Flow characterization of a pharmaceutical excipient using the shear cell method

Technological, Biochemical and Microbiological Evaluation of Dehydrated Pleurotus ostreatus Powder for Nutraceutical Applications

Abstract:

Background: Mushroom-based products can serve as superior nutraceuticals in both preventing and alleviati human diseases. Dehydrated powder of Pleurotus ostreatus grown in Cuba has a rich nutritional composition and a large number of therapeutic properties. However, technological parameters (e.g. rheological), as well as biochemical and microbiological quality control standards for its use as a raw material in the manufacture of solid dosage forms with nutraceutical and biopharmaceutical applications have not been established yet.

Objective:

The study aims to determine the technological, biochemical and microbiological quality parameters of dehydrated Pleurotus ostreatus powder.

Method:

Rheological ngproperties (Carr´s index, Hausner´s ratio, angle of repose and flow rate) were determined in seven batches of mushroom powder. Biochemical and microbiological analyses were performed using standard methods. Other physicochemical properties (mean particle size, pH and moisture) were also determined.

Results:

Technical parameters showed a mean particle size of 224.08±7.96 µm, Carr´s compressibility index (23.08-26.58%), Hausner´s ratio (1.30-1.36), angle of repose (36.6-41.90°) and flow rate (3.69-6.93 g cm-2 s-1), typical of materials with poor flowability. Biochemical analyses indicated significant nutraceutical composition: protein (25.0-30.4%), carbohydrate (45-60%), ash (6.1-9.8%), fiber (5-9%), -D-Glucans (1.47-1.61%), iron (21-50 mg/100 g), zinc (3.8-8.0 mg/100 g), and polyphenols (123-160 mg/100 g). Moisture content was ≤3.50% and microbiological analyses were in agreement with ISO standards.

Conclusion:

Dehydrated P. ostreatus powder exhibits good nutraceutical composition and microbiological quality. Technological parameters evidenced poor flow properties, suggesting the need to include excipients to improve the rheological properties for applications as an active ingredient in solid dosage forms for health benefits.

Starch flow behavior alone and under different glidants action using the shear cell method

The objective of this work was to analyze the flow behavior of a commonly used filler (pregelatinised starch) and the effect of two of the most used lubricants (talc and colloidal silicon dioxide). The studies were carried out according to the conventional methods (Angle of Repose, Bulk and Tapped densities and from these the Compressibility Index) and shear cell methods (Brookfield Powder Flow Tester apparatus) described in European Pharmacopeia (Ph. Eur.). The results showed some surprising and unexpected values for the flow behavior of this filler under influence of the methods and the used glidants. Regarding pure starch and mixtures containing talc, the flow behavior was similar between them and the Flow Index (ff_c) values varied between 1.8 and 4 (very cohesive and cohesive) as consolidation stress (σ₁) increased. In this case, the glidant effect was not observed. However, for the mixtures of starch with colloidal silicon dioxide this effect was observed providing Flow Index (ff_c) values between 2.6 and 8.9 (cohesive and easy-flowing) as consolidation stress (σ₁) increased. Other parameters that are also used to characterize flow properties, more specifically, within silos, chutes and hoppers, such as effective angle of internal friction (φe), effective angle of wall friction (φx), critical arching and critical rathole values, provided similar information. Based in the obtained results from all tests it can be said that the talc did not induce improvement on the starch flow behavior in the used conditions in opposition to the effect produced by colloidal silicon dioxide.HighlightsExample 1. A good flowability of powders is needed in order to be compressed/filled;Example 2. The overcome the poor flow it is usual to use glidants;Example 3. CSD improved the pregelatinised starch (Starch 1500®) flow;Example 4. Talc do not have relevant effect in the pregelatinised starch (Starch 1500®) flow;Example 5. Powder FlowTester method showed more complete and consistent results.

Lactose monohydrate flow characterization using shear cell method

The flow properties of pharmaceutical powders have a great importance in the manufacturing of solid dosage forms. In order to ensure the performance in the production line this parameter must be determined. There are several methods described in European Pharmacopeia that are used to measure these properties. Some of them were used in this study and the results obtained from conventional methods (Conv) and shear cell using the powder flow tester (PFT) showed differences that were more evident in fractions with smaller particle size (F < 63) and for bulk powder (F_Total). The various powder behaviors showed to be related with the size of the particles. An increase of the ff_c (Flow Index) was observed with the increase of the particle size. It was also found for the different fractions that the ff_c always increases with increasing major principal consolidation stress (σ₁). This study shown to be predictive because it also allowed the behavior profiles of other LactMN fractions to be known by interpolation of the median size (Dv50) or σ₁ values ranged between the studied intervals. Furthermore, it was also observed that ff_c of the F_Total was similar to the F < 63, showing the same behavior under σ₁. The occurrence of caking was not observed.