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[Lactase deficiency and lactose intolerance-related symptoms in adult healthy subjects from western France].

The prevalence of lactase deficiency (LD) and lactose intolerance is not well known in France. Using breath hydrogen and methane analysis after 50 g oral lactose load, we investigated the prevalences of LD, lactose intolerance, and methane producer status in 102 healthy adults born in western France, and we examined the relationships between these parameters and the daily milk consumption. In 10 subjects with LD and lactose intolerance, we studied the reproducibility of the lactose hydrogen breath test results for the diagnosis of LD and lactose intolerance and estimated the quantity of lactose malabsorbed in comparison with the lactulose hydrogen breath test. The prevalence of LD was 23.4 percent and symptoms of lactose intolerance were observed in 50 percent of the 24 subjects with LD. The daily milk consumption was not significantly different in the 24 subjects with LD and in the 78 subjects without LD (281 +/- 197 vs 303 +/- 217 ml/24 h). The prevalence of methane producer status was 42.1 percent. The symptomatic group of lactose malabsorbers (n = 12) was characterized by a shorter lactose mouth to caecum transit time (39 +/- 20 vs 88 +/- 48 min; P less than 0.05), and more marked hydrogen production (6.1 +/- 2.3 vs 3.4 +/- 2.4 10(3) ppm.min; P less than 0.04). In the 10 subjects with LD and lactose intolerance, the hydrogen breath test was reproducible for diagnosis of LD and lactose intolerance, and for hydrogen production. The quantity of lactose malabsorbed was 60 percent. In France, symptoms of lactose intolerance are not severe and do not affect the daily consumption of milk and dairy products.

Abdominal Pain↗

Absorption of lactose, glucose polymers, or combination in premature infants.

STUDY OBJECTIVE: To determine the digestion and absorption of lactose, a combination of lactose and glucose polymers, and glucose polymers alone in infants born at 28 to 42 weeks of gestation. DESIGN: Each infant received the three carbohydrate solutions (85 gm/L concentration) in random order. SETTING: Tertiary care urban children's hospital. INTERVENTIONS: A double-lumen perfusion catheter was placed in the duodenum-jejunum. Absorption was defined as the disappearance of the carbohydrate and all its components (e.g., for lactose: galactose, glucose). MEASUREMENTS AND MAIN RESULTS: Absorption of lactose was less than that of the lactose-glucose polymer combination and the glucose polymers alone. There was no relationship between lactose absorption and postnatal age, whereas absorption of the lactose-glucose polymer combination and the glucose polymers alone correlated with age. Lactose absorption was not related to the number of days that the infants received full-strength feedings or the total number of days of feeding before the study, whereas absorption of both the lactose-glucose polymer combination and the glucose polymers alone was related to both. Absorption of the three solutions was not related to gestational age or to the number of days before the initial feeding. Lactose absorption was greater in infants who received formula alone than in infants fed formula together with human milk. CONCLUSIONS: Premature infants do not digest and absorb lactose as well as glucose polymers. However, lactose does not impair the absorption of glucose polymers. Lactose assimilation is not affected by maturation, but the type of diet may affect lactose digestion and absorption. In contrast, digestion and absorption of glucose polymers are related to both postnatal age and diet.

Absorption↗

The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance.

1) Most humans, like other mammals, gradually lose the intestinal enzyme lactase after infancy and with it the ability to digest lactose, the principle sugar in milk. At some point in prehistory, a genetic mutation occurred and lactase activity persisted in a majority of the adult population of Northern and Central Europe. 2) Persistence of intestinal lactase, the uncommon trait worldwide, is inherited as a highly penetrant autosomal-dominant characteristic. Both types of progeny are almost equally common when one parent is a lactose maldigester and the other a lactose digester. 3) The incidence of lactose maldigestion is usually determined in adults by the administration in the fasting state of a 50-g dose of lactose in water, the equivalent of that in 1 L of milk. Measurement is made of either the subsequent rise in blood glucose or the appearance of additional hydrogen in the breath. It is also sometimes identified by measuring lactase activity directly in a biopsy sample from the jejunum. For children the test dose is reduced according to weight. Depending on the severity of the lactase deficiency and other factors, the test dose may result in abdominal distention, pain, and diarrhea. 4) The frequency of lactose maldigestion varies widely among populations but is high in nearly all but those of European origin. In North American adults lactose maldigestion is found in approximately 79% of Native Americans, 75% of blacks, 51% of Hispanics, and 21% of Caucasians. In Africa, Asia, and Latin America prevalence rates range from 15-100% depending on the population studied. 5) Whenever the lactose ingested exceeds the capacity of the intestinal lactase to split it into the simple sugars glucose and galactose, which are absorbed directly, it passes undigested to the large intestine. There it is fermented by the colonic flora, with short-chain fatty acids and hydrogen gas as major products. The gas produced can cause abdominal distention and pain and diarrhea may also result from the fermentation products. 6) Among individuals with incomplete lactose digestion, there is considerable variation in awareness of lactose intolerance and in the quantity of lactose that can be ingested without symptoms. A positive standard lactose test is not a reliable predictor of the ability of an individual to consume moderate amounts of milk and milk products without symptoms. In usual situations the quantity of lactose ingested at any one time is much less than in the lactose-tolerance test.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Enhancement of Ca++ uptake by lactose in the rat small intestine.

