Modification of α-lactose monohydrate as a direct compression excipient using roller compaction

Lactose in tablets: Functionality, critical material attributes, applications, modifications and co-processed excipients

Lactose is one of the most widespread excipients used in the pharmaceutical industry. Because of its water solubility and acceptable flowability, lactose is generally added into tablet formulation to improve wettability and undesirable flowability. Based on Quality by Design, a better understanding of the critical material attributes (CMAs) of raw materials is beneficial in guiding the improvement of tablet quality and the development of lactose. Additionally, the modifications and co-processing of lactose can introduce more-desirable characteristics to the resulting particles. This review focuses on the functionality, CMAs, applications, modifications and co-processing of lactose in tablets.

Multiparticulate Systems of Meloxicam for Colonic Administration in Cancer or Autoimmune Diseases

The aim of this research is the development of new colonic release systems of meloxicam (MLX) a non-steroidal anti-inflammatory drug (NSAIDs) with pH and time-dependent vehicles for cancer or autoimmune diseases. The colon has a higher pH than the rest of the gastrointestinal tract (GIT) and this can be used as a modified release strategy. Eudragit^® polymers are the most widely used synthetic products in the design of colonic release formulations because they might offer mucoadhesiveness and pH-dependent release. Colonic delivery systems produced with pH-dependent and permeable polymers (FS-30D) or with pH-independent and low permeability polymers (NM-30D), must dissolve at a pH range of 6.0–7.0 to delay the release of the drug and prevent degradation in the GIT, before reaching the colon. The conditions prepared to simulate a gastrointestinal transit showed the CNM multiparticulate system, composed of Eudragit^® NM and cellulose, as the best release option for MLX with a more sustained release with respect to the other formulations. CNM formulation followed Higuchi and First-order release kinetics, thus MLX release was controlled by a combination of diffusion and polymers swelling/eroding processes.

A new parameter for characterization of tablet friability based on a systematical study of five excipients

In this paper, a new parameter highly relevant to tablet friability is proposed based on a systematical study of the tablet quality attributes and texture performances of five different direct compression excipients, including microcrystalline cellulose, starch, lactose, mannitol, and dicalcium phosphate anhydrous. The new parameter, named Strain/Stress Max, could indicate the tablet's ability against external force to maintain integrity. It was directly obtained from the diametrical breaking test which is extensively used to assess tablet mechanical strength, and thus no extra work is required. The values varied significantly among the tablets formed by materials with different mechanical properties under the same compression pressure. A design space was developed to achieve <1% tablet friability at various combinations of Strain/Stress Max and tensile strength. Additionally, data from binary mixture tablets validated the availability of the constructed design space. And the upper limit of Strain/Stress Max value was advisable for 1.5 MPa^-1 for pharmaceutical tablets. In conclusion, the new parameter and design space are available for fast identification of the tablets with acceptable friability to facilitate the development of tablet formulation using as few active pharmaceutic ingredients as possible.

Improving Tableting Performance of Lactose Monohydrate by Fluid-Bed Melt Granulation Co-Processing

Co-processing is commonly used approach to improve functional characteristics of pharmaceutical excipients to become suitable for tablet production by direct compression. This study aimed to improve tableting characteristics of lactose monohydrate (LMH) by co-processing by fluid-bed melt granulation with addition of hydrophilic (PEG 4000 and poloxamer 188) and lipophilic (glyceryl palmitostearate) meltable binders. In addition to binding purpose, hydrophilic and lipophilic excipients were added to achieve self-lubricating properties of mixture. Co-processed mixtures exhibit superior flow properties compared to pure LMH and comparable or better flowability relative to commercial excipient Ludipress^®. Compaction of mixtures co-processed with 20% PEG 4000 and 20% poloxamer 188 resulted in tablets with acceptable tensile strength (>2 MPa) and good lubricating properties (ejection and detachment stress values below 5 MPa) in a wide range of compression pressures. While the best lubricating properties were observed when glyceryl palmitostearate was used as meltable binder, obtained tablets failed to fulfil required mechanical characteristics. Although addition of meltable binder improves interparticle bonding, disintegration time was not prolonged compared to commercial excipient Ludipress^®. Co-processed mixtures containing 20% of either PEG 4000 or poloxamer 188 showed superior tabletability and lubricant properties relative to LMH and Ludipress^® and can be good candidates for tablet production by direct compression.

