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42 May/June 2021 Tablets & Capsules powder flow makes a positive impact here, too. Figure 7 shows that content is clearly more uniform in tablets con- taining SMCC when compared to MCC alone or a physical blend Consider the content Content uniformity is also criti- cal to performance. If API content changes drastically from tablet to tab- let, it could affect the formulation's overall efficacy. SMCC's improved cellulose (MCC) can achieve faster granule build with higher density and less water, which in turn leads to faster drying as desired. IFF researchers compared two MCC varieties offered by IFF (Avi- cel PH-101 and PH-301) for granule size as a function of water addition. Both forms of MCC have compara- ble median particle sizes but possess different bulk densities. PH-301 has a bulk density of approximately 0.4 grams per cubic centimeter (g/cc), while PH-101 has a bulk density of 0.3 g/cc. According to the results shown in Figure 5, using a higher- density MCC results in faster granule build with less water. This has the dual benefit of speeding up granu- lation and shortening drying time because of the reduction in water use. Increasing throughput to the highest limit is of utmost importance in CM, so any excipient that can shorten these processes should be considered by formulators. Tablet pressing and coating The last phase of CM, where the end product is formed and pre- pared for mass consumption, also depends on the right selection of excipients. By incorporating the right co- processed excipients into the CM process, formulators stand to bene- fit from improved process control, which in turn leads to a robust final product with consistent weight and uniform content. No lightweight Superior powder flow results in lower weight variation, as shown in Figure 6. This benefit holds up across two very different APIs at both low and high doses, suggesting that SMCC can provide formulators with a consistent method of maintain- ing tablet weight during tableting. SMCC showed improvement in tab- let weight variability when compared to both neat MCC and a physical blend of MCC and silica, suggest- ing a synergistic improvement in the co-processed product. Figure 3 Improved tensile strength of SSF 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 1 2 3 4 5 6 7 Tensile strength (MPa) SSF MgSt Figure 4 Improved disintegration time and friability of SSF 30 25 20 15 10 5 0 2.5 2.0 1.5 1.0 0.5 0.0 Disintegration (sec) Friability (%) Batch 1 2 3 4 5 6 SSF MgSt Figure 5 MCC granule size as a function of water addition in CM 300 250 200 150 100 50 25 30 35 40 45 50 55 Water addition (ml) Mean granule size, d0.5 (µm) With Avicel PH-101 With Avicel PH-301 Placebo formulation 80% Lactose 200M 15% Avicel PH 5% Polyvinylpyrrolidone Total dry (powder) weight: 300g