In previous experiments, lactose was shown to increase the absorption of Ca++ by the small intestine of the rat and other mammals. To further investigate the mechanism of the lactose effect, Ca++ uptake was studied in everted gut sac preparations. Gut sacs from the rat ileum were preincubated with or without lactose for 45 minutes, and then the tissue uptake of 45Ca over the first 3 minutes was measured in the presence or absence of lactose. The presence of 160 mM lactose increased the initial rate of Ca++ uptake in the first minute by 64% compared to the NaCl control. The lactose effect was dependent on the presence of lactose in the preincubation medium only and not on the presence of lactose during the measurement of Ca++ uptake. Lactose increased Ca++ absorption when the Ca++ concentrations ranged from 0.1 to 10 mM. However, the magnitude of the enhancement was dependent on the lactose concentration and was reduced below 160 mM lactose. When Ca++ and lactose uptake during a 45 minute period was measured in parallel experiments, no evidence for the co-transport of lactose and Ca++ into the tissue was found. These and other data indicated that lactose is not interacting directly with Ca++ in solution but is interacting with the absorptive cells of the intestine to increase their permeability to Ca++.

Age Factors↗

In vitro lactose fermentation by human colonic bacteria is modified by Lactobacillus acidophilus supplementation.

Adaptation of the colonic flora to lactose may contribute to lactose digestion in lactose maldigesters, and supplementation with Lactobacillus acidophilus may modify colonic fermentation of lactose and short-chain fatty acid production. We evaluated the capability of colonic bacteria to ferment lactose and the ability of L. acidophilus to modify lactose fermentation by the colonic microflora in vitro. An anaerobic continuous culture was established and inoculated with fresh samples of human feces. Lactose infusion was maintained at 25 g/d and pH at 6.7. L. acidophilus strain LA-1 (1.5 x 10(10) cells) was introduced into the fermenter on d 0 or added daily on d 0 through 4. The control was the continuous culture without the addition of lactobacilli. Rapid adaptation of colonic bacteria to lactose occurred within 1-2 d, with a significant decrease in lactose concentration and increase in beta-galactosidase activity, and lactose concentrations fell below 3 mmol/L by d 7. Supplementation with strain LA-1 resulted in a significantly greater decrease in lactose concentration and greater increase in acetate and propionate production within the first day compared with the control group. However, there was no significant difference between the fermentation treated with L. acidophilus daily and the control after the first day. These data suggest that the colonic bacteria adapt quickly to lactose, causing efficient utilization of lactose. L. acidophilus supplementation may enhance lactose fermentation during early periods when the adaptation is not established in this model.

Adult↗

The influence of crystallization conditions on the morphology of lactose intended for use as a carrier for dry powder aerosols.

