Does the amorphous content of spray-dried lactose have a negative effect on tablet hardness or disintegration time?
On the contrary, the amorphous content of spray-dried lactose is a component in ensuring good compaction. Crystallisation of the amorphous content can cause a reduction in compactability of spray dried lactose. Tablets containing spray dried lactose can harden slightly on storage, but the disintegration time tends to decrease. Both effects are consistent with crystallisation of the spray dried component.
Which direct compression product has the best flow performance?
In general the spray dried and the granulated Lactopress® and SuperTab® products have better flow than anhydrous products. However, SuperTab® 22AN has been specifically developed for applications in which anhydrous lactose with improved flow is required.
What is the difference between milled and sieved lactose and direct compression lactose?
Milled lactose and sieved lactose are grades of alpha-lactose monohydrate that are processed to give a particular particle size distribution. Sieved grades are coarser than milled grades. In general milled lactose is primarily used for wet granulation applications where its fine particle size helps to confer good tablet hardness, but it does no flow well.
Sieved lactose flows well but it does not compact well on its own. It may be used in some direct compression tablet applications, but it should be combined with an excipient with good compaction properties, such as Pharmacel® (microcrystalline cellulose).
Direct Compression lactose is processed especially to have both good flow and good compaction properties, the two key properties for a direct compression excipient.
Which material is best suited for a low dosage formulation?
In direct compression we find that all Lactopress
® and SuperTab
® grades can be used and good content uniformity can be achieved if a good blending scheme is employed. In particular we recommend the inclusion of a step that disperses any drug agglomerates. Such step includes passing a pre-mix of drug and Lactopress
® and SuperTab
® through a screen (500μm is suitable) or blending a premix with a mixer that includes an intensifier bar.
What are recommended storage conditions?
It is recommended to store the product in the original and closed packaging protected form solvents and under normal warehouse conditions between temperatures of 5 and 25 degrees Celcius and relative humidity of max. 70%.
Can medicines containing lactose be taken by lactose intolerant persons?
Yes. Lactose intolerance (the symptoms of intestinal discomfort) are caused by high quantities of lactose.
For example:
“In patients with mild tolerance, up to 15 g of lactose can be taken within a short time without symptoms.”
Gordon A. Greenberg: Modern Nutrition in Health and Disease, Maurice E. Shils, Vernon R. Young, Lea & Febiger, Philadelphia, 1988
“… lactose malabsorbing subjects can tolerate amounts of lactose up to 11 g, if lactose is combined with a meal. It is likely that even higher amounts are tolerated when distributed across meals over the day...”
G. Schaafsma and G. van Poppel in Lactose intolerance: nutritional implications, TNO-report V96.948
“… the amount of ingested lactose required to produce symptoms varies but is reported to be about 12 to 18 g…”
DL Swagerty Jr., M.D., M.P.H., AD. Walling, M.D., and RM Klein, Ph.D. American Family Physician, Vol 65 No. 9, May 1st 2002,
The quantity of lactose in a typical tablet varies but 200mg may be taken as typical. Thus 50 or more such tablets would be required to provoke lactose intolerance.
May lactose used in medicine cause allergy?
Lactose is highly purified and the allergenic components (proteins) in cow’s milk are removed or denatured during processing.
A number of studies have demonstrated the non-allergenicity of lactose:
“Even children hypersensitive to CM (cow’s milk) are clinically tolerant to lactose and can safely consume foods and drugs with lactose from bovine sources as an ingredient.” A. Fiocchi, …, Clinical tolerance to lactose in children with cow's milk allergy. Pediatrics. 2003 Aug;112(2):359-62.
Even in asthmatic patients, lactose did not provoke an allergic response when inhaled. “.. this study showed that high concentrations of lactose were not associated with any clinically important changes in FEV1 or airway conductance in asthmatic patients. No statistically significant difference from placebo was observed.” P. Thoren,.. The effect of different concentrations of lactose powder on the airway function of adult asthmatics, Respiratory medicine, 2001, 95, 870 – 875.