|Year : 2014 | Volume
| Issue : 2 | Page : 99-104
Single dose metformin kinetics after co-administration of nisha-amalaki powder or mamejwa ghanavati, ayurvedic anti-diabetic formulations: A randomized crossover study in healthy volunteers
Amrutesh Puranik1, Nutan Nabar2, Jayashree Joshi2, Ashok Amonkar2, Sanjiv Shah2, Sasikumar Menon3, Rama Vaidya2, Ashok D.B. Vaidya2
1 Department of Reverse Pharmacology, Medical Research Center, Kasturba Health Society, ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine Mumbai, Maharashtra; Department of Integrative Biology and Physiology, School of Medicine, University of Minnesota, MN 55455, USA
2 Department of Reverse Pharmacology, Medical Research Center, Kasturba Health Society, ICMR Advanced Centre of Reverse Pharmacology in Traditional Medicine Mumbai, Maharashtra, India
3 Therapeutic Drug Monitoring Laboratory, Sion Koliwada, Sion East, Mumbai, Maharashtra, India
|Date of Submission||07-Feb-2014|
|Date of Decision||03-Mar-2014|
|Date of Acceptance||14-Apr-2014|
|Date of Web Publication||12-Jun-2014|
Source of Support: CSIR NMITLI for funding the project at our center,, Conflict of Interest: None
Objective: The aim was to study herb-drug interaction of two ayurvedic formulations - DMFN01 (Nisha-Amalaki) powder and DMFN02 (Mamejava) ghanavati with metformin at a single dose in healthy volunteers. Materials and Methods: This was an open-labelled, single dose, crossover, and randomized volunteer study. Healthy volunteers were studied in two groups (6/group). Volunteers were randomized to oral metformin (500 mg single dose) alone or with concurrent DMFN01 (10 g), or DMFN02 (750 mg). Venous blood samples were collected at different time points from 0 to 24 h. Plasma metformin concentrations were measured by high performance liquid chromatography coupled with an ultraviolet detector. Results: Simultaneous administration of DMFN01 with metformin showed a reduction in the mean area under the curve (AUC [0-24 h]) of metformin by 51% (P < 0.002) when compared with metformin alone. However, co-administration of DMFN02 did not show any significant difference in the mean AUC of metformin (P = 0.645). One volunteer had a reduction of 41% in AUC of metformin with DMFN 02. Conclusions: These data raise relevant questions on therapeutic control of hyperglycemia when DMFN01 choorna is given concurrently with metformin. Based on known absorption pattern of metformin an interval of 2 h between the oral doses of metformin and ayurvedic formulations would be advisable to avoid interactions. In reverse pharmacological studies, at an early stage, such interaction studies are desirable.
Keywords: Ayurveda, Council for Scientific and Industrial Research′s-New Millennium Indian Technology Leadership Initiative, herb-drug interaction, Mamejava, metformin, Nisha-Amalaki, reverse pharmacology, type 2 diabetes
|How to cite this article:|
Puranik A, Nabar N, Joshi J, Amonkar A, Shah S, Menon S, Vaidya R, Vaidya AD. Single dose metformin kinetics after co-administration of nisha-amalaki powder or mamejwa ghanavati, ayurvedic anti-diabetic formulations: A randomized crossover study in healthy volunteers. J Obes Metab Res 2014;1:99-104
|How to cite this URL:|
Puranik A, Nabar N, Joshi J, Amonkar A, Shah S, Menon S, Vaidya R, Vaidya AD. Single dose metformin kinetics after co-administration of nisha-amalaki powder or mamejwa ghanavati, ayurvedic anti-diabetic formulations: A randomized crossover study in healthy volunteers. J Obes Metab Res [serial online] 2014 [cited 2019 May 20];1:99-104. Available from: http://www.jomrjournal.org/text.asp?2014/1/2/99/134423
| Introduction|| |
Herb-drug interaction is an under-reported issue. The consumption of complementary and alternative medicines (CAM) is on the rise worldwide in last two decades. WHO reports approximately 70% of world's population uses CAM in the form of herbals.  CAM is classified as dietary supplements in the US and the office of dietary supplements in the National Institutes of Health mentions that 50% or more of Americans use dietary supplements daily.  It is estimated that more than 50% of patients with chronic disease use dietary supplements. CAM is used as prescription drugs or as over-the-counter products with or without conventional drugs. About 60% of the world population and 70% of Indian population uses traditional medicine. ,,
There is a high prevalence of type 2 diabetes in India and herbal medicines are used by 67.8% of diabetic patients in India. ,, Concurrent use of many drugs is more likely to cause drug interactions.  An Ayurvedic pharmacoepidemiological study has shown that 41% of diabetic patients are taking anti-diabetic ayurvedic and conventional medicines concurrently. 