Lactose has been widely used as a carrier for inhalation aerosols. The carrier morphology is believed to affect the delivery of the drug. The aim of this study was to investigate the effects of crystallization conditions on the morphology of alpha-lactose monohydrate intended for use as the carrier for dry powder aerosols. The crystallization of lactose was carried out from aqueous solutions at different supersaturations, temperatures, different stages of crystallization and in the presence of different water-miscible organic solvents. The majority of lactose crystals were found to be either tomahawk-shaped or pyramidal after crystallization at an initial lactose concentration between 33-43% w/w, but these became prismatic if the lactose concentration was increased to 50% w/w. A further increase in the lactose concentration to 60% w/w led to the preparation of elongated cuboidal crystals. Higher initial lactose concentrations tended to result in the crystallization of more elongated particles. Crystallization at 40 degrees C was shown to prepare lactose crystals with a more regular shape and a smoother surface than those crystallized at 0 degrees C. Lactose particles generated during the later stage of crystallization were found to be more regular in shape with a smoother surface than those prepared in the earlier stage. The addition of 10% (v/v) methanol or ethanol or acetone to the mother liquor increased the growth rate of lactose particles whereas addition of propanol or glycerine inhibited the rate of crystal growth. Lactose crystals prepared in the presence of glycerine were more regularly shaped with a smoother surface than those prepared in the presence of ethanol or acetone. All the resultant crystals were shown to comprise alpha-lactose monohydrate. Lactose crystals could be prepared with a precisely defined morphology by means of carefully controlling the crystallization conditions.

Aerosols↗

Utilization of a low-lactose milk.

This study was undertaken to determine if a milk containing prehydrolyzed lactose, yet affording full nutritional benefits, could be ingested by a milk intolerant (MI) population without the symptoms of lactose intolerance. MI was defined by the failure of serum glucose to rise greater than 20 mg/100 ml after ingestion of 50 gm of lactose as well as by subjective and objective symptoms and signs after consumption of both 12.5 gm of lactose in water and 250 ml of skim milk. Lactose tolerance (LT) was evidenced by both lack of symptoms and a concomitant rise in serum glucose of greater than 20 mg/100 ml after ingestion of 50 gm lactose in water. A series of four, two hr tolerance tests were given to 12 MI patients and 12 LT controls. The following solutions were employed: 12.5 gm lactose, 250 ml skim milk. 250 ml low-lactose skim milk, and 6 gm glucose plus 6 gm galactose. In the MI group, significant differences were apparent between the tolerance test utilizing skim milk and that using low-lactose skim milk; no such differences were observed in the LT group. These observations indicate that in the MI population the lactose in skim milk was poorly absorbed or tolerated, but after hydrolysis the low-lactose skim milk was well tolerated. A MI individual then, appears able to absorb the monosaccharides of the prehydrolyzed milk and can, furthermore, tolerate the low-lactose skim milk without suffering from symptoms normally associated with lactose intolerance.

Animals↗

Lactose malabsorption in recurrent abdominal pain of childhood.

In order to evaluate the role of lactose malabsorption in children with recurrent abdominal pain, we performed a prospective controlled double-blinded study in 40 children with RAP of at least three months' duration. Children were studied for lactose malabsorption by breath hydrogen determinations after ingestion of lactose (2 gm/kg of body weight; maximum 50 gm). Lactose malabsorbers were retested with 12.5 gm lactose; lactose absorbers were retested with lactose for ability to produce hydrogen. All children underwent a dietary trial which included two lactose elimination periods. Although 12 children (30%) were lactose malabsorbers, only three malabsorbed part of the smaller, more physiologic, lactose load. Improvement rates of lactose malabsorbers and absorbers during lactose elimination were not significantly different as judged by their physicians and as determined by a 50% or more decrease in pain frequency. These results suggest that lactose malabsorption is of little importance in children with RAP.

Abdomen↗

Do patients with short-bowel syndrome need a lactose-free diet?

We compared the tolerance of a diet providing 20 g/d lactose and a lactose-free diet in 14 patients with short-bowel syndrome with either the colon in continuity (group A, n = 8) or a terminal jejunostomy (group B, n = 6). Lactose tolerance was studied after a single 20-g lactose load in the fasting state, and during two 3-d periods during which the subjects consumed their usual diet plus either 20 g/d lactose, with no more than 4 g/d as milk, or no lactose. Records and measurements included symptoms, fecal weight, and during the 8 h after the lactose load, breath-hydrogen excretion (group A) or lactose and hexoses flow rates in stomal effluents (group B). Results are expressed as medians with ranges in parentheses. Lactose absorption was 61% (0-90) in group A and 53% (18-84) in group B, and no symptoms of intolerance were noticed. During the lactose-rich diet as compared to the lactose-free diet, no symptoms were noticed nor was there any worsening of diarrhea: 1534 g/d (240-4760) versus 1466 (1590-7030) in group A, and 4122 g/d (1730-6830) versus 3496 (1590-7030) in group B. We conclude that a diet providing 20 g/d lactose with no more than 4 g/d as milk is well tolerated in the majority of patients with short-bowel syndrome, and that a lactose-free diet has usually no benefit in these subjects.

