AYU (An International Quarterly Journal of Research in Ayurveda)

: 2014  |  Volume : 35  |  Issue : 4  |  Page : 438--441

Bioavailability study of calcium sandoz-250 by atomic absorption spectroscopy in albino rats

Bimalkumar N Patel1, N Krishnaveni2, Nurrrudin P Jivani1, Akruti S Khodakiya3, Moorti S Khodakiya3, Saswat K Parida1,  
1 Department of Pharmaceutical Analysis, C.U. Shah College of Pharmacy and Research, Wadhwan, Gujarat, India
2 Department of Pharmaceutical Analysis, J.S.S. College of Pharmacy, Ooty, Tamil Nadu, India
3 Department of Pharmaceutics, C.U. Shah College of Pharmacy and Research, Wadhwan, Gujarat, India

Correspondence Address:
Bimalkumar N Patel
68, Kunta Park Society, Near Taramani Township, New 80 Feet Road, Wadhwan City, Surendranagar - 363 035, Gujarat


Background: Calcium sandoz-250 is an Ayurvedic calcium supplement, containing Khatika Churna. Bioavailability study of the formulation is essential for estimation of peak plasma concentration (Cmax ), time to Cmax and rate of absorption. Aim: To evaluate the absorption parameters of calcium sandoz-250 in albino rats by atomic absorption spectroscopic (AAS) method. Materials and Methods: Study was carried out as a single dose, open-label, randomized study. Estimation of calcium was carried out by AAS, after validating the method for a few parameters for the estimation. Pharmacokinetic parameters such as Cmax , time to peak concentration (Tmax ), area under the plasma concentration - time curve were calculated for calcium on administration of calcium sandoz-250. Results: Linearity curve was plotted for 0.5-2.5 ppm, given R2 value 0.9975. The Cmax , i.e. Cmax after administration of calcium sandoz-250 was 0.793 mg/ml at 90 min (Tmax ). Measurable calcium-blood levels were noticed in all subjects up to 3.0 h after administration of calcium sandoz-250. Conclusion: Calcium sandoz-250, consisting of Khatika Churna, increases the blood calcium level in albino rats.

How to cite this article:
Patel BN, Krishnaveni N, Jivani NP, Khodakiya AS, Khodakiya MS, Parida SK. Bioavailability study of calcium sandoz-250 by atomic absorption spectroscopy in albino rats.AYU 2014;35:438-441

How to cite this URL:
Patel BN, Krishnaveni N, Jivani NP, Khodakiya AS, Khodakiya MS, Parida SK. Bioavailability study of calcium sandoz-250 by atomic absorption spectroscopy in albino rats. AYU [serial online] 2014 [cited 2021 Apr 18 ];35:438-441
Available from: https://www.ayujournal.org/text.asp?2014/35/4/438/159020

Full Text


Calcium (Ca) is one of the most important extracellular cation. [1] Approximately, 99% of the body's Ca is stored in the bones and teeth. [2] Apart from supporting the skeletal integrity, Ca plays an important role in blood clots, muscular contractility and nervous excitability. [3] Although serum Ca levels can be maintained in the normal range by bone resorption, dietary intake is the only source by which the body can replenish stores of Ca in bone. Ca is absorbed almost exclusively within the duodenum, jejunum and ileum. Each of these intestinal segments has a high absorptive capacity for Ca, with their relative Ca absorption being dependent on the length of each respective intestinal segment and the transit time of the food bolus. The calcium intake is critical during the 1 st year of life for the anatomical structure. [4] Prospective studies demonstrated that the biggest increase of the bone mass occurs principally during the age of puberty. [5] An inadequate calcium intake during the growth period may cause a failure to reach the increase in bone mass. This situation produces different bone and illnesses such as osteopenia, osteoporosis, decreased skeletal integrity, increasing the fracture risk in later life. [6] Some of the researchers have reported that the increase in calcium intake attenuates the bone mass loss during the age of menopause. [7],[8],[9] It appears that all the calcium in food or other source is available for absorption, but the absolute amount is determined by physiological factors such as efficiency of absorption, calcium need, vitamin D, age and hormonal status, etc. [10],[11]

Calcium sandoz is a popular brand of calcium supplement, used widely throughout the world; mainly by children and women. Calcium sandoz contains calcium carbonate as the main ingredient. [12] However, calcium sandoz-250 contains Khatika Churna, as it is an ayurvedic preparation and it is claimed to have 250 mg calcium equivalent in each chewable tablet. [13],[14] Bioavailability of calcium from calcium sandoz-250 was studied in animal model as a preclinical trial. There have been no studies in humans about the bioavailability of calcium from calcium sandoz-250. As calcium sandoz-250 is an Ayurvedic formulation, the absorption might shows variations from the data of the allopathic formulation of calcium supplements or food. [15],[16],[17]

 Materials and Methods


Adult male wistar albino rats (n = 12) weighing 120-150 g were procured from central animal facility and housed in cages under standard laboratory conditions (10 h dark/14 h light, temperature 20-25°C, relative humidity 65%) for 7 days.