Madhumeha (diabetes mellitus) is described in Ayurveda as a type of advanced Prameha. Nisha-Amalaki is the formulation of choice in the management of Prameha i.e. prediabetic stage.  Nisha i.e. Curcuma longa Linn and Amalaki i.e. Phyllanthus emblica Linn described in ayurvedic classical texts and Nighantus, are recommended for various diseased conditions including diabetes.  In vivo and in vitro studies confirm the anti-diabetic activity of C. longa and P. emblica., Mamejava i.e. Enicostemma littorale Blume is a herb, which is available as over the counter product for diabetes. Anti-diabetic and anti-dyslipidemic activities of this plant are reported in the literature. ,, Metformin is most common anti-diabetic oral drug used by diabetics. It is known to have interactions with several drugs.  Herb-drug interactions are reported with Ginkgo (Ginkgo biloba), St. John's Wort (Hypericum perforatum), Ginseng (Panax ginseng), Echinacea (Echinacea species), saw palmetto (Sereno arepens) and kava (Piper methysticum). [ 9],,,,,
Council for Scientific and Industrial Research's New Millennium Indian Technology Leadership Initiative - a national herbal drug discovery project based on the novel approach of reverse pharmacology was conducted for type 2 diabetes mellitus.  Nisha-Amalaki powder in the ratio of (2:3) was formulated and nominated as DMFN01 while Mamejwa ghanavati was named as DMFN02. It was clinically observed that hyperglycemia of some diabetic patients on DMFN01 formulation was not well controlled as compared to DMFN02.  Therefore, we investigated the possibility of drug interaction to determine the effect of co-administration of ayurvedic formulations namely DMFN01 and DMFN02 with metformin on bioavailability of metformin.
| Materials and methods|| |
Ethics Committee permission was taken prior to three clinical studies. The first two studies were conducted in groups of six volunteers each viz. Group A (DMFN01) and Group B (DMFN02). (ISBEC/NR/-/AS/VM/2004, -/689/AS/VM/2005), first two studies had single dose, randomized crossover design with 7 days washout period between the crossovers. A third study was carried out with one volunteer common to both earlier studies (ISBEC/NR/223/AS/VM/2006). Informed consents were given by all volunteers.
Selection of volunteers
Clinically, healthy male volunteers, 21-26 years of age with normal clinical biochemistry (erythrocyte sedimentation rate, aspartate aminotransferase, alanine aminotransferase, serum creatinine, serum bilirubin, lipid profile, and routine urinalysis), and body mass index between 18 and 25, were included in the study.
Ayurvedic formulations and metformin
The formulation is composed of powders from two medicinal plants named Nisha i.e, turmeric (C. longa Linn, rhizome) and Amalaki i.e, emblic myrobalan (P. emblica Linn, fruit) in 2:3 ratio. This standardized powder (choorna) was provided for the study by Zandu Pharmaceutical Works Pvt. Ltd (ZPWL). Mumbai, India. Passport data, microbial load, aflatoxin test, pesticides, and heavy metal test reports were within permissible limits according to WHO standards under the project (batch no. 1, manufacturing date December 2003).