Animals↗

Clinical tolerance to lactose in children with cow's milk allergy.

OBJECTIVE: Adverse reactions following the ingestion of lactose have been reported in children with cow's milk (CM) allergy. Whether this is attributable to the contamination of lactose with CM proteins is unknown. In this paper, we assessed clinical tolerance of lactose derived from CM whey in children hypersensitive to CM from 2 university hospital pediatric departments. DESIGN: Twenty-four children (5 girls and 19 boys, median 25 months old; range: 2-107 months) with immediate CM allergy confirmed at history or during double-blind, placebo-controlled food challenge (DBPCFC) were enrolled. DBPCFC with CM could be conducted in 11 of 24 patients. Children with a history of immediate/delayed reactions to soy formula (SF) were excluded. Clinical tolerance to CM, SF, and SF + lactose was assessed by: 1) skin prick test with casein, lactalbumin, soy commercial allergen preparations, fresh CM, SF, SF and lactose, lactose (Official Pharmacopoeia) in 4 concentrations (0.01%, 0.1%, 1%, 10%); 2) specific serum immunoglobulin E determination by CAP system technology; 3) DBPCFC in 8 incremental doses of SF + lactose and using SF as a placebo to make up a total of 240 mL of reconstituted formula. RESULTS: With a positive cutoff point of > or = 3 mm wheal diameter at SPT, all patients were sensitized to fresh CM, lactalbumin, and/or casein. Twenty-three of 24 patients (95.8%) were SPT-positive to CM formula, 16 of 24 to lactalbumin (66.6%), 14 of 24 to casein (58.3%), and none to SF, SF + lactose, or lactose alone at all dilutions. Complexed immunoglobulin E determinations were positive for CM in 23 of 24 cases and negative in all cases for soy. Challenge with SF + lactose was negative in all cases. CONCLUSIONS: Even children hypersensitive to CM are clinically tolerant to lactose and can safely consume foods and drugs with lactose from bovine sources as an ingredient. Lactose exclusion is unwarranted from soy preparations on grounds of potential allergic reactions to CM protein residue.

Animals↗

Loss of lactose metabolism in lactic streptococci.

Lactose-negative mutants occurred spontaneously in broth cultures of Streptococcus lactis C(2)F. Instability of lactose metabolism was noted in other strains of S. lactis, in strains of S. cremoris, and in S. diacetilactis. Colonies of S. lactis C(2)F grown with lactose as the carbohydrate source also possessed lac(-) cells. Treatment of lactic streptococci with the mutagen acriflavine (AF) increased the number of non-lactose-fermenting variants. The effect of AF on growth and on loss of lactose-fermenting ability in S. lactis C(2)F was consequently further examined. The presence of AF appears to favor competitively the growth of spontaneously occurring lactose-negative cells and appears to act in the conversion of lactose-positive to non-lactose-fermenting cells. The lactose-negative mutants partially revert to lactose-positive variants which remain defective in lactose metabolism and remain unable to coagulate milk. The lactose-negative cells become dominant in continuous culture growth and provide evidence that alterations in the characteristics of starter strains can be produced by continuous culture, in this case, the complete loss in ability to ferment lactose.

Acridines↗

Effects of substituting deproteinized whey and(or) crystalline lactose for dried whey on weanling pig performance.

We conducted two trials to determine the effects of replacing the lactose provided by spray-dried, edible-grade whey with edible-grade deproteinized whey or crystalline lactose on pig performance. In Exp. 1, 180 weanling pigs (initially 4.1 kg and 22 +/- 4 d of age) were allotted randomly to dietary treatments containing 18% lactose supplied by 1) 25% dried whey, 2) 12.5% dried whey and 9% crystalline lactose, 3) 18% crystalline lactose, 4) 12.5% dried whey and 10.9% deproteinized whey, or 5) 21.7% deproteinized whey. Casein was used to replace the lysine provided by dried whey in diets containing lactose and deproteinized whey. From d 0 to 14 after weaning, no differences (P > .10) were observed in ADG or ADFI. Pigs fed diets containing 18% crystalline lactose or 21% deproteinized whey had a higher (P < .05) gain:feed ratio (G/F) than did pigs fed diets containing 25% dried whey or 12.5% dried whey and 9% lactose. In addition, pigs fed diets containing 21% deproteinized whey had increased G/F compared to pigs fed the diet containing 10.9% deproteinized whey and 12.5% dried whey. In Exp. 2, 344 pigs (initially 4.4 kg and 14 +/- 2 d of age) were fed dietary treatments based on four sources of crystalline lactose replacing the lactose provided by dried whey in the positive control diet (20% dried whey). In addition, a negative control diet was formulated with 7.2% crystalline lactose. Casein was used to replace the lysine provided by dried whey. From d 0 to 14 after weaning, no differences (P > . 10) were observed in performance. However, pigs initially fed the positive control diet subsequently (d 14 to 28) consumed more feed than pigs fed the negative control diet. These results indicate that edible-grade deproteinized whey and crystalline lactose can replace the lactose provided by high-quality dried whey without affecting pig performance.

