The efficient development of a sildenafil orally disintegrating tablet using a material sparing and expedited approach

Testing the disintegration and texture-related palatability predictions for orodispersible tablets using an instrumental tool coupled with multivariate analysis: Focus on process variables and analysis settings

Orodispersible tablets (ODTs) represent a growing category of dosage forms intended to increase the treatment acceptability for special groups of patients. ODTs are designed to rapidly disintegrate in the oral cavity and to be administered without water. In addition, ODTs are easy to manufacture using standard excipients and pharmaceutical equipment. This study adds to previously published research that developed an instrumental tool to predict oral disintegration and texture-related palatability of ODTs with different formulations. The current study aimed to challenge the predictive capacity of the models under variable process conditions. The studied process parameters with potential impact on the pharmaceutical properties, texture profiles, and palatability were the compression pressure, punch shape and diameter. Subsequently, for all the placebo and drug-loaded ODTs, the in vivo disintegration time and texture-related palatability were determined with healthy volunteers. Previously developed regression models were applied to predict the formulation's disintegration time and texture-related palatability characteristics of ODTs obtained under different experimental conditions. The influence of process variables on the predictive performance of the models was estimated by calculating the residuals as the difference between the predicted and observed values for the investigated response. Increasing the speed of the analyser`s probe from 0.01 mm/s to 0.02 mm/s led to an improved differentiation of the texture profiles. The in vivo disintegration time and texture-related palatability scores were only influenced by the mechanical resistance and the tablet shape. Lower score was observed for the larger diameter tablets (10 mm). Overall, the prediction of the disintegration time at 0.02 mm/s was more accurate, except for stronger tablets. The best prediction of texture-related palatability was achieved for the 10 mm tablets, tested at 0.01 mm/s speed. The same model achieved good predictions of the oral disintegration time for all API-loaded formulations, which confirmed the ability of the texture analysis to capture process-related variability. Drug loading decreased the predictive capacity of the texture-related palatability because of the taste effect.

Evaluating the Effect of Microcrystalline Cellulose Variations on Tablet Quality of Natural Plant Product Using a Design of Experiment Approach

Microcrystalline cellulose (MCC) of different grades from different manufacturers differ in particulate and powder properties significantly. The choice of MCC is important to the development of a tablet formulation with satisfactory quality. In this study, the effects of five different MCCs (KG 802, Pharmacel 102, MC 302, M 200, and PH 112) that had different compactibility and tablet disintegration on the tablet quality of two different natural plant products (NPPs) were evaluated systematically, including Crataegi Folium ethanol extract (CF-E) and Sarcandrae Herba water extract (SH-W). The result of D-optimal mixture designs demonstrated that KG 802 showed the best ability to improve compression properties and tensile strength, followed by Pharmacel 102, MC 302, and M 200. PH 112 did the weakest. However, MCCs of different grades had no different influence on the disintegration of NPP tablets. Similar results were found in the experiments of the two different NPP powders, suggesting the generalization of the finding. Moreover, KG 802-containing CF-E formulations showed the largest optimum region size, that is, the lowest production risk. The design space sizes of SH-W were hardly sensitive to the change of MCCs, due to the better tabletability. In conclusion, the properties of MCCs could transfer to the high NPP loading (70%) formulations, leading to the variations on the compression properties and tablet quality. The poorer the tabletability of NPP, the more obvious the variation. The result is promising for the use of MCC and the manufacturing of high drug-loading NPP tablets by direct compression.

An update on microcrystalline cellulose in direct compression: Functionality, critical material attributes, and co-processed excipients

Microcrystalline cellulose (MCC) is one of the most popular cellulose derivatives in the pharmaceutical industry. Thanks to its outstanding tabletability, MCC is generally included in direct compression (DC) tablet formulations containing poor-tabletability active pharmaceutical ingredients. Nowadays, numerous grades of MCC from various brands are accessible for pharmaceutical manufacturers, leading to variability in MCC properties. Hence, it seems to be worthy and urgent to evaluate the influences of MCC variability on tablet quality and to identify critical material attributes (CMAs) based on the idea of Quality by Control. Besides, MCC-based co-processed excipients can effectively combine the functions of the filler, binder, disintegrant, lubricant, glidant, or flavor, and thus have drawn extensive interest. In this review, we focused specifically on the recent advances and development of MCC on DC tableting, including the functions in tablet formulations, potential CMAs, and MCC-based co-possessed excipients, therefore providing a reference for further studies.

Exploitation of Design-of-Experiment Approach for Design and Optimization of Fast-Disintegrating Tablets for Sublingual Delivery of Sildenafil Citrate with Enhanced Bioavailability Using Fluid-Bed Granulation Technique

Sildenafil citrate undergoes first-pass metabolism, resulting in poor oral bioavailability at 25-41% of the administered dose. This study aimed to design and optimize fast-disintegrating tablets for the sublingual delivery of sildenafil citrate to improve bioavailability and facilitate rapid onset of action. The design-of-experiment (DoE) approach using 32 full factorial design was conducted to develop a new formulation of sildenafil fast-disintegrating sublingual tablets (FDSTs) using the fluid-bed granulation technique. The levels of partially pre-gelatinized starch (5-15%) and microcrystalline cellulose (10-60%) were selected as independent formulation variables. The prepared FDSTs were investigated for physical properties. Further, the optimum formulation was chosen for in vivo study in rabbits. Regression analysis showed that independent variables have a significant (p < 0.05) influence on critical attributes of FDSTs. The optimized formulation showed acceptable mechanical strength (friability < 1.0%) with very fast disintegration (14.561 ± 0.84 s) and dissolution (94.734 ± 2.76% after 15 min). Further, the optimized formulation demonstrated a significant increase (p < 0.01) in Cmax and AUC0-∞ with short tmax compared to the market product (Viagra®). Based on these results, using the DoE approach, a high level of assurance was achieved for FDSTs' product quality and performance.

Sildenafil 4.0-Integrated Synthetic Chemistry, Formulation and Analytical Strategies Effecting Immense Therapeutic and Societal Impact in the Fourth Industrial Era

Sildenafil is a potent selective, reversible inhibitor of phosphodiesterase type 5 (PDE5) approved for the treatment of erectile dysfunction and pulmonary arterial hypertension. Whilst twenty years have passed since its original approval by the US Food and Drug Administration (USFDA), sildenafil enters the fourth industrial era catalyzing the treatment advances against erectile dysfunction and pulmonary hypertension. The plethora of detailed clinical data accumulated and the two sildenafil analogues marketed, namely tadalafil and vardenafil, signify the relevant therapeutic and commercial achievements. The pharmacokinetic and pharmacodynamic behavior of the drug appears complex, interdependent and of critical importance whereas the treatment of special population cohorts is considered. The diversity of the available formulation strategies and their compatible administration routes, extend from tablets to bolus suspensions and from per os to intravenous, respectively, inheriting the associated strengths and weaknesses. In this comprehensive review, we attempt to elucidate the multi-disciplinary elements spanning the knowledge fields of chemical synthesis, physicochemical properties, pharmacology, clinical applications, biopharmaceutical profile, formulation approaches for different routes of administration and analytical strategies, currently employed to guide the development of sildenafil-based compositions.