1. A COMPARATIVE STUDY ON THE IN VITRO DISSOLUTION PROFILES OF COMMERCIALLY AVAILABLE CLARITHROMYCIN ORAL DOSAGE FORMS IN NAIROBI COUNTY, KENYA By: Manani O. Rebecca U59/81391/2012 Department of Pharmaceutical Chemistry School of Pharmacy University of Nairobi November 13, 2014

2. OUTLINE  Introduction  Study justification  Study objectives  Methodology  Results and discussion  Conclusion  Recommendations  Acknowledgements 2

3. INTRODUCTION : MACROLIDES  Natural and semi-synthetic antibiotics characterised by macrocyclic rings with attached sugars  Source: Streptomyces and micromonospora species  Classification  14– erythromycin, clarithromycin, roxithromycin  15 – semi-synthetic azalides: azithromycin, gamithromycin  16 – josamycin, spiramycin, rokitamycin 3

4. MACROLIDES ( CONT ’ D )  Mode of Action  Inhibit protein synthesis; prevent transpeptidation  Spectrum of Activity  G+ve: S. aureus, Str. pyogenes, Str. pneumoniae  G-ve: H. influenzae, N. meningitidis, H. pylori  Atypical: M. pneumoniae, C. trachomatis, Mycobacteria, Toxoplasma, Borrelia spp.  Limitations of Natural Macrolides  Acid instability, GIT side-effects, resistance, narrow spectrum 4

5. CLARITHROMYCIN  Chemistry  2 nd generation semi-synthetic macrolide 5

6. STABILITY OF CLARITHROMYCIN  Oxidative; basic; acidic conditions 6

7. STUDY JUSTIFICATION  Quality of drugs crucial in treatment outcomes  Previous reports of poor quality products in 3 rd world countries  Clarithromycin is in EML - Kenya, WHO  BCS classification  Tablets – class II (Low aq. solubility, low permeability)  Suspensions – class IV (Low aq. solubility, low permeability)  Generics used as a cost cutting measure  No bioequivalence testing centres in Kenya  No previous PMS studies on CLA in Kenya 7

8. STUDY OBJECTIVES  General Objective  To conduct comparative in vitro dissolution studies on oral clarithromycin products in Nairobi County  Specific Objectives  To carry out product sampling in Nairobi County  To carry out identification and assay tests  To carry out comparative dissolution testing – innovator, generics  To determine pharmaceutical equivalence 8

9. METHODOLOGY I : SAMPLING  Study population – 125 mg/5 mL susp, 500 mg tablets  Time frame – January to March 2014  Stocking patterns revealed uneven distribution  Sites –11 outlets in Nairobi, 1 in England, UK  16 samples – 12 tabs and 4 suspensions (67% stocking rate in Nairobi)  Sample size – 60 tablets and 500 mL suspensions 9

10. METHODOLOGY II : METHOD OPTIMIZATION  MOA – published method (Abuga et al. 2001)  Method optimization  Detection wavelength, Sample injection volume, Mobile phase flow rate  Quenching conditions - dissolution pH 1.2  Optimum conditions: mp - ACN-0.2 M phosphate buffer, pH 6.80-water (40:3.5:56.5, v/v/v), flow rate -1.5 mL/min, sp - XTerra RP C 18, 5  m (250 mm x 4.6 mm ID), temp - 56 o C detection 205 nm, quenching – 3 mL of 0.2 M NaOH 10

11. METHOD OPTIMIZATION ( CONT ’ D )  Fig.1 - Typical assay chromatogram for clarithromycin working standard under the optimum chromatographic conditions 11

12. METHODOLOGY III : ASSAY AND DISSOLUTION  USP and BP methods for sample preparation  Tabs – uniformity of weight (BP), assay  Granules – RD, extraction (USP), assay  Dissolution carried out at pH 1.2, 4.5, 6.8  Run time - 60 min. tabs, 90 min. suspensions  6 sampling time points  Dissolution profiles generated and f 2 factors calculated  f 2 = 50×log {[1+ (1/n) Σ t=1 n (R t -T t ) 2 ] -0.5 ×100} 12