DMFN02 (Mamejava ghanavati)
The formulation is from a single medicinal plant Mamejava (E. littorale Blume) in the form of tablets. It was provided by Shree Dhootpapeshwar Ltd. Passport data, microbial load, aflatoxin test, pesticides, and heavy metal test reports were within permissible limits according to WHO standards under the project. (Batch no.: H-44/03-04, manufacturing date March 2004).
During the process of formulation development, tablets of Nisha-Amalaki powder were also prepared and bioavailability of metformin was studied in one volunteer who was common to both groups. The formulation is composed from the powders of 50% alcoholic extracts (prepared separately) from C. longa Linn to P. emblica Linn) in 3:2 proportion (500 mg/tablet). It was provided for the study by ZPWL (batch no. 1A manufacturing date March 2006).
Tablets of metformin (500 mg each) (batch no. 4310 manufacturing - December 2004 and batch no. 18001736, manufacturing - August 2005) were used for the study.
Chemicals and reagents
Metformin hydrochloride Indian Pharmacopoeial grade was purchased from LGC Prochem India. Dipotassium hydrogen phosphate Excela R grade was procured from Qualigens; acetonitrile, and 1-heptanesulfonic acid sodium salt high performance liquid chromatography (HPLC) grade were procured from Merck India.
Metformin high performance liquid chromatography assay
This study adapts a similar method for detection of metformin as reported in literature and in our previous study. , In brief, the HPLC system of Waters (Waters, Corporation, USA) was used. The mobile phase, consisting of 5% acetonitrile and 95% 0.05 M (NH 4 ) 2 HPO 4 with 0.10 g/100 ml heptanesulfonic acid was pumped at a flow-rate of 1 ml/min. The detector wavelength was set at 235 nm and peak areas were measured. De-proteinization of 250 μl of human plasma samples was carried by adding 5 μl of 60% perchloric acid. The mixture was vortex-mixed for 1 min and then centrifuged at 13,000 ×g for 5 min. 20 μl supernatant was injected in the Varian Pursuit XRs C18 ( 5 µ, 250 × ×4.6 mm) column (Agilent Technologies, Santa Clara, CA, USA).
Clinical study protocol
The clinical study was carried out as a day clinic procedure in the outpatient clinical pharmacology unit. The study was planned in two groups.
Collection of blood samples
- Group A: Healthy volunteers (n = 6) were randomized to metformin alone or with DMFN01 powder in a crossover design with 7 days wash out period. A single dose of metformin (500 mg) alone or with DMFN01 (10 g powder, i.e. choorna) was administered simultaneously orally on empty stomach and sample was collected at 0 h.
- Group B: Healthy volunteers (n = 6) were randomized to metformin alone or with DMFN02 tablets in a crossover design with 7 days wash out period. A single dose of metformin (500 mg) alone or with DMFN02 (750 mg), ayurvedic tablets, was administered simultaneously orally on an empty stomach and sample was collected at 0 h.
After collecting fasting blood sample, a single dose of metformin (500 mg) alone or formulation along with metformin was administered on an empty stomach. Breakfast was given after the blood sample for 1 h was collected. Multiple blood samples were collected through an indwelling catheter. Venous blood samples were taken at 0, , 1, 1, 2, 2, 3, 4, 5, 7, 9, and 24 h. After a washout period of 1 week, they were given metformin alone or along with ayurvedic formulations as per the randomization and the metformin bioavailability was measured again. Volunteers were provided with standard breakfast, lunch and tea on the day of study and were under observation throughout the kinetic study. All samples were preserved at –20°C until analysis was carried out.
