The Effect of a Biscuit Containing the Extract of Salacia Reticulata on Glycaemia in Patients With Type 2 Diabetes Mellitus Randomized Triple Blind Placebo Controlled Two Period Two Sequence Crossover Clinical Trial
Phase: PHASE3
Conditions: Type 2 Diabetes Mellitus
Sponsor: Rajarata University, Sri Lanka

 
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The effect of a biscuit containing the extract of Salacia reticulata on the 
glycaemia in patients with Type 2 Diabetes Mellitus 
A single center randomized triple blind placebo controlled two period two-
sequence crossover clinical trial 
 Study title for general public 
The effect of a biscuit containing Kothala Himbutu on blood glucose in patients 
with diabetes; A randomized control study 
NCT02290925 
Date of the document 25th October 2018 
 
 
 
 
 
 
 
 
 
 
Project proposal 
VERSION – 13 
 
Sisira Siribaddana 
Arjuna Medagama 
Devaka Fernando 
Suneth Agampodi 
 
 
 
 
 

 
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1. INTRODUCTION: 
Herbal medicines have been in use for millennia. In recent years, there has been 
increasing interest in herbal medicines as they have increased in popularity in the 
developed world. The use of self-prescribed herbal medicines in USA increased from 2.5 
to 12.1% between 1990 and 1997 and frequency of consultations with practitioners of 
herbal medicine rose from 10.2 to 15.1% (1). A similar increase has been reported in 
Europe (2).  The justification for using these remedies appears to be based on traditional 
use rather than evidence from clinical trials. 
Many herbal preparations are used in the treatment of diabetes mellitus in Sri Lanka. As 
in Europe, many patients use them concurrently with prescribed medication but do not 
tell their doctor about it (3). There is anecdotal evidence of such patients showing 
improved control and even an increased incidence of hypoglycemia in such patients. 
There is some evidence from animal studies and non-randomized uncontrolled studies 
in humans for the efficacy of some of these remedies (4).   
The alpha glucosidase inhibitor acarbose is used in clinical practice (5).  An alpha 
glucosidase inhibitor kotalanol has been identified in one commonly used herb, Salacia 
reticulata called Kothala Himbutu in Sinhalese by traditional physicians (6).  Data on the 
efficacy of the herbal preparation from randomized controlled clinical trials is not 
available. Traditionally this preparation is ingested as an herbal tea (Kothala Himbutu 
tea), where the herbal mixture is ingested in a cup of boiled water and in the form of a 
tea bag prepared using a formula passed on in an oral tradition to members of the family 
of the Ayurvedic physician. Efficacy of tea bags containing Salacia reticulata in lowering 
blood glucose in people with type 2 diabetes and its safety in a double blind randomized 
cross over trial was demonstrated in 2006 (7). Recently biscuit containing extract of 
Salacia reticulata (Kothala Himbutu biscuit) was tested and found to have low glycaemic 
index compared to a biscuit not containing Salacia reticulata (8). This biscuit is available 
in the market in Sri Lanka and consumes by customers. 
2. OBJECTIVE: 
We intend to conduct a triple blind randomized clinical trial to investigate the effect of a 
biscuit containing the extract of Salacia reticulata on the fasting blood glucose levels and 

 
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HBA1C in patients with Type 2 diabetes mellitus and also to find out whether there are 
any side effects on other vital organs such as kidneys and liver. 
 
3. PATIENTS AND METHODS: 
Patients with diabetes mellitus will be selected for screening from those seeking 
treatment at university departmentsof Medicine in University Rajarata. One hundred and 
sixty patients (112) with diabetes mellitus Type 2 will be included in a triple blind 
randomized placebo controlled two-period two-sequence cross over study (AB/BA). 
3a. Selection criteria: 
Male and female patients who have been diagnosed as having Type 2 diabetes mellitus 
for a minimum period of 6 months, who are interested in seeking Ayurvedic treatment as 
sole treatment or as complimentary treatment to western medical treatment and meet 
the following criteria will be selected to participate in this study. 
1. Onset of diabetes mellitus for six months. 
2. Aged between 30 and 65 years 
3. Stable glycaemic control over the preceding 2-3 months. They will be initially 
selected from a range of HBA1C varying from 7 – 14 and the individual subject 
should not have a variation of >20% between the previous HBA1C and the 
HBA1C done at the commencement of the study 
3b. Exclusion Criteria: 
The following patients will be excluded from the study. 
Exclusion Criteria: 
1. Chronic kidney disease with estimated Glomerular filtration rate less than 
30ml/hour 
2. Severe valvular heart disease or heart failure.  
3. Those on Insulin therapy 
4. Severe liver disease (AST > 10 X times the upper limit) 
 
4. RECRUITMENT 
Patients who seek treatment for diabetes mellitus will be screened for participation in 
the study. The subjects will be provided with a detailed patient information sheet 
supplemented by a verbal explanation and reviewed at a later date to obtain written 
consent in order to give them an opportunity to discuss their participation with family 
and other relevant persons whose advice is deemed of value by the subject.  

