Development of direct compression entecavir 0.5 mg-loaded tablet exhibiting enhanced content uniformity

Blend Segregation in Tablets Manufacturing and Its Effect on Drug Content Uniformity-A Review

Content uniformity (CU) of the active pharmaceutical ingredient is a critical quality attribute of tablets as a dosage form, ensuring reproducible drug potency. Failure to meet the accepted uniformity in the final product may be caused either by suboptimal mixing and insufficient initial blend homogeneity, or may result from further particle segregation during storage, transfer or the compression process itself. This review presents the most relevant powder segregation mechanisms in tablet manufacturing and summarizes the currently available, up-to-date research on segregation and uniformity loss at the various stages of production process—the blend transfer from the bulk container to the tablet press, filling and discharge from the feeding hopper, as well as die filling. Formulation and processing factors affecting the occurrence of segregation and tablets’ CU are reviewed and recommendations for minimizing the risk of content uniformity failure in tablets are considered herein, including the perspective of continuous manufacturing.

Mixing of low-dose cohesive drug and overcoming of pre-blending step using a new gentle-wing high-shear mixer granulator

The objective of this study was to examine the influence of drug amount and mixing time on the homogeneity and content uniformity of a low-dose drug formulation during the dry mixing step using a new gentle-wing high-shear mixer. Moreover, the study investigated the influence of drug incorporation mode on the content uniformity of tablets manufactured by different methods. Albuterol sulfate was selected as a model drug and was blended with the other excipients at two different levels, 1% w/w and 5% w/w at impeller speed of 300 rpm and chopper speed of 3000 rpm for 30 min. Utilizing a 1 ml unit side-sampling thief probe, triplicate samples were taken from nine different positions in the mixer bowl at selected time points. Two methods were used for manufacturing of tablets, direct compression and wet granulation. The produced tablets were sampled at the beginning, middle, and end of the compression cycle. An analysis of variance analysis indicated the significant effect (p < .05) of drug amount on the content uniformity of the powder blend and the corresponding tablets. For 1% w/w and 5% w/w formulations, incorporation of the drug in the granulating fluid provided tablets with excellent content uniformity and very low relative standard deviation (∼0.61%) during the whole tableting cycle compared to direct compression and granulation method with dry incorporation mode of the drug. Overall, gentle-wing mixer is a good candidate for mixing of low-dose cohesive drug and provides tablets with acceptable content uniformity with no need for pre-blending step.

Direct compaction: An update of materials, trouble-shooting, and application

Direct compaction (DC) is the preferred choice for tablet manufacturing; however, only less than 20% of active pharmaceutical ingredients could be compacted via DC as its high requirement for functional properties of materials. Materials with improper functionalities could lead to serious troubles during DC manufacturing, such as content non-uniformity, sticking, and capping, all of which profoundly affect the properties of final products and, thus, severely restrict the practical application of DC. With undoubted importance, these seem to be unexpectedly ignored by reviewers but not researchers in terms of many original research articles published recently. Therefore, as an informative supplement and update, this review mainly focused on trouble-shooting and application situation of DC, together with several newly reported materials.

Cefdinir Solid Dispersion Composed of Hydrophilic Polymers with Enhanced Solubility, Dissolution, and Bioavailability in Rats

The aim of this work was to develop cefdinir solid dispersions (CSDs) prepared using hydrophilic polymers with enhanced dissolution/solubility and in vivo oral bioavailability. CSDs were prepared with hydrophilic polymers such as hydroxypropyl-methylcellulose (HPMC; CSD1), carboxymethylcellulose-Na (CMC-Na; CSD2), polyvinyl pyrrolidone K30 (PVP K30; CSD3) at the weight ratio of 1:1 (drug:polymer) using a spray-drying method. The prepared CSDs were characterized by aqueous solubility, differential scanning calorimetry (DSC), powder X-ray diffraction (p-XRD), scanning electron microscopy (SEM), aqueous viscosity, and dissolution test in various media. The oral bioavailability of CSDs was also evaluated in rats and compared with cefdinir powder suspension. The cefdinir in CSDs was amorphous form, as confirmed in the DSC and p-XRD measurements. The developed CSDs commonly resulted in about 9.0-fold higher solubility of cefdinir and a significantly improved dissolution profile in water and at pH 1.2, compared with cefdinir crystalline powder. Importantly, the in vivo oral absorption (represented as AUC_inf) was markedly increased by 4.30-, 6.77- and 3.01-fold for CSD1, CSD2, and CSD3, respectively, compared with cefdinir suspension in rats. The CSD2 prepared with CMC-Na would provide a promising vehicle to enhance dissolution and bioavailability of cefdinir in vivo.