The possibility of powder form (choorna) as a formulation interfering with the absorption was thought of after the analysis of the first study was available. DMFN01 was further developed from powder to a tablet (DMFN01A) as mentioned above. Since there were no safety issues in the healthy volunteer the ethics committee granted permission to explore the possibility. A volunteer, common to both the groups, was administered a single dose of 500 mg tablet of DMFN01A. The study with DMFN10A in 6 volunteers could not be completed due to time and budget constraints.
| Results|| |
The absorption of metformin was fast in the majority of cases with mean maximum concentration (Cmax) of 0.94-2.44 μg/ml between 1.5 and 5 h. The mean area under the curve (AUC) was 9.22 ± 2.48 (mean ± standard deviation [SD]) μg/ml × h for all 12 volunteers, with no significant (NS) difference between Group A and Group B when metformin alone is considered. Tmax for metformin plasma levels in all 12 volunteers was between 1.5 and 4 h.
In Group A, simultaneous administration of DMFN01, showed a reduction in the mean Cmax from 1.58 ± 0.52 (mean ± SD) μg/ml to 0.71 ± 0.2 μg/ml (a mean decrease of 55%), and in the mean of AUC (0-24 h) from 10.07 ± 3.41 (mean ± SD) μg/ml × h to 4.94 ± 1.39 μg/ml × h (mean decrease of 51%) of metformin (Student's paired t-test; P < 0. 002). There was NS difference in Tmax of metformin with or without DMFN01. All volunteers showed a reduction from 25% to 71% in Cmax and from 37% to 65% of AUC of metformin [Figure 1].
|Figure 1. Plasma concentrations (mean ± standard deviation) of metformin after a single dose (500 mg) in six healthy volunteers with or without concurrent DMFN01 powder (10 g)|
Click here to view
In Group B the results were variable. There was NS reduction in the mean Cmax of Metformin alone or metformin with DMFN02 from 1.42 ± 0.19 versus 1.35 ± 0.4 (mean ± SD) μg/ml, and also in the mean AUC (0-24 h) of 8.38 ± 2.1 μg/ml × h versus 7.77 ± 1.78 (mean ± SD) ng/ml × h (paired t-test; P = 0.645) respectively [Figure 2]. Volunteer no. 1 showed an increase of 26.5% and volunteer no. 5 showed a decrease of 44% in Cmax of metformin and reduced AUC by 41% (individual data not shown). Rest of the volunteers (n = 4) showed a decrease of <20% in Cmax of metformin. The Cmax ranged from 0.74 to 1.86 μg/ml in this group, when metformin was co-administered with DMFN02 tablets. There was NS difference in the mean AUC of metformin with or without DMFN02. However, in volunteer no. 3, AUC was increased by 44.3%. In volunteers 5 and 6 there was a reduction in AUC of 41.2% and 22.8% respectively. There was NS difference in Tmax of metformin with or without DMFN02.
|Figure 2. Plasma concentrations (mean ± standard deviation) of metformin after a single dose (500 mg) in six healthy volunteers with or without concurrent DMFN02 tablet (750 mg)|
Click here to view
Metformin plasma levels in volunteer no. 1, who was common to both groups and participated in DMFN01A study are shown in [Figure 3]. This volunteer showed a reduction in peak concentration of metformin by 60% and AUC by 65% when metformin was co-administered with DMFN01 powder. However, when co-administered with DMFN01-A tablets there was NS difference in Cmax or AUC of metformin as compared to metformin alone (Cmax 1336 μg/ml vs. 1409 μg/ml; AUC-6179 μg/ml × h vs. 6816 μg/ml × h; paired t-test NS).
|Figure 3. Plasma levels of metformin in volunteer no. 1 with metformin given alone, or with DMFN01 powder, or DMFN01A tablet, or DMFN02 tablets. AA m: Plasma level of metformin given alone, AA m + FN01: Plasma level of metformin with concurrent DMFN01 powder, AA m + FN01A: Plasma level of metformin with concurrent DMFN01A tablet, AA m + FN02: Plasma level of metformin with concurrent DMFN02 tablet|
Click here to view
There were no adverse clinical reactions to metformin or DMFN01, DMFN02 and DMFN01A (during the study).
