A total of 34 indigenously manufactured pharmaceutical oral liquids were purchased from different patent medicine stores in Owerri main market from August to October. They were examined microbiologically to ascertain the common contaminants associated with them. The result of analysis showed that Staphylococcus species, Escherichia Coli and Pseudomonas are the main contaminants of these oral liquids.

While Bacillus spp and klebsiella were also identify, paracetamol syrup and emcap were found to meet the standard of B.P while bonagyl and parkalin did not meet the standard, and hence not safe for use in any treatment.


Title page
Certification = = = = = = = ii
Dedication = = = = = = = iii
Acknowledgment = = = = = = = iv
Abstract = = = = = = = = V
Table of content = = = = = = = vi
1.0 Introduction = = = = = = 1
1.2 Factors important in determining the
rate at which a drug is absorbed from
its site of administration are = = = 5
1.3 Effect of microorganisms on drugs = = 6
1.4 Systemic availability of drug = = = 7
1.5 Raw materials = = = = = = 12
1.6 Water supply = = = = = = = 13
1.7 Air = = = = = = = = 13
1.8 Equipment = = = = = = = 14
1.9 Personnel = = = = = = = 15
1.10 Containers/packaging materials = = 16
2.0 Literature review = = = = = 17
3.0 Materials and methods = = = = 22
3.1 Sterilization of materials and
aseptic techniques = = = = = 23
3.2 Pharmaceutical industry visited = = 23
3.3 Collection of samples = = = = 23
3.4 Preparation of media = = = = = 24
3.5 Analysis of the samples = = = = 24
3.6 Sub culturing of samples = = = = 25
3.7 Isolation of bacterial on selective media = 26
3.8 Identification of isolates = = = = = 26
3.9 Method of preparation of media = = 27
3.10 Gram’s-staining = = = = = 28
3.11 Catalase test = = = = = = 29
3.12 Indole test = = = = = = 29
3.13 Motility test = = = = = = = 30
13.14 Methyl red test = = = = 30
3.15 Voges proskauer test = = = 31
3.16 Sugar fermentation test = = = 32
3.17 Triple sugar iron agar (TSI) 32
3.18 Colonial and cellular characteristics
of organisms isolated in drul4g sample on
different media = = = = = = 33
4.0 Discussion and Conclusion = = 36
Conclusion = = = = = = 41
Recommendations = = = = = 43
References = = = = = = 44
Appendix 1 = = = = = = 47
Appendix 2 = = = = = = 52




Pharmaceutical oral liquids — syrups or suspensions are among the numerous pharmaceutical products and have different compositions and diversity of contaminating microorganisms, each with its specific application and problems, some products are however more imperilled to be contaminated with microorganisms and they are more hazardous than other ones.

We have seen a number of problems associated with the microbiological contamination of tropical drug products, nasal solutions and inhalation products (U. S. F. D. A, 2006).

Pharmaceutical products such as liquids (syrups) are generally required to be sterile; however, it is desirable that, they contain low level of microbial contamination in the biodegradation of the products which in essence, constitute a health hazard to its consumers. The most important component of the living matter is water. Multiplication and survival of microorganisms in drugs. This reports emphasized the need to monitor the microbiological quality on non-sterile pharmaceutical products, dispensed and sold in the public hospitals, pharmacies and potent medicine stores Taylor, R. B; Behrens, and low, A. S (2001).

ORAL LIQUIDS: They are homogenous liquids preparations, usually consisting of a solution, a suspension or emulsion of suitable vehicle which are more active to be swallowed either undiluted or after dilution. Oral liquids may contain auxiliary substance such as suitable antimicrobial preservatives dispensing, suspending, emulsifying, stabilizing, flavouring, colouring and sweeten agents. The vehicle for any particular oral liquid should be chosen having regard to be nature of the active ingredients and to produce organoleptic characteristics appropriate to the intended se of the preparation.

ORAL SUSPENSION: Are oral liquids containing one or more active ingredients suspended in suitable vehicle.

Suspended solid may slowly separate on standing but are easily redispened.

ORAL DROP: Are oral liquid that are intended to be administered in small volume in the aid of a suitable measuring device.

MIXTURE: Are oral liquids containing one or more active ingredient dissolved, suspended or dispersed in a suitable

vehicle. Suspended solids may separate slowly on standing but easily redispersed on shaking.

ORAL SOLUTIONS: Are oral liquids containing one or more active ingredients dissolved in a suitable vehicle.

ELIXIRS: Are oral liquids that contains one or more active ingredients dissolved in a vehicle that usually contains a high proportion of sucrose or a suitable polyhydric alcohol or alcohols and may also contains ethanol (96%) or a dilute ethanol.

LINCTUSES: Are viscous oral liquids that may contain one or more active ingredients in solution.

