July 14, 2021: Pharmaceutical Interview Questions and Answers

1. What are the different sizes of hard gelatin capsules?

The capsule sizes are 000, 00, 0, 1, 2, 3, 4, and 5 from the largest to the smallest. There are few special size of capsule are available such as 2el, 1el, 0el, 0el+, 0xel, 00el etc. Details are tabulated below.

2. What are the US Mesh size and corresponding micron, mm and inch for commonly used sieves, provide few examples?

U.S. Mesh	Microns	Inches	Millimeters
3	6730	0.2650	6.730
4	4760	0.1879	4.760
5	4000	0.1570	4.000
6	3360	0.1320	3.360
7	2830	0.1110	2.830
8	2380	0.0937	2.380
10	2000	0.0787	2.000
12	1680	0.0661	1.680
14	1410	0.0555	1.410
16	1190	0.0469	1.190
18	1000	0.0394	1.000
20	840	0.0311	0.841
25	707	0.0280	0.707
30	595	0.0232	0.595
35	500	0.0197	0.500
40	400	0.0165	0.400
45	354	0.0138	0.354
50	297	0.0117	0.297
60	250	0.0098	0.250
70	210	0.0083	0.210
80	177	0.007	0.177
100	149	0.0059	0.149
120	125	0.0049	0.125
140	105	0.0041	0.105
170	88	0.0035	0.088
200	74	0.0029	0.074
230	63	0.0024	0.063
270	53	0.0021	0.053
325	44	0.0017	0.044
400	37	0.0015	0.037
450	32	0.0013	0.032
500	25	0.0010	0.025
550	25	0.0009	0.023
635	20	0.0008	0.020
800	15	0.0006	0.015
1250	10	0.0004	0.010

Reference: ASTM E11

3. Give examples of sieve size and corresponding number of Apertures per Linear inch.

Sr. No.	Sieve Size	Number of Apertures per Linear Inch
1	10 #	9-11
2	12#	11-13
3	14#	13-15
4	16#	15-17
5	20#	19-21
6	24#	23-25
7	30#	28-32
8	40#	38-42
9	60#	57-63
10	80#	77-83
11	100#	97-103

4. What is aperture size of screen?

The size of a square opening (length of clear space between individual wires) is called the aperture size of screen.

5. What is Mesh number of screen?

Mesh number of screen is defined as number of aperture or opening per liner inch of the screen.  E.g. A screen having 10 square opening per inch is said to have Mesh no. 10. Higher the mesh number, smaller the aperture size of screen.