| Discussion|| |
People all over the globe consume CAM with the hope of better quality-of-life and prevention of complications. Usually in Diabetes, multiple drug therapy is required for management of blood sugar and prevention of complications. Drug-drug interactions have clinical relevance when oral hypoglycemic agents (OHA) are co-prescribed with statins, and anti-hypertensive agents.  Herbs viz. G. biloba, St John's Wort, ginseng, garlic, etc., have interaction with prescribed drugs like cyclosporine, digoxin, oral contraceptives, etc., when used concurrently.  Herbs and drugs may have pharmacodynamic or pharmacokinetic interactions. Metformin is known to have interactions with several drugs, diet and even with Guargum.
In this study, Cmax of metformin single dose alone (500 mg) was in the range of 0.94-2.44 μg/ml, which is similar with values reported in the literature as 1.00-3.1 μg/ml in healthy volunteers.  Robert et al. also reported the Cmax of metformin single dose (850 mg) as 1.7 ± 0.1 μg/ml in healthy subjects.  Lalau et al. have recently reported metformin levels in emergency situation of lactic acidosis in diabetic patients receiving metformin in various doses as 2.7 ± 7.3 μg/ml. Published therapeutic values are said to be 0.5 ± 0.4 μg/ml.  Similar plasma levels of metformin were observed when given alone in the present study with a dose of 500 mg in Group A; DMFN01 study (0.71 ± 0.2 μg/ml [mean ± SD]).
It was noted that concurrent use of DMFN01 powder had decreased metformin plasma levels in all volunteers. It is likely that the large bulk of powder or the plants' constituents caused this effect. Thus, this study shows a markedly reduced absorption of metformin and a possibility of drug interaction.
In Group B, it was observed that in volunteer no. 5, metformin Cmax and AUC was decreased by >40% suggesting the possibility of drug interaction of DMFN02 in this volunteer; whilst NS change was observed in remaining five volunteers. This formulation was in a tablet form and it is not known whether tablet form interferes less with absorption of metformin than a powder form.
With respect to volunteer no. 1 [Figure 3], in whom both the tablet or the powder form of DMFN01 were co-administered with metformin, it was observed that when administered in powder form, bioavailability of metformin was significantly reduced, but not with the DMFN01A tablet. In this individual Tmax of metformin when administered alone was at 2 h at both the occasions. With DMFN01 powder, it was delayed to 4 h with reduction of Cmax (55%). However, with DMFN01A tablet, Tmax was at 2.5 h and there was no reduction in Cmax. This suggests that change in the dosage form could make a significant difference in the absorption of metformin. Hence, a study in a larger number of volunteers is desirable, but unfortunately could not be carried out under this project.
Food intake is known to reduce the absorption of metformin with a reduction in Cmax, AUC and delay of Tmax.  In this study, metformin was administered in the fasting condition, hence the food metformin interaction is unlikely.
Both Nisha-Amalaki (DMFN01) and Mamejava (DMFN02) have anti-diabetic activity and have the potential to reduce complication of diabetes. , Hence, in order to have the benefits of complementary therapy, it is important to carry out specific drug interaction studies before advising integrative therapy. Keeping an interval between the administrations of these medicines with respect to metformin can help in avoiding drug interaction. This recommendation is based on the physiological knowledge of gastric emptying time and known absorption pattern of metformin. Since metformin is absorbed within 1-2 h and the interaction is likely to occur at the level of absorption a postdose interval of 2 h will give enough time for metformin absorption. The AUC curve shows that the levels of metformin are below normal right from the beginning and this indicates defective absorption rather than metabolism or excretion. Moreover, the dosage forms are also in favor of an interaction at the gastric level when the powder can interfere with the absorption of released metformin.