The vehicle usually contain large amount of sucrose or alcohols. Linctuses are intended for use in the treatment or relief of cough being sipped and swallowed slowly count and addition of water.

ORAL EMULSIONS: Are oral liquids containing one or more active ingredient. They are stabilized oil-in-water dispersions, either or both phases of which may contain dissolved solids. Solid may also be suspended in oral emulsions.

In oral emulsions prepared according to the formula and directions given for extemporaneous preparation and quantity of emulsifying agent specified in individual monographs may be consistence provided by doing and stability of the preparation in not affected when in uses, oral emulsions should be supplied.


  1. Dosage form
  2. Solubility in the tissue in which it is placed
  3. Blood flow through the tissue

(Laurence, D. R. and Bennett, P.N 1987)

Definitions of drug: World Health Organization (WHO) define drug as “any substance or product that is used or intended to be used to modify or explore physiological systems or pathological states for the benefit of the recipient

(WHO 1988).

A drug is a simple chemical substance that forms the active ingredient of a medicine, which latter may contain many other substances to deliver the drug in a stable form, acceptable and convenient to patient (Laurence D. R. and Bennett P. N 1987).

Drug should be selectively toxic meaning they should kill or inhibit microbial cells without simultaneously damaging host tissue. Best drug are those that block the actions or synthesis of molecules in microorganisms but not in vertebrate cells.


Example is drugs with selective toxicity are those that block the synthesis of the cell walls in bacteria (penicillin). They have low toxicity and few direct effects on human cells because cells lack a wall and are thus natural to these actions of the antibiotic. Among the most toxic to human cells are drugs that act upon a structure common to both the ineffective agent and the host cell such as the cell membrane (Kathlene P. T. 2005).

PHARMACOLOGISTS (one who specialize in the scientific study of drugs and their uses in medicine) say that drug comprises two broad divisions.

  1. PHARMACODYNAMICS: The biological and therapeutic effect of drugs ie. What drug dose in the body.
  2. PHARMACOKINETICS: Absorption, distribution, metabolism and excretion of drugs ie. What the body does to the drugs (Laurence D. R. and Bennett P. N, 1987).


When drug is injected intravenously, it gains access to the systemic circulation and hence to the tissue and receptor ie. 100% s a available to exert its therapeutic effect, if the same quantity of drug is swallowed, it does not follow that the entire amount will reach first the portal blood and then the systemic blood that is its availability for therapeutic effect may be less than 100%. The anticipated response to drug may not be achieved unless biological availability is taken into account. In a sense, consideration of drugs that are slowly absorbed. Drugs may also bind to food constituents eg. Tetracycline to calcium and to iron, or to other drugs e.g. Acidic drug to reduced availability apply whenever any drug intended for systemic effect given by any other route rather than the intravenous, but in practice the tissue concerns enteral administration. This may be thought in three ways:

  1. Pharmaceutical (Drug/Medicine) Factor:- The amount of drug that is released from a dose form is highly dependant on its formulations. Manufacturers are expected to produce a formulation with an unvarying biological availability (Bio-availability) so that the same amount of drug is released with the same speed from whatever band the patients may be taking e.g. with syrups, particle size, surface area exposed to solution) diluting substances, syrup size and pressure used in the machine may effect the disintegration and dissolution and so the biological availability of drug is difference in biological which can be demonstrated if different blood concentration of the same amount of drug are given to a single individual one after another but in manufacturing practice, measurement of the time a syrups takes to mixture up in water (disintegration time) are used to check consistency of different batches. Cowan, S. T. and Stanley (1994).
  2. Biological factors:- It relates to the guts. These include destruction of drug by gastric acid e.g. benzyl penicillin and impaired absorption due to intestinal which is important for all drugs that are slowly absorbed.
  3. Pre- systemic elimination or hepatic effect: Despite the fact that they pas rapidly through the gut mucosal cell membrane, some drugs appear in low concentration in the systemic circulation. The reason lies in the considerable extent to which such drugs are metabolized in a single passage through the gut wall and liver and an important feature of the oral route is that all drugs that is absorbed cannot escaped these elimination processes. As little as 10-20% of the parent drug may reach the systemic circulation unchanged. By contrast, if the same dose is given intravenously, 100% is systematically available and the patient is exposed to higher concentrations with great effect once the drug is in systemic circulation, irrespective of which route is used, about 20% is subjected to hepatic metabolic process in each circulation because that is the proportion of cardia output that supplies the liver i.e. Blood flow (main determinate of metabolism). (Laurence D. R. and Bennett P. N. 1987).

Considerations in selecting an antimicrobic drug before actual antimicrobic therapy can begin. It is important that at least three factors are known.

