT formulation using the QbD approach serves as a model for ODT product development, with optimal product performance based on the specification of quality target product profiles. To understand more specific phenomena, one point in the middle of the design for each factor should be added to more powerfully estimate this effect and avoid the lack of estimate due to an inadequate equation.

Comparative study of different approaches for preparation of chlorzoxazone orodispersible tablets

CONTEXT

Muscle spasm is a painful involuntary contraction of muscles, which causes involuntary movement and distortion. Chlorzoxazone is a centrally acting muscle-relaxant with sedative properties, but given orally, it is hepatically metabolized leading to decreased bioavailability.

OBJECTIVE

Orodispersible tablets (ODTs) of chlorzoxazone were formulated using two different approaches; by coprocessed excipients (CE) or by liquisolid (LS) technique.

MATERIALS AND METHODS

Pharmaburst^® 500, Starlac^®, Pearlitol flash^®, Prosolv^® odt and F-melt^® were used as coprocessed superdisintegrants, whereas in LS, Avicel^® PH101, Microcelac^® 100 and Cellactose^® 80 were used as carriers, while Aerosil^® 200 was the coating material. ODTs were evaluated in terms of weight and thickness variations, drug content, hardness, friability, wetting time, dissolution, disintegration time (DT) and palatability.

RESULTS

In vitro DT of CE-ODTs ranged from 26.43 ± 1.693 s to >180 s, whereas it was between 25.42± 0.203 s to >180 s in LS-ODTs. Complete drug release within 15 min was attained by CE1 prepared with 92.5 mg Pharmaburst^® 500. In vivo DT of CE1 and LS3 were 19.779 ± 0.810 and 18.105 ± 0.423 s, respectively, using six volunteers. Volunteers found that CE1 had more acceptable taste and was more palatable than LS3.

CONCLUSION

It was concluded that chlorzoxazone ODTs could be successfully formulated using either CE or LS techniques and be used as novel dosage forms for pediatrics and geriatrics showing improved drug release. Moreover, CE technique was superior to LS technique in terms of palatability.

A pharmaceutical study on chlorzoxazone orodispersible tablets: formulation, in-vitro and in-vivo evaluation

CONTEXT

Muscle spasm needs prompt relief of symptoms. Chlorzoxazone is a centrally muscle relaxant.

OBJECTIVES

The aim of this study was to prepare chlorzoxazone orodispersible tablets (ODTs) allowing the drug to directly enter the systemic circulation and bypassing the first-pass metabolism for both enhancing its bioavailability and exerting a rapid relief of muscular spasm.

MATERIALS AND METHODS

ODTs were prepared by direct compression method using Pharmaburst®500, Starlac®, Pearlitol flash®, Prosolv® odt and F-melt® as co-processed excipients. Three ratios of the drug to the other excipients were used (0.5:1, 1:1 and 2:1).

RESULTS AND DISCUSSION

All ODTs were within the pharmacopeial limits for weight and content. ODTs containing Pharmaburst®500 showed the shortest wetting time (∼45.33 s), disintegration time (DT) (∼43.33 s) and dissolution (Q_15min 100.63%). By increasing the ratio of CLZ: Pharmaburst®500 from 0.5:1 to 1:1 and 2:1, the DT increased from 26.43 to 28.0 and 43.33 s, respectively. By using Prosolv® odt, ODTs failed to disintegrate in an acceptable time >180 s. DT of ODTs using different co-processed excipients can be arranged as follows: Pharmaburst® 500 < F-melt® <Pearlitol flash® <Starlac® <Prosolv® odt. Pharmacokinetic study of the optimum formula F1 (50 mg CLZ) in rabbits using HPLC-UV detector revealed a shorter T_max (0.333 h) compared with Myofen® capsules (250 mg CLZ) (1.083 h) which is considered a promising treatment, especially for the rapid relief of muscle spasm.

CONCLUSION

It could be concluded that orodispersible tablets are a promising carrier for CLZ designed for management of muscle spasm due to the enhanced dissolution and rapid absorption of the drug through the oral mucosa.