| Conclusion|| |
The decrease in the metformin levels with DNFN01 powder suggests that the bulk of the formulation may interfere with the absorption of metformin. Interaction perhaps may not be expected from the DMFN01A tablets. However, a larger study is needed. Similarly, DMFN02 also is likely to have interference in absorption, though we observed it in a single case. The potential interactions related to metformin absorption can be avoided by spacing the intake of metformin and ayurvedic medicines at least 2 h apart giving sufficient time for absorption of metformin.
| Acknowledgments|| |
We are thankful to CSIR NMITLI for funding the project at our center. We are indebted to Shri Dhirubhai Mehta, President of Kasturba Health Society, for his guidance and encouragement. We also acknowledge the facility at Therapeutic Drug Monitoring Lab at Matunga, Mumbai for HPLC assay. Amrutesh Puranik is thankful to the Lady Tata Memorial Trust for Jr. Research Fellowship.
| References|| |
|1.||Fact sheet N°134. Available from: http://www.who.int/mediacentre/factsheets/fs134/en/. [Last accessed on 2008 Dec 15]. |
|2.||Available from: http://www.fda.gov/forconsumers/consumerupdates/ucm096386.htm. [Last accessed on 2008 dec 15]. |
|3.||Modak M, Dixit P, Londhe J, Ghaskadbi S, Devasagayam TP. Indian herbs and herbal drugs used for the treatment of diabetes. J Clin Biochem Nutr 2007;40:163-73. |
|4.||Vaidya AD, Devasagayam TP. Current status of herbal drugs in India: An overview. J Clin Biochem Nutr 2007;41:1-11. |
|5.||Gogtay NJ, Bhatt HA, Dalvi SS, Kshirsagar NA. The use and safety of non-allopathic Indian medicines. Drug Saf 2002;25:1005-19. |
|6.||Egede LE, Ye X, Zheng D, Silverstein MD. The prevalence and pattern of complementary and alternative medicine use in individuals with diabetes. Diabetes Care 2002;25:324-9. |
|7.||Mehrotra R, Bajaj S, Kumar D. Use of complementary and alternative medicine by patients with diabetes mellitus. Natl Med J India 2004;17:243-5. |
|8.||Chang HY, Wallis M, Tiralongo E. Use of complementary and alternative medicine among people living with diabetes: Literature review. J Adv Nurs 2007;58:307-19. |
|9.||Smith JW, Seidl LG, Cluff LE. Studies on the epidemiology of adverse drug reactions. V. Clinical factors influencing susceptibility. Ann Intern Med 1966;65:629-40. |
|10.||Nabar NS, Vaidya RA, Shah SJ, Vaidya AD. Simultaneous use of ayurvedic and modern antidiabetic medicines in diabetic patients. ICMR Workshop for Training in Reverse Pharmacology; March 2011. p. 34. |
|11.||Acharya JT. Charak Samhita. Chakrapanitika. 5 th ed. Varanasi: Choukhambha Sanskrit Sansthan; 2001. p. 211-6. |
|12.||Gogte VM. Ayurvedic Pharmacology and Therapeutic uses of Medicinal Plants (Dravyagunavidnyan-Translation). Mumbai: The Academic Team of Bhavan's SPARC, Bharatiya Vidya Bhavan; 2000. p. 514, 309. |
|13.||Kuroda M, Mimaki Y, Nishiyama T, Mae T, Kishida H, Tsukagawa M, et al. Hypoglycemic effects of turmeric (Curcuma longa L. rhizomes) on genetically diabetic KK-Ay mice. Biol Pharm Bull 2005;28:937-9. |
|14.||Qureshi SA, Warda A, Viqar S. The effect of Phyllantus emblica linn on type-II diabetes, triglycerides and liver-specific enzyme. Pak J Nutr 2009;8:125-8. |
|15.||Selected Medicinal Plants of India. CHEMECXIL, Bhavan's SPARC. Juhu, Mumbai: TATA Press; 1992. p. 145-6. |