 
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Type I Diabetes will be excluded by clinically. Participant will have two HBA1C within the 
two months period to ensure stability of glycemic level. This is done to exclude 
recruiting patients who have rapidly changing glycaemic values. As this trial is a 
crossover trial stability of the glycemic control over time needs to be assured to prevent 
excessive variation of HBA1C interfering with study outcome. A medical officer will 
perform a complete history and clinical examination with blood pressure. Blood and 
urine samples will be tested for baseline investigations such as FBC, UFR, LFT, CRP, renal 
& liver profiles. 
4a Primary outcome variable 
I. 
Glycaemic control evaluated with HBA1C carried out centrally with ion exchange 
HPLC and the units will be NGSP standard.  
II. 
Serious liver and kidney adverse events when taking the biscuits containing the 
extract of Salacia reticulata. 
4b Secondary outcome variable 
Fasting blood glucose measured by glucose oxidase method.  
5. THE STUDY PRODUCT 
A biscuit containing the extract of Salacia reticulata is the active treatment. The study 
product is available in the market. Both study biscuit containing Salacia reticulata and 
the placebo will be wrapped in identical covers for concealment. 
1. To ensure the uniformity of the product between successive batches, Ceylon Biscuits 
Ltd (CBL) adheres to strict quality control measures during the production process 
and prior to release of the product to the market. 
2. Formulation of the biscuit (study product): By CBL. 
a. Placebo biscuit & formulation: - A biscuit identical to the study product, 
without the extract of Salacia reticulata. The fiber content of the biscuit 
containing Kothala himbutu extract and the placebo will be identical. 
b. Contents of the study biscuit 
Name of ingredient Quantity (As %) 
Wheat flour 
73.51 
Yeast  
1.06 
Vegetable fat  
12.82 
Wheat bran 
8.12 
Leavening agents 
0.82 
Salt 
 
1.48 

 
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Soya lecithin 
0.15 
Water extract of Kothala himbutu 
6. SAMPLE SIZE & RANDOMIZATION 
1. Consecutive patients who seek treatment for diabetes mellitus will be screened 
for eligibility.  
2. Those who are eligible will be invited for the study. 
3. Sample size calculation:  
Sample size was initially calculated by using a formula specific for crossover studies 
(9). The standard deviation (0.9) to calculate the standard error was taken from the 
baseline data (7). Clinically significant improvement of HbA1c in the intervention 
group over the placebo group was estimated as 0.5 units of HbA1c (difference in 
means). As this gave very low sample size (13 in each arm) we calculated the sample 
size for parallel studies according to Pocock (10). Significance level (alpha) 0.05 and 
power (1-beta) = 0.8 giving rise total of 51 patients were in each arm. With 
anticipated dropout rate of 10%, 112 patients were estimated sample size for a 
single center study 
6b Randomization 
SBA will generate randomization code (A or B) using a computer and prepared sealed, 
serially numbered, opaque envelopes. All eligible participants will be identified and 
given a serial number on the day of randomization (after run-in period). A study 
assistant will open the envelope and assign the patient to either biscuit A (placebo) or B 
(KH) and deliver the biscuit boxes to the patient. The manufacturers (Ceylon Biscuits 
Ltd) held randomization code.  
6C. Allocation concealment 
Investigators, patients and those assessing the analysis will be masked to the group 
outcome. Both Kothala Himbutu (KH) and placebo biscuits are identical in size, wrapped 
in same cover, and packed in identical boxes.  
Patients participating in the trial will be asked about prior consumption of KH biscuits 
bought from the market (to exclude contamination). At the end of each period patients 
were asked whether they could assume the type of biscuit (KH biscuit or placebo) given 
to them and their preference for the type. 
7. STATISTICAL ANALYSIS (10) 
1. Being a cross over trial, the analysis will be done as a paired analysis. 
2. Intention to treat analysis. 