Aging↗

Prevalence of primary adult lactose malabsorption in three populations of northern China.

Lactose absorption capacity was examined in 641 apparently healthy adolescents and adults (447 males and 194 females with an average age of 22.9 years and an age range of 16-46 years) using a field version of the lactose tolerance test with breath hydrogen determination. In the total sample, 89 lactose absorbers and 552 lactose malabsorbers were identified. Lactose malabsorption was most frequent in a subgroup of Han (Chinese) from northeastern China (229 of 248 subjects, 92.3%). Among 198 Mongols from Inner Mongolia, there were 174 lactose malabsorbers (87.9%). The frequency of lactose malabsorption was lowest in a group of Kazakhs, traditional herders from the northwestern region of Xinjiang (149 of 195 subjects, 76.4%). Reported symptoms of lactose intolerance were significantly more frequent in lactose malabsorbers. The findings in northern Han are similar to the reported lactose malabsorption frequency in southern (mainly overseas) Chinese, and correspond with the absence of animal milk from traditional Chinese diets. The relatively low prevalence of lactose malabsorption among the Kazakhs suggests that lactose persistence may be frequent in herding pastoralist populations of southwest Asia.

Adolescent↗

A randomized trial of Lactobacillus acidophilus BG2FO4 to treat lactose intolerance.

BACKGROUND: Lactose intolerance is the most common disorder of intestinal carbohydrate digestion. Lactobacillus acidophilus BG2FO4 is a strain of lactobacilli with properties of marked intestinal adherence and high beta-galactosidase activity. OBJECTIVE: This study was designed to determine whether oral feeding of Lactobacillus acidophilus BG2FO4 leads to a lactose-tolerant state. DESIGN: We studied 42 subjects with self-reported lactose intolerance and performed breath-hydrogen tests to determine whether they were lactose maldigesters. Subjects with established lactose maldigestion (n = 24) were invited to be randomly assigned to an omeprazole-treated (hypochlorhydric) group or a non-omeprazole-treated group, but 6 subjects chose not to participate. All randomly assigned subjects (n = 18) ingested Lactobacillus acidophilus BG2FO4 twice per day for 7 d and stool samples were collected. Breath-hydrogen tests were performed and symptom scores were recorded at baseline and after lactobacilli ingestion. RESULTS: Lactose maldigestion was established in 24 of 42 subjects (57%) with self-reported lactose intolerance. In 18 lactose-maldigesting subjects, overall hydrogen production and symptom scores after ingestion of Lactobacillus acidophilus BG2FO4 were not significantly different from baseline values. Live Lactobacillus acidophilus BG2FO4 was recovered in stool samples from 7 subjects. CONCLUSIONS: Lactose intolerance is overreported in subjects with gastrointestinal symptoms after lactose ingestion. Treatment of lactose-maldigesting subjects with and without hypochlorhydria with Lactobacillus acidophilus BG2FO4 for 7 d failed to change breath-hydrogen excretion significantly after lactose ingestion.

Adult↗

Colonic fermentation may play a role in lactose intolerance in humans.