Contrasting the crospovidones functionality as excipients for direct compression

Specific values of technological properties of excipients allow the establishment of numerical parameters to define and compare their functionality. This study investigates the functionality of Polyplasdones XL and XL10. Parameters studied included tablet disintegration profiles, compactibility profiles and powder flow. The results allowed the establishment of quantitative surrogate functionalities of technological performance, such as absolute number, and as a value relative to the known microcrystalline cellulose type 102. Moreover, the establishment of an explicit functionality to improve the technological performance of two diluents and a model drug was investigated, as was setting up of these functionalities, as quantitative values, to determine the input variables of each material and its probable functionality in a drug product. Disintegration times of pure Polyplasdone XL and its admixtures were around half that of Polyplasdone XL10. The improvement in tablet compactibility was 25-50% greater for Polyplasdone XL10 than Polyplasdone XL. Crospovidones proportions of up to 10% have little effect on the flow properties of other powders, although pure Polyplasdone XL10 and its admixtures display compressibility indexes about 20% greater than Polyplasdone XL. The observed results are in line with a smaller particle size of Polyplasdone XL10 compared to Polyplasdone XL.

Development of fast dispersing tablets of nebivolol: experimental and computational approaches to study formulation characteristics

Formulation of FDT (fast dispersing tablets) of nebivolol was optimized and evaluated using simplex lattice design (SLD). The influence of type and concentration of three disintegrants viz.,Ac-Di-Sol, Primojel and Polyplasdone XL on hardness, friability and disintegration time of tablet was studied. Response surface plot and the polynomial equations were used to evaluate influence of polymer on the tablet properties. Results were statistically analyzed using ANOVA, and a p < 0.05 was considered statistically significant. Results reveal that fibrous integrity and optimal degree of substitution in Primojel and Ac-Di-Sol are mainly responsible for the hardness of the tablet. Use of Polyplasdone in higher percentage in tablet formulation may result in high friability. Increase in concentration of Ac-Di-Sol increases the disintegration time but increased concentration of Primojel in the tablet formulation decreases the disintegration time. This is also evident from model terms for disintegration time with a high 'F' value of 14.69 and 'p' value of 0.0031 (<0.05). The reason could be that Primojel has higher swelling properties and an optimum hydration capacity, which favors fast disintegration of a tablet. In conclusion, careful selection of disintegrant for FDT could improve their properties. Use of Simplex Lattice Design for formulation development could simplify the formulation process and reduce the production cost.

Functionality of disintegrants and their mixtures in enabling fast disintegration of tablets by a quality by design approach

Investigation of the effect of disintegrants on the disintegration time and hardness of rapidly disintegrating tablets (RDTs) was carried out using a quality by design (QbD) paradigm. Ascorbic acid, aspirin, and ibuprofen, which have different water solubilities, were chosen as the drug models. Disintegration time and hardness of RDTs were determined and modeled by executing combined optimal design. The generated models were validated and used for further analysis. Sodium starch glycolate, croscarmellose sodium, and crospovidone were found to lengthen disintegration time when utilized at high concentrations. Sodium starch glycolate and crospovidone worked synergistically in aspirin RDTs to decrease disintegration time. Sodium starch glycolate-crospovidone mixtures, as well as croscarmellose sodium-crospovidone mixtures, also decreased disintegration time in ibuprofen RDTs at high compression pressures as compared to the disintegrants used alone. The use of sodium starch glycolate in RDTs with highly water soluble active ingredients like ascorbic acid slowed disintegration, while microcrystalline cellulose and crospovidone drew water into the tablet rapidly and quickened disintegration. Graphical optimization analysis demonstrated that the RDTs with desired disintegration times and hardness can be formulated with a larger area of design space by combining disintegrants at difference compression pressures. QbD was an efficient and effective paradigm in understanding formulation and process parameters and building quality in to RDT formulated systems.

Development and evaluation of orodispersible tablets using a natural polysaccharide isolated from Cassia tora seeds

BACKGROUND

Orodispersible tablets or fast dissolving tablets dissolve or disintegrate immediately on the patients' tongue or buccal mucosa. This drug delivery system is suitable for drugs undergoing high first pass metabolism. It improves bioavailability, reduces dosing frequency, and thereby minimizes the side effects and also makes the dosage form more cost-effective. In this study, polysaccharide isolated from the seeds of Cassia tora was investigated as a superdisintegrant in the orodispersible tablets. The model drug chosen was valsartan, an antihypertensive drug.

METHODS

Valsartan tablets were prepared separately using different concentrations (1%, 2.5%, 5%, and 7.5% w/w) of isolated C. tora seed polysaccharide (natural) and sodium starch glycolate (synthetic) as superdisintegrant by the direct compression method. Evaluation of tablets was done for various pre- and postcompression parameters. The stability studies were performed on optimized formulation F4. The disintegration time and in vitro drug release of the formulation F4 were compared with marketed formulations (conventional tablets).

RESULTS

The drug excipient interactions were characterized by Fourier transform infrared studies. The formulation F4 containing 7.5% polysaccharide showed good wetting time and disintegration time as compared to a formulation prepared using a synthetic superdisintegrant at the same concentration level. Hence, batch F4 was considered optimized formulation.