Human Health Effects of Lactose Consumption as a Food and Drug Ingredient

Lactose is a reducing sugar consisting of galactose and glucose, linked by a β (1→4) glycosidic bond, considered as an antioxidant due to its α-hydroxycarbonyl group. Lactose is widely ingested through the milk and other unfermented dairy products and is considered to be one of the primary foods. On the other hand, lactose is also considered as one of the most widely used excipients for the development of pharmaceutical formulations. In this sense, lactose has been related to numerous drug-excipient or drug-food pharmacokinetic interactions. Intolerance, maldigestion and malabsorption of carbohydrates are common disorders in clinical practice, with lactose-intolerance being the most frequently diagnosed, afflicting 10% of the world's population. Four clinical subtypes of lactose intolerance may be distinguished, namely lactase deficiency in premature infants, congenital lactase deficiency, adult-type hypolactasia and secondary lactase intolerance. An overview of the main uses of lactose in human nutrition and in the pharmaceutical industry and the problems derived from this circumstance are described in this review.

Influence of Chitin Source and Polymorphism on Powder Compression and Compaction: Application in Drug Delivery

The objective of the research reported herein is to compare the compaction properties of three different chitin extracts from the organisms most used in the seafood industry; namely crabs, shrimps and squids. The foregoing is examined in relation to their polymorphic forms as well as compression and compaction behavior. Chitin extracted from crabs and shrimps exhibits the α-polymorphic form whilst chitin extracted from squid pins displays a β-polymorphic form. These polymorphs were characterized using FTIR, X-ray powder diffraction and scanning electron microscopy. Pore diameter and volume differ between the two polymorphic powder forms. The β form is smaller in pore diameter and volume. Scanning electron microscopy of the two polymorphic forms shows clear variation in the arrangement of chitin layers such that the α form appears more condensed due to the anti-parallel arrangement of the polymer chains. True, bulk and tapped densities of these polymorphs and their mixtures indicated poor flowability. Nevertheless, compression and compaction properties obtained by applying Heckle and Kawakita analyses indicated that both polymorphs are able to be compacted with differences in the extent of compaction. Chitin compacts, regardless of their origin, showed a very high crushing strength with very fast dissolution which makes them suitable for use as fast mouth dissolving tablets. Moreover, when different chitin powders are granulated with two model drugs, i.e., metronidazole and spiramycin they yielded high crushing strength and their dissolution profiles were in accordance with compendial requirements. It is concluded that the source of chitin extraction is as important as the polymorphic form when compression and compaction of chitin powders is carried out.

A New Perspective of Multiple Roller Compaction of Microcrystalline Cellulose for Overcoming Re-Compression Drawbacks in Tableting Processing

In this paper, new scientific insights in relation to the re-compaction of microcrystalline cellulose (MCC; Avicel®® PH-101) under specific compaction conditions are reported. MCC was subjected to multiple compaction cycles (1st, 2nd, and 3rd) under high compaction pressures, up to 20,000 kPa, using a roller compactor of 100 kg/h capacity. Initially, granules from the 1st and 2nd compaction cycles produced tablets with lower crushing strength compared to those made from the original non-compacted MCC. Tablet weakness was found to be correlated to the generation of a higher intra-granular pore size (diameter) and hence higher tablet porosity compared to that of the original MCC particles. Using Kawakita and Heckel compression analyses, it is suggested that such behavior is attributed to the formation of harder granules of re-compressed powder with a larger diameter than non-compacted MCC particles. Moreover, these granules resulted in a reduction in powder bed volume after the powders were subjected to the 1st and 2nd compaction cycles. Surprisingly, granules resulting from the 3rd compaction cycle produced tablets displaying a higher crushing force than non-compacted MCC. Results from compression analysis indicated a reduction in both the intra-granular pore size (diameter) and in tablet porosity of Avicel PH-101-3rd compaction cycle compared to that of the original non-compacted MCC. It is concluded that intense compression causes shedding of one or more layer from MCC fibers exposing new surfaces with strong binding ability. The foregoing results infer that intensified roller compaction can be employed to improve MCC powder compactibility without any deleterious effects on compact strength.

Understanding the Performance of a Novel Direct Compression Excipient Comprising Roller Compacted Chitin

Chitin has been investigated in the context of finding new excipients suitable for direct compression, when subjected to roller compaction. Ball milling was concurrently carried out to compare effects from different energy or stress-inducing techniques. Samples of chitin powders (raw, processed, dried and humidified) were compared for variations in morphology, X-ray diffraction patterns, densities, FT-IR, flowability, compressibility and compactibility. Results confirmed the suitability of roller compaction to convert the fluffy powder of raw chitin to a bulky material with improved flow. X-ray powder diffraction studies showed that, in contrast to the high decrease in crystallinity upon ball milling, roller compaction manifested a slight deformation in the crystal lattice. Moreover, the new excipient showed high resistance to compression, due to the high compactibility of the granules formed. This was correlated to the significant extent of plastic deformation compared to the raw and ball milled forms of chitin. On the other hand, drying and humidification of raw and processed materials presented no added value to the compressibility and compactibility of the directly compressed excipient. Finally, compacted chitin showed direct compression similarity with microcrystalline cellulose when formulated with metronidazole (200 mg) without affecting the immediate drug release action of the drug.