Reagents and chemicals

Ultra-pure water, metal standard solutions of calcium (sigma Aldrich) were prepared by appropriate dilutions of 1000 mg/L stock solutions.


Shimadzu model AA 6300 flame atomic absorption spectrometer (AAS) (Tokyo-Japan) equipped with a deuterium background corrector and a hydride vapor generator for analysis of arsenic. Hollow cathode lamps of specific metals were used as a radiation source.

Study design

The study was randomized single dose study, included two equal groups of animals (n = 6 in each). The protocol was duly approved by the Institutional animal ethics committee (No. JSSCP/IAEC/M.PHARM/PHARM.ANALYSIS/05/2009-2010).

Drug assignment

Two equal groups were made from all albino rats. First group received calcium sandoz-250 (dose was calculated according to the body weight of the animal) and the second group kept as control.

Single dose of calcium sandoz was given to each of the six rats after an overnight fasting. Blood sample was collected from the tail vein of rats after 0.0, 0.15, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 6.0, 8.0, 12.0, 24.0 and 36.0 hrs of drug administration. The amount of calcium sandoz was measured by a suitable flame AAS method.

Preparation of standard calcium solution

Standard calcium solutions were prepared from 1000 mg/L stock solution. A serial dilution containing 0.5, 1.0, 1.5, 2.0 and 2.5 ppm of calcium were prepared and used as working standards.

These solutions were then subjected to analysis by flame AAS under the following instrumental conditions:


The absorbances of the standard solutions were recorded and the calibration curve was plotted by taking concentration in X-axis and absorbance in Y-axis.

Estimation of calcium in plasma samples

Optimization of the extraction procedure

For the estimation of calcium in plasma, animal plasma was spiked with standard calcium solution. To precipitate the plasma protein as they may coagulate on heating, the following methods were tried:

Precipitation of plasma proteins with perchloric acid (10%)Precipitation of plasma proteins with trichloroacetic acid (10% and 20%)Precipitation of plasma proteins with nitric acidDilution of the plasma samples 50 fold with deionized water.


A total volume of 0.2 ml plasma was taken, to this appropriate amount of standard calcium solution (2.0 ppm) and 0.2 ml of precipitating agents (perchloric acid, trichloroacetic acid and nitric acid) were added. The volume was made to 1 ml with deionized water. The resulting solutions were centrifuged at 4000 rpm for 5 min and supernatant was taken and diluted to 10 ml with deionized water.

However in all cases recovery were found to be less than 50%, so finally direct estimation was done by diluting the plasma by 50 fold using deionized water. The resulting samples on analysis gave good recovery (above 95%).

Calibration curve was plotted for the concentration range of 0.5 ppm to 2.5 ppm in plasma and the method was validated for following parameters


The samples obtained from the animal study were analyzed by the same method.

 Results and Discussion

Linearity curve was plotted for the solutions of calcium solutions ranging from 0.5 μg/ml to 2.5 μg/ml [Table 1], giving R2 value 0.9975 and slope 0.0163 [Figure 1].{Figure 1}{Table 1}

Extraction method was optimized for extraction of calcium from the plasma. Recovery with protein precipitation was less than 50% for almost all precipitating agent, while direct determination of calcium with 50 fold dilution gave 98.5% recovery [Table 2]. Recovery was studied for all the concentration of the calibration curve giving the result between 94.28% and 107.14% [Table 3].{Table 2}{Table 3}

Calibration curve was plotted for the plasma samples spiked with the known amount of calcium, with R2 value 0.995, slope 0.014 and intercept 0.001 [Table 4], [Figure 2].{Figure 2}{Table 4}

Plasma samples collected from the animals at different intervals were analyzed for the calcium content after blank was introduced, detectable amount measured after 15 min of administration. Pharmacokinetic parameters such as peak plasma concentration (Cmax ), Time to peak concentration (Tmax ), Area under the plasma concentration-time curve (AUC 0-t and AUC 0-∞ ) were calculated for calcium on administration of calcium sandoz-250 [Table 5].{Table 5}