CONCLUSION

The present work revealed that C. tora seed polysaccharide has a good potential as a disintegrant in the formulation of orodispersible tablets. Because C. tora polysaccharide is inexpensive as compared to synthetic superdisintegrants, nontoxic, compatible, and easy to manufacture, it can be used in place of currently marketed superdisintegrants.

Formulation and evaluation of time-controlled triple-concentric mefenamic acid tablets for rheumatoid arthritis

A triple-concentric time-controlled release mefenamic acid (MA) tablet was developed using Carbopol and Ethocel polymers. The burst dose was programed to release immediately after an ingestion of tablet to be followed by a lag period of 2-4 h, and thereafter an 8 h controlled release of MA from core tablet. Core tablets were prepared using Carbopols 971P, 974P, 71G or 907 at various concentrations. The core tablet provided a controlled release of MA and the release rate decreased with increasing polymer concentration. Highly cross-linked Carbopol 974P released MA at a faster rate compared to release from Carbopol 971P with medium degree of cross-linking. Carbopols 71G and 971P exhibited essentially similar release rates. Carbopol 907, a linear polymer, showed fastest release of MA. The extent of uptake of dissolution medium by core tablets was inversely related to the rate of release of MA from the tablets. Compression coating of core tablet with Ethocel provided the lag period to delay release of MA from core tablet. Increase in lateral coating thickness decreased MA release and increased lag period. Compression forces applied during compression coating with Ethocel for lag period, and immediate-release MA coating for burst release did not affect the integrity of core tablet.

Influence of dissolution media pH and USP1 basket speed on erosion and disintegration characteristics of immediate release metformin hydrochloride tablets

PURPOSE

To investigate the influence of the pH of the dissolution medium on immediate release 850 mg metformin hydrochloride tablets.

METHODS

A traditional wet granulation method was used to manufacture metformin hydrochloride tablets with or without a disintegrant. Tablet dissolution was conducted using the USP apparatus I at 100 rpm.

RESULTS

In spite of its pH-independent high solubility, metformin hydrochloride tablets dissolved significantly slower in 0.1 N HCl (pH 1.2) and 50 mM pH 4.5 acetate buffer compared with 50 mM pH 6.8 phosphate buffer, the dissolution medium in the USP. Metformin hydrochloride API compressed into a round 1200 mg disk showed a similar trend. When basket rotation speed was increased from 100 to 250 rpm, the dissolution of metformin hydrochloride tablets was similar in all three media. Incorporation of 2% w/w crospovidone in the tablet formulation improved the dissolution although the pH-dependent trend was still evident, but incorporation of 2% w/w croscarmellose sodium resulted in rapid pH-independent tablet dissolution.

CONCLUSION

In absence of a disintegrant in the tablet formulation, the dissolution was governed by the erosion-diffusion process. Even for a highly soluble drug, a super-disintegrant was needed in the formulation to overcome the diffusion layer limitation and change the dissolution mechanism from erosion-diffusion to disintegration.

New direct compression excipient from tigernut starch: physicochemical and functional properties

Tigernut starch has been isolated and modified by forced retrogradation of the acidic gel by freezing and thawing processes. Relevant physicochemical and functional properties of the new excipient (tigernut starch modified by acid gelation and accelerated (forced) retrogradation (ST(AM))) were evaluated as a direct compression excipient in relation to the native tigernut starch (ST(NA)), intermediate product (tigernut starch modified by acid gelation (ST(A))), and microcrystalline cellulose (MCC). The particle morphology, swelling capacity, moisture sorption, differential scanning calorimeter (DSC) thermographs and X-ray powder diffraction (XRD) patterns, flow, dilution capacity, and tablet disintegration efficiency were evaluated. The particles of ST(NA) were either round or oval in shape, ST(A) were smooth with thick round edges and hollowed center while ST(AM) were long, smooth, and irregularly shaped typically resembling MCC. The DSC thermographs of ST(NA) and MCC showed two endothermic transitions as compared with ST(A) and ST(AM) which showed an endothermic and an exothermic. The moisture uptake, swelling, flow, and dilution capacity of ST(AM) were higher than those of MCC, ST(A), and ST(NA). The XRD pattern and moisture sorption profile of ST(AM) showed similarities and differences with ST(NA), ST(A), and MCC that relate the modification. Acetylsalicylic acid (ASA) tablets containing ST(AM) disintegrated at 3±0.5 min as compared with the tablets containing ST(NA), ST(A), and MCC which disintegrated at 8.5±0.5, 10±0.5, and 58±0.8 min, respectively. The study shows the physicochemical properties of tigernut starch modified by forced retrogradation as well as its potential as an efficient direct compression excipient with enhanced flow and disintegration abilities for tablets production.