 
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3. Formal tests for period effect, treatment effect, carryover effect and 
interaction between treatment and period will be carried out. 
8. PROCESS OF THE TRIAL 
After running period where stability of HBA1C is assured patients will be randomized to 
receive either a standard preparation of Kothala himbutu biscuits or a placebo, a similar 
biscuit without the extract of Salacia reticulata. The study product and the placebo will 
be given to the participants and the investigators and the participants will be blinded to 
the treatment.  
Four biscuits will be taken as a mid morning and afternoon snack, at 10am and 4 pm 
respectively. Oral hypoglycemic treatment for diabetes taken at the time of recruitment 
will be continued but subject to change if the condition of the patient changes, as 
determined by treating clinician.  
Patients will continue treatment for a period of seven months separated by a washout 
period of one month at cross over. On completion of the first three months on either 
treatment or placebo patients will not receive either placebo or biscuit with the active 
ingredient during a wash out period of one month. The wash out period is determined as 
one month to minimize the carry over bias. In the event that significant difference exists 
between the two groups at the end of three months, the study will be terminated at that 
point.  
During this time the subjects will have a minimum of eight to ten visits inclusive of the 
booking visit and will meet with a medical officer at each visit for review of glycaemic 
control and other possible complications. A six-point blood glucose profile (pre and post 
breakfast, pre and post lunch, pre and post dinner samples) will be performed on one 
day during the week prior to each visit.  
HBA1C will be performed at recruitment, at three months and on completion of the study 
at seven months. Existing oral medication and doses for diabetes mellitus will be 
adjusted as requested during the study.  
In the event that the clinical investigators feel that significant deterioration of glycaemic 
control has occurred or that the patient would require a step up to insulin, patients will 
be withdrawn from the study.  
Specific written instructions will be provided for the timing of snacks in the standard 
dosage. Counting the unused biscuits will assess compliance. All adverse events will be 
recorded. Patient preference for the biscuits will also be assessed.  
8 a. Visit Schedule  
V1  - 
Selecting patients and Recruitment 

 
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Check for inclusion and exclusion criteria 
Informed written consent form signed 
Obtain demographic data 
History and examination 
Dietary advice  
Screening investigations 
FBC, liver profile, renal profile, FBS, HBA1c, ECG, Urine for microalbumin 
V2  - 
8 weeks after V1 
              Review investigation reports of V1 in relevance with exclusion criteria 
              2nd HbA1c, Lipid profile, UFR 
V3         Trace laboratory reports 
               Provision of a glucometer 
 Glucometer Training and self-monitoring of blood glucose  
V4        Randomization  
Checking for glucometer capability 
Review the blood sugar series 
              History and examination 
Providing biscuit  
V5  -  May be over the phone (1 week after providing biscuit) 
Evaluate the compliance for the biscuit 
V6  - 
1month after providing biscuit 
Evaluate the blood sugar series 
History and examination 
Review dosage of other drugs 
Provide stock of biscuit for 1 month 
SGPT, SGOT, Serum creatinine 
V7  - 
2months after providing biscuit 
Evaluate the blood sugar series 
Trace laboratory reports 
History and examination 
Review dosage of other drugs 
Provide stock of biscuit for 1 month 
SGPT, SGOT, Serum creatinine 
V8  -  3 months after providing biscuit 
Stop biscuits 

 
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History and examination 
Trace the laboratory reports 
Review dosage of other drugs  
SGPT, SGOT, Serum creatinine, HbA1c, FBS, Urine for microalbumin 
1 month washout period 
V9  -     1 month after stopping biscuits 
Evaluate the blood sugar series 
History and examination 
 
 Trace the laboratory reports 
 
 Review dosage of other drugs  
 
 Change to other group of biscuit (provide biscuit for 1 month) 
 
 SGPT, SGOT, Serum creatinine 
V10     1 month after changing biscuits  
Evaluate the blood sugar series 
History and examination 
Trace laboratory reports 
Review the dosage of other drugs 
SGPT, SGOT, Serum creatinine 
Provide stock of biscuit for 1 month 
V11      2 month after changing biscuits  
Evaluate the blood sugar series 
History and examination  
Trace laboratory reports 
Review dosage of other drugs 
SGPT, SGOT, Serum creatinine 
Provide stock of biscuit for 1 month 
V12      3 month after changing biscuits 
History and examination 
Trace laboratory reports 
Review dosage of other drugs 
SGPT, SGOT, Serum creatinine, HbA1c, FBS, Urine for microalbumin 
V13      9 months after changing biscuits 
             HbA1c 
8a. Ethics and informed consent 