[Figure 3] shows bioavailability curve of the calcium after oral administration of calcium sandoz-250. A summary of different pharmacokinetic parameters was depicted in [Table 6].{Figure 3}{Table 6}

Pharmacokinetics data of calcium sandoz-250 obtained from bioavailability study

Pharmacokinetic parameters such as Cmax , Tmax , AUC 0-t and AUC 0-∞ were calculated for calcium on administration of calcium sandoz-250Measurable calcium-blood levels were noticed in all subjects up to 3.0 h after administration of calcium sandoz-250The Cmax , i.e. Cmax after administration of calcium sandoz-250 was 0.793 μg/ml at 90 min (Tmax )AUC 0-t and AUC 0-∞ were found to be 79.28571 and 80.82454 respectivelyK eli and half-life for the calcium sandoz-250 (Ayurvedic formulation) were found to be 0.030172 and 22.97 min respectively.


On the basis of the results obtained from the study, conclusion can be drawn that calcium Sandoz-250, consisting of Khatika Churna, increases the blood calcium level in albino rats. Hence, further investigation should be carried out to evaluate the effect of calcium sandoz-250 on human blood calcium level.


1Brunton LL, editors. Goodman and Gilman′s The Pharmacological Basis of Therapeutics. 8 th ed. New York: Pergamon Press; 1990.
2Committee to Review Dietary Reference Intakes for Vitamin D and Calcium, Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press; 2010. Available from: http://www.iom.edu. [Last accessed on 2013 Aug 12].
3Levenson DI, Bockman RS. A review of calcium preparations. Nutr Rev 1994;52:221-32.
4Anderson JJ. Calcium, phosphorus and human bone development. J Nutr 1996;126:1153S-8.
5Johnston CC Jr, Miller JZ, Slemenda CW, Reister TK, Hui S, Christian JC, et al. Calcium supplementation and increases in bone mineral density in children. N Engl J Med 1992;327:82-7.
6Matkovic V, Fontana D, Tominac C, Goel P, Chesnut CH 3 rd . Factors that influence peak bone mass formation: A study of calcium balance and the inheritance of bone mass in adolescent females. Am J Clin Nutr 1990;52:878-88.
7Elders PJ, Netelenbos JC, Lips P, Van Ginkel FC. Calcium supplementation reduces perimenopausal bone loss. J Bone Miner Res 1989;4:1128.
8Prince RL, Smith M, Dick IM, Price RI, Webb PG, Henderson NK, et al. Prevention of postmenopausal osteoporosis. A comparative study of exercise, calcium supplementation, and hormone-replacement therapy. N Engl J Med 1991;325:1189-95.
9Recker RR, Saville PD, Heaney RP. Effect of estrogens and calcium carbonate on bone loss in postmenopausal women. Ann Intern Med 1977;87:649-55.
10Morrissey PA, Flynn A. Bioavailability of minerals in milks. In: Kon SK, editor. Milk and Milk Products in Human Nutrition. FAO Nutritional Studies, Woodhead Publishing; 1972. p. 27.
11Mortensen L, Charles P. Bioavailability of calcium supplements and the effect of Vitamin D: Comparisons between milk, calcium carbonate, and calcium carbonate plus vitamin D. Am J Clin Nutr 1996;63:354-7.
12Available from: http://www.mims.com/India/drug/info/CALCIUM%20SANDOZ/CALCIUM%20SANDOZ%20chewable%20tab. [Last accessed on 2013 Aug 12].
13Mengshetti P. Novartis says Khatika Churna-Calcium [email protected] contains no calcium, April 14, 2009. Available from: http://pharmaweb4u.blogspot.in/2009/04/novartis-says-khatika-churna-calcium.html. [Last accessed on 2013 Aug 12].
14India Business Insight, April 09, 2009. Available from: http://www.accessmylibrary.com/article-1G1-200709783/trade-objects-novartis-sale.html. [Last accessed on 2013 Aug 12]
15Kruger MC, Gallaher BW, Schollum LM. Bioavailability of calcium is equivalent from milk fortified with either calcium carbonate or milk calcium in growing male rats. Nutr Res 2003;23:1229-37.
16Sarabia MI. Bioavailability, biodistiubution and toxicity of biocaltm, a new calcium source, comparative studies in rats. Nutr Res 1999;19:1223-31.
17Ranhotra GS, Gelroth JA, Leinen SD, Rao A. Bioavailability of calcium in a high calcium whey fraction. Nutr Res 1997;17:1660-70.