|16.||Maroo J, Vasu VT, Gupta S. Dose dependent hypoglycemic effect of aqueous extract of Enicostemma littorale blume in alloxan induced diabetic rats. Phytomedicine 2003;10:196-9. |
|17.||Upadhyay UM, Goyal RK. Efficacy of Enicostemma littorale in Type 2 diabetic patients. Phytother Res 2004;18:233-5. |
|18.||Triplitt C. Drug interactions of medications commonly used in diabetes. Diabetes Spectr 2006;19:202-11. |
|19.||Cupp MJ. Herbal remedies: Adverse effects and drug interactions. Am Fam Physician 1999;59:1239-45. |
|20.||Izzo AA, Ernst E. Interactions between herbal medicines and prescribed drugs: An updated systematic review. Drugs 2009;69:1777-98. |
|21.||Fugh-Berman A, Ernst E. Herb-drug interactions: Review and assessment of report reliability. Br J Clin Pharmacol 2001;52:587-95. |
|22.||Gin H, Orgerie MB, Aubertin J. The influence of Guar gum on absorption of metformin from the gut in healthy volunteers. Horm Metab Res 1989;21:81-3. |
|23.||Stockley IH. Drug Interaction. 2 nd ed. London: Oxford Blackwell Scientific Publisher; 1981. p. 1-13. |
|24.||Vaidya AD. Reverse pharmacology correlates of ayurvedic drug action. Ramnath Chopra award oration. Indian J Pharmacol 2006;38:311-5. |
|25.||Completion report of CSIR NMITLI diabetes project 2002-2007. Herbal Based formulations in type 2 diabetes mellitus with emphasis on insulin resistance. |
|26.||NDA 20-357/S-031 NDA 21-202/S-016 Page 3 GLUCOPHAGE® (metformin hydrochloride tablets). Available from: http://www.accessdata.fda.gov/drugsatfda_docs/label/2008/020357s031,021202s016lbl.pdf. [Last accessed on 2008 Dec 12]. |
|27.||Puranik AS, Halade G, Kumar S, Mogre R, Apte K, Vaidya AD, et al. Cassia auriculata: Aspects of safety pharmacology and drug interaction. Evid Based Complement Alternat Med 2011;2011:915240. |
|28.||Scheen AJ. Drug interactions of clinical importance with antihyperglycaemic agents: An update. Drug Saf 2005;28:601-31. |
|29.||Devis S. Insulin, oral hypoglycemic agent and the pharmacology of the endocrine pancreas. In: Brunton LL, Lazo JS, Parker KL, editors. Goodman and Gilman's The Pharmacological Basis of Therapeutics. 11 th ed., Ch. 60. McGraw-Hill Publications; 2006. p. 1638-40, 1847. |
|30.||Robert F, Fendri S, Hary L, Lacroix C, Andréjak M, Lalau JD. Kinetics of plasma and erythrocyte metformin after acute administration in healthy subjects. Diabetes Metab 2003;29:279-83. |
|31.||Lalau JD, Lemaire-Hurtel AS, Lacroix C. Establishment of a database of metformin plasma concentrations and erythrocyte levels in normal and emergency situations. Clin Drug Investig 2011;31:435-8. |
|32.||Sambol NC, Brookes LG, Chiang J, Goodman AM, Lin ET, Liu CY, et al. Food intake and dosage level, but not tablet vs solution dosage form, affect the absorption of metformin HCl in man. Br J Clin Pharmacol 1996;42:510-2. |
|33.||Faizal P, Suresh S, Satheesh Kumar R, Augusti KT. A study on the hypoglycemic and hypolipidemic effects of an ayurvedic drug Rajanyamalakadi in diabetic patients. Indian J Clin Biochem 2009;24:82-7. |
|34.||Sonawane RD, Vishwakarma SL, Lakshmi S, Rajani M, Padh H, Goyal RK. Amelioration of STZ-induced type 1 diabetic nephropathy by aqueous extract of Enicostemma littorale Blume and swertiamarin in rats. Mol Cell Biochem 2010;340:1-6. |
[Figure 1], [Figure 2], [Figure 3]