 
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Written informed consent will be obtained from the patients and ethical clearance 
obtained from the Ethics Review Committees of Peradeniya Medical Faculty and Rajarata 
Medical Faculty.  
The trial will be registered with the International Standard Randomized Controlled Trial  
Number Register.  
8. TRIAL MONITORING 
8a. Data monitoring & Safety Board 
Independent data and safety monitoring board will regularly review interim data from 
the trial. The composition of this body is as follows. 
1. Dr NJ Dahanayake MBBS MD, Senior Lecturer & head Department of Medicine FMAS, RUSL. 
2. Prof Samath Dharmarathne MBBS MD MSc Associate Professor in Community Medicine 
Peradeniya Medical Faculty. 
8b. Trial Steering Committee 
1. Prof. Sisira Siribaddana – MBBS MD FRCPE FCCP 
2. Dr. Arjuna Medagama     - MBBS MD MRCP 
3. Dr Suneth Agampodi  MBBS, MSc, MPH, MD  
4. Prof. Devaka Fernando. MBBS, MD, FRCP, FRCPE 
8c Conduct of trials:  
The trial will be conducted at the medical clinic of the Department of Medicine, Faculty of 
Medicine & Allied Sciences, and Rajarata University of Sri Lanka at Teaching Hospital 
Anuradhapura under the direct supervision of Prof. Sisira Siribaddana. 
9. DATA AND SAMPLE COLLECTION 
The data will be entered into a structured questionnaire and will contain demographic 
data as well as a detailed history regarding the course, treatment and control of diabetes 
mellitus in individual patients.  All blood samples will be immediately transported to a 
pre-planned, selected laboratory for analysis. Each sequential data item will be added to 
the patient records maintained in written (structured questionnaire) and computer data 
base forms (Microsoft Access) either on line or uploaded to the central database within 5 
working days of receipt. 
10. DATA ANALYSIS AND PRESENTATION: 
There will be interim analysis of data after the end of first treatment period.  to observe 
the progress of each patient to ensure good glycaemic control. Standard statistical 
packages will be used in data analysis. Patient flow will be presented in a CONSORT 
diagram.  
11. FUNDING: 

 
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The cost of the study will be met by an unreserved unconditional research grant from 
Ceylon Biscuits Ltd. The investigators as a group have the right to publish their findings 
in peer reviewed journals. Individual centers will not present or publish findings 
independently but will do so as part of a two center collaborative research group. 
References & Notes:  
1. Eisenberg DM, David RB, Ettner SL, Appel S, Wilkey SM, Kessler RC. Trends in 
alternative medicine use in the United States 1990–1997. Journal of the 
American Medical Association 1998; 280: 1569 - 1575. 
2. Ward A. Complementary medicine in Europe. British Medical Journal 1994; 
309:107–111. 
3. Fernando MR, Thabrew MI, Karunanayake EH. Hypoglycaemic activity of some 
medicinal plants in Sri Lanka.  General Pharmacology 1990; 21: 779–782. 
4. Hardy ML, Coulter I, Venuturupalli S, Roth EA, Favreau J, Morton SC, Shekelle P. 
Ayurvedic interventions for diabetes mellitus: a systematic review. Agency for 
Healthcare Research and Quality 2001; 41: 01-E040. 
5. Hoffman J, Spengler M. Efficacy of 24 week monotherapy with acarbose, 
glibenclamide or placebo in NIDDM patients. Diabetes Care 1994; 17: 561–566. 
6. Yoshikawa M, Murkami T, Yashiro K., Matsuda H. Kotalonol, a potent alpha 
glucosidase inhibitor with thiosugar sulfonium sulfate structure from anti 
diabetic Ayurvedic medicine Salacia reticulata. Chemical and Pharmaceutical 
Bulletin 1998; 46: 1339–1340.  
7. Jayawardena MH, De Alwis NM, Hettigoda V, Fernando DJ. A double blind 
randomised placebo controlled cross over study of an herbal preparation 
containing Salacia reticulata. Journal of Ethnopharmacology 2005; 97: 215-218.  
8. Ekanayake S, Perera N, Senaratne A, Rathnayake N, Fernando T. Glycemic load 
of a cracker targeting diabetic populations (abstract). 2nd International ISEKI 
Food Conference 2011. 
9. Hills M, Armitage P. The Two-period Cross-over Clinical Trial. Br J Clin 
Pharmacol. 1979;8:7–20. 
10. Pocock SJ. Clinical trials A practical approach 1983; ISBN 0 471 90155 5:   
pp110-127