The results of our previous study suggested that in addition to the small intestinal lactase activity and transit time, colonic processing of lactose may play a role in lactose intolerance. We investigated whether colonic fermentation of lactose is correlated with lactose intolerance. After 28 Chinese subjects had undergone 1 glucose (placebo) and 2 lactose challenges, consistent lactose tolerant (n = 7) and intolerant (n = 5) subjects with no complaints after glucose administration were classified on the basis of the 6-h symptom scores. Before the challenges, fecal samples were collected for in vitro incubation with lactose. The incubation was carried out in a static system under anaerobic conditions for 5 h during which samples were taken for measurement of short-chain fatty acids, lactate, lactose, glucose, and galactose. Fecal bacterial composition was determined by fluorescent in situ hybridization. The tolerant and intolerant groups did not differ in the rate or degree of hydrolysis of lactose or production of glucose and galactose. The intolerant group produced d- and l-lactate, acetate, propionate, and butyrate significantly faster than the tolerant group. In the intolerant group, the amounts of acetate, propionate, butyrate, and l-lactate produced were higher than those in the tolerant group. Fecal bacterial composition did not differ between the 2 groups. The results indicate that the degree and rate of lactose hydrolysis in the colon do not play a role in lactose intolerance. However, after lactose is hydrolyzed, a faster and higher production of microbial intermediate and end metabolites may be related to the occurrence of symptoms.

Adult↗

Improved accuracy of lactose tolerance test in children, using expired H2 measurement.

Expired hydrogen and blood glucose were measured during an oral lactose tolerance test in 163 children aged between 9 months and 14 years. Lactose malabsorption, defined as an abnormal increase in expired H2 during a lactose tolerance test, was found in 54 children. Of these, 30 were found to be lactose intolerant as the increased expired H2 was accompanied by clinical symptoms. The other 109 children, in whom there was no rise in expired H2, were assumed to have normal lactose absorption. In children with lactose intolerance the increase in expired H2 tended to occur earlier after lactose ingestion than in children with malabsorption. The mean value of the rise in blood glucose was 2.4 mmol/100 ml) in the lactose-tolerant children and 1.0 mmol/1 (18 mg/100 ml) in the lactose-intolerant ones. Although this difference is significant (p less than 0.001), the rise in blood glucose, in predicting the correct diagnosis, was wrong in 13% of cases in the lactose-tolerant group, and wrong in 37% in the lactose-intolerant group (95% confidence limits 9-19% and 22-53% respectively). It is concluded that a rise in blood glucose, whether or not of more that 1.2 mmol/1 (22mg/100 ml) is of little help in differentiating lactose tolerance from intolerance.

Adolescent↗

Does mutarotation influence lactose digestion? Experimental investigations and a mathematical model.

The nutrient lactose acts as a potential dietary fibre. Depending on the composition of diet, lactose can partially escape from digestion and absorption in the small intestine and is utilised by the colonic microflora. The suggested mechanism, i.e. different rates of enzymatic hydrolysis of the lactose anomers and an influence of food ingredients on lactose mutarotation, seems to be supported by experimental results. The Michaelis constant of the mucosal beta-galactosidase of rats is 14 mmol/l with alpha-lactose and 50 mmol/l with beta-lactose as substrates. During intestinal perfusion of human infants, alpha-lactose is digested at a significantly higher rate than beta-lactose. The mutarotation of lactose is influenced by general acid-base catalysis. Milk formulae containing a high concentration of weak-acid anions, e.g. cow milk which is rich in phosphate and citrate, accelerate mutarotation, but milk formulae with a low content of these anions do not. With these experimental results a mathematical model has been set up simulating lactose digestion in the small intestine of human infants and of rats. The data show that certain dietary components may influence the ratio between lactose anomers, but, surprisingly, they do not influence the amount of digested lactose.

Animals↗

The use of lactose recrystallised from carbopol gels as a carrier for aerosolised salbutamol sulphate.

Lactose was crystallised either from Carbopol gel without stirring or from a constantly-stirred aqueous solution, to obtain lactose crystals designated as Carbo and control lactose, respectively. The Carbo lactose was shown to have a more regular shape with smoother surface as compared with the control lactose. These lactoses were fractionated by sieving to produce batches with different sizes before blending separately with salbutamol sulphate (SS, VMD 5.8 microm) in a ratio of 67.5:1 w/w using the same mixing procedure. SS dispersion and deaggregation were investigated using a 4-stage liquid impinger after aerosolisation at 28.3, 60.0 and 96.0 l/min via a Rotahaler. At all flow rates, the Carbo lactose produced significantly higher (ANOVA, P<0.01) emission of SS from the Rotahaler as compared with the control lactose of a similar size. The Carbo lactose also resulted in a significantly (P<0.05) higher fine particle fraction of SS than the control lactose. Moreover, drug emission from formulations containing the Carbo lactose was consistently more reproducible than those of the control lactose blends. In conclusion, the efficiency and reproducibility of drug delivery by dry powder inhalers can be improved using carrier particles of precisely defined morphological features.

Acrylic Resins↗