Particulate Contamination in Single-Dose Parenteral Antibiotics in Iran

1. Introduction

      For safety reasons, all parenteral dosage forms should be essentially free from particles.   Therefore,   international   pharma copoeias  have  set  stringent  guidelines  to limit number of particles in these pharma ceuticals.   Particles   could   be   produced through manufacturing, packaging, or even dispensing  processes  of  pharmaceuticals. The nature of the particles are varied and could be of drug itself, packaging debris, rubber, plastic, cotton, fiber, or glass particles, which might be produced during the breakage of an ampoule. Opening ampoules, breaking   container   seals,   insertion   of syringes or needles during transfer of solvents  or  additives  into  the  ampoules  are among the most common sources of particle contaminations [1-5]. Numerous reports in the literature have claimed that particle con- tamination have caused insult to the brain, lungs, spleen, kidneys, liver and venous sys- tem in animals [5]. Particles introduced into a vein could travel to the right heart and then proceed to the right atrium, the right ventricle and then to the pulmonary artery which terminates to a vast capillary bed in the lung. Particulate contamination of intravenous flu- ids    or    fluids     introduced    into    the epidural/subarachnoid space has been recog- nized for years [6-7].

      The  size  of  particulates  greatly  influences the terminal location as well as the chronic complications following their intra- venous administration. It has been previous- ly  reported that large silica particles with diameters of 10-12 micrometer were com- monly found lodged in the pulmonary capillaries and evoked a foreign body response with   resultant   granuloma  formation  [3]. Small silica particles were capable of passing through the lung and eventually occupying  the  liver,  spleen,  and  hepatic  lymph nodes. Advanced  cirrhosis has been developed as a result of fibrosis, beginning in the portal connective tissue. Large particles may get fixed in the pulmonary capillaries with the potential to interfere with respiratory gas exchange  [3].  Particulate  contamination plays a role in the development of phlebitis related to infusion, the most common com- plication of  intravenous treatment. In  this study, the incidence and nature of particles in some   of   the   injectable  pharmaceutical dosage  forms  in  Iranian  drug  market  is investigated.

2. Materials and methods

2.1. Materials

      Ceftriaxone, cefotaxime and ceftazidim freeze  dried  powder  for  injection  and amikacin solution for injection, produced by four different local pharmaceutical compa- nies, were purchased from pharmacies.

2.2. Sample preparations

     In order to remove dust from outside of samples, they were wiped using damp cotton cleaner and transferred to a laminar air flow cabinet  for  further  preparation.  Distilled water, which was used for preparation of the samples, was filtered through a 0.22 micron filter before use, and was checked for particle  contamination  using  a  HIAC-Royco model  3000   particle  counter,  and  was regarded as blank. Possible particle contam- ination of water was recorded and was subtracted  from  the  value  for  corresponding samples. Samples’ label were removed using either warm water or  ethanol. Vials were then rinsed with filtered distilled water under a  laminar  air  flow  cabinet.  Reconstituted samples with the proper volume (according to the manufacturer instruction) of distilled and  filtered  water  were   examined  using instrumental and visual inspection, both by unaided eye and microscopic  examination. In  order to  evaluate the  effect of  sample preparation on particle production, the samples were prepared by breaking ampoules in the patients’ room in the hospital, and were pulled into a syringe, as it is in routine prac- tice in clinics and hospitals. The particles in syringes were also examined using a Leitz- Dialux 22 microscope.

2.3. Visual inspection

      After removing the labels and preparing the samples, twenty vials/ampoules of each sample   were  examined  according  to  the monograph of international pharmacopoeia for  visual inspection of small volume parenterals [9-11]. Briefly, the vials containing powder  for  injection were reconstituted by adding the proper volume of distilled and filtered  water,  and  all  of  the  samples  were examined in a light box with white and black background  by  three  independent  trained examiners.  Each  examiner  scored  his/her observation and recorded the results in a separate sheet. However, the national standard [12], which is a modified version of DAC  [13], was used to quantify the samples for the presence of particulates. According to this  protocol,  samples  with  SE20  greater than 4.5 were rejected. SE20 is the visual result of the vials tested by examiners and it is calculated by dividing sum of the awarded points by examiners to the vials based on the presence of particles in the vials by 20 (the number of the examined vials).

2.4. Instrumental examination

     Samples  were  counted  by  a  HIAC- Royco model 3000 particle counter accord ing to the international pharmacopoeia and the  instrument  manufacturer  instructions. Powders  for  injection  were  reconstituted using filtered distilled water.

2.5. Microscopic examination

     Samples  were  prepared  as  mentioned above,  and  were  filtered  through  a  0.44 micron filter using a vacuum pump (20 PSi). Then  the  filters  were  examined  under  a Leitz-Dialux 22 microscope. Particles were counted and their sizes were measured using a micrometer.