Functional assessment of four types of disintegrants and their effect on the spironolactone release properties

Spironolactone is a drug derived from sterols that exhibits an incomplete oral absorption due to its low water solubility and slow dissolution rate. In this study, formulations of spironolactone with four disintegrants named as croscarmellose sodium, crospovidone, sodium starch glycolate and microcrystalline cellulose II (MCCII) were conducted. The effect of those disintegrants on the tensile strength, disintegration time and dissolution rate of spironolactone-based compacts was evaluated using a factorial design with three categorical factors (filler, lubricant, and disintegrant). The swelling values, water uptake and water sorption studies of these disintegrants all suggested that MCCII compacts disintegrate by a wicking mechanism similar to that of crospovidone, whereas a swelling mechanism was dominant for sodium starch glycolate and croscarmellose sodium. The disintegration time of MCCII and sodium starch glycolate remained unchanged with magnesium stearate. However, this lubricant delayed the disintegration time of crospovidone and croscarmellose sodium. MCCII presented the fastest disintegration time independent of the medium and lubricant employed. The water sorption ratio and swelling values determined sodium starch glycolate followed by croscarmellose sodium as the largest swelling materials, whereas crospovidone and MCCII where the least swelling disintegrants. The swelling property of sodium starch glycolate and croscarmellose sodium was strongly affected by the medium pH. The disintegration time of spironolactone compacts was faster when starch was used as a filler due to the formation of soft compacts. In this case, the type of filler employed rather than the disintegrant had a major effect on the disintegration and dissolution times of spironolactone.

Enhancement of dissolution of Telmisartan through use of solid dispersion technique - surface solid dispersion

The present study was aimed to increase the solubility of the poorly water soluble drug Telmisartan by using Surface solid dispersion (SSD) made of polymers like Poloxamer 407, PEG 6000 by Solvent evaporation method. The drug was solubilized by surfactants and/or polymers then adsorbed onto the surface of extremely fine carriers to increase its surface area and to form the SSD which give the more Surface area for absorption of the drug. A 2² full factorial design was used to investigate for each carrier the joint influence of formulation variables: Amount of carrier and adsorbent. Saturation solubility studies shows the improvement in solubility of drug batch SSD 8 give more solubility improvement than the other batch, in-vitro dissolution of pure drug, physical mixtures and SSDs were carried out in that SSDs were found to be effective in increasing the dissolution rate of Telmisartan in form of SSD when compared to pure drug. Also FT-IR spectroscopy, differential scanning calorimetry and X-ray diffractometry studies were carried out in order to characterize the drug and Surface solid dispersion. Furthermore, both DSC and X-ray diffraction showed a decrease in the melting enthalpy and reduced drug crystallinity consequently in SSDs. However, infrared spectroscopy revealed no drug interactions with the carriers.

Formulation and evaluation of microsphere based oro dispersible tablets of itopride hcl

BACKGROUND

The purpose of the present work is to mask the intensely bitter taste of Itopride HCl and to formulate an Oro dispersible tablet (ODT) of the taste-masked drug by incorporation of microspheres in the tablets for use in specific populations viz. pediatrics, geriatrics and patients experiencing difficulty in swallowing.

METHODS

With this objective in mind, microspheres loaded with Itopride HCl were prepared by solvent evaporation method using acetone as solvent for pH-sensitive polymer, Eudragit EPO and light liquid paraffin as the encapsulating medium. The prepared microspheres were characterized with regard to yield, drug content, flow properties, particle size and size distribution, surface features, in vitro drug release and taste. The ODTs so prepared from these microspheres were evaluated for hardness, thickness, weight variation, friability, disintegration time, drug content, wetting time, water absorption ratio, moisture uptake, in vitro dispersion, in vitro disintegration, in vitro drug release and stability.

RESULTS

The average size of microspheres was found to be satisfactory in terms of the size and size distribution. Microspheres prepared were of a regular spherical shape. Comparison of the dissolution profiles of microspheres in different pH media showed that microspheres having drug: polymer ratio of 1:2 produced a retarding effect in simulated salivary fluid (pH 6.8) and were further used for formulation into ODTs after addition of suitable amounts of excipients such as superdisintegrant, diluent, sweetener and flavor of directly compressible grade.

CONCLUSIONS

Effective taste-masking was achieved for Itopride HCl by way of preparation of microspheres and ODTs of acceptable characteristics.