  1. The nature of the microorganism causing the infection.
  2. The degree of the microorganisms susceptibility (also called sensitivity) to various drugs and
  3. The overall medical condition of the patient (Kathlen P. Talaro 2005).

Some syrups and solutions contain preservatives and sugar concentrations, which suppress the growth of most microorgarisms except the osmotolerant one (Grigo 1976). Because of their low water content, liquids are normally protected against microbial growth but are sometimes attached by some microorganisms and fungi especially when mixed with sweat, which act as a good nutrient medicine for them. Liquids (syrups) do not allow excessive microbial multiplication after manufacturing because of their low water activity except when exposed to air or during dispersing. Under bad storage conditions, a local increase of water content may permit microbial growth. This trend is not seen in the cases of not using multi-dose containers for injections because of the high risks of contamination. (Water man, R. R) Sumner, E.D Baldwinz J. N 2001).

Microbiological qualities of pharmaceutical products are influenced by the environment in which they are manufactured, packaged/handled and dispensed, and also the materials used in their production (Farero, et al 1989).


The source of raw materials used in the production of the various pharmaceutical products determine the level of microbial contamination. Raw materials of animals and vegetable origin were repeatedly shown to be contaminated with viable organisms and molds, which can render a preparation objectionable or even dangerous (chamber, et al; 1988).

However, irradiation is being used to endure that the hygienic quality of this product in Belgium and the Nether lands. On the other hand, synthetic and or semi-synthetic materials usually contain low microbial contamination (Underwood, 1983).


This plays an important role in pharmacy formations being the source of many potential harmful organisms, especially the coliforms and the same time providing medium for the growth of organisms introduced from other sources. The microorganisms frequently encountered are bacteria, fungi, algae and protozoa (Chukwura 2001). Even treated or distilled water can still readily pick up organism from pipe and storage containers without effective treatment to minimize contaminations.

1.7 AIR

Air can harbour large numbers of microorganisms particularly the sporulating bacteria such as clostricdium species, the non-sporing bacteria and the molds, such as penicillium spp, cladosporium species, aspergillus species and mucor as well as yeast, such as Rhodoturola species (Underwood, al; 1983).

Microorganisms are carried into the atmosphere suspended in particle of dusts, talking, coughing, sneezing. These organisms can survive for a long period of time since they are usually protected by the dust particle; the number in the air depends on the activity in the environment and the amount of dust which is disturbed and also its humidity (Remington’s pharmasc. 1992).


Apparatus and machines in the manufacture of various non-sterile pharmaceutical products and those used in dispensing may harbour microorganisms which might growth in the product. Therefore it is important to eliminate such microbial reservoir by sterilization to prevent them from contaminating subsequent products.


Human beings may harbour various organisms in their respiratory tnacts, intestinal canal, on the skin, on their hairs and even in the finger nails. The nasal passages may contain large numbers of organisms which are secreted during normal respiratory function and speech (Underwood et al 1983).

They may also contaminate these products thoughts through handling of strict personal hygiene in not observed. Therefore, t is very important that all employees in pharmaceutical industries should be given an adequate training in fundamental personal hygiene and also protective measures like nose masks and hand gloves should be used both in manufacturing and dispensing of these products to minimize contaminations. Khante, S. Nikore, RL, and Joshi, B (1992).


Containers for syrups should be well sterilised; the products should be properly checked to know if there is any leakage. The microflora in the final product may represent contaminatloeri from the raw materials or the equipment with which it was made, air or from operator.

The aim of this study therefore, is to investigate the incidence of microflora in syrups especially those dispensed from large containers/packages. The data obtained herein, would provide information of the extent and nature of microbial contamination of these products, which would inevitably assist in determining and controlling the source of such contamination in future.


Akerele, 3.. 0, and Ukoh, G. C (2002). Aspects of microbial contamination of syrups dispensed in hospitals and community pharmacies in Benin City, Nigeria Tropical Journal of Pharmaceutical Research. (1):23-28.

Baird, R. M, Crowden, C. A. 0, Farrel, S. M, and Shorter, R. A (1999). Microbial contamination of
pharmaceutical products. Home Journal of hygiene. 83:277-283.

Chambers, C. W., and Clarke, N. A. (1988). Control of bacteria in non- domestic water. Advances in Applied Bacteriology. 8: 105-143.

Chukwura, E. I (2001). Some microorganisms usually encountered in fresh water aquatic microbiology pp. 107-108.

Cowan, S.. T, and Stanley K. J. (1994). Manual for the identification of medical bacteria, 2nd edition Cambridge, Cambridge University press.

Devleeschovwer, M. ] and Dony, J. F, (1989). Bacteriological quality of some pharmaceutical products marked by drug vehicles in Nigeria. African Journal of Health science. 11 (3-4):128-133.

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