3. Results

         As shown in Table 1, 60% of the samples of reconstituted powders for injection with filtered  distilled  water  complied  with  the national  standards for  the  examination of powders for injection. However, three of the freeze dried samples showed  substantially higher   scores   and   were   unacceptable. Amikacin was practically free from visual size  particles. Table 2  shows  the  average numbers of the large size particles in each sample. Samples with high numbers of the large size particles such as cefotaxime 1 g also showed high SE20 scores (Table 1). The presence of the large size particles in the samples was  also confirmed using micro scopic  examination  (Figures  1,  2).  The results of the examination of the freeze dried samples with a HIAC/Royco particle counter are summarized in Table 3. Again, cefotaxime 1 g had high numbers of particles. Opening of the amikacin ampoules using the routine practice in clinics created an average of 81 glass particles larger than 10 microm eters per ampoule, of which 18 were larger than 50 micrometers (Figure 3). However, despite  the  presence  of  high  numbers  of small size particles in some of the samples, all of them were in the acceptable range of international pharmacopoeia [9-11].

Table 1. Scores for reconstituted powders for injection and solution samples inspected for the presence of particulates.

Data are mean ± SD of three independent observations. ^a1-4 are samples from different producers. ^bRejected samples.

Figure 1. Micrograph of a fiber particle in a sample of reconstituted powder for injection (x 100).

Figure 2. Micrograph of an unidentified particle in a sample of reconstituted powder for injection (x 100).

Figure 3. Micrograph of a glass particle produced during opening of an ampoule (x 100).

Table 2. Results of microscopic examination of reconstituted powders for injection and solution samples inspected for the presence of particulates.

^a20 vials or ampoules from each drug were examined. b1-4 are samples from different producers.

4. Discussion

       Due to the possible health risks of the presence of particles in parenteral prepara tions,  these  pharmaceutical  dosage  forms should essentially be free from visible particles.  Since  1972  stringent  guidelines  for manufactures  of  large  volume  parenterals have  virtually  eliminated  this  problem. However,  despite the  existence of  similar standards for small volume parenterals and freeze dried powders for injection, there are problems regarding these types of parenter als [14]. Unaided human eye is able to detect particles with a size of 50 micrometers and more [14], and there is general agreement that the presence of particles with these sizes in  the  parenteral dosage forms  should be limited to as low as practically possible. The large size particles are apparently very harmful due to the risk of vascular occlusion in places where compensation by collateral circulation does not occur [1]. Parenteral solutions may be contaminated during manufac ture, storage or preparation for use. There have been reports of pulmonary microem boli, thrombi and granulomas as a result of particle  contamination  with  glass,  rubber, cellulose fiber,  plastics, and  drug  crystals found in the large volume intravenous infusions.   Cases   of   pulmonary   granuloma caused by cellulose fiber and the presence of particles in the lung and brain have been reported previously [3].

Table 3. Particles counted in samples using particle counter instrument.

    ^a20 vials or ampoules from each drug were examined. ^b1-4 are samples from different producers.

      In this study, some of the freeze dried and solution antibiotics from Iranian market have been examined for the presence of particles. Samples were from four different pro ducers and were purchased from pharmacies. All of the samples were contaminated with visible particles, and 40% of the samples contained unacceptable levels of particles.

     Although some of the samples showed substantially high numbers of the small size particles, all of them met the international standards for the presence of the small size particles  [9-11].  It  has  been  previously reported that high numbers of the small size particles could also create substantial health risks [14]. Since the possibilities for counting the large size particles with HIAC/Royco instrument appear to be limited, microscopic and  visual  counts of samples would be a valuable method [1].

      One  of  the  hazards  of  glass  ampoule opening  is  glass  particle  contamination. Ampoule neck breakage usually is not uniform and smooth creating breaks which may create particle contamination of the ampoule contents.  Several  previous  reports  have examined ampoules following their opening for the presence of glass particles [7, 15]. The results of the present study also shows that opening of ampoules using the routine practice in clinics  creates significant numbers of particles, some of them lager than 50 micrometers, which can be hazardous to the patients.

     In conclusion, the results of this study showed  that  the  small  volume  parenteral dosage forms in the Iranian market contain substantial numbers of particles. The use of parenterals is always associated with possible adverse effects such as phlebitis, abscess and  infection [16,  17]. Therefore, particle contamination of parenterals may also create an additional risk for the patients. However, the contribution of particulate matters may be reduced by “in line filters” with pore sizes of  0.2-0.5  micrometer.  Previously,  it  was reported that filtering devices placed in-line or  contained  within  the  needle  used  for injection of ampoule contents have success- fully  reduced  the  particle  load  [18,  19]. There are also  some contradictory reports indicating  that  in-line  filters  may  not  be effective  in   reducing   the  incidence  of phlebitis as the most common complication of intravenous therapy [14]. However, they do appear to be effective in reducing the par- ticle loading of the  ampoule contents and even syringes and infusion sets in which the presence of particles has been reported, pre- viously [18]. The reduction of particle load will clearly benefit the patients, especially those receiving multiple injections.