13. RESULTS I : ASSAY Table 1 (a) – Assay Results for CLA Tablets Table 1 (b) – Assay Results for CLA Suspensions 13 Sample Code C1C2C3C4C5C6C7 % Content100.9100.2100.1102.198.899.398.7 C8C9C10C11C12C17 101.5102.098.898.4105.9103.5 Sample Code C13C14C15C16C18 % Content107.8108.899.5109.6110.1

14. RESULTS II : ACIDIC DEGRADATION  CLA std incubation - 37 o C in 0.1 M H 3 PO 4 (pH 1.4) and 0.1 M HCl (pH 1.2) Table 2 – Acid Degradation Parameters for CLA Std 14 Degradation Parameters pH 1.4pH 1.2 Half life (min)18536.7 Rate constant (min -1 )3.7 x 10 -3 19 x 10 -3 % API degradation in 40 min 13.860

15. RESULTS III : DISSOLUTION AT PH 1.2 Fig. 2 – Chrm for dissolution at pH 1.2, 30 min.  Dissolution proceeded with concurrent degradation – profiles created using Total Clarithromycins 15

16. RESULTS IV : F 2 FACTORS AT PH 1.2 Fig. 3 – Similarity factors at pH 1.2  Compliance rate 50% (6/12) 16

17. RESULTS V : F 2 FACTORS AT PH 4.5 Fig. 4 – Similarity factors at pH 4.5  Compliance rate 67% (8/12) 17

18. RESULTS VI : F 2 FACTORS AT PH 6.8 Fig. 5 – Similarity factors at pH 6.8  Compliance rate 50% (6/12) 18

19. F 2 FACTORS – COMPLIANT SAMPLES Table 3: Similarity factors for compliant samples  Overall compliance rate 25% (4/16 products) 19 Sample Code Dosage Form f 2 factors (%) pH 1.2pH 4.5pH 6.8 C1Tablet80.493.654.8 C6Tablet54.652.464.4 C11Tablet64.780.961.8 C17Tablet72.275.255.2

20. F 2 FACTORS – NON - COMPLIANT SAMPLES Table 4: Similarity factors for non-compliant samples 20 Sample Code Dosage Form f 2 Factors (%) pH 1.2pH 4.5pH 6.8 C2Tablet46.030.054.8 C3Tablet40.253.735.5 C4Capsule69.216.926.5 C5Tablet28.861.533.3 C7Tablet37.925.327.6 C8Tablet58.969.545.4 C9Tablet44.834.234.7 C10Tablet22.256.679.7 C13Susp.ND 42.4 C14Susp.ND 14.3 C15Susp.ND 15.2 C18Susp.ND 42.0

21. DISCUSSION  Variability in product performance Table 5 – Inconsistent Products  Gastric pH 0.5 - 2 adults, 1.5 - 3 children,  2 sick state  Gastric residence time 0.5 – 2 hrs  Significant degradation noted at 30 min, pH 1.2 Product Code f 2 factors (%) pH 1.2pH 4.5pH 6.8 C246.030.055.8 C858.969.545.4 C1022.256.679.7 21

22. DISCUSSION ( CONT ’ D )  Variability in performance of innovator products in different markets:  Significant differences not expected due to change in site – GMP, SUPAC-related guidelines  Minimal API release for suspensions C14 and C15 – implications of sub-optimal product dissolution 22 pH1.24.56.8 f 2 Value (Tabs)727555 f 2 Value (Susp.)ND 42

23. CONCLUSION  Not all available CLA products meet quality standards  Proof of quality and pharmaceutical equivalence requires more than assay and single point dissolution tests  Role of DRAs critical in QA of pharmaceuticals  Pre-registration  Pharmacovigilance - effective, sustained, targeted  Staff – proper education, training, experience 23

24. RECOMMENDATION  In vitro dissolution profiling to be included in routine QC and post-marketing surveillance tests  Sustained PMS and PV activities by DRAs  Sufficiently deterrent measures for non- compliant products by DRAs to discourage circulation of poor quality products  Further studies on other antibiotics in circulation, special attention paid to macrolides 24

25. ACKNOWLEDGEMENTS  Supervisors - Dr. K. O. Abuga - Dr. H. K. Chepkwony  NQCL management and staff  University of Nairobi  Ministry of Health  Technical staff – C. Rotich, D. Nyamweya, J. Kalama, H. Mugo, O. King’ondu, J